[{"id":3669714,"web_url":"http://patchwork.ozlabs.org/comment/3669714/","msgid":"<4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>","list_archive_url":null,"date":"2026-03-26T13:03:11","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":78856,"url":"http://patchwork.ozlabs.org/api/people/78856/","name":"Niklas Schnelle","email":"schnelle@linux.ibm.com"},"content":"On Wed, 2026-03-25 at 14:31 +0100, Julian Ruess wrote:\n> Add a vfio_pci variant driver for the s390-specific Internal Shared\n> Memory (ISM) devices used for inter-VM communication.\n> \n> This enables the development of vfio-pci-based user space drivers for\n> ISM devices.\n> \n> On s390, kernel primitives such as ioread() and iowrite() are switched\n> over from function-handle-based PCI load/stores instructions to PCI\n> memory-I/O (MIO) loads/stores when these are available and not\n> explicitly disabled. Since these instructions cannot be used with ISM\n> devices, ensure that classic function-handle-based PCI instructions are\n> used instead.\n> \n> The driver is still required even when MIO instructions are disabled, as\n> the ISM device relies on the PCI store block (PCISTB) instruction to\n> perform write operations.\n> \n> Stores are not fragmented, therefore one ioctl corresponds to exactly\n> one PCISTB instruction. User space must ensure to not write more than\n> 4096 bytes at once to an ISM BAR which is the maximum payload of the\n> PCISTB instruction.\n> \n> Reviewed-by: Alexandra Winter \n> Reviewed-by: Niklas Schnelle \n> Signed-off-by: Julian Ruess \n> ---\n> drivers/vfio/pci/Kconfig | 2 +\n> drivers/vfio/pci/Makefile | 2 +\n> drivers/vfio/pci/ism/Kconfig | 10 ++\n> drivers/vfio/pci/ism/Makefile | 3 +\n> drivers/vfio/pci/ism/main.c | 408 ++++++++++++++++++++++++++++++++++++++++++\n> 5 files changed, 425 insertions(+)\n> \n--- snip ---\n> +\n> +static int ism_vfio_pci_ioctl_get_region_info(struct vfio_device *core_vdev,\n> +\t\t\t\t\t struct vfio_region_info *info,\n> +\t\t\t\t\t struct vfio_info_cap *caps)\n> +{\n> +\tstruct vfio_pci_core_device *vdev =\n> +\t\tcontainer_of(core_vdev, struct vfio_pci_core_device, vdev);\n> +\tstruct pci_dev *pdev = vdev->pdev;\n> +\n> +\tswitch (info->index) {\n> +\tcase VFIO_PCI_CONFIG_REGION_INDEX:\n> +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n> +\t\tinfo->size = pdev->cfg_size;\n> +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n> +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n> +\t\tbreak;\n> +\tcase VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:\n> +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n> +\t\tinfo->size = pci_resource_len(pdev, info->index);\n> +\t\tif (!info->size) {\n> +\t\t\tinfo->flags = 0;\n> +\t\t\tbreak;\n> +\t\t}\n> +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n> +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n> +\t\tbreak;\n> +\tdefault:\n> +\t\tinfo->offset = 0;\n> +\t\tinfo->size = 0;\n> +\t\tinfo->flags = 0;\n> +\t\treturn -EINVAL;\n\nThinking more about this, the above default handling actually breaks\nadditional regions such as the one added by Farhan for the error\nevents. I think this needs to instead call the generic\nvfio_pci_ioctl_get_region_info() for other regions.\n\n> +\t}\n> +\treturn 0;\n> +}\n--- snip ---","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256\n header.s=pp1 header.b=lQiP3cBU;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.232.135.74; helo=sto.lore.kernel.org;\n envelope-from=linux-pci+bounces-51179-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=\"lQiP3cBU\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=148.163.156.1","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=linux.ibm.com"],"Received":["from sto.lore.kernel.org (sto.lore.kernel.org [172.232.135.74])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fhPB671qcz1y1x\n\tfor ; Fri, 27 Mar 2026 00:04:29 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sto.lore.kernel.org (Postfix) with ESMTP id F2EC63039726\n\tfor ; Thu, 26 Mar 2026 13:04:25 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 17A3126463A;\n\tThu, 26 Mar 2026 13:04:25 +0000 (UTC)","from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com\n [148.163.156.1])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id BD2BE50276;\n\tThu, 26 Mar 2026 13:04:23 +0000 (UTC)","from pps.filterd (m0353729.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id\n 62Q2x7j1755965;\n\tThu, 26 Mar 2026 13:04:19 GMT","from ppma11.dal12v.mail.ibm.com\n (db.9e.1632.ip4.static.sl-reverse.com [50.22.158.219])\n\tby mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4d1kty58b8-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tThu, 26 Mar 2026 13:04:18 +0000 (GMT)","from pps.filterd (ppma11.dal12v.mail.ibm.com [127.0.0.1])\n\tby ppma11.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id\n 62QCjJYf004369;\n\tThu, 26 Mar 2026 13:04:17 GMT","from smtprelay06.wdc07v.mail.ibm.com ([172.16.1.73])\n\tby ppma11.dal12v.mail.ibm.com (PPS) with ESMTPS id 4d28c2asm8-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tThu, 26 Mar 2026 13:04:17 +0000","from smtpav02.dal12v.mail.ibm.com (smtpav02.dal12v.mail.ibm.com\n [10.241.53.101])\n\tby smtprelay06.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id\n 62QD4FEE8127212\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK);\n\tThu, 26 Mar 2026 13:04:15 GMT","from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 755005805A;\n\tThu, 26 Mar 2026 13:04:15 +0000 (GMT)","from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 1F28658065;\n\tThu, 26 Mar 2026 13:04:12 +0000 (GMT)","from [9.52.215.169] (unknown [9.52.215.169])\n\tby smtpav02.dal12v.mail.ibm.com (Postfix) with ESMTP;\n\tThu, 26 Mar 2026 13:04:11 +0000 (GMT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774530265; cv=none;\n b=hrU5g/921h9hFeKI5q3eYAHaA6cGSChH0uYF1oTCW9tpmv/lqAW9q9OcLQAEoApO+EN8sxEFNAdVVLj5IyOp68rOTXJgTRoj5h1GZUlKfk9/NRwizwat+Cy7fEwBYpi2Z/25bnSded8VZ/bPacW/vGeI4PFxqtSB8Q9PZhAXooc=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774530265; c=relaxed/simple;\n\tbh=7pkuYooJ4+xr5DrTnHJSuPzU6Rh4xSprvGMBMFA6QY4=;\n\th=Message-ID:Subject:From:To:Cc:In-Reply-To:References:Content-Type:\n\t Date:MIME-Version;\n b=WLt56GpGQIUpNQ9BuwLXfJQUSnQvuSYqJs1LQ8PbbHlYKH0bxFbpBCJtS6I7TfIwD8QF+DKtnwTP+Qi9ynfeHkvqs8OXFg5o9DMTPIM+cVNyo9Uhie3didu6uPb2SbqHFSX6uuNdgZKOkSsMI55Xh4eBdXLdJk0ux2RNHaN/BCQ=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com;\n spf=pass smtp.mailfrom=linux.ibm.com;\n dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=lQiP3cBU; arc=none smtp.client-ip=148.163.156.1","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc\n\t:content-transfer-encoding:content-type:date:from:in-reply-to\n\t:message-id:mime-version:references:subject:to; s=pp1; bh=JQVkWD\n\t67IAuQHYr5Od1jVkMObbCIr3crzp3D8I2JI+E=; b=lQiP3cBU9XqhtmtUnZsAFo\n\txrK0L4ZB8SLJqf5SjXzv1IC2qbrbEnpqSZFWoSPMw8UUZhlBS1Uq94CELB+lyzcf\n\tqlptCM7vMHyhUiv9ukomutLH0PCsiFJ6kwDjLLuN8/zz9I4RzLGOmWsIeW958p40\n\tNpd4l9Sm6gQOSnDFW4HnEPUJNcrF2ukJaAVVsmY2t+f/zNAWZuuMetVGy2lRq+at\n\tDHJqrmmLggtQAEK9hnA5z7J5VnEpvvrcipZpJiK1ZRy9g96x1HJas9y3GUqRAVNA\n\tW5O8g0LEZepgbCIzy6CM9bYZa36toqeffbL41RgHtGG68cGSUkK0N5KC4LTE1dGA\n\t==","Message-ID":"<4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","From":"Niklas Schnelle ","To":"Julian Ruess , wintera@linux.ibm.com,\n ts@linux.ibm.com, oberpar@linux.ibm.com, gbayer@linux.ibm.com,\n Alex\n Williamson\t , Jason Gunthorpe ,\n Yishai\n Hadas\t ,\n Shameer Kolothum ,\n Kevin Tian\t ","Cc":"mjrosato@linux.ibm.com, alifm@linux.ibm.com, raspl@linux.ibm.com,\n hca@linux.ibm.com, agordeev@linux.ibm.com, gor@linux.ibm.com,\n kvm@vger.kernel.org, linux-kernel@vger.kernel.org,\n linux-s390@vger.kernel.org, linux-pci@vger.kernel.org","In-Reply-To":"<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>","Autocrypt":"addr=schnelle@linux.ibm.com; prefer-encrypt=mutual;\n keydata=mQINBGHm3M8BEAC+MIQkfoPIAKdjjk84OSQ8erd2OICj98+GdhMQpIjHXn/RJdCZLa58k\n /ay5x0xIHkWzx1JJOm4Lki7WEzRbYDexQEJP0xUia0U+4Yg7PJL4Dg/W4Ho28dRBROoJjgJSLSHwc\n 3/1pjpNlSaX/qg3ZM8+/EiSGc7uEPklLYu3gRGxcWV/944HdUyLcnjrZwCn2+gg9ncVJjsimS0ro/\n 2wU2RPE4ju6NMBn5Go26sAj1owdYQQv9t0d71CmZS9Bh+2+cLjC7HvyTHKFxVGOznUL+j1a45VrVS\n XQ+nhTVjvgvXR84z10bOvLiwxJZ/00pwNi7uCdSYnZFLQ4S/JGMs4lhOiCGJhJ/9FR7JVw/1t1G9a\n UlqVp23AXwzbcoV2fxyE/CsVpHcyOWGDahGLcH7QeitN6cjltf9ymw2spBzpRnfFn80nVxgSYVG1d\n w75ksBAuQ/3e+oTQk4GAa2ShoNVsvR9GYn7rnsDN5pVILDhdPO3J2PGIXa5ipQnvwb3EHvPXyzakY\n tK50fBUPKk3XnkRwRYEbbPEB7YT+ccF/HioCryqDPWUivXF8qf6Jw5T1mhwukUV1i+QyJzJxGPh19\n /N2/GK7/yS5wrt0Lwxzevc5g+jX8RyjzywOZGHTVu9KIQiG8Pqx33UxZvykjaqTMjo7kaAdGEkrHZ\n dVHqoPZwhCsgQARAQABtChOaWtsYXMgU2NobmVsbGUgPHNjaG5lbGxlQGxpbnV4LmlibS5jb20+iQ\n JXBBMBCABBAhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAhkBFiEEnbAAstJ1IDCl9y3cr+Q/Fej\n CYJAFAmmAWs8FCQl6sYAACgkQr+Q/FejCYJAn2g//UKzlXOgizdk0wudLooRbGzDo23ktGSPK5Oj9\n 9o5z6v4Jz5+qOHo5835683cqkMLM9//udA1ZcKV88LVwyfmoHChPW24cWBmOEy7RJOWCR4WeEINaO\n pZUGF5YOx7oKTkPs511ky2FR0Heg35754pgTuTMEpYzRXr5pNMPS8mHXcXSARFPDPaCF+uBJ9BafO\n L7XbpSwKRttePsWAlPHbSbloeDApBfHUhcF/pbuM9GNs+c/8V9NK+SwwqNK214t7jaSq9k+19/hfE\n jvU45nbiYQM4VqGCelxVFRWol93JnwPFp/JaMgxgV1VYFH9Ijtgh+qNVVBqO8bbTjioFKy1bHdprN\n 9GyPLDxoaI/lBg+5CwKewzazUjFd0xaqZbTXSgNK4ev/IuNI3qZV8tpvZZWwIgZU1K0Bhplt8Sku+\n O9Yl2H54erq9zuzwXjqBJtoW0+MaKbe+1gZ/v2/AVE2VeQMugPUWDg+2bpJaApRkeA4xQ9XfeW6Bp\n It7xYrwwbVhQtWRC0sRh+QNlU9HI28wPSnLWn7HFBeWupaIrxSp4IEL3eHUn8xv4aA8lpdNsHXD/X\n vqOSUwy5jlTPTlemvwaC9mNHagNdVXng8C6+hxiDLhZ6xH2P4qNHTKmjW61NsdF6Y/HfWP+lmbi8/\n 474UNCltDt/fP01ajqogfWZKFymoH0O0KU5pa2xhcyBTY2huZWxsZSA8bmlrbGFzLnNjaG5lbGxlQ\n GlibS5jb20+iQJUBBMBCAA+AhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEEnbAAstJ1IDCl9y\n 3cr+Q/FejCYJAFAmmAWusFCQl6sYAACgkQr+Q/FejCYJAtIw//WmQW/Z+SLdfrlDH5J2bvixzFNnO\n TOvp8uM8vcNZsxZwPXem4AeCXHayCqipxpa0iXWufEIvdMxkBxWvvM//V+rTUgQnJe6nhDxfLGklx\n 5Mb2H+K/ndS73ElCuA30MPYq7mHr8i3gEmi2ZFX1W47JecJ8hno/DQxhHRG7bd+GFsiKCbsjLWXNq\n s/VaAK9uyOTQx7m6/2nR8L+Mvl1BrRXwkj7Qp0qxfQSd4r+IVNBzNFOcrGagBqsyHrN7Is7IICktH\n 9VFl/G8P+hfviHQLnlxw9ltzpM1Dy6N1+BM3kbqD59gX+L6wqiLJI42eh+SHCiy35FvD3AFlYx4jZ\n MWE6qIgFnbwcL1kvcA7nnwfr3ZizCYPm8e334xXxslXBoRGsvjXSbAeAyZo2dvJXffNHdcDdUbJSl\n CfOixNGGKiQvs00X9ekfq9WmmRFvmYHu/m3lg1OXnMjFFIO41O51ZdhbEYJiqZEki7jA8Hd9xuWwQ\n nFDHhacU3xxivZ4BKQGQc+4XZ3yp/q6+7ux9prepRy/LeRyoaAmE67oxEsAgj+qyA3Tfy5nRTDdRQ\n E//gpaIt9H1VEx+68dRWHroxBQeozpnFPi25AlX3k4/EtVZjcItPWgE9iru1qT4DH3BBrz7Kd1zUw\n NnQC77zDJyZD2WUj1E+5bftO0aeE+7HZXj3tM/ea0K05pa2xhcyBTY2huZWxsZSA8bmlrbGFzLnNj\n aG5lbGxlQGdtYWlsLmNvbT6JAlQEEwEIAD4CGwEFCwkIBwIGFQoJCAsCBBYCAwECHgECF4AWIQSds\n ACy0nUgMKX3Ldyv5D8V6MJgkAUCaYBa6wUJCXqxgAAKCRCv5D8V6MJgkF/TEACOY2kL4NGFIbWeM5\n TUhatxqe8c3RT6jvNjq32CkvaK/cSZzBkS0smddyOzxt2WnsvMgkr9cM7P+CevoMwhT3e0lgQbqBD\n /vXZJjWKddC+iKXeqWkjMVcgCOsWNZ7PWEzRUT5X1AEFq2zzxQAQ/bCWEYNqIbHN4b6G1Wk+2Y598\n +KypZ3FS0bwiItnPQOWzOOqJCGxDxaEUuXFx4ah8HtVdtIev8jPS/5uzQO9iG2vZQUWeMEYZtfMHW\n sbFWqo2A3lxB+KPzNIYFhul4Lyx1CwvKUAGSHOx7FZuc2xI5DYt/Wdh2QyKFYr7xVzv3uwJjeS1+3\n 6gvyB7DJaQuY+PziNPv4GPr5wy0cRkJ6Ps15fgC6y6wNwoNdNXKlwiuclIsBzJKa7A0pZMIfpCpIJ\n bEHP7oy3drBRAhIrBx7Lx1lyqqodDqc+ok5IQ5WcKG/TOrH732mTmJX6fxYTiCVxcU4WLJSNZbrZ/\n pjF0AWXs7E+onAkQy6RLg/XU1iiU5QdMvug+fTA6TpPSUMdujWtGWUt3/4nC+69AVc8tXtRQTZ7gP\n t7uIcQFwPqUuJGS26vl0w/6dIABQAyU9acvE3adCZra+/PBKFZi/yxT1WgV1T2mexKSWwQgLcR57J\n Yp5oWnQRgi/S6fAoskIWkp9UVcfAQPY0p45NwO5cZR9/g06JZmyrQhTmlrbGFzIFNjaG5lbGxlIDx\n uaWtzQGtlcm5lbC5vcmc+iQJUBBMBCAA+AhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEEnbAA\n stJ1IDCl9y3cr+Q/FejCYJAFAmmAWusFCQl6sYAACgkQr+Q/FejCYJAz4A/9F+dMhzu7YonagL4qh\n WDz5IpRD4vzYKOBZ+qwYp1ugJz1BIUppN9i68HKoS4ARfgP97Sv9GpOy9g7L0lymH2MPF8hRPK0Yn\n 7DKIkeu/r28YWEoWfoVm5reC+gpxMgmxBz4JScE4f6xfa7+Nw0bbTDl+nxftJD7lf/dTiruNJsXph\n HQnZ5wPXmxeH6XVJikfpyrGe8iJZALbtHtjlx6Omu7NvRGikenB8trrWS5W0F60ZdbqH1HdmDDcrZ\n pDq6LtAARHK5tGRm0SK6sZpKe3nULFeeCt7T/edk2FC6KVh4sL1jw1kyceX4DjiMffqYBPrhK5gz5\n cDIixLBF9C6Wt1ObvuDBrIQf1/3q6EZrUrUuf6qtaXDMuC6cSlShm47qaPEvVYh67O9JZQ7vzvaea\n UI74DJUb8Pjnz7mTOmMOzsS1gUhCue4n2YSSM6ythioCGb/3bgMGTpuer3JhvZG5s5uKD9yyj8s8x\n 35qJkCFfjmjVx9s3vSUS48X+cUpYcMispErKzFu7C0YgKoxvJ4XTfXlDBiMFMPYcN67hsb2jeYHVJ\n wzE+fIZiDx9JLh1oQW2krwjweisE+3glOaKXZKi0fBtkxyH41iemLtLNYZRJopv6ykdl3hiI+Nh+a\n 3FZJPTo/OpqchMm8XIeDxC4NFFiPMpyLeYzIxO7eZpiGrAjVTE=","Content-Type":"text/plain; charset=\"UTF-8\"","Content-Transfer-Encoding":"quoted-printable","Date":"Thu, 26 Mar 2026 14:03:11 +0100","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","User-Agent":"Evolution 3.58.3 (3.58.3-1.fc43) ","X-TM-AS-GCONF":"00","X-Authority-Analysis":"v=2.4 cv=IqITsb/g c=1 sm=1 tr=0 ts=69c52ed2 cx=c_pps\n a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17\n a=IkcTkHD0fZMA:10 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22\n a=RnoormkPH1_aCDwRdu11:22 a=uAbxVGIbfxUO_5tXvNgY:22 a=VnNF1IyMAAAA:8\n a=1PxgIlfdUITKwrrNq7QA:9 a=QEXdDO2ut3YA:10","X-Proofpoint-Spam-Details-Enc":"AW1haW4tMjYwMzI2MDA4OSBTYWx0ZWRfXwpPExkef/jdr\n 2TEo2vtvDLY0FZIO3DT/677K5SYe+B9j9K8sJ6cjHdsm4VG4rnwanmMI3+mnHLIRCmSv8xUH8Ne\n TLH1wstfOlVMUJgFVPKJIBsXv+YJ56XmMNXveV48JzO7nX6L7nwYURam9wm4kgh9RmCSzWRujaw\n x9pl7G5QDIZFyndbKY2exWqxcjyhx8YY5YrlF/h7BSb1U3fz3d9xdETMyYkR05RUfZqyj7nvP/l\n cKdSThmfN0q1oXYBIEqjyIXy2wtlebJyxuERGbu9a23aTpYENysATGlXFcwNUzt3kFDlG3mmY9Z\n WaygALUMqWlr4FzoF1r/0Yk9t8mj/z69XCVFUPFiCB5hToe0PfJPSZRPMWHVdD7kfeT227CJrYd\n GthZqFs2RhzVOIqP0SuWpg5+rGDgPlUKkc0hQtp+gB3p8dPimKUH7ZcoDRa8qzuufKrCyyLIH2G\n TvSZrHfHGs4HW2aL8Pg==","X-Proofpoint-GUID":"mkz5J9aYqsaY2XFVQnFT0ItDldMwUOp6","X-Proofpoint-ORIG-GUID":"mkz5J9aYqsaY2XFVQnFT0ItDldMwUOp6","X-Proofpoint-Virus-Version":"vendor=baseguard\n engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49\n definitions=2026-03-26_02,2026-03-24_01,2025-10-01_01","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n malwarescore=0 clxscore=1015 spamscore=0 impostorscore=0 suspectscore=0\n phishscore=0 bulkscore=0 adultscore=0 priorityscore=1501 lowpriorityscore=0\n classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0\n reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603260089"}},{"id":3669916,"web_url":"http://patchwork.ozlabs.org/comment/3669916/","msgid":"<3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>","list_archive_url":null,"date":"2026-03-26T19:05:27","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":73785,"url":"http://patchwork.ozlabs.org/api/people/73785/","name":"Farhan Ali","email":"alifm@linux.ibm.com"},"content":"On 3/26/2026 6:03 AM, Niklas Schnelle wrote:\n> On Wed, 2026-03-25 at 14:31 +0100, Julian Ruess wrote:\n>> Add a vfio_pci variant driver for the s390-specific Internal Shared\n>> Memory (ISM) devices used for inter-VM communication.\n>>\n>> This enables the development of vfio-pci-based user space drivers for\n>> ISM devices.\n>>\n>> On s390, kernel primitives such as ioread() and iowrite() are switched\n>> over from function-handle-based PCI load/stores instructions to PCI\n>> memory-I/O (MIO) loads/stores when these are available and not\n>> explicitly disabled. Since these instructions cannot be used with ISM\n>> devices, ensure that classic function-handle-based PCI instructions are\n>> used instead.\n>>\n>> The driver is still required even when MIO instructions are disabled, as\n>> the ISM device relies on the PCI store block (PCISTB) instruction to\n>> perform write operations.\n>>\n>> Stores are not fragmented, therefore one ioctl corresponds to exactly\n>> one PCISTB instruction. User space must ensure to not write more than\n>> 4096 bytes at once to an ISM BAR which is the maximum payload of the\n>> PCISTB instruction.\n>>\n>> Reviewed-by: Alexandra Winter \n>> Reviewed-by: Niklas Schnelle \n>> Signed-off-by: Julian Ruess \n>> ---\n>> drivers/vfio/pci/Kconfig | 2 +\n>> drivers/vfio/pci/Makefile | 2 +\n>> drivers/vfio/pci/ism/Kconfig | 10 ++\n>> drivers/vfio/pci/ism/Makefile | 3 +\n>> drivers/vfio/pci/ism/main.c | 408 ++++++++++++++++++++++++++++++++++++++++++\n>> 5 files changed, 425 insertions(+)\n>>\n> --- snip ---\n>> +\n>> +static int ism_vfio_pci_ioctl_get_region_info(struct vfio_device *core_vdev,\n>> +\t\t\t\t\t struct vfio_region_info *info,\n>> +\t\t\t\t\t struct vfio_info_cap *caps)\n>> +{\n>> +\tstruct vfio_pci_core_device *vdev =\n>> +\t\tcontainer_of(core_vdev, struct vfio_pci_core_device, vdev);\n>> +\tstruct pci_dev *pdev = vdev->pdev;\n>> +\n>> +\tswitch (info->index) {\n>> +\tcase VFIO_PCI_CONFIG_REGION_INDEX:\n>> +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n>> +\t\tinfo->size = pdev->cfg_size;\n>> +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n>> +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n>> +\t\tbreak;\n>> +\tcase VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:\n>> +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n>> +\t\tinfo->size = pci_resource_len(pdev, info->index);\n>> +\t\tif (!info->size) {\n>> +\t\t\tinfo->flags = 0;\n>> +\t\t\tbreak;\n>> +\t\t}\n>> +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n>> +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n>> +\t\tbreak;\n>> +\tdefault:\n>> +\t\tinfo->offset = 0;\n>> +\t\tinfo->size = 0;\n>> +\t\tinfo->flags = 0;\n>> +\t\treturn -EINVAL;\n> Thinking more about this, the above default handling actually breaks\n> additional regions such as the one added by Farhan for the error\n> events. I think this needs to instead call the generic\n> vfio_pci_ioctl_get_region_info() for other regions.\n\nNote for error events we are using a VFIO device feature and not a \nregion. At this point we actually don't have additional regions. I do \nagree that if we were to add a zpci specific region we would need to \nupdate here and ism_vfio_pci_rw() to allow region read/write ops. This \nISM driver would also need to support all the possible callbacks in \nstruct vfio_pci_regops.\n\nGiven that we don't have any additional regions yet, I am conflicted if \nit makes sense to add all the code to support additional regions without \na good way to test it. Maybe its something we can defer when if we add \nadditional regions? Thanks\n\nFarhan\n\n\n>> +\t}\n>> +\treturn 0;\n>> +}\n> --- snip ---","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256\n header.s=pp1 header.b=Zv6Xlvpf;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.105.105.114; helo=tor.lore.kernel.org;\n envelope-from=linux-pci+bounces-51229-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=\"Zv6Xlvpf\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=148.163.156.1","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=linux.ibm.com"],"Received":["from tor.lore.kernel.org (tor.lore.kernel.org [172.105.105.114])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fhYRf4THgz1xy1\n\tfor ; Fri, 27 Mar 2026 06:16:46 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby tor.lore.kernel.org (Postfix) with ESMTP id B775930BBD30\n\tfor ; Thu, 26 Mar 2026 19:05:39 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 7C4B634FF40;\n\tThu, 26 Mar 2026 19:05:38 +0000 (UTC)","from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com\n [148.163.156.1])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 17B2933A9FC;\n\tThu, 26 Mar 2026 19:05:36 +0000 (UTC)","from pps.filterd (m0360083.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id\n 62Q89MDS3011996;\n\tThu, 26 Mar 2026 19:05:32 GMT","from ppma13.dal12v.mail.ibm.com\n (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221])\n\tby mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4d1kxqpujh-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tThu, 26 Mar 2026 19:05:32 +0000 (GMT)","from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1])\n\tby ppma13.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id\n 62QFtHua011824;\n\tThu, 26 Mar 2026 19:05:31 GMT","from smtprelay03.wdc07v.mail.ibm.com ([172.16.1.70])\n\tby ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 4d27vkc4wp-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tThu, 26 Mar 2026 19:05:31 +0000","from smtpav01.wdc07v.mail.ibm.com (smtpav01.wdc07v.mail.ibm.com\n [10.39.53.228])\n\tby smtprelay03.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id\n 62QJ550C5046990\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK);\n\tThu, 26 Mar 2026 19:05:05 GMT","from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 5DA3F58055;\n\tThu, 26 Mar 2026 19:05:29 +0000 (GMT)","from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 7E5C958059;\n\tThu, 26 Mar 2026 19:05:27 +0000 (GMT)","from [9.61.247.58] (unknown [9.61.247.58])\n\tby smtpav01.wdc07v.mail.ibm.com (Postfix) with ESMTP;\n\tThu, 26 Mar 2026 19:05:27 +0000 (GMT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774551938; cv=none;\n b=BEJE5aAYbaXoDnbuacPoOGCStm66R7vMGa+hfzqJxNffaeDsCR/swapgjHiml0VmarXU4ZlNugZTbh1lySkpCFtwdfbJwwXpyq2NJepvLR5jPCHbrvnXfwVhs5SrEI0bYoeu1UfmVmGXWRCeDHi68Pd2XOk4H6EoF6FE2eK8fp8=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774551938; c=relaxed/simple;\n\tbh=dwdYpT7gHFwLIVM/vV2jTq1BZSxOXfyEuivKQvtyja8=;\n\th=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:\n\t In-Reply-To:Content-Type;\n b=oi7g3tRHizAhRO4IHm+w47ULpMAsL40w1pCqUGST/FHdKhbwdHsURiIDhq7KlIsjaXDfiPA60PGi73FXRszdLh4MCld7yQi8XondvbqJiYCEthrQ+9ZhxtXPOSQfEllG9o30qxGfOU6bszuTwIwLFauWCK0iFep/X5tLe40hQSo=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com;\n spf=pass smtp.mailfrom=linux.ibm.com;\n dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=Zv6Xlvpf; arc=none smtp.client-ip=148.163.156.1","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc\n\t:content-transfer-encoding:content-type:date:from:in-reply-to\n\t:message-id:mime-version:references:subject:to; s=pp1; bh=RegP/k\n\tY2TA8NJMDdQN28ncPjNidJcrgVawfmnm71jZU=; b=Zv6Xlvpfg/Tu4plMqfbnpC\n\t++rpcOEK/pc2V/A9J6Cf8QaaKr5lZFmYIacouUquLJkOXhuL/6Wst/ceeVJXGeSp\n\t6GtY58QPhttJL7NetqB/fICoLT7uUBX5eNBn8zTeOKxvaFrPv/OpKQDG+xApv+Gm\n\twGYRtWMDByu2F3YTiWo20Z6heMDsjFAvWqRAZyqmxlgQSZj3PdP7KHjLrTJLjjtB\n\tsVT1Bn4h6ER8sRZO96WfLu6k0V4yTaB6JkdchYrI1InPgng0KSez9SYqYXr1/7gW\n\tzXhgjNevIQQq1sDrUCgb2466hGwYpQzPZzMHGCRXXlyHwABjZ4FaWG0AQjdZ5PFA\n\t==","Message-ID":"<3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>","Date":"Thu, 26 Mar 2026 12:05:27 -0700","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","To":"Niklas Schnelle ,\n Julian Ruess , wintera@linux.ibm.com,\n ts@linux.ibm.com, oberpar@linux.ibm.com, gbayer@linux.ibm.com,\n Alex Williamson , Jason Gunthorpe ,\n Yishai Hadas ,\n Shameer Kolothum\n ,\n Kevin Tian ","Cc":"mjrosato@linux.ibm.com, raspl@linux.ibm.com, hca@linux.ibm.com,\n agordeev@linux.ibm.com, gor@linux.ibm.com, kvm@vger.kernel.org,\n linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n linux-pci@vger.kernel.org","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n <4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>","Content-Language":"en-US","From":"Farhan Ali ","In-Reply-To":"<4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>","Content-Type":"text/plain; charset=UTF-8; format=flowed","Content-Transfer-Encoding":"7bit","X-TM-AS-GCONF":"00","X-Proofpoint-ORIG-GUID":"iofcWBWmC3FuwplsueNdk_00KF2trhKr","X-Proofpoint-Spam-Details-Enc":"AW1haW4tMjYwMzI2MDEzNSBTYWx0ZWRfX5LTuzM/ZXY4X\n EMGzXi5f7nmgqxCJ7TH8cXKx37peozQHxaD3eGvDD+Nd6fe70w5S2no1MONLmQvRolWyREHg+yv\n KcfRpKD7/9NCtiV4OtQUJCD0KRjIlS8An3j409/BR0aVxiTrX0w7yWvUmHQfRmZ+wZins5wyThX\n VOobPuHybaWjjJSI8u+1CdhIAN6dBGVnst2SCvQF/p5NdT2JEMswXBaTRvhVLXfH9gInYhAK8+m\n JXpa/MC5I+EWQgHbDFuTyqaoG9Fjp4ZTxqOZMgt6aT3cE6vOAGNWdlo74Ki5JZ2O8CxDJv2CaCw\n XH6l0M4VHU+0+EyGtzs0ekbYl1cgs8Y1cMgI0DpkMLUL9nV+hIgo95oMVYz5e06v4R5f0U3Lii4\n ac238bQaLVq4zKlGGDK4ciB0mKNu1OyZoc7qnglc0R6D2pSZFKFX1GYVtJbsYMmJ2HXchYh7mcy\n WxM53sZR8y8y2H0ZP+A==","X-Authority-Analysis":"v=2.4 cv=bLEb4f+Z c=1 sm=1 tr=0 ts=69c5837c cx=c_pps\n a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17\n a=IkcTkHD0fZMA:10 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22\n a=RnoormkPH1_aCDwRdu11:22 a=iQ6ETzBq9ecOQQE5vZCe:22 a=VnNF1IyMAAAA:8\n a=8knF3OVK0f20Sk4uvPEA:9 a=QEXdDO2ut3YA:10","X-Proofpoint-GUID":"iofcWBWmC3FuwplsueNdk_00KF2trhKr","X-Proofpoint-Virus-Version":"vendor=baseguard\n engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49\n definitions=2026-03-26_03,2026-03-26_01,2025-10-01_01","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n spamscore=0 adultscore=0 clxscore=1015 phishscore=0 impostorscore=0\n malwarescore=0 lowpriorityscore=0 suspectscore=0 bulkscore=0\n priorityscore=1501 classifier=typeunknown authscore=0 authtc= authcc=\n route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001\n definitions=main-2603260135"}},{"id":3670388,"web_url":"http://patchwork.ozlabs.org/comment/3670388/","msgid":"<64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>","list_archive_url":null,"date":"2026-03-27T14:53:30","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":78856,"url":"http://patchwork.ozlabs.org/api/people/78856/","name":"Niklas Schnelle","email":"schnelle@linux.ibm.com"},"content":"On Thu, 2026-03-26 at 12:05 -0700, Farhan Ali wrote:\n> On 3/26/2026 6:03 AM, Niklas Schnelle wrote:\n> > On Wed, 2026-03-25 at 14:31 +0100, Julian Ruess wrote:\n> > > Add a vfio_pci variant driver for the s390-specific Internal Shared\n> > > Memory (ISM) devices used for inter-VM communication.\n> > > \n> > > This enables the development of vfio-pci-based user space drivers for\n> > > ISM devices.\n> > > \n> > > On s390, kernel primitives such as ioread() and iowrite() are switched\n> > > over from function-handle-based PCI load/stores instructions to PCI\n> > > memory-I/O (MIO) loads/stores when these are available and not\n> > > explicitly disabled. Since these instructions cannot be used with ISM\n> > > devices, ensure that classic function-handle-based PCI instructions are\n> > > used instead.\n> > > \n> > > The driver is still required even when MIO instructions are disabled, as\n> > > the ISM device relies on the PCI store block (PCISTB) instruction to\n> > > perform write operations.\n> > > \n> > > Stores are not fragmented, therefore one ioctl corresponds to exactly\n> > > one PCISTB instruction. User space must ensure to not write more than\n> > > 4096 bytes at once to an ISM BAR which is the maximum payload of the\n> > > PCISTB instruction.\n> > > \n> > > Reviewed-by: Alexandra Winter \n> > > Reviewed-by: Niklas Schnelle \n> > > Signed-off-by: Julian Ruess \n> > > ---\n> > > drivers/vfio/pci/Kconfig | 2 +\n> > > drivers/vfio/pci/Makefile | 2 +\n> > > drivers/vfio/pci/ism/Kconfig | 10 ++\n> > > drivers/vfio/pci/ism/Makefile | 3 +\n> > > drivers/vfio/pci/ism/main.c | 408 ++++++++++++++++++++++++++++++++++++++++++\n> > > 5 files changed, 425 insertions(+)\n> > > \n> > --- snip ---\n> > > +\n> > > +static int ism_vfio_pci_ioctl_get_region_info(struct vfio_device *core_vdev,\n> > > +\t\t\t\t\t struct vfio_region_info *info,\n> > > +\t\t\t\t\t struct vfio_info_cap *caps)\n> > > +{\n> > > +\tstruct vfio_pci_core_device *vdev =\n> > > +\t\tcontainer_of(core_vdev, struct vfio_pci_core_device, vdev);\n> > > +\tstruct pci_dev *pdev = vdev->pdev;\n> > > +\n> > > +\tswitch (info->index) {\n> > > +\tcase VFIO_PCI_CONFIG_REGION_INDEX:\n> > > +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n> > > +\t\tinfo->size = pdev->cfg_size;\n> > > +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n> > > +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n> > > +\t\tbreak;\n> > > +\tcase VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:\n> > > +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n> > > +\t\tinfo->size = pci_resource_len(pdev, info->index);\n> > > +\t\tif (!info->size) {\n> > > +\t\t\tinfo->flags = 0;\n> > > +\t\t\tbreak;\n> > > +\t\t}\n> > > +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n> > > +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n> > > +\t\tbreak;\n> > > +\tdefault:\n> > > +\t\tinfo->offset = 0;\n> > > +\t\tinfo->size = 0;\n> > > +\t\tinfo->flags = 0;\n> > > +\t\treturn -EINVAL;\n> > Thinking more about this, the above default handling actually breaks\n> > additional regions such as the one added by Farhan for the error\n> > events. I think this needs to instead call the generic\n> > vfio_pci_ioctl_get_region_info() for other regions.\n> \n> Note for error events we are using a VFIO device feature and not a \n> region. At this point we actually don't have additional regions. I do \n> agree that if we were to add a zpci specific region we would need to \n> update here and ism_vfio_pci_rw() to allow region read/write ops. This \n> ISM driver would also need to support all the possible callbacks in \n> struct vfio_pci_regops.\n> \n> Given that we don't have any additional regions yet, I am conflicted if \n> it makes sense to add all the code to support additional regions without \n> a good way to test it. Maybe its something we can defer when if we add \n> additional regions? Thanks\n> \n> Farhan\n\n@Alex, we experimented a bit and it turns out with the custom\nISM_VFIO_PCI_OFFSET_SHIFT it becomes quite tricky to reliably call into\ncommon vfio-pci code for handling other regions as that again relies on\nthe normal VFIO_PCI_OFFSET_SHIFT.\n\nSo we came up with two options:\n\n1) vfio-pci-ism will only support this basic set of regions. It seems\nto us that new extensions like Farhan's error events should use device\nfeatures anyway, so this to us seems like an acceptable limitation and\nwould essentially mean we take this patch as is.\n\n2) We revisit the original idea of adjusting VFIO_PCI_OFFSET_SHIFT\nglobally but do so only for CONFIG_64BIT so as not to break 32 bit\nplatforms. This would simplify vfio-pci-ism and cause less code\nduplication but also affects everyone else.\n\nEither option works for us, so I'm hoping for your input.\n\nThanks,\nNiklas","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256\n header.s=pp1 header.b=SbHV+1eM;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c04:e001:36c::12fc:5321; helo=tor.lore.kernel.org;\n envelope-from=linux-pci+bounces-51283-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=\"SbHV+1eM\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=148.163.158.5","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=linux.ibm.com"],"Received":["from tor.lore.kernel.org (tor.lore.kernel.org\n [IPv6:2600:3c04:e001:36c::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fj3gB5WMbz1y1x\n\tfor ; Sat, 28 Mar 2026 01:58:30 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby tor.lore.kernel.org (Postfix) with ESMTP id 8E0DD305093B\n\tfor ; Fri, 27 Mar 2026 14:54:53 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id BE7513FA5C3;\n\tFri, 27 Mar 2026 14:54:52 +0000 (UTC)","from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com\n [148.163.158.5])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 763733FA5F0;\n\tFri, 27 Mar 2026 14:54:42 +0000 (UTC)","from pps.filterd (m0360072.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id\n 62R5hLVN196681;\n\tFri, 27 Mar 2026 14:54:36 GMT","from ppma22.wdc07v.mail.ibm.com\n (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92])\n\tby mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4d1kun1jw1-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tFri, 27 Mar 2026 14:54:36 +0000 (GMT)","from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1])\n\tby ppma22.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id\n 62REq86L005972;\n\tFri, 27 Mar 2026 14:54:36 GMT","from smtprelay01.wdc07v.mail.ibm.com ([172.16.1.68])\n\tby ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4d262000se-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tFri, 27 Mar 2026 14:54:36 +0000","from smtpav01.dal12v.mail.ibm.com (smtpav01.dal12v.mail.ibm.com\n [10.241.53.100])\n\tby smtprelay01.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id\n 62REsYGo4653948\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK);\n\tFri, 27 Mar 2026 14:54:34 GMT","from smtpav01.dal12v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 578C058062;\n\tFri, 27 Mar 2026 14:54:34 +0000 (GMT)","from smtpav01.dal12v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 2608958059;\n\tFri, 27 Mar 2026 14:54:31 +0000 (GMT)","from [9.111.77.47] (unknown [9.111.77.47])\n\tby smtpav01.dal12v.mail.ibm.com (Postfix) with ESMTP;\n\tFri, 27 Mar 2026 14:54:30 +0000 (GMT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774623292; cv=none;\n b=YInOgaWWNnf6SBg3kmFqpa5vmuQcDgrnq8fTX6uTvMe9FjeVqsVVYnPS3774zvZDQ9aHyzAbdyFwJ6B49UqRypw9zns9ojtKemuMrmhpsXJRTQqoSQyHwiY6zCGuRAAES+t/bYCsUuOSCnZaGYQkyxtYD8T0RERVxOiutFb4Uwc=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774623292; c=relaxed/simple;\n\tbh=sBDkQZ0IMKKrYQG4KzoUcctk38Cd+7kL8vp1ws6Ti9I=;\n\th=Message-ID:Subject:From:To:Cc:In-Reply-To:References:Content-Type:\n\t Date:MIME-Version;\n b=s4JFHl4FUejqQVxI3NCnDgKm+0oLDoLtIhA8lAvbeQGnhGmk/eq2mt6sLbp+k+/VZHkNVJgAJfeeHf7OqGs2EhVJ8B6apqF8/mt5j+pe86Hd3Bl9R+p/EO9Rl4Yn8lwKJdqkAWNTRrW3e1RIRgEc3ofSn2lYIaeh/MQGlZ6ITz8=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com;\n spf=pass smtp.mailfrom=linux.ibm.com;\n dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=SbHV+1eM; arc=none smtp.client-ip=148.163.158.5","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc\n\t:content-transfer-encoding:content-type:date:from:in-reply-to\n\t:message-id:mime-version:references:subject:to; s=pp1; bh=Wwr6oR\n\t7eBM1GT1fLWWpsP40CvLQOt/4IGzocrdyOk0k=; b=SbHV+1eMq4OxA02yjl0NCN\n\tdqMI0gY6PZhARXtHEsrobKbTzomJEJr9In4rB5vCCB6IuixIqKUoNa5M9neNCvXG\n\tuX+eXdnymM9yeLrm6nBqsBSmLQ16eovjEeo/MxIBo4JnoEO3FI10YJYupXdN8Hpl\n\tPHR64Ap94SQIbp9d8vLSPDw9oDxfDKUyoJBp70qIwqqJEGa6TLz91PrnVWIP1t59\n\tpuEA1gk2NslXBIrQHzMTs2VZgCOrfPr2pffhJlUxEBANMq7NDKWSc0NYZmVWdw2H\n\tuvQuMpXWNf+JC/fHf2RLZ0PqF0HGK6UJ9ExXM2o2AivKgietpqi5Eyd8RIOjOIeg\n\t==","Message-ID":"<64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","From":"Niklas Schnelle ","To":"Farhan Ali , Julian Ruess ,\n wintera@linux.ibm.com, ts@linux.ibm.com, oberpar@linux.ibm.com,\n gbayer@linux.ibm.com, Alex Williamson ,\n Jason Gunthorpe\t\n , Yishai Hadas ,\n Shameer Kolothum\t\n ,\n Kevin Tian ","Cc":"mjrosato@linux.ibm.com, raspl@linux.ibm.com, hca@linux.ibm.com,\n agordeev@linux.ibm.com, gor@linux.ibm.com, kvm@vger.kernel.org,\n linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n linux-pci@vger.kernel.org","In-Reply-To":"<3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n\t <4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n\t <3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>","Autocrypt":"addr=schnelle@linux.ibm.com; prefer-encrypt=mutual;\n keydata=mQINBGHm3M8BEAC+MIQkfoPIAKdjjk84OSQ8erd2OICj98+GdhMQpIjHXn/RJdCZLa58k\n /ay5x0xIHkWzx1JJOm4Lki7WEzRbYDexQEJP0xUia0U+4Yg7PJL4Dg/W4Ho28dRBROoJjgJSLSHwc\n 3/1pjpNlSaX/qg3ZM8+/EiSGc7uEPklLYu3gRGxcWV/944HdUyLcnjrZwCn2+gg9ncVJjsimS0ro/\n 2wU2RPE4ju6NMBn5Go26sAj1owdYQQv9t0d71CmZS9Bh+2+cLjC7HvyTHKFxVGOznUL+j1a45VrVS\n XQ+nhTVjvgvXR84z10bOvLiwxJZ/00pwNi7uCdSYnZFLQ4S/JGMs4lhOiCGJhJ/9FR7JVw/1t1G9a\n UlqVp23AXwzbcoV2fxyE/CsVpHcyOWGDahGLcH7QeitN6cjltf9ymw2spBzpRnfFn80nVxgSYVG1d\n w75ksBAuQ/3e+oTQk4GAa2ShoNVsvR9GYn7rnsDN5pVILDhdPO3J2PGIXa5ipQnvwb3EHvPXyzakY\n tK50fBUPKk3XnkRwRYEbbPEB7YT+ccF/HioCryqDPWUivXF8qf6Jw5T1mhwukUV1i+QyJzJxGPh19\n /N2/GK7/yS5wrt0Lwxzevc5g+jX8RyjzywOZGHTVu9KIQiG8Pqx33UxZvykjaqTMjo7kaAdGEkrHZ\n dVHqoPZwhCsgQARAQABtChOaWtsYXMgU2NobmVsbGUgPHNjaG5lbGxlQGxpbnV4LmlibS5jb20+iQ\n JXBBMBCABBAhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAhkBFiEEnbAAstJ1IDCl9y3cr+Q/Fej\n CYJAFAmmAWs8FCQl6sYAACgkQr+Q/FejCYJAn2g//UKzlXOgizdk0wudLooRbGzDo23ktGSPK5Oj9\n 9o5z6v4Jz5+qOHo5835683cqkMLM9//udA1ZcKV88LVwyfmoHChPW24cWBmOEy7RJOWCR4WeEINaO\n pZUGF5YOx7oKTkPs511ky2FR0Heg35754pgTuTMEpYzRXr5pNMPS8mHXcXSARFPDPaCF+uBJ9BafO\n L7XbpSwKRttePsWAlPHbSbloeDApBfHUhcF/pbuM9GNs+c/8V9NK+SwwqNK214t7jaSq9k+19/hfE\n jvU45nbiYQM4VqGCelxVFRWol93JnwPFp/JaMgxgV1VYFH9Ijtgh+qNVVBqO8bbTjioFKy1bHdprN\n 9GyPLDxoaI/lBg+5CwKewzazUjFd0xaqZbTXSgNK4ev/IuNI3qZV8tpvZZWwIgZU1K0Bhplt8Sku+\n O9Yl2H54erq9zuzwXjqBJtoW0+MaKbe+1gZ/v2/AVE2VeQMugPUWDg+2bpJaApRkeA4xQ9XfeW6Bp\n It7xYrwwbVhQtWRC0sRh+QNlU9HI28wPSnLWn7HFBeWupaIrxSp4IEL3eHUn8xv4aA8lpdNsHXD/X\n vqOSUwy5jlTPTlemvwaC9mNHagNdVXng8C6+hxiDLhZ6xH2P4qNHTKmjW61NsdF6Y/HfWP+lmbi8/\n 474UNCltDt/fP01ajqogfWZKFymoH0O0KU5pa2xhcyBTY2huZWxsZSA8bmlrbGFzLnNjaG5lbGxlQ\n GlibS5jb20+iQJUBBMBCAA+AhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEEnbAAstJ1IDCl9y\n 3cr+Q/FejCYJAFAmmAWusFCQl6sYAACgkQr+Q/FejCYJAtIw//WmQW/Z+SLdfrlDH5J2bvixzFNnO\n TOvp8uM8vcNZsxZwPXem4AeCXHayCqipxpa0iXWufEIvdMxkBxWvvM//V+rTUgQnJe6nhDxfLGklx\n 5Mb2H+K/ndS73ElCuA30MPYq7mHr8i3gEmi2ZFX1W47JecJ8hno/DQxhHRG7bd+GFsiKCbsjLWXNq\n s/VaAK9uyOTQx7m6/2nR8L+Mvl1BrRXwkj7Qp0qxfQSd4r+IVNBzNFOcrGagBqsyHrN7Is7IICktH\n 9VFl/G8P+hfviHQLnlxw9ltzpM1Dy6N1+BM3kbqD59gX+L6wqiLJI42eh+SHCiy35FvD3AFlYx4jZ\n MWE6qIgFnbwcL1kvcA7nnwfr3ZizCYPm8e334xXxslXBoRGsvjXSbAeAyZo2dvJXffNHdcDdUbJSl\n CfOixNGGKiQvs00X9ekfq9WmmRFvmYHu/m3lg1OXnMjFFIO41O51ZdhbEYJiqZEki7jA8Hd9xuWwQ\n nFDHhacU3xxivZ4BKQGQc+4XZ3yp/q6+7ux9prepRy/LeRyoaAmE67oxEsAgj+qyA3Tfy5nRTDdRQ\n E//gpaIt9H1VEx+68dRWHroxBQeozpnFPi25AlX3k4/EtVZjcItPWgE9iru1qT4DH3BBrz7Kd1zUw\n NnQC77zDJyZD2WUj1E+5bftO0aeE+7HZXj3tM/ea0K05pa2xhcyBTY2huZWxsZSA8bmlrbGFzLnNj\n aG5lbGxlQGdtYWlsLmNvbT6JAlQEEwEIAD4CGwEFCwkIBwIGFQoJCAsCBBYCAwECHgECF4AWIQSds\n ACy0nUgMKX3Ldyv5D8V6MJgkAUCaYBa6wUJCXqxgAAKCRCv5D8V6MJgkF/TEACOY2kL4NGFIbWeM5\n TUhatxqe8c3RT6jvNjq32CkvaK/cSZzBkS0smddyOzxt2WnsvMgkr9cM7P+CevoMwhT3e0lgQbqBD\n /vXZJjWKddC+iKXeqWkjMVcgCOsWNZ7PWEzRUT5X1AEFq2zzxQAQ/bCWEYNqIbHN4b6G1Wk+2Y598\n +KypZ3FS0bwiItnPQOWzOOqJCGxDxaEUuXFx4ah8HtVdtIev8jPS/5uzQO9iG2vZQUWeMEYZtfMHW\n sbFWqo2A3lxB+KPzNIYFhul4Lyx1CwvKUAGSHOx7FZuc2xI5DYt/Wdh2QyKFYr7xVzv3uwJjeS1+3\n 6gvyB7DJaQuY+PziNPv4GPr5wy0cRkJ6Ps15fgC6y6wNwoNdNXKlwiuclIsBzJKa7A0pZMIfpCpIJ\n bEHP7oy3drBRAhIrBx7Lx1lyqqodDqc+ok5IQ5WcKG/TOrH732mTmJX6fxYTiCVxcU4WLJSNZbrZ/\n pjF0AWXs7E+onAkQy6RLg/XU1iiU5QdMvug+fTA6TpPSUMdujWtGWUt3/4nC+69AVc8tXtRQTZ7gP\n t7uIcQFwPqUuJGS26vl0w/6dIABQAyU9acvE3adCZra+/PBKFZi/yxT1WgV1T2mexKSWwQgLcR57J\n Yp5oWnQRgi/S6fAoskIWkp9UVcfAQPY0p45NwO5cZR9/g06JZmyrQhTmlrbGFzIFNjaG5lbGxlIDx\n uaWtzQGtlcm5lbC5vcmc+iQJUBBMBCAA+AhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEEnbAA\n stJ1IDCl9y3cr+Q/FejCYJAFAmmAWusFCQl6sYAACgkQr+Q/FejCYJAz4A/9F+dMhzu7YonagL4qh\n WDz5IpRD4vzYKOBZ+qwYp1ugJz1BIUppN9i68HKoS4ARfgP97Sv9GpOy9g7L0lymH2MPF8hRPK0Yn\n 7DKIkeu/r28YWEoWfoVm5reC+gpxMgmxBz4JScE4f6xfa7+Nw0bbTDl+nxftJD7lf/dTiruNJsXph\n HQnZ5wPXmxeH6XVJikfpyrGe8iJZALbtHtjlx6Omu7NvRGikenB8trrWS5W0F60ZdbqH1HdmDDcrZ\n pDq6LtAARHK5tGRm0SK6sZpKe3nULFeeCt7T/edk2FC6KVh4sL1jw1kyceX4DjiMffqYBPrhK5gz5\n cDIixLBF9C6Wt1ObvuDBrIQf1/3q6EZrUrUuf6qtaXDMuC6cSlShm47qaPEvVYh67O9JZQ7vzvaea\n UI74DJUb8Pjnz7mTOmMOzsS1gUhCue4n2YSSM6ythioCGb/3bgMGTpuer3JhvZG5s5uKD9yyj8s8x\n 35qJkCFfjmjVx9s3vSUS48X+cUpYcMispErKzFu7C0YgKoxvJ4XTfXlDBiMFMPYcN67hsb2jeYHVJ\n wzE+fIZiDx9JLh1oQW2krwjweisE+3glOaKXZKi0fBtkxyH41iemLtLNYZRJopv6ykdl3hiI+Nh+a\n 3FZJPTo/OpqchMm8XIeDxC4NFFiPMpyLeYzIxO7eZpiGrAjVTE=","Content-Type":"text/plain; charset=\"UTF-8\"","Content-Transfer-Encoding":"quoted-printable","Date":"Fri, 27 Mar 2026 15:53:30 +0100","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","User-Agent":"Evolution 3.58.3 (3.58.3-1.fc43) ","X-TM-AS-GCONF":"00","X-Proofpoint-GUID":"UG4dm3Y2oBhExZJg3MheE7j3O2b8zM80","X-Proofpoint-ORIG-GUID":"UG4dm3Y2oBhExZJg3MheE7j3O2b8zM80","X-Proofpoint-Spam-Details-Enc":"AW1haW4tMjYwMzI3MDEwMiBTYWx0ZWRfX8b1H2eNq0rpR\n 1V0JcIDvmlp0CVODbbKu9QnMiPkiuUlV4uFoFE+JKp66O3x3CIu4gFvs2CeoLbL39N7zT8MOFGf\n 0MzUDolRGn49RTW7aBikc5rO8F0Q0fD6nzZchUxgsL4USFjMgxhvudWV9JJFixCidIkTD3pqA96\n EzGheOLKJ4NkkKzxVA9ZGVVY2oJ5zRTRdfCdIW1nwgyFniIxsxobIyzHCIdLy0yDm52UE2yqDuw\n JPwP5JXG//WYWxQGkx9vn1wcxUguKv+S5NCidXJ6csFDfLHESMesDGDICBFcDLe4f26PBfWZcnb\n oUOnoCSeFOolAt5/M5zrlQgVq590AomFmRDNdOTFdSDgivSxqxuvUmH8r5lvk1X+qXRMkzqPHgS\n 6Ukz2cn8jvBUw6vW2jYmcPhIbgbsgbcbHysG7UykLlbIUxLpYgm4mK+9GwkausFJFxi6rcCZhnf\n 0yeI66nJchW29YRdl6Q==","X-Authority-Analysis":"v=2.4 cv=KbXfcAYD c=1 sm=1 tr=0 ts=69c69a2c cx=c_pps\n a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17\n a=IkcTkHD0fZMA:10 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22\n a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=VnNF1IyMAAAA:8\n a=pcDmQ4xKrVFVuDfWhAIA:9 a=QEXdDO2ut3YA:10","X-Proofpoint-Virus-Version":"vendor=baseguard\n engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49\n definitions=2026-03-26_04,2026-03-26_01,2025-10-01_01","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n suspectscore=0 impostorscore=0 malwarescore=0 adultscore=0 clxscore=1015\n priorityscore=1501 bulkscore=0 lowpriorityscore=0 phishscore=0 spamscore=0\n classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0\n reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603270102"}},{"id":3671195,"web_url":"http://patchwork.ozlabs.org/comment/3671195/","msgid":"<20260330093646.03b0455f@shazbot.org>","list_archive_url":null,"date":"2026-03-30T15:36:46","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":91887,"url":"http://patchwork.ozlabs.org/api/people/91887/","name":"Alex Williamson","email":"alex@shazbot.org"},"content":"On Fri, 27 Mar 2026 15:53:30 +0100\nNiklas Schnelle wrote:\n\n> On Thu, 2026-03-26 at 12:05 -0700, Farhan Ali wrote:\n> > On 3/26/2026 6:03 AM, Niklas Schnelle wrote: \n> > > On Wed, 2026-03-25 at 14:31 +0100, Julian Ruess wrote: \n> > > > Add a vfio_pci variant driver for the s390-specific Internal Shared\n> > > > Memory (ISM) devices used for inter-VM communication.\n> > > > \n> > > > This enables the development of vfio-pci-based user space drivers for\n> > > > ISM devices.\n> > > > \n> > > > On s390, kernel primitives such as ioread() and iowrite() are switched\n> > > > over from function-handle-based PCI load/stores instructions to PCI\n> > > > memory-I/O (MIO) loads/stores when these are available and not\n> > > > explicitly disabled. Since these instructions cannot be used with ISM\n> > > > devices, ensure that classic function-handle-based PCI instructions are\n> > > > used instead.\n> > > > \n> > > > The driver is still required even when MIO instructions are disabled, as\n> > > > the ISM device relies on the PCI store block (PCISTB) instruction to\n> > > > perform write operations.\n> > > > \n> > > > Stores are not fragmented, therefore one ioctl corresponds to exactly\n> > > > one PCISTB instruction. User space must ensure to not write more than\n> > > > 4096 bytes at once to an ISM BAR which is the maximum payload of the\n> > > > PCISTB instruction.\n> > > > \n> > > > Reviewed-by: Alexandra Winter \n> > > > Reviewed-by: Niklas Schnelle \n> > > > Signed-off-by: Julian Ruess \n> > > > ---\n> > > > drivers/vfio/pci/Kconfig | 2 +\n> > > > drivers/vfio/pci/Makefile | 2 +\n> > > > drivers/vfio/pci/ism/Kconfig | 10 ++\n> > > > drivers/vfio/pci/ism/Makefile | 3 +\n> > > > drivers/vfio/pci/ism/main.c | 408 ++++++++++++++++++++++++++++++++++++++++++\n> > > > 5 files changed, 425 insertions(+)\n> > > > \n> > > --- snip --- \n> > > > +\n> > > > +static int ism_vfio_pci_ioctl_get_region_info(struct vfio_device *core_vdev,\n> > > > +\t\t\t\t\t struct vfio_region_info *info,\n> > > > +\t\t\t\t\t struct vfio_info_cap *caps)\n> > > > +{\n> > > > +\tstruct vfio_pci_core_device *vdev =\n> > > > +\t\tcontainer_of(core_vdev, struct vfio_pci_core_device, vdev);\n> > > > +\tstruct pci_dev *pdev = vdev->pdev;\n> > > > +\n> > > > +\tswitch (info->index) {\n> > > > +\tcase VFIO_PCI_CONFIG_REGION_INDEX:\n> > > > +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n> > > > +\t\tinfo->size = pdev->cfg_size;\n> > > > +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n> > > > +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n> > > > +\t\tbreak;\n> > > > +\tcase VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:\n> > > > +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n> > > > +\t\tinfo->size = pci_resource_len(pdev, info->index);\n> > > > +\t\tif (!info->size) {\n> > > > +\t\t\tinfo->flags = 0;\n> > > > +\t\t\tbreak;\n> > > > +\t\t}\n> > > > +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n> > > > +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n> > > > +\t\tbreak;\n> > > > +\tdefault:\n> > > > +\t\tinfo->offset = 0;\n> > > > +\t\tinfo->size = 0;\n> > > > +\t\tinfo->flags = 0;\n> > > > +\t\treturn -EINVAL; \n> > > Thinking more about this, the above default handling actually breaks\n> > > additional regions such as the one added by Farhan for the error\n> > > events. I think this needs to instead call the generic\n> > > vfio_pci_ioctl_get_region_info() for other regions. \n> > \n> > Note for error events we are using a VFIO device feature and not a \n> > region. At this point we actually don't have additional regions. I do \n> > agree that if we were to add a zpci specific region we would need to \n> > update here and ism_vfio_pci_rw() to allow region read/write ops. This \n> > ISM driver would also need to support all the possible callbacks in \n> > struct vfio_pci_regops.\n> > \n> > Given that we don't have any additional regions yet, I am conflicted if \n> > it makes sense to add all the code to support additional regions without \n> > a good way to test it. Maybe its something we can defer when if we add \n> > additional regions? Thanks\n> > \n> > Farhan \n> \n> @Alex, we experimented a bit and it turns out with the custom\n> ISM_VFIO_PCI_OFFSET_SHIFT it becomes quite tricky to reliably call into\n> common vfio-pci code for handling other regions as that again relies on\n> the normal VFIO_PCI_OFFSET_SHIFT.\n> \n> So we came up with two options:\n> \n> 1) vfio-pci-ism will only support this basic set of regions. It seems\n> to us that new extensions like Farhan's error events should use device\n> features anyway, so this to us seems like an acceptable limitation and\n> would essentially mean we take this patch as is.\n> \n> 2) We revisit the original idea of adjusting VFIO_PCI_OFFSET_SHIFT\n> globally but do so only for CONFIG_64BIT so as not to break 32 bit\n> platforms. This would simplify vfio-pci-ism and cause less code\n> duplication but also affects everyone else.\n> \n> Either option works for us, so I'm hoping for your input.\n\nThere's risk involved with changing the default shift. The fear is\nthere's userspace drivers that hard code the shift. DPDK was even such\na user at one point, iirc. Maybe it's ok to break such users, maybe\nthere are actually no such users left and it's all FUD at this point.\nEither way, I have a hard time justifying that risk for a single,\nobscure S390 device.\n\nRather than using CONFIG_64BIT as a basis for using a different\ndefault, should we start out with a more narrow scope of CONFIG_S390?\n\nIt's likely inevitable that we'll hit this wall in general, but maybe\nS390 can be the \"crash test dummy\" to prove to userspace that they\nreally need to use the uAPI rather than hard coded values.\n\nFarhan's series is a bit of a straw-man since it doesn't actually\nconvey the error codes via regions, but I can certainly agree that\nusing a unique region shift becomes an ongoing burden relative to\nvfio-pci-core helpers. I can accept an S390 specific (for now) change\nto the region spacing if that's the most sensible path. Thanks,\n\nAlex","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=shazbot.org header.i=@shazbot.org header.a=rsa-sha256\n header.s=fm1 header.b=XUi53fPo;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=messagingengine.com header.i=@messagingengine.com\n header.a=rsa-sha256 header.s=fm1 header.b=tvvDmLqx;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=linux-pci+bounces-51466-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=\"XUi53fPo\";\n\tdkim=pass (2048-bit key) header.d=messagingengine.com\n header.i=@messagingengine.com header.b=\"tvvDmLqx\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=103.168.172.151","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=shazbot.org"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fkwXy3p0Lz1yG8\n\tfor ; Tue, 31 Mar 2026 02:44:34 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id D06203007E38\n\tfor ; Mon, 30 Mar 2026 15:36:54 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 72CCE3624BC;\n\tMon, 30 Mar 2026 15:36:53 +0000 (UTC)","from fout-a8-smtp.messagingengine.com\n (fout-a8-smtp.messagingengine.com [103.168.172.151])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 8E66C3624CE;\n\tMon, 30 Mar 2026 15:36:50 +0000 (UTC)","from phl-compute-04.internal (phl-compute-04.internal [10.202.2.44])\n\tby mailfout.phl.internal (Postfix) with ESMTP id AE68EEC01F3;\n\tMon, 30 Mar 2026 11:36:49 -0400 (EDT)","from phl-frontend-04 ([10.202.2.163])\n by phl-compute-04.internal (MEProxy); Mon, 30 Mar 2026 11:36:49 -0400","by mail.messagingengine.com (Postfix) with ESMTPA; Mon,\n 30 Mar 2026 11:36:47 -0400 (EDT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774885013; cv=none;\n b=NFA9zGgtxDpwONwM1k+NrGhNEpkj4AVF2WcaS4jlwZs34KKWazTlVFLM9L5qaeCW/qLSyGavVhKZ/yxK2gqaAaqVM1f6X7tGWrCkm7uKVWRhQJ9zNH918MAhd10FKlF0aeFIEJGfqv+xGrdjGl7v0mEYrUF8ymLyZtr94P4zw0Q=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774885013; c=relaxed/simple;\n\tbh=8XpL0hz6gQ4RRLu/LAP84ILPYxRrFhAWzSNsaZ08To4=;\n\th=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:\n\t MIME-Version:Content-Type;\n b=VzPBweA65V3IVNXZBA84OiD0f6jTa+LXmNveOZ/mcby0B91WpjCe8tDT8HwISQUNW8IiwiCIKsphUI1KGEydRBktHuYhVsQD+PhrVgA0kHamQpeURJ2lm1yH6khYdVaaoH+/SnRdvTMExQrLQDODWGobuH1MHWyolPsXJyH1G6I=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org;\n spf=pass smtp.mailfrom=shazbot.org;\n dkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=XUi53fPo;\n dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com\n header.b=tvvDmLqx; arc=none smtp.client-ip=103.168.172.151","DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/relaxed; d=shazbot.org; h=\n\tcc:cc:content-transfer-encoding:content-type:content-type:date\n\t:date:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to; s=fm1; t=1774885009;\n\t x=1774971409; bh=cbEOkWUc2U4Fm/hMCSAf19Rx3s2OVVkD2oFlIw7xFjs=; b=\n\tXUi53fPo+vcTcJzlnn43osylDk2eMSCXVjsq08kai8dYCJP2sFlg0N6SDlSA3Zh8\n\t9zHsKgqqh1+T4IeimdBp2GIFOR+/mfgU4zQBZ89qM8Ex+tKfJ/U/4abnTLqzPVCd\n\tNxQTHX+sr/l79gxoWvGKGdHYIKp1mmw6sKIwzt+4S00HoAElomDpWFQ8+EbkL6Cf\n\tSrofoMC9sn6K5Lqf6tD/sSx4qHuk0bCXpk5mLxOeO/PV9vKEGFRfy+nOrI3XfQrl\n\t1/uNt9UmmsuxwNUeX7Nw4KQkpZgqSvdeQ0zRdfYafJtC1AjZM7YmZY0nbjIaMZ6z\n\t9ZMgE/1zFwlj7Jq0TIp/dA==","v=1; a=rsa-sha256; c=relaxed/relaxed; d=\n\tmessagingengine.com; h=cc:cc:content-transfer-encoding\n\t:content-type:content-type:date:date:feedback-id:feedback-id\n\t:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to:x-me-proxy\n\t:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t=1774885009; x=\n\t1774971409; bh=cbEOkWUc2U4Fm/hMCSAf19Rx3s2OVVkD2oFlIw7xFjs=; b=t\n\tvvDmLqx9mqW3T+j5R/vYnHRQ5sB9mdXoqUYZb0B1XaTouMnNSlIp/g6cV5pY725G\n\tY6OZSQgAnz5LQZm2eumILePTf07B5yMZStuO6Facj3SkdQaNYy4Lo+dc9DHSIc5d\n\tPPXpseZirM4FqSdUS/Y/7gZm/BWrAsqQqhbiwnT/qw6dbOtOvcp0SJJWSbAZUYOl\n\t1d8WeQwxAGx+iSs+479ZK5lsBbXKtqAiZy4XXE9hTJdlveVdjh70eqmRqI5hFv91\n\t05neSkXFbTp77Zsv3atz8cuneNNHJQ4v7ydGFWw0rOlMPZZiPXKzpo2k1uARMeXk\n\tTdcJD9Z2a3KDuh3nCeJZA=="],"X-ME-Sender":"\n ","X-ME-Received":"\n ","X-ME-Proxy-Cause":"\n gggruggvucftvghtrhhoucdtuddrgeefgedrtddtgdeffeelfeehucetufdoteggodetrf\n dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceu\n rghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujf\n gurhepfffhvfevuffkjghfofggtgfgsehtjeertdertddvnecuhfhrohhmpeetlhgvgicu\n hghilhhlihgrmhhsohhnuceorghlvgigsehshhgriigsohhtrdhorhhgqeenucggtffrrg\n htthgvrhhnpedvkeefjeekvdduhfduhfetkedugfduieettedvueekvdehtedvkefgudeg\n veeuueenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpe\n grlhgvgiesshhhrgiisghothdrohhrghdpnhgspghrtghpthhtohepvddupdhmohguvgep\n shhmthhpohhuthdprhgtphhtthhopehstghhnhgvlhhlvgeslhhinhhugidrihgsmhdrtg\n homhdprhgtphhtthhopegrlhhifhhmsehlihhnuhigrdhisghmrdgtohhmpdhrtghpthht\n ohepjhhulhhirghnrheslhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopeifihhnth\n gvrhgrsehlihhnuhigrdhisghmrdgtohhmpdhrtghpthhtohepthhssehlihhnuhigrdhi\n sghmrdgtohhmpdhrtghpthhtohepohgsvghrphgrrheslhhinhhugidrihgsmhdrtghomh\n dprhgtphhtthhopehgsggrhigvrheslhhinhhugidrihgsmhdrtghomhdprhgtphhtthho\n pehjghhgseiiihgvphgvrdgtrgdprhgtphhtthhopeihihhshhgrihhhsehnvhhiughirg\n drtghomh","X-ME-Proxy":"\n \n \n \n ","Feedback-ID":"i03f14258:Fastmail","Date":"Mon, 30 Mar 2026 09:36:46 -0600","From":"Alex Williamson ","To":"Niklas Schnelle ","Cc":"Farhan Ali , Julian Ruess ,\n wintera@linux.ibm.com, ts@linux.ibm.com, oberpar@linux.ibm.com,\n gbayer@linux.ibm.com, Jason Gunthorpe\t , Yishai Hadas\n , Shameer Kolothum\t , Kevin\n Tian , mjrosato@linux.ibm.com, raspl@linux.ibm.com,\n hca@linux.ibm.com, agordeev@linux.ibm.com, gor@linux.ibm.com,\n kvm@vger.kernel.org, linux-kernel@vger.kernel.org,\n linux-s390@vger.kernel.org, linux-pci@vger.kernel.org, alex@shazbot.org","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","Message-ID":"<20260330093646.03b0455f@shazbot.org>","In-Reply-To":"<64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n\t<4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n\t<3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n\t<64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>","X-Mailer":"Claws Mail 4.3.1 (GTK 3.24.51; x86_64-pc-linux-gnu)","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=US-ASCII","Content-Transfer-Encoding":"7bit"}},{"id":3671205,"web_url":"http://patchwork.ozlabs.org/comment/3671205/","msgid":"<20260330155651.GD246076@ziepe.ca>","list_archive_url":null,"date":"2026-03-30T15:56:51","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":73018,"url":"http://patchwork.ozlabs.org/api/people/73018/","name":"Jason Gunthorpe","email":"jgg@ziepe.ca"},"content":"On Mon, Mar 30, 2026 at 09:36:46AM -0600, Alex Williamson wrote:\n> There's risk involved with changing the default shift. The fear is\n> there's userspace drivers that hard code the shift. DPDK was even such\n> a user at one point, iirc. Maybe it's ok to break such users, maybe\n> there are actually no such users left and it's all FUD at this point.\n> Either way, I have a hard time justifying that risk for a single,\n> obscure S390 device.\n\nIf we go ahead with that DMABUF series could obscure cases like this\nbe told to just get a DMABUF FD and then mmap it? Avoid this whole\nissue?\n\nJason","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n secure) header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256\n header.s=google header.b=J4bfIjOb;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=linux-pci+bounces-51468-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca\n header.b=\"J4bfIjOb\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=209.85.219.49","smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=ziepe.ca","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=ziepe.ca"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fkwz71vgyz1yG8\n\tfor ; Tue, 31 Mar 2026 03:03:47 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id 499B9303A6DC\n\tfor ; Mon, 30 Mar 2026 15:56:57 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id E971836CDE8;\n\tMon, 30 Mar 2026 15:56:55 +0000 (UTC)","from mail-qv1-f49.google.com (mail-qv1-f49.google.com\n [209.85.219.49])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 87912374172\n\tfor ; Mon, 30 Mar 2026 15:56:54 +0000 (UTC)","by mail-qv1-f49.google.com with SMTP id\n 6a1803df08f44-8a00566c11bso24170206d6.2\n for ; Mon, 30 Mar 2026 08:56:54 -0700 (PDT)","from ziepe.ca\n (mctnnbsa70w-159-2-73-22.dhcp-dynamic.fibreop.nb.bellaliant.net.\n [159.2.73.22])\n by smtp.gmail.com with ESMTPSA id\n 6a1803df08f44-89ecf865ccesm66356736d6.39.2026.03.30.08.56.52\n (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n Mon, 30 Mar 2026 08:56:52 -0700 (PDT)","from jgg by wakko with local (Exim 4.97)\n\t(envelope-from )\n\tid 1w7Eyx-00000003cgN-4AHM;\n\tMon, 30 Mar 2026 12:56:52 -0300"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774886215; cv=none;\n b=eED/Wkw608VQAK6l66UmFO0GvFJ/eu1/EpEkPm+zfgfgwWghCPhXLIYrDDRS46E4ZjHrN3gL16M3ZnGs+B2zSyuDAqjU6Tl9yvgu1hypgTvf4QXXobJxsgtxbds6HggJ4uynBSurTedqBkQ3//CrzmdAAhsQZB/GQcvS5vJwR4k=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774886215; c=relaxed/simple;\n\tbh=MvxaAIkc/vMbD2wvC/YxOU7JwZEPwJRXPevAKf4Yi4Q=;\n\th=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:\n\t Content-Type:Content-Disposition:In-Reply-To;\n b=bD7gcCO2miCHE4SV2xUcA6AnRI3Alj2TtBA64BN/BfYcdDvs7d3RMgkUhX8o0ckd7Vt1eKcZMCtdF5Is5Q54+Rn8tWnQryKtOuc4EMa/04mJOaFTXjfQ2JoJrsmMoXpg4KoNPNULemDaADte/Ye10UxZe5kXnhnf3I+TdLgoanM=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=ziepe.ca;\n spf=pass smtp.mailfrom=ziepe.ca;\n dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca\n header.b=J4bfIjOb; arc=none smtp.client-ip=209.85.219.49","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=ziepe.ca; s=google; t=1774886213; x=1775491013;\n darn=vger.kernel.org;\n h=in-reply-to:content-disposition:mime-version:references:message-id\n :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to;\n bh=HeZbDTptZg5lfUHxFUgvvXT20LbyuaUKO1YdEoXFrgs=;\n b=J4bfIjObsxswXFEH6G5gRmOuEYhC7Z/GfJgprhC/N560AJLgMRNrqlZM5KDuz2zeel\n QPCP1WK8I/C9uUutoV2Hr6tTdWwH6Oi5kPVnqzudJzaIMp+Mexuv+rHpvHyanmj1VXfq\n 56MAs1r2g6IqxIyVKXnigsvWiVZaleft7uJU1rj2+jXg9DumfpRw4cWJ8/OsFsKbuUvf\n 1yC9RKjJ9b0s0OLP316+HZWj0u3J9hLW5lzD1ab4S3l2aF2URWAgWSHNDilXawrHE7XY\n xIjEO3llrQ+0HFquDbbG/JkL2lQnln6kH5YSM9pDS3B81XcEkW335CXJitrBf4kI479K\n bNMA==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=1e100.net; s=20251104; t=1774886213; x=1775491013;\n h=in-reply-to:content-disposition:mime-version:references:message-id\n :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc\n :subject:date:message-id:reply-to;\n bh=HeZbDTptZg5lfUHxFUgvvXT20LbyuaUKO1YdEoXFrgs=;\n b=n6V3lgyyhp7fKqTSgIX8p7PsAM0BXi8doKVJmhgzdvZ4q6091ze/Vgfcfu/6GLA2Xk\n XAaOnU4hv1DwrYaM/+9SkQOuWuN8UAl4IH6te3oPQK8wlWRtt7mnQzb/jkvKZZ7gGTl5\n XK8R65RsZDDn6tXlnTLkg/dnzvt/Wa9XzpMQuHCY0+7lzf3qSab7HaPGz94gyjus/eIy\n sFIxYInEOgJYgCYmVVpqvNpkKWwT5PTHQpwoVMHawSXMje1Q2y/qY48/GLojsw93sLxn\n qQ7Qc4fOLLFCnbiikd8Gq9ksHG1nBtdIoIgsEz3L5RxnVyhz3A5RIQu8g/N40mxIEArG\n zIlA==","X-Forwarded-Encrypted":"i=1;\n AJvYcCWChsBU8/x7QI8D/NCAcpd4J8Lsxs2nuDRTtkSUEA6iZmidd6Wu2PW2aiFfUw6l9dMyW7sZbaGVVQU=@vger.kernel.org","X-Gm-Message-State":"AOJu0YzGndJy6SkTcLV6fuabGEtbQJ0zhN0B0ZvjwrYKLMXdzi+rNFYi\n\txkawPK00n+RfSUw9acXxFjo9xQ6TjX7sPqftPcap8vD/uk/EonMFmzhMfiCeH2qAnu4=","X-Gm-Gg":"ATEYQzzP6vSvAio7cE93gc9X0F1EvkmxtPg4PPAepiLn6dVbyGYgpSjCiygpZD0P+E+\n\tCP3uROdCzKl0Td1gbyaDaHcdGUjjmYARoI1oU9ECg0E3gZVDxpfP2ONLRrf1QPb9rWhmtR2etgB\n\tX+QzYTuGX9VdkFwJkPx9XC+9G//afO8YJwmWaK9HxZXnzjdavjg3x43LyOPt1zUOAKpY2P5KKsE\n\tcw4bPkGMA9xwJEBdNideRN0Rr16bR8RVWuo5wSLvykWUiSWRFPe/F4CWXtkp0HOd1Q+2yhYwtZd\n\tcxSaf5ComURl75QUUofoqBauoo2uHu1m0Q5xG8tzPPbvLHIVzr1fCajAJ6tenhQqgviKwLgNRgI\n\tklBLU8TUxCl58VQD7SgH1MBTPkZ83vCtmR6DYdwzNuS1mvTGwkBWPsfv1FIuMH9wCpFYW228Sj4\n\tceKs3vziUChqLhT0hv45S+vLN5wrtB+lUO3psvTxYOkRyIllbE/ma3XC3OeTdziVdyJaL7Gw==","X-Received":"by 2002:a05:6214:4a05:b0:899:fab4:730f with SMTP id\n 6a1803df08f44-89ce8e2a475mr188167876d6.49.1774886213420;\n Mon, 30 Mar 2026 08:56:53 -0700 (PDT)","Date":"Mon, 30 Mar 2026 12:56:51 -0300","From":"Jason Gunthorpe ","To":"Alex Williamson ","Cc":"Niklas Schnelle ,\n\tFarhan Ali ,\n\tJulian Ruess , wintera@linux.ibm.com,\n\tts@linux.ibm.com, oberpar@linux.ibm.com, gbayer@linux.ibm.com,\n\tYishai Hadas ,\n\tShameer Kolothum ,\n\tKevin Tian , mjrosato@linux.ibm.com,\n\traspl@linux.ibm.com, hca@linux.ibm.com, agordeev@linux.ibm.com,\n\tgor@linux.ibm.com, kvm@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n\tlinux-pci@vger.kernel.org","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","Message-ID":"<20260330155651.GD246076@ziepe.ca>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n <4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n <3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n <64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>\n <20260330093646.03b0455f@shazbot.org>","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":"<20260330093646.03b0455f@shazbot.org>"}},{"id":3671255,"web_url":"http://patchwork.ozlabs.org/comment/3671255/","msgid":"<20260330120945.023b2295@shazbot.org>","list_archive_url":null,"date":"2026-03-30T18:09:45","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":91887,"url":"http://patchwork.ozlabs.org/api/people/91887/","name":"Alex Williamson","email":"alex@shazbot.org"},"content":"On Mon, 30 Mar 2026 12:56:51 -0300\nJason Gunthorpe wrote:\n\n> On Mon, Mar 30, 2026 at 09:36:46AM -0600, Alex Williamson wrote:\n> > There's risk involved with changing the default shift. The fear is\n> > there's userspace drivers that hard code the shift. DPDK was even such\n> > a user at one point, iirc. Maybe it's ok to break such users, maybe\n> > there are actually no such users left and it's all FUD at this point.\n> > Either way, I have a hard time justifying that risk for a single,\n> > obscure S390 device. \n> \n> If we go ahead with that DMABUF series could obscure cases like this\n> be told to just get a DMABUF FD and then mmap it? Avoid this whole\n> issue?\n\nThe ISM device here doesn't support mmap, so that much is still a\nproblem. However, if we imagine a future where we've fully converted\nto dma-buf for both DMA and CPU access to BARs, then maybe... I don't\nknow how we'd describe a region overflow in the \"legacy\" ioctls to\nmaintain some consistency between what's exposed through the region\nversus the dma-buf. Thanks,\n\nAlex","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=shazbot.org header.i=@shazbot.org header.a=rsa-sha256\n header.s=fm1 header.b=TzqQBR2Y;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=messagingengine.com header.i=@messagingengine.com\n header.a=rsa-sha256 header.s=fm1 header.b=HwbJnNz3;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=104.64.211.4; helo=sin.lore.kernel.org;\n envelope-from=linux-pci+bounces-51488-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=\"TzqQBR2Y\";\n\tdkim=pass (2048-bit key) header.d=messagingengine.com\n header.i=@messagingengine.com header.b=\"HwbJnNz3\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=103.168.172.148","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=shazbot.org"],"Received":["from sin.lore.kernel.org (sin.lore.kernel.org [104.64.211.4])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fkzml0Vj1z1xtJ\n\tfor ; Tue, 31 Mar 2026 05:09:59 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sin.lore.kernel.org (Postfix) with ESMTP id 1ECB53006916\n\tfor ; Mon, 30 Mar 2026 18:09:56 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id E910E3845C2;\n\tMon, 30 Mar 2026 18:09:52 +0000 (UTC)","from fout-a5-smtp.messagingengine.com\n (fout-a5-smtp.messagingengine.com [103.168.172.148])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A96830DEB0;\n\tMon, 30 Mar 2026 18:09:50 +0000 (UTC)","from phl-compute-01.internal (phl-compute-01.internal [10.202.2.41])\n\tby mailfout.phl.internal (Postfix) with ESMTP id B69E8EC0221;\n\tMon, 30 Mar 2026 14:09:49 -0400 (EDT)","from phl-frontend-04 ([10.202.2.163])\n by phl-compute-01.internal (MEProxy); Mon, 30 Mar 2026 14:09:49 -0400","by mail.messagingengine.com (Postfix) with ESMTPA; Mon,\n 30 Mar 2026 14:09:47 -0400 (EDT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774894192; cv=none;\n b=MVJPxLEOOUVchrXTFvjS/8avrOylIc1jmtdH1Bp+BBMyDXXkINnbwvv/nmQ6zw28+6cv/gIUzclGNr/9sMI9KyMt6yB1LZigEq5mdk+LvY0DAbKio6z5F9bpe/ZrqtBqaQd8b25cuOYaDaCQ5QrXZyPRNfjhFPHqzeAAXzcPlxc=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774894192; c=relaxed/simple;\n\tbh=75+5fFJFyUQFkda8RvZG8+2ldWjpRSvYlyVFKOtZpdY=;\n\th=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:\n\t MIME-Version:Content-Type;\n b=n63sQVqGzDnayHKVGicAF4JT4K+EO88qSZ1fPzjZzTt73uK/O1wkZxJ777ONGYUpuptuiiiBeHNQg+H0JrU8oZUn3jhhmUM4a0c5us2U40WdGNrwFsoX80i548viAnjdAOUVlKizjk+GGs4QFfsPuGcJPwZfMf0oQDkhwFZSbKw=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org;\n spf=pass smtp.mailfrom=shazbot.org;\n dkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=TzqQBR2Y;\n dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com\n header.b=HwbJnNz3; arc=none smtp.client-ip=103.168.172.148","DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/relaxed; d=shazbot.org; h=\n\tcc:cc:content-transfer-encoding:content-type:content-type:date\n\t:date:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to; s=fm1; t=1774894189;\n\t x=1774980589; bh=PxnB1idRPklbhSng1j8iSiRberE5zUGTRcSSDsXHQBg=; b=\n\tTzqQBR2Y7OfhUppYl3vObej4dhN/25IlgN57F3vZK/i2QpYDHSoOXVZJIWeospmH\n\tXgb+K0jIrsPCJv5vkYZPL/THvSjVZrrO+KTymV20YnBY1oNurwq1uIZblaPVEWIm\n\tHZrCcfKXOEcq5yXK8sHO6ZUe8LlPOq8Ez2xfnsYxSdWBGm75WHmukxzQZosm3XJl\n\t5mIsr9ElACXbnpjaKpks6jcFyYhjKRo8DCPxPcr2l1zq0lUWjazy4o0RiK58Xo4o\n\to7Rm2ok2mNlL3T14OXLBVKLyeIDY9P3BYpb3ANRIeym1f0SYUB5+cV9xluC/AuoH\n\tkAsbljk/k9YHWof5nCC9sA==","v=1; a=rsa-sha256; c=relaxed/relaxed; d=\n\tmessagingengine.com; h=cc:cc:content-transfer-encoding\n\t:content-type:content-type:date:date:feedback-id:feedback-id\n\t:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to:x-me-proxy\n\t:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t=1774894189; x=\n\t1774980589; bh=PxnB1idRPklbhSng1j8iSiRberE5zUGTRcSSDsXHQBg=; b=H\n\twbJnNz3NDdLIRV+GJe8z/NRXJfkxd3a9h4JVOglSCXLC1r9GSWVPT9c9S7+kDdyt\n\tezhcGj7S1K3X6zg/JAgvmj2OiM3GLSwBsRcbcv5erU70ktDhvjDy0mTJ4mLqjAPC\n\tCtv2bcJm5gC1YWbBttF/rD0z6DNjUDTmwN6coLiRYtPP5DrN+Idd/3UIXU6rhDDC\n\tFrVT4JrECqwRgYcfDhZurV4Xc0WeyxE7GKT5FKopk+/mnMFdXlfbkalA/bdKtfpm\n\t/cFAtAfBT1P/DOXnKnWIFFZCQZFqFbWqi/rzHPRnxSlWCLJeTcZIuK0BaVTa03w0\n\tXG5kzzrM06MFgdH6NAJbQ=="],"X-ME-Sender":"\n ","X-ME-Received":"\n ","X-ME-Proxy-Cause":"\n gggruggvucftvghtrhhoucdtuddrgeefgedrtddtgdeffeelieeiucetufdoteggodetrf\n dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceu\n rghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujf\n gurhepfffhvfevuffkjghfofggtgfgsehtjeertdertddvnecuhfhrohhmpeetlhgvgicu\n hghilhhlihgrmhhsohhnuceorghlvgigsehshhgriigsohhtrdhorhhgqeenucggtffrrg\n htthgvrhhnpedvkeefjeekvdduhfduhfetkedugfduieettedvueekvdehtedvkefgudeg\n veeuueenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpe\n grlhgvgiesshhhrgiisghothdrohhrghdpnhgspghrtghpthhtohepvddupdhmohguvgep\n shhmthhpohhuthdprhgtphhtthhopehjghhgseiiihgvphgvrdgtrgdprhgtphhtthhope\n hstghhnhgvlhhlvgeslhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopegrlhhifhhm\n sehlihhnuhigrdhisghmrdgtohhmpdhrtghpthhtohepjhhulhhirghnrheslhhinhhugi\n drihgsmhdrtghomhdprhgtphhtthhopeifihhnthgvrhgrsehlihhnuhigrdhisghmrdgt\n ohhmpdhrtghpthhtohepthhssehlihhnuhigrdhisghmrdgtohhmpdhrtghpthhtohepoh\n gsvghrphgrrheslhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopehgsggrhigvrhes\n lhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopeihihhshhgrihhhsehnvhhiughirg\n drtghomh","X-ME-Proxy":"\n \n \n \n ","Feedback-ID":"i03f14258:Fastmail","Date":"Mon, 30 Mar 2026 12:09:45 -0600","From":"Alex Williamson ","To":"Jason Gunthorpe ","Cc":"Niklas Schnelle , Farhan Ali\n , Julian Ruess ,\n wintera@linux.ibm.com, ts@linux.ibm.com, oberpar@linux.ibm.com,\n gbayer@linux.ibm.com, Yishai Hadas , Shameer Kolothum\n , Kevin Tian ,\n mjrosato@linux.ibm.com, raspl@linux.ibm.com, hca@linux.ibm.com,\n agordeev@linux.ibm.com, gor@linux.ibm.com, kvm@vger.kernel.org,\n linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n linux-pci@vger.kernel.org, alex@shazbot.org","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","Message-ID":"<20260330120945.023b2295@shazbot.org>","In-Reply-To":"<20260330155651.GD246076@ziepe.ca>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n\t<4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n\t<3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n\t<64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>\n\t<20260330093646.03b0455f@shazbot.org>\n\t<20260330155651.GD246076@ziepe.ca>","X-Mailer":"Claws Mail 4.3.1 (GTK 3.24.51; x86_64-pc-linux-gnu)","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=US-ASCII","Content-Transfer-Encoding":"7bit"}},{"id":3671258,"web_url":"http://patchwork.ozlabs.org/comment/3671258/","msgid":"<404bd986fd27e2b6934f86f6057d8e3bb23ad812.camel@linux.ibm.com>","list_archive_url":null,"date":"2026-03-30T18:15:04","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":78856,"url":"http://patchwork.ozlabs.org/api/people/78856/","name":"Niklas Schnelle","email":"schnelle@linux.ibm.com"},"content":"On Mon, 2026-03-30 at 09:36 -0600, Alex Williamson wrote:\n> On Fri, 27 Mar 2026 15:53:30 +0100\n> Niklas Schnelle wrote:\n> \n> > On Thu, 2026-03-26 at 12:05 -0700, Farhan Ali wrote:\n> > > On 3/26/2026 6:03 AM, Niklas Schnelle wrote: \n> > > > On Wed, 2026-03-25 at 14:31 +0100, Julian Ruess wrote: \n> > > > > Add a vfio_pci variant driver for the s390-specific Internal Shared\n> > > > > Memory (ISM) devices used for inter-VM communication.\n> > > > > \n> > > > > This enables the development of vfio-pci-based user space drivers for\n> > > > > ISM devices.\n> > > > > \n> > > > > On s390, kernel primitives such as ioread() and iowrite() are switched\n> > > > > over from function-handle-based PCI load/stores instructions to PCI\n> > > > > memory-I/O (MIO) loads/stores when these are available and not\n> > > > > explicitly disabled. Since these instructions cannot be used with ISM\n> > > > > devices, ensure that classic function-handle-based PCI instructions are\n> > > > > used instead.\n> > > > > \n> > > > > The driver is still required even when MIO instructions are disabled, as\n> > > > > the ISM device relies on the PCI store block (PCISTB) instruction to\n> > > > > perform write operations.\n> > > > > \n> > > > > Stores are not fragmented, therefore one ioctl corresponds to exactly\n> > > > > one PCISTB instruction. User space must ensure to not write more than\n> > > > > 4096 bytes at once to an ISM BAR which is the maximum payload of the\n> > > > > PCISTB instruction.\n> > > > > \n> > > > > Reviewed-by: Alexandra Winter \n> > > > > Reviewed-by: Niklas Schnelle \n> > > > > Signed-off-by: Julian Ruess \n> > > > > ---\n> > > > > drivers/vfio/pci/Kconfig | 2 +\n> > > > > drivers/vfio/pci/Makefile | 2 +\n> > > > > drivers/vfio/pci/ism/Kconfig | 10 ++\n> > > > > drivers/vfio/pci/ism/Makefile | 3 +\n> > > > > drivers/vfio/pci/ism/main.c | 408 ++++++++++++++++++++++++++++++++++++++++++\n> > > > > 5 files changed, 425 insertions(+)\n> > > > > \n> > > > --- snip --- \n> > > > > +\n> > > > > +static int ism_vfio_pci_ioctl_get_region_info(struct vfio_device *core_vdev,\n> > > > > +\t\t\t\t\t struct vfio_region_info *info,\n> > > > > +\t\t\t\t\t struct vfio_info_cap *caps)\n> > > > > +{\n> > > > > +\tstruct vfio_pci_core_device *vdev =\n> > > > > +\t\tcontainer_of(core_vdev, struct vfio_pci_core_device, vdev);\n> > > > > +\tstruct pci_dev *pdev = vdev->pdev;\n> > > > > +\n> > > > > +\tswitch (info->index) {\n> > > > > +\tcase VFIO_PCI_CONFIG_REGION_INDEX:\n> > > > > +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n> > > > > +\t\tinfo->size = pdev->cfg_size;\n> > > > > +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n> > > > > +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n> > > > > +\t\tbreak;\n> > > > > +\tcase VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:\n> > > > > +\t\tinfo->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);\n> > > > > +\t\tinfo->size = pci_resource_len(pdev, info->index);\n> > > > > +\t\tif (!info->size) {\n> > > > > +\t\t\tinfo->flags = 0;\n> > > > > +\t\t\tbreak;\n> > > > > +\t\t}\n> > > > > +\t\tinfo->flags = VFIO_REGION_INFO_FLAG_READ |\n> > > > > +\t\t\t VFIO_REGION_INFO_FLAG_WRITE;\n> > > > > +\t\tbreak;\n> > > > > +\tdefault:\n> > > > > +\t\tinfo->offset = 0;\n> > > > > +\t\tinfo->size = 0;\n> > > > > +\t\tinfo->flags = 0;\n> > > > > +\t\treturn -EINVAL; \n> > > > Thinking more about this, the above default handling actually breaks\n> > > > additional regions such as the one added by Farhan for the error\n> > > > events. I think this needs to instead call the generic\n> > > > vfio_pci_ioctl_get_region_info() for other regions. \n> > > \n> > > Note for error events we are using a VFIO device feature and not a \n> > > region. At this point we actually don't have additional regions. I do \n> > > agree that if we were to add a zpci specific region we would need to \n> > > update here and ism_vfio_pci_rw() to allow region read/write ops. This \n> > > ISM driver would also need to support all the possible callbacks in \n> > > struct vfio_pci_regops.\n> > > \n> > > Given that we don't have any additional regions yet, I am conflicted if \n> > > it makes sense to add all the code to support additional regions without \n> > > a good way to test it. Maybe its something we can defer when if we add \n> > > additional regions? Thanks\n> > > \n> > > Farhan \n> > \n> > @Alex, we experimented a bit and it turns out with the custom\n> > ISM_VFIO_PCI_OFFSET_SHIFT it becomes quite tricky to reliably call into\n> > common vfio-pci code for handling other regions as that again relies on\n> > the normal VFIO_PCI_OFFSET_SHIFT.\n> > \n> > So we came up with two options:\n> > \n> > 1) vfio-pci-ism will only support this basic set of regions. It seems\n> > to us that new extensions like Farhan's error events should use device\n> > features anyway, so this to us seems like an acceptable limitation and\n> > would essentially mean we take this patch as is.\n> > \n> > 2) We revisit the original idea of adjusting VFIO_PCI_OFFSET_SHIFT\n> > globally but do so only for CONFIG_64BIT so as not to break 32 bit\n> > platforms. This would simplify vfio-pci-ism and cause less code\n> > duplication but also affects everyone else.\n> > \n> > Either option works for us, so I'm hoping for your input.\n> \n> There's risk involved with changing the default shift. The fear is\n> there's userspace drivers that hard code the shift. DPDK was even such\n> a user at one point, iirc. Maybe it's ok to break such users, maybe\n> there are actually no such users left and it's all FUD at this point.\n> Either way, I have a hard time justifying that risk for a single,\n> obscure S390 device.\n> \n> Rather than using CONFIG_64BIT as a basis for using a different\n> default, should we start out with a more narrow scope of CONFIG_S390?\n> \n> It's likely inevitable that we'll hit this wall in general, but maybe\n> S390 can be the \"crash test dummy\" to prove to userspace that they\n> really need to use the uAPI rather than hard coded values.\n\nI fear we'd not be a very good crash test dummy / canary in the coal\nmine. We don't have DPDK support, nor a good selection of devices.\nAlso, apart from us developers almost our entire user base is on slow\nmoving enterprise distributions running critical but also slowly\nupdated enterprise workloads. If we want to do this long term maybe a\nbetter approach would be a specific experimental/sanitizing Kconfig\noption? As a user of a fast moving rolling distribution on my private\nsystems I'm all for trying things out in the right environments and\nmaybe such a distro would be willing to play canary ;)\n\n> \n> Farhan's series is a bit of a straw-man since it doesn't actually\n> convey the error codes via regions, but I can certainly agree that\n> using a unique region shift becomes an ongoing burden relative to\n> vfio-pci-core helpers. I can accept an S390 specific (for now) change\n> to the region spacing if that's the most sensible path. Thanks,\n> \n> Alex\n\nYes, as Farhan noted this was a false alarm. We did actually have a\npatch in internal review that did use an extra region but we already\ndecided that this should instead take the same approach as Farhan's\nwork.\n\nSo overall I think I think we should go with the first option.\nWe don't know of any extra regions we'll have to support and we can\ndocument that this is not supported for vfio-pci-ism. Then if we do\nneed it we can still revisit option 2.\n\nThanks,\nNiklas","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256\n header.s=pp1 header.b=lopomNnd;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c15:e001:75::12fc:5321; helo=sin.lore.kernel.org;\n envelope-from=linux-pci+bounces-51489-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=\"lopomNnd\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=148.163.156.1","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=linux.ibm.com"],"Received":["from sin.lore.kernel.org (sin.lore.kernel.org\n [IPv6:2600:3c15:e001:75::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fkzz12mssz1y1q\n\tfor ; Tue, 31 Mar 2026 05:18:53 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sin.lore.kernel.org (Postfix) with ESMTP id 0BBF93027486\n\tfor ; Mon, 30 Mar 2026 18:16:24 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 2CC702FD7D3;\n\tMon, 30 Mar 2026 18:16:17 +0000 (UTC)","from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com\n [148.163.156.1])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 9D4D427A462;\n\tMon, 30 Mar 2026 18:16:15 +0000 (UTC)","from pps.filterd (m0353729.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id\n 62UEonBJ141217;\n\tMon, 30 Mar 2026 18:16:12 GMT","from ppma21.wdc07v.mail.ibm.com\n (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91])\n\tby mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4d66nng2xw-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tMon, 30 Mar 2026 18:16:11 +0000 (GMT)","from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1])\n\tby ppma21.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id\n 62UEj7Yt022197;\n\tMon, 30 Mar 2026 18:16:10 GMT","from smtprelay07.dal12v.mail.ibm.com ([172.16.1.9])\n\tby ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4d6tamwxv4-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tMon, 30 Mar 2026 18:16:10 +0000","from smtpav01.wdc07v.mail.ibm.com (smtpav01.wdc07v.mail.ibm.com\n [10.39.53.228])\n\tby smtprelay07.dal12v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id\n 62UIG9OO24511088\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK);\n\tMon, 30 Mar 2026 18:16:09 GMT","from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id E3AE75804B;\n\tMon, 30 Mar 2026 18:16:08 +0000 (GMT)","from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 45FB558059;\n\tMon, 30 Mar 2026 18:16:05 +0000 (GMT)","from [9.111.21.174] (unknown [9.111.21.174])\n\tby smtpav01.wdc07v.mail.ibm.com (Postfix) with ESMTP;\n\tMon, 30 Mar 2026 18:16:05 +0000 (GMT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774894577; cv=none;\n b=b/Z8BOBWPjQADQdrxTYw8q001fK9+8b4/IM/8slPOgxCY1h/d6r3SO9i6lJV4JggcuFkzKJSiyW8A4J1IHzwJ9batRCKU4ZITj79ZYozKZKjCHZ//yJMT5wDUva6xhXAeJRrI1hqfy4RlpcrzWrqOTwSQm6EZSPKgMbi/OOao4Q=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774894577; c=relaxed/simple;\n\tbh=xJVre+VWeF7bSFVAdozzRPCtzv+mN4Zeyoe3KArZUV4=;\n\th=Message-ID:Subject:From:To:Cc:In-Reply-To:References:Content-Type:\n\t Date:MIME-Version;\n b=pZPOu8gaOqVWogC36Pn+9+3N0ASM6zPdPluEwaBfMoQUvQWJfWdOE5UkLW33/MIAf48kP+9CNlsfL9VdKjoHLhdjNcodd3v0fmb1WFAjLKHo1P4Ij8kYNG7odiZeWb4JEu8/Nb7Lk5BWDsSgfUoJX5P34fRXmTfJoBA9zvMCjEw=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com;\n spf=pass smtp.mailfrom=linux.ibm.com;\n dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=lopomNnd; arc=none smtp.client-ip=148.163.156.1","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc\n\t:content-transfer-encoding:content-type:date:from:in-reply-to\n\t:message-id:mime-version:references:subject:to; s=pp1; bh=NDV1Sl\n\t1SweAsMFBLkcg4MMdF87gxkkxUX9SP8ps0YbM=; b=lopomNndsEHMFcwOxNSbS+\n\tZOoKUwLODyJscgXg/1EJii2rV1kDQZZW5Ch0s44grWLXt2wa4R0o5REp7usGoOsz\n\tsHovccqCzHFAPmeT2zdAjvK22QPmw14lUYNdArKdyv6TwcRSJwpBc4vPN3dn4gRS\n\tVjOO8WX+f64g0cD7OfZ6cZitpiVnv1lH2vNbIG7goSGOyrknthjVcDsJEBp9KYfS\n\tbxrbNRaTIKn/sqfId9Hr20QSorer2UZO1k4zgyMl9qGKwncJrrmuZa7E2uj/OZHb\n\tykVOWZncDgSIwfZ8apV5Q9o7cj4E9nV89A13GRdm4hbA4dI3BycOTzk90PuaUR+A\n\t==","Message-ID":"<404bd986fd27e2b6934f86f6057d8e3bb23ad812.camel@linux.ibm.com>","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","From":"Niklas Schnelle ","To":"Alex Williamson ","Cc":"Farhan Ali , Julian Ruess ,\n wintera@linux.ibm.com, ts@linux.ibm.com, oberpar@linux.ibm.com,\n gbayer@linux.ibm.com, Jason Gunthorpe ,\n Yishai Hadas\t\n ,\n Shameer Kolothum ,\n Kevin\n Tian\t , mjrosato@linux.ibm.com,\n raspl@linux.ibm.com, hca@linux.ibm.com, agordeev@linux.ibm.com,\n gor@linux.ibm.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org,\n linux-s390@vger.kernel.org, linux-pci@vger.kernel.org","In-Reply-To":"<20260330093646.03b0455f@shazbot.org>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t\t<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n\t\t<4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n\t\t<3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n\t\t<64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>\n\t <20260330093646.03b0455f@shazbot.org>","Autocrypt":"addr=schnelle@linux.ibm.com; prefer-encrypt=mutual;\n keydata=mQINBGHm3M8BEAC+MIQkfoPIAKdjjk84OSQ8erd2OICj98+GdhMQpIjHXn/RJdCZLa58k\n /ay5x0xIHkWzx1JJOm4Lki7WEzRbYDexQEJP0xUia0U+4Yg7PJL4Dg/W4Ho28dRBROoJjgJSLSHwc\n 3/1pjpNlSaX/qg3ZM8+/EiSGc7uEPklLYu3gRGxcWV/944HdUyLcnjrZwCn2+gg9ncVJjsimS0ro/\n 2wU2RPE4ju6NMBn5Go26sAj1owdYQQv9t0d71CmZS9Bh+2+cLjC7HvyTHKFxVGOznUL+j1a45VrVS\n XQ+nhTVjvgvXR84z10bOvLiwxJZ/00pwNi7uCdSYnZFLQ4S/JGMs4lhOiCGJhJ/9FR7JVw/1t1G9a\n UlqVp23AXwzbcoV2fxyE/CsVpHcyOWGDahGLcH7QeitN6cjltf9ymw2spBzpRnfFn80nVxgSYVG1d\n w75ksBAuQ/3e+oTQk4GAa2ShoNVsvR9GYn7rnsDN5pVILDhdPO3J2PGIXa5ipQnvwb3EHvPXyzakY\n tK50fBUPKk3XnkRwRYEbbPEB7YT+ccF/HioCryqDPWUivXF8qf6Jw5T1mhwukUV1i+QyJzJxGPh19\n /N2/GK7/yS5wrt0Lwxzevc5g+jX8RyjzywOZGHTVu9KIQiG8Pqx33UxZvykjaqTMjo7kaAdGEkrHZ\n dVHqoPZwhCsgQARAQABtChOaWtsYXMgU2NobmVsbGUgPHNjaG5lbGxlQGxpbnV4LmlibS5jb20+iQ\n JXBBMBCABBAhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAhkBFiEEnbAAstJ1IDCl9y3cr+Q/Fej\n CYJAFAmmAWs8FCQl6sYAACgkQr+Q/FejCYJAn2g//UKzlXOgizdk0wudLooRbGzDo23ktGSPK5Oj9\n 9o5z6v4Jz5+qOHo5835683cqkMLM9//udA1ZcKV88LVwyfmoHChPW24cWBmOEy7RJOWCR4WeEINaO\n pZUGF5YOx7oKTkPs511ky2FR0Heg35754pgTuTMEpYzRXr5pNMPS8mHXcXSARFPDPaCF+uBJ9BafO\n L7XbpSwKRttePsWAlPHbSbloeDApBfHUhcF/pbuM9GNs+c/8V9NK+SwwqNK214t7jaSq9k+19/hfE\n jvU45nbiYQM4VqGCelxVFRWol93JnwPFp/JaMgxgV1VYFH9Ijtgh+qNVVBqO8bbTjioFKy1bHdprN\n 9GyPLDxoaI/lBg+5CwKewzazUjFd0xaqZbTXSgNK4ev/IuNI3qZV8tpvZZWwIgZU1K0Bhplt8Sku+\n O9Yl2H54erq9zuzwXjqBJtoW0+MaKbe+1gZ/v2/AVE2VeQMugPUWDg+2bpJaApRkeA4xQ9XfeW6Bp\n It7xYrwwbVhQtWRC0sRh+QNlU9HI28wPSnLWn7HFBeWupaIrxSp4IEL3eHUn8xv4aA8lpdNsHXD/X\n vqOSUwy5jlTPTlemvwaC9mNHagNdVXng8C6+hxiDLhZ6xH2P4qNHTKmjW61NsdF6Y/HfWP+lmbi8/\n 474UNCltDt/fP01ajqogfWZKFymoH0O0KU5pa2xhcyBTY2huZWxsZSA8bmlrbGFzLnNjaG5lbGxlQ\n GlibS5jb20+iQJUBBMBCAA+AhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEEnbAAstJ1IDCl9y\n 3cr+Q/FejCYJAFAmmAWusFCQl6sYAACgkQr+Q/FejCYJAtIw//WmQW/Z+SLdfrlDH5J2bvixzFNnO\n TOvp8uM8vcNZsxZwPXem4AeCXHayCqipxpa0iXWufEIvdMxkBxWvvM//V+rTUgQnJe6nhDxfLGklx\n 5Mb2H+K/ndS73ElCuA30MPYq7mHr8i3gEmi2ZFX1W47JecJ8hno/DQxhHRG7bd+GFsiKCbsjLWXNq\n s/VaAK9uyOTQx7m6/2nR8L+Mvl1BrRXwkj7Qp0qxfQSd4r+IVNBzNFOcrGagBqsyHrN7Is7IICktH\n 9VFl/G8P+hfviHQLnlxw9ltzpM1Dy6N1+BM3kbqD59gX+L6wqiLJI42eh+SHCiy35FvD3AFlYx4jZ\n MWE6qIgFnbwcL1kvcA7nnwfr3ZizCYPm8e334xXxslXBoRGsvjXSbAeAyZo2dvJXffNHdcDdUbJSl\n CfOixNGGKiQvs00X9ekfq9WmmRFvmYHu/m3lg1OXnMjFFIO41O51ZdhbEYJiqZEki7jA8Hd9xuWwQ\n nFDHhacU3xxivZ4BKQGQc+4XZ3yp/q6+7ux9prepRy/LeRyoaAmE67oxEsAgj+qyA3Tfy5nRTDdRQ\n E//gpaIt9H1VEx+68dRWHroxBQeozpnFPi25AlX3k4/EtVZjcItPWgE9iru1qT4DH3BBrz7Kd1zUw\n NnQC77zDJyZD2WUj1E+5bftO0aeE+7HZXj3tM/ea0K05pa2xhcyBTY2huZWxsZSA8bmlrbGFzLnNj\n aG5lbGxlQGdtYWlsLmNvbT6JAlQEEwEIAD4CGwEFCwkIBwIGFQoJCAsCBBYCAwECHgECF4AWIQSds\n ACy0nUgMKX3Ldyv5D8V6MJgkAUCaYBa6wUJCXqxgAAKCRCv5D8V6MJgkF/TEACOY2kL4NGFIbWeM5\n TUhatxqe8c3RT6jvNjq32CkvaK/cSZzBkS0smddyOzxt2WnsvMgkr9cM7P+CevoMwhT3e0lgQbqBD\n /vXZJjWKddC+iKXeqWkjMVcgCOsWNZ7PWEzRUT5X1AEFq2zzxQAQ/bCWEYNqIbHN4b6G1Wk+2Y598\n +KypZ3FS0bwiItnPQOWzOOqJCGxDxaEUuXFx4ah8HtVdtIev8jPS/5uzQO9iG2vZQUWeMEYZtfMHW\n sbFWqo2A3lxB+KPzNIYFhul4Lyx1CwvKUAGSHOx7FZuc2xI5DYt/Wdh2QyKFYr7xVzv3uwJjeS1+3\n 6gvyB7DJaQuY+PziNPv4GPr5wy0cRkJ6Ps15fgC6y6wNwoNdNXKlwiuclIsBzJKa7A0pZMIfpCpIJ\n bEHP7oy3drBRAhIrBx7Lx1lyqqodDqc+ok5IQ5WcKG/TOrH732mTmJX6fxYTiCVxcU4WLJSNZbrZ/\n pjF0AWXs7E+onAkQy6RLg/XU1iiU5QdMvug+fTA6TpPSUMdujWtGWUt3/4nC+69AVc8tXtRQTZ7gP\n t7uIcQFwPqUuJGS26vl0w/6dIABQAyU9acvE3adCZra+/PBKFZi/yxT1WgV1T2mexKSWwQgLcR57J\n Yp5oWnQRgi/S6fAoskIWkp9UVcfAQPY0p45NwO5cZR9/g06JZmyrQhTmlrbGFzIFNjaG5lbGxlIDx\n uaWtzQGtlcm5lbC5vcmc+iQJUBBMBCAA+AhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEEnbAA\n stJ1IDCl9y3cr+Q/FejCYJAFAmmAWusFCQl6sYAACgkQr+Q/FejCYJAz4A/9F+dMhzu7YonagL4qh\n WDz5IpRD4vzYKOBZ+qwYp1ugJz1BIUppN9i68HKoS4ARfgP97Sv9GpOy9g7L0lymH2MPF8hRPK0Yn\n 7DKIkeu/r28YWEoWfoVm5reC+gpxMgmxBz4JScE4f6xfa7+Nw0bbTDl+nxftJD7lf/dTiruNJsXph\n HQnZ5wPXmxeH6XVJikfpyrGe8iJZALbtHtjlx6Omu7NvRGikenB8trrWS5W0F60ZdbqH1HdmDDcrZ\n pDq6LtAARHK5tGRm0SK6sZpKe3nULFeeCt7T/edk2FC6KVh4sL1jw1kyceX4DjiMffqYBPrhK5gz5\n cDIixLBF9C6Wt1ObvuDBrIQf1/3q6EZrUrUuf6qtaXDMuC6cSlShm47qaPEvVYh67O9JZQ7vzvaea\n UI74DJUb8Pjnz7mTOmMOzsS1gUhCue4n2YSSM6ythioCGb/3bgMGTpuer3JhvZG5s5uKD9yyj8s8x\n 35qJkCFfjmjVx9s3vSUS48X+cUpYcMispErKzFu7C0YgKoxvJ4XTfXlDBiMFMPYcN67hsb2jeYHVJ\n wzE+fIZiDx9JLh1oQW2krwjweisE+3glOaKXZKi0fBtkxyH41iemLtLNYZRJopv6ykdl3hiI+Nh+a\n 3FZJPTo/OpqchMm8XIeDxC4NFFiPMpyLeYzIxO7eZpiGrAjVTE=","Content-Type":"text/plain; charset=\"UTF-8\"","Content-Transfer-Encoding":"quoted-printable","Date":"Mon, 30 Mar 2026 20:15:04 +0200","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","User-Agent":"Evolution 3.58.3 (3.58.3-1.fc43) ","X-TM-AS-GCONF":"00","X-Proofpoint-GUID":"sQCddJuf9OzJnZKB9qABTo8n2DSRP4C6","X-Authority-Analysis":"v=2.4 cv=KslAGGWN c=1 sm=1 tr=0 ts=69cabdeb cx=c_pps\n a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17\n a=IkcTkHD0fZMA:10 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22\n a=RnoormkPH1_aCDwRdu11:22 a=uAbxVGIbfxUO_5tXvNgY:22 a=VnNF1IyMAAAA:8\n a=T-k_-fjKFfvp7OGpXRwA:9 a=QEXdDO2ut3YA:10","X-Proofpoint-Spam-Details-Enc":"AW1haW4tMjYwMzMwMDE0NiBTYWx0ZWRfX8LVbeg/fdtTW\n exuabRSIONFOsfogki9qRmRTMyUoZ6TJSXE4ULvyHUXAecbcWGhC4q0Cv1h5ciCDFTpMKkV4DhX\n bj/Ybd5HTzNITZNZONjddcX6ktdN8C+oKFu/z48BF6OWqBHDD5cCvpGhkVSEPCikbzq6XmnP/Cy\n ioIff2nsXNZ1g+cHCqN2xOOCwkizHZ4JzNRyt2DmYaZ7269Kau9sUwCZqRMKGhqJ1gWsH5wm1+F\n f4u5IpdJawopAfk/MV6i7KV2Cac3fe4/89oo6RPTaTkeofXLDUvE8eIJOq5emmpJFxV5LNqABaB\n /1pEipD7tifQECpQ2kH06hjJuihD2km3n6t1dEBNjYdKbQY+C+XpPG5qjbQ+FCHvbwIGfVSXFnm\n 8olQ/XuZKf54X+bLGH83YX4FoLE+Jq2nq5hqgQwVzhfSIMxp++Mj8z1qR+f0lSbXXn9BGKenA3v\n fcnTcMvwg3Fxd03i2AQ==","X-Proofpoint-ORIG-GUID":"sQCddJuf9OzJnZKB9qABTo8n2DSRP4C6","X-Proofpoint-Virus-Version":"vendor=baseguard\n engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49\n definitions=2026-03-30_01,2026-03-28_01,2025-10-01_01","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n malwarescore=0 lowpriorityscore=0 priorityscore=1501 suspectscore=0\n phishscore=0 adultscore=0 bulkscore=0 impostorscore=0 clxscore=1015\n spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound\n adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001\n definitions=main-2603300146"}},{"id":3671259,"web_url":"http://patchwork.ozlabs.org/comment/3671259/","msgid":"<20260330181645.GE246076@ziepe.ca>","list_archive_url":null,"date":"2026-03-30T18:16:45","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":73018,"url":"http://patchwork.ozlabs.org/api/people/73018/","name":"Jason Gunthorpe","email":"jgg@ziepe.ca"},"content":"On Mon, Mar 30, 2026 at 12:09:45PM -0600, Alex Williamson wrote:\n> On Mon, 30 Mar 2026 12:56:51 -0300\n> Jason Gunthorpe wrote:\n> \n> > On Mon, Mar 30, 2026 at 09:36:46AM -0600, Alex Williamson wrote:\n> > > There's risk involved with changing the default shift. The fear is\n> > > there's userspace drivers that hard code the shift. DPDK was even such\n> > > a user at one point, iirc. Maybe it's ok to break such users, maybe\n> > > there are actually no such users left and it's all FUD at this point.\n> > > Either way, I have a hard time justifying that risk for a single,\n> > > obscure S390 device. \n> > \n> > If we go ahead with that DMABUF series could obscure cases like this\n> > be told to just get a DMABUF FD and then mmap it? Avoid this whole\n> > issue?\n> \n> The ISM device here doesn't support mmap, so that much is still a\n> problem. However, if we imagine a future where we've fully converted\n> to dma-buf for both DMA and CPU access to BARs, then maybe... I don't\n> know how we'd describe a region overflow in the \"legacy\" ioctls to\n> maintain some consistency between what's exposed through the region\n> versus the dma-buf. Thanks,\n\nOh, Ok.. I go back to what I've said before many times, if we fix this\nwe should fix it by making the region offset fully dynamic and managed\nby a maple tree.\n\nWe can detect at runtime when the vfio device is created if it is\ncompatible with the legacy indexs and use them by default to maintain\ncompatibility. But cases like this where the region is just too big\n(and GPUs will get there soon too!) can run a full dynamic mode.\n\nJason","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n secure) header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256\n header.s=google header.b=XKD1a8DX;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c15:e001:75::12fc:5321; helo=sin.lore.kernel.org;\n envelope-from=linux-pci+bounces-51490-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca\n header.b=\"XKD1a8DX\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=209.85.160.176","smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=ziepe.ca","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=ziepe.ca"],"Received":["from sin.lore.kernel.org (sin.lore.kernel.org\n [IPv6:2600:3c15:e001:75::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fl0070TbJz1y1q\n\tfor ; Tue, 31 Mar 2026 05:19:51 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sin.lore.kernel.org (Postfix) with ESMTP id 4D1C8301AA99\n\tfor ; Mon, 30 Mar 2026 18:16:52 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id BD7DD3A785A;\n\tMon, 30 Mar 2026 18:16:49 +0000 (UTC)","from mail-qt1-f176.google.com (mail-qt1-f176.google.com\n [209.85.160.176])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 2B62E383C69\n\tfor ; Mon, 30 Mar 2026 18:16:48 +0000 (UTC)","by mail-qt1-f176.google.com with SMTP id\n d75a77b69052e-506251815a3so41727061cf.0\n for ; Mon, 30 Mar 2026 11:16:47 -0700 (PDT)","from ziepe.ca\n (mctnnbsa70w-159-2-73-22.dhcp-dynamic.fibreop.nb.bellaliant.net.\n [159.2.73.22])\n by smtp.gmail.com with ESMTPSA id\n d75a77b69052e-50bb2cccbc4sm74354021cf.13.2026.03.30.11.16.46\n (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n Mon, 30 Mar 2026 11:16:46 -0700 (PDT)","from jgg by wakko with local (Exim 4.97)\n\t(envelope-from )\n\tid 1w7HAL-00000004Dsi-3Duh;\n\tMon, 30 Mar 2026 15:16:45 -0300"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774894609; cv=none;\n b=muDv/NO3oeDlxvX+HdLF0leE2Jpw1GA1kq2GUmg5BBKPFX6/7psYqO7hBrdE+zxxvhgc7J+KP4dHzKkJPIRp9jaW8fgkAZ+WgtT0DKkLO5eORr114fUo/fOzSg4jcu7doEZmv/fX2AkEM48Q2nXEQfr2zqVqhXnvqQaLt6q5Zsc=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774894609; c=relaxed/simple;\n\tbh=FxGhEP4CgH8a2w9XYbVg4vOa7jSLaLx43B2rQNZ8QBo=;\n\th=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:\n\t Content-Type:Content-Disposition:In-Reply-To;\n b=f4B2HRkapEW7V8WyPw44Jcc9/PpdQRbTU9qT0Hfy+2PjPlPXZqoLLCmUcaIUTeESZ1EvjhhhFBSnjdK//bh2uq2JJXHTwi8U1fdRpLLP4pSvQ05jAZE8kXTrmHR5jDClCKc6plcUEiFdDd/hR3UH5PL+qrN92I54SaDk+djSpSs=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=ziepe.ca;\n spf=pass smtp.mailfrom=ziepe.ca;\n dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca\n header.b=XKD1a8DX; arc=none smtp.client-ip=209.85.160.176","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=ziepe.ca; s=google; t=1774894607; x=1775499407;\n darn=vger.kernel.org;\n h=in-reply-to:content-disposition:mime-version:references:message-id\n :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to;\n bh=g7XmGXHOl2bFszmYCbs7mBB7gqdOkxQGV5l4CdFJV8g=;\n b=XKD1a8DXk+Z1HY3u3TuFzk0kaipfEI11BxokPX+pr0riyT8kiMvucZqNqOEJW1RqhW\n TWcE6uLY4i4N8RBAjRNkxzuD2LppnInEke7WqljGXhi8kdXqHHV1xvleihVds96aARRF\n jH/TCwWodWeIcNeK1V4gdupzhW8TMv3aZx63I2q4l6ec8Rx2c7TNxzJDqzR1i+90Or0C\n tv4XaVK5/kgO5KP4TP3Xg/kn7wuvT9/FR0lWAsVBitCr9kMstIeMRXteWcc6MzLhvKYK\n MruvTKuqf12QilLdDQl6CuW5advltFYGsBRfZicUeJsf43iVKcHjlF2BY2bsIJrK2051\n rk/w==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=1e100.net; s=20251104; t=1774894607; x=1775499407;\n h=in-reply-to:content-disposition:mime-version:references:message-id\n :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc\n :subject:date:message-id:reply-to;\n bh=g7XmGXHOl2bFszmYCbs7mBB7gqdOkxQGV5l4CdFJV8g=;\n b=WKfeJxzRu4oJZ4/Ol9knqSrhbgAYIZu3eo/KGUcMJ0hTJPpyNH/lwv39oLPxIoRVwi\n 44LLnzVNnZR2ebzkKTWxfdJot+ii2+KDnMuz2hYhEW7TSGqUdFbzBEEuIsLKefjc2zkg\n iB17dJ43o1VxuY0CeMM7n90ziOHwT3BgFOod5Ib7K8KJelnePHuroZFCbtx3FztU1wHh\n 06bycTOe5z0ik1dDZUfd+K2ZDPCbFt7tPSabjqMoLyBbm6lvgNQ4Ja6QyA7M1A6XwHtP\n qRWpu1FAUKRtoLKLAHo+moWOQcxjcO45DGcVCBIk9yFf9rk1dCpK3xBASJvYl6AgRkWK\n QX5w==","X-Forwarded-Encrypted":"i=1;\n AJvYcCVfGZZjzUhd+n8WRsbW5lTwkWkhd2fqrYrsaVdEkYQKyn/mScGMcOA388eXLcORY8sbNUgVczgryek=@vger.kernel.org","X-Gm-Message-State":"AOJu0Yx611UJYOWQblunu5IBunwln36V1T9mVZD48XJJphDRXrjimcD0\n\t+PvSlcccRK0XtgQgtOQ+nsSwry03d8Rmhqs9W7ahxu7rn0NMchqp1ERQ7xvshRqWbqY=","X-Gm-Gg":"ATEYQzykVdh49k5GPTsPAvBoQ+aHVTN0ts7cCaTLWkyBrPeH4uCSOs4DEdmjwALj0GX\n\t7E0o1xB96eN0SDpa/uFAsFNELvnl+fagMn0A+n2rvWzSAVkUZ96vpB/P+zoikU1AFXNm5UffHx4\n\t6GGT1O7zHOnUjRDDSOHacqiYyyom5AIeYFOzSEAs4y/YYCX4NaL/PJENBZjQHoP4mQlqIus1Dos\n\tYqfyu8+KfJN2/ywe0qpUtAxAbtXPuxMBnsEKx0Ee3LpIOnLTCvi3D6LudF4hx47iTMzEUSQR25P\n\tfOEZ+heSPjvpr26Y4H7jzAsqW+8xBDhFX+5bZjU5ma5fEQgo691F4+51u+RoEAt4797jzOvUi2w\n\ttHjq9RLrzm+mG5X6767dSc/GabtJaEPqvNtKhwYq3WxJlB7HVQkO8fqtoQF5Z2piC1bqW5oF0jg\n\tC0/yMTDgU1ysf3ZsVeLUmzzwODQvAI+Dfz9nOg2Pmq8YSMfS1B0Wz5F55+A+oIpNTb1huOQcw47\n\trPLhwid","X-Received":"by 2002:a05:622a:20a:b0:50b:49e5:989b with SMTP id\n d75a77b69052e-50ba385dc34mr181731851cf.22.1774894607076;\n Mon, 30 Mar 2026 11:16:47 -0700 (PDT)","Date":"Mon, 30 Mar 2026 15:16:45 -0300","From":"Jason Gunthorpe ","To":"Alex Williamson ","Cc":"Niklas Schnelle ,\n\tFarhan Ali ,\n\tJulian Ruess , wintera@linux.ibm.com,\n\tts@linux.ibm.com, oberpar@linux.ibm.com, gbayer@linux.ibm.com,\n\tYishai Hadas ,\n\tShameer Kolothum ,\n\tKevin Tian , mjrosato@linux.ibm.com,\n\traspl@linux.ibm.com, hca@linux.ibm.com, agordeev@linux.ibm.com,\n\tgor@linux.ibm.com, kvm@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n\tlinux-pci@vger.kernel.org","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","Message-ID":"<20260330181645.GE246076@ziepe.ca>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n <4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n <3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n <64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>\n <20260330093646.03b0455f@shazbot.org>\n <20260330155651.GD246076@ziepe.ca>\n <20260330120945.023b2295@shazbot.org>","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":"<20260330120945.023b2295@shazbot.org>"}},{"id":3671264,"web_url":"http://patchwork.ozlabs.org/comment/3671264/","msgid":"<20260330123925.713edac4@shazbot.org>","list_archive_url":null,"date":"2026-03-30T18:39:25","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":91887,"url":"http://patchwork.ozlabs.org/api/people/91887/","name":"Alex Williamson","email":"alex@shazbot.org"},"content":"On Mon, 30 Mar 2026 15:16:45 -0300\nJason Gunthorpe wrote:\n\n> On Mon, Mar 30, 2026 at 12:09:45PM -0600, Alex Williamson wrote:\n> > On Mon, 30 Mar 2026 12:56:51 -0300\n> > Jason Gunthorpe wrote:\n> > \n> > > On Mon, Mar 30, 2026 at 09:36:46AM -0600, Alex Williamson wrote: \n> > > > There's risk involved with changing the default shift. The fear is\n> > > > there's userspace drivers that hard code the shift. DPDK was even such\n> > > > a user at one point, iirc. Maybe it's ok to break such users, maybe\n> > > > there are actually no such users left and it's all FUD at this point.\n> > > > Either way, I have a hard time justifying that risk for a single,\n> > > > obscure S390 device. \n> > > \n> > > If we go ahead with that DMABUF series could obscure cases like this\n> > > be told to just get a DMABUF FD and then mmap it? Avoid this whole\n> > > issue? \n> > \n> > The ISM device here doesn't support mmap, so that much is still a\n> > problem. However, if we imagine a future where we've fully converted\n> > to dma-buf for both DMA and CPU access to BARs, then maybe... I don't\n> > know how we'd describe a region overflow in the \"legacy\" ioctls to\n> > maintain some consistency between what's exposed through the region\n> > versus the dma-buf. Thanks, \n> \n> Oh, Ok.. I go back to what I've said before many times, if we fix this\n> we should fix it by making the region offset fully dynamic and managed\n> by a maple tree.\n> \n> We can detect at runtime when the vfio device is created if it is\n> compatible with the legacy indexs and use them by default to maintain\n> compatibility. But cases like this where the region is just too big\n> (and GPUs will get there soon too!) can run a full dynamic mode.\n\nYes, that would be the ideal balance of enabling larger BARs while\nretaining compatibility for existing devices. Sounds like we'll\ncontinue down the variant driver path for this one-off device for\nnow. It remains fairly self contained so long as we don't add more\nregions for vfio-pci-core to manage.\n\nThis could be a good project if someone is looking though, especially\nif it had a build-time config option to set the minimum region size so\nwe can exercise it before we hit 1TB BARs. Thanks,\n\nAlex","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=shazbot.org header.i=@shazbot.org header.a=rsa-sha256\n header.s=fm1 header.b=dHFQdM38;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=messagingengine.com header.i=@messagingengine.com\n header.a=rsa-sha256 header.s=fm1 header.b=rXd7v7Lp;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c15:e001:75::12fc:5321; helo=sin.lore.kernel.org;\n envelope-from=linux-pci+bounces-51491-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=\"dHFQdM38\";\n\tdkim=pass (2048-bit key) header.d=messagingengine.com\n header.i=@messagingengine.com header.b=\"rXd7v7Lp\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=103.168.172.152","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=shazbot.org"],"Received":["from sin.lore.kernel.org (sin.lore.kernel.org\n [IPv6:2600:3c15:e001:75::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fl0RB6TV5z1xtJ\n\tfor ; Tue, 31 Mar 2026 05:39:50 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sin.lore.kernel.org (Postfix) with ESMTP id 43DD33009E34\n\tfor ; Mon, 30 Mar 2026 18:39:40 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id B1B4A3C7DE8;\n\tMon, 30 Mar 2026 18:39:36 +0000 (UTC)","from fhigh-a1-smtp.messagingengine.com\n (fhigh-a1-smtp.messagingengine.com [103.168.172.152])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id CAF1A382391;\n\tMon, 30 Mar 2026 18:39:33 +0000 (UTC)","from phl-compute-01.internal (phl-compute-01.internal [10.202.2.41])\n\tby mailfhigh.phl.internal (Postfix) with ESMTP id 0C9BD140026B;\n\tMon, 30 Mar 2026 14:39:33 -0400 (EDT)","from phl-frontend-04 ([10.202.2.163])\n by phl-compute-01.internal (MEProxy); Mon, 30 Mar 2026 14:39:33 -0400","by mail.messagingengine.com (Postfix) with ESMTPA; Mon,\n 30 Mar 2026 14:39:29 -0400 (EDT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774895976; cv=none;\n b=BdCqr+6FP02qZlRK56A0Ur8Pjpqt3//Ou6C6MGIrqoeJYQYEhfdpMG73FCOE2nBZ0V2dW1BSLxsxr8+tYHvgo1Umc7Uyva/LQB6zw8lahrLv4JZWgJPLnS2qrThegGlp7gI2XqrTpOu7Snc9Yg5HEPI+YZjxobFHEK2FwrQd9EQ=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774895976; c=relaxed/simple;\n\tbh=mnv9e8QJ/jw0xqPEuiuY4pozE+28iBaA0mh8sFehcCs=;\n\th=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:\n\t MIME-Version:Content-Type;\n b=TypjxUfFTbggf0SGZUbzUWDGP/4ZPE5zmDrGGv7hZ1SEuk6YGd3kItmVeV7oQVOcwKkIZ5aNTzTF7ps/qZyMQ3NmEQ08sD9EuRY5AQDFu4iMH19TxNzoTba+lEzKuj9D6mlkST3tBWiM/kSgnusLJdcfKyNopENQXzHPgnfKIHw=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org;\n spf=pass smtp.mailfrom=shazbot.org;\n dkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=dHFQdM38;\n dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com\n header.b=rXd7v7Lp; arc=none smtp.client-ip=103.168.172.152","DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/relaxed; d=shazbot.org; h=\n\tcc:cc:content-transfer-encoding:content-type:content-type:date\n\t:date:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to; s=fm1; t=1774895973;\n\t x=1774982373; bh=ZplfpB0cjd9kg8wAfMC2ogmEVqs/9HnbmdmVOnPFHWc=; b=\n\tdHFQdM38a0uSgcDg05vc44mWJng1bAG+FBaN1Xeo4D4sHzjHGiuTdILIKYwNfa14\n\tIQCb2fsqW1uYYzINpUkxi+V+spAB1WDlXe2uMX6s+0+cjRxxxugSP/ob/xx2Y6Zv\n\tL+nrRjS/4NseD4EZpUlTuxosvFiy4rGwq2QVLU6op+AB5klTgxEBxjsI+0ByCvrg\n\tEa1d65X2cWwpAPkaB2c8RaYDMf4N3hX2wiUWxqGT5XsIe3FcnYoELEtBW2KDVynD\n\tcQXyRkS09nbNu4Z+gp/72WJ1hvB1lcGqNQ6p2hdMuCGQxl6yu1YGH65OC0rm8A6D\n\tAgZ5wGyG4HTK/T+tApXqBA==","v=1; a=rsa-sha256; c=relaxed/relaxed; d=\n\tmessagingengine.com; h=cc:cc:content-transfer-encoding\n\t:content-type:content-type:date:date:feedback-id:feedback-id\n\t:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to:x-me-proxy\n\t:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t=1774895973; x=\n\t1774982373; bh=ZplfpB0cjd9kg8wAfMC2ogmEVqs/9HnbmdmVOnPFHWc=; b=r\n\tXd7v7Lpm2dORlnjGCEewzaeZUQcSNCxzL0OlK1NkJtEuTtdn0EPDHlSUDOYpSLQL\n\tvqTgRggLk8uUvJkSMQi4eJfKnRWacIhfSQ+jFq8h8/2PNFK+LKw+QOd1utMPPMli\n\tz7bAcErl6HjIr8c1caLWrhsps3tRKySqZ2zgTL9iCe5IwTJvdxajBmXgkbQvq+Yg\n\tZ2tYoZNZwANkIbT6uyS+/4VQfbTv6mu4YjLAhFHWBqE8joVsVxcILoSE3cBBlTKT\n\tvd6rMAKVGWhW2YTFGePapIWCEiqI4aM2smpoz7gNPKPuId6ytYdUXrISyD7Fo8Kz\n\trkEtM8UrrYIQzpnvg+BFg=="],"X-ME-Sender":"\n ","X-ME-Received":"\n ","X-ME-Proxy-Cause":"\n gggruggvucftvghtrhhoucdtuddrgeefgedrtddtgdeffeeljedvucetufdoteggodetrf\n dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceu\n rghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujf\n gurhepfffhvfevuffkjghfofggtgfgsehtjeertdertddvnecuhfhrohhmpeetlhgvgicu\n hghilhhlihgrmhhsohhnuceorghlvgigsehshhgriigsohhtrdhorhhgqeenucggtffrrg\n htthgvrhhnpedvkeefjeekvdduhfduhfetkedugfduieettedvueekvdehtedvkefgudeg\n veeuueenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpe\n grlhgvgiesshhhrgiisghothdrohhrghdpnhgspghrtghpthhtohepvddupdhmohguvgep\n shhmthhpohhuthdprhgtphhtthhopehjghhgseiiihgvphgvrdgtrgdprhgtphhtthhope\n hstghhnhgvlhhlvgeslhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopegrlhhifhhm\n sehlihhnuhigrdhisghmrdgtohhmpdhrtghpthhtohepjhhulhhirghnrheslhhinhhugi\n drihgsmhdrtghomhdprhgtphhtthhopeifihhnthgvrhgrsehlihhnuhigrdhisghmrdgt\n ohhmpdhrtghpthhtohepthhssehlihhnuhigrdhisghmrdgtohhmpdhrtghpthhtohepoh\n gsvghrphgrrheslhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopehgsggrhigvrhes\n lhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopeihihhshhgrihhhsehnvhhiughirg\n drtghomh","X-ME-Proxy":"\n \n \n \n ","Feedback-ID":"i03f14258:Fastmail","Date":"Mon, 30 Mar 2026 12:39:25 -0600","From":"Alex Williamson ","To":"Jason Gunthorpe ","Cc":"Niklas Schnelle , Farhan Ali\n , Julian Ruess ,\n wintera@linux.ibm.com, ts@linux.ibm.com, oberpar@linux.ibm.com,\n gbayer@linux.ibm.com, Yishai Hadas , Shameer Kolothum\n , Kevin Tian ,\n mjrosato@linux.ibm.com, raspl@linux.ibm.com, hca@linux.ibm.com,\n agordeev@linux.ibm.com, gor@linux.ibm.com, kvm@vger.kernel.org,\n linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n linux-pci@vger.kernel.org, alex@shazbot.org","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","Message-ID":"<20260330123925.713edac4@shazbot.org>","In-Reply-To":"<20260330181645.GE246076@ziepe.ca>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n\t<4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n\t<3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n\t<64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>\n\t<20260330093646.03b0455f@shazbot.org>\n\t<20260330155651.GD246076@ziepe.ca>\n\t<20260330120945.023b2295@shazbot.org>\n\t<20260330181645.GE246076@ziepe.ca>","X-Mailer":"Claws Mail 4.3.1 (GTK 3.24.51; x86_64-pc-linux-gnu)","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=US-ASCII","Content-Transfer-Encoding":"7bit"}},{"id":3671370,"web_url":"http://patchwork.ozlabs.org/comment/3671370/","msgid":"<20260331000334.GI246076@ziepe.ca>","list_archive_url":null,"date":"2026-03-31T00:03:34","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":73018,"url":"http://patchwork.ozlabs.org/api/people/73018/","name":"Jason Gunthorpe","email":"jgg@ziepe.ca"},"content":"On Mon, Mar 30, 2026 at 12:39:25PM -0600, Alex Williamson wrote:\n> Yes, that would be the ideal balance of enabling larger BARs while\n> retaining compatibility for existing devices. Sounds like we'll\n> continue down the variant driver path for this one-off device for\n> now. It remains fairly self contained so long as we don't add more\n> regions for vfio-pci-core to manage.\n> \n> This could be a good project if someone is looking though, especially\n> if it had a build-time config option to set the minimum region size so\n> we can exercise it before we hit 1TB BARs. Thanks,\n\nWell, it took claude an hour to vibe code a draft from a four sentence\nprompt.. I see many things that need changing/cleaning in here, but\nthe patch strategy and general idea looks sound.\n\nI guess another day of effort would probably get things into something\npresentable. We are not so far away - maybe the variant driver path is\nnot necessary?\n\nhttps://github.com/jgunthorpe/linux/commits/vfio_maple_tree/\n\nJason","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n secure) header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256\n header.s=google header.b=SLP4FRdH;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.105.105.114; helo=tor.lore.kernel.org;\n envelope-from=linux-pci+bounces-51517-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca\n header.b=\"SLP4FRdH\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=209.85.222.180","smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=ziepe.ca","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=ziepe.ca"],"Received":["from tor.lore.kernel.org (tor.lore.kernel.org [172.105.105.114])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fl7cz2Z6Mz1y1q\n\tfor ; Tue, 31 Mar 2026 11:03:47 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby tor.lore.kernel.org (Postfix) with ESMTP id 6881F3035A5A\n\tfor ; Tue, 31 Mar 2026 00:03:38 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 30D1CEACD;\n\tTue, 31 Mar 2026 00:03:38 +0000 (UTC)","from mail-qk1-f180.google.com (mail-qk1-f180.google.com\n [209.85.222.180])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id A4CEC1A724C\n\tfor ; Tue, 31 Mar 2026 00:03:36 +0000 (UTC)","by mail-qk1-f180.google.com with SMTP id\n af79cd13be357-8cd77786e97so511593585a.3\n for ; Mon, 30 Mar 2026 17:03:36 -0700 (PDT)","from ziepe.ca\n (mctnnbsa70w-159-2-73-22.dhcp-dynamic.fibreop.nb.bellaliant.net.\n [159.2.73.22])\n by smtp.gmail.com with ESMTPSA id\n af79cd13be357-8d02806a37bsm712637385a.34.2026.03.30.17.03.34\n (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n Mon, 30 Mar 2026 17:03:34 -0700 (PDT)","from jgg by wakko with local (Exim 4.97)\n\t(envelope-from )\n\tid 1w7MZy-00000005rSd-0n0u;\n\tMon, 30 Mar 2026 21:03:34 -0300"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774915418; cv=none;\n b=mP6C9aSk2O4kCNyT3GxLOjdDdZ31Q3I+h3lFsC8KHZ6m5+KgXGgiOfCQ7FhFVeXT12EFe+iEm5NEaMPEJuucGObJk9gKL5stzyuYBKn6HfFiwyd+1IpN2UqHEUacxOARmqVcMij4NG33MnVYFUCGCKtD99e0gtIutUuoRoX2F5c=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774915418; c=relaxed/simple;\n\tbh=tGFV2VhgTREgrfP98G0uJ3HUP/CSGaSbu+qGayezE0E=;\n\th=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:\n\t Content-Type:Content-Disposition:In-Reply-To;\n b=olZ+Ax+2ZX4P6Dm+zB0anbiXdHHzvio27Bl/+j+Gc3/TUFU53+4keZDH79WL0WYmI71xLGx1aeimfEuA/2zevp0KhhAJQPf9MuX/Y+1Fz+9nsdge+mtnqpqLP4stClqwFppFdnyN8DvK95fW3LUX8DY750QMmd3EaUj88jsFqbs=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=ziepe.ca;\n spf=pass smtp.mailfrom=ziepe.ca;\n dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca\n header.b=SLP4FRdH; arc=none smtp.client-ip=209.85.222.180","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=ziepe.ca; s=google; t=1774915416; x=1775520216;\n darn=vger.kernel.org;\n h=in-reply-to:content-disposition:mime-version:references:message-id\n :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to;\n bh=W4YBgDlQG7t09O0fcPskt9PfuzfmSkfNvE01lxkkeEk=;\n b=SLP4FRdHz+CzxQ6VGVwelbz2oEWoQ1X35DiIGfJpcj0QPxlYn/KmJAsUuNzt6fcjDS\n oWFof3bAvc5j9KdXtQI9f0VMQa0DvcYaweoG2FV3kW+pV2IW7exO/w0Jq5JoXb7RzBFU\n +adMRpEIOxmBYmoJ6Cd4CIPGogUaGjpgg9R7KlEUEusODFVhLu9PmurFQGEwwH568in0\n /c3nKwBolvQhoYhiQw+G+W9H4e+vTwj4jenX2n+3SNc/Hx90+MZzdERumY/6y3+1RkKq\n xHRskO965ayYetBnW41UBqBIEHmT4XK4G3bUOJVLeZZjQms3kAdDJ6ChpuO093uiFxnf\n Q5Sg==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=1e100.net; s=20251104; t=1774915416; x=1775520216;\n h=in-reply-to:content-disposition:mime-version:references:message-id\n :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc\n :subject:date:message-id:reply-to;\n bh=W4YBgDlQG7t09O0fcPskt9PfuzfmSkfNvE01lxkkeEk=;\n b=guQxd31kzh0/Ce35TpofYMwpkZBxlx9Z5ku3tW8XD+lEx3K7StEOjntJvuaCfeuWqN\n 6+99tRdx3Xmu3UP1VIRhvn9jdhz1VGsqBVsE/Y1Qb+zPsTysFYGgwm/HLX01HzVAxPRz\n P982WaeN7GkCJ746iWQnk37afscYjEJZTmMtVp/6//AfCAuSyYGZC6Q60WE+PdUjicnA\n CrirSEy9nd8zu03Xl5ZMW5kqBFtZVqxa5QKGFvQD8VOXkLAkq/rZ2s49FWzXh4CYuwdJ\n fY4w1324m1FJTX7+h2g/E/m3Fkq3oDlsdIHJABglTfj1lUIefCPI4wqvkNkrPSrqdwbi\n aS0w==","X-Forwarded-Encrypted":"i=1;\n AJvYcCVBHFXh+FASka91AwZOZMMlxq6uSsqLlAVW/zk1Z6TJSufpier9ERGBNB0CGJOH9VtClpn56x0KCdM=@vger.kernel.org","X-Gm-Message-State":"AOJu0YwLHcMVY3FKP5ul+iTuX4Euh+d5xJeziAcSvioARf6CiseORyaI\n\tueZRj6H1drcRRgvntO3Bqf/wt2RGkBx1SsWv9ZtLL1XsJnQwstgP9/ItT/gvVrA3Ot4=","X-Gm-Gg":"ATEYQzw+zJgWzRwHsO7ejuulbXOYI3RuIvcHkFfB4zPt6m5WWvJwaYBzV/qyKzkgiQO\n\thByjXKAVqulUacX0g5uulVkQIQ5VO0eXl8FZRj4IIRLh5DrfMTy2F3rZeNFMpEO4DVhSkDEnWIW\n\tMVd0YpmO7L54MVH+jDWDwG9Rh9RBFyN9cvhlAXjxpb0tqX14YmXPM68d/d5RtqaCfQbTdT2FvlV\n\t2dxYm5OvR5OhkaLRhUURzVAdd3pqAdoQyQcKgyTcwj1wDV7dA8xitYpY60VkDC/FVEqYPf9XDXK\n\tJ97Cnp9pl2YLGa7LMXAYNxIRiTUOzWol89k8/NaS5tRmPjLFU4kgTuaPdirXEyfbnXuVHajjOmY\n\t5NmJQKuP/IISEMYSCuHREjtFLW7vhrtu0HWGZD3/zXhtVjVRCW8xUtGWDGMWOKqdIZsVJDTdHAU\n\tonEbj3jY3RjVqpWURA8SvR/jLAYf/iRVUYkZ7ciPgYwC/CZcy6OoUj0YCxZvh4fbeFNBvH3g==","X-Received":"by 2002:a05:620a:4482:b0:8ca:fe5c:ea6d with SMTP id\n af79cd13be357-8d01c842aa8mr1753223385a.59.1774915415598;\n Mon, 30 Mar 2026 17:03:35 -0700 (PDT)","Date":"Mon, 30 Mar 2026 21:03:34 -0300","From":"Jason Gunthorpe ","To":"Alex Williamson ","Cc":"Niklas Schnelle ,\n\tFarhan Ali ,\n\tJulian Ruess , wintera@linux.ibm.com,\n\tts@linux.ibm.com, oberpar@linux.ibm.com, gbayer@linux.ibm.com,\n\tYishai Hadas ,\n\tShameer Kolothum ,\n\tKevin Tian , mjrosato@linux.ibm.com,\n\traspl@linux.ibm.com, hca@linux.ibm.com, agordeev@linux.ibm.com,\n\tgor@linux.ibm.com, kvm@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n\tlinux-pci@vger.kernel.org","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","Message-ID":"<20260331000334.GI246076@ziepe.ca>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n <4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n <3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n <64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>\n <20260330093646.03b0455f@shazbot.org>\n <20260330155651.GD246076@ziepe.ca>\n <20260330120945.023b2295@shazbot.org>\n <20260330181645.GE246076@ziepe.ca>\n <20260330123925.713edac4@shazbot.org>","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":"<20260330123925.713edac4@shazbot.org>"}},{"id":3671533,"web_url":"http://patchwork.ozlabs.org/comment/3671533/","msgid":"<4fb2b835ec81ca0ef24bc1c867d177a7d04b4873.camel@linux.ibm.com>","list_archive_url":null,"date":"2026-03-31T08:29:31","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":78856,"url":"http://patchwork.ozlabs.org/api/people/78856/","name":"Niklas Schnelle","email":"schnelle@linux.ibm.com"},"content":"On Mon, 2026-03-30 at 21:03 -0300, Jason Gunthorpe wrote:\n> On Mon, Mar 30, 2026 at 12:39:25PM -0600, Alex Williamson wrote:\n> > Yes, that would be the ideal balance of enabling larger BARs while\n> > retaining compatibility for existing devices. Sounds like we'll\n> > continue down the variant driver path for this one-off device for\n> > now. It remains fairly self contained so long as we don't add more\n> > regions for vfio-pci-core to manage.\n> > \n> > This could be a good project if someone is looking though, especially\n> > if it had a build-time config option to set the minimum region size so\n> > we can exercise it before we hit 1TB BARs. Thanks,\n> \n> Well, it took claude an hour to vibe code a draft from a four sentence\n> prompt.. I see many things that need changing/cleaning in here, but\n> the patch strategy and general idea looks sound.\n> \n> I guess another day of effort would probably get things into something\n> presentable. We are not so far away - maybe the variant driver path is\n> not necessary?\n> \n> https://github.com/jgunthorpe/linux/commits/vfio_maple_tree/\n> \n> Jason\n\nI'm in no way against changing the offset handling in general but for\nwhat it's worth, we need a variant driver for ISM regardless, though it\nwould be smaller with large offset support. This is because besides the\nlarge BAR we also have to use our classic function handle based PCI\ninstructions to access that BAR instead of the newer memory-I/O (MIO)\nPCI instructions. And sadly the way the ISM device uses the PCI Store\nBlock instruction there is no straight forward way to enable the newer\ninstructions even if we changed the device implementation. This also\nmeans that we would want to keep the no-mmap() restriction.\n\nThanks,\nNiklas","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256\n header.s=pp1 header.b=HXyY125h;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.232.135.74; helo=sto.lore.kernel.org;\n envelope-from=linux-pci+bounces-51537-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=\"HXyY125h\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=148.163.158.5","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=linux.ibm.com"],"Received":["from sto.lore.kernel.org (sto.lore.kernel.org [172.232.135.74])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4flLtt3HD7z1y1q\n\tfor ; Tue, 31 Mar 2026 19:31:34 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sto.lore.kernel.org (Postfix) with ESMTP id BB9F4301E323\n\tfor ; Tue, 31 Mar 2026 08:30:46 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 30E963E0252;\n\tTue, 31 Mar 2026 08:30:44 +0000 (UTC)","from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com\n [148.163.158.5])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id C5BE4175A71;\n\tTue, 31 Mar 2026 08:30:42 +0000 (UTC)","from pps.filterd (m0360072.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id\n 62V6YvFi4032815;\n\tTue, 31 Mar 2026 08:30:37 GMT","from ppma13.dal12v.mail.ibm.com\n (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221])\n\tby mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4d66ms1ugh-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tTue, 31 Mar 2026 08:30:37 +0000 (GMT)","from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1])\n\tby ppma13.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id\n 62V7p1gR031034;\n\tTue, 31 Mar 2026 08:30:36 GMT","from smtprelay02.dal12v.mail.ibm.com ([172.16.1.4])\n\tby ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 4d6uhjr1nk-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tTue, 31 Mar 2026 08:30:36 +0000","from smtpav05.dal12v.mail.ibm.com (smtpav05.dal12v.mail.ibm.com\n [10.241.53.104])\n\tby smtprelay02.dal12v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id\n 62V8UZIK56623416\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK);\n\tTue, 31 Mar 2026 08:30:35 GMT","from smtpav05.dal12v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 9588C5807B;\n\tTue, 31 Mar 2026 08:30:35 +0000 (GMT)","from smtpav05.dal12v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 5130F5807A;\n\tTue, 31 Mar 2026 08:30:32 +0000 (GMT)","from [9.52.215.169] (unknown [9.52.215.169])\n\tby smtpav05.dal12v.mail.ibm.com (Postfix) with ESMTP;\n\tTue, 31 Mar 2026 08:30:32 +0000 (GMT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774945844; cv=none;\n b=fYckGtdAURjTTNWZDJe/oTh4vz++TmbfipXrEiVZhNBGCDqc9fDBagEsbXZguSHB+GXOkVDphol4GHqKy1MCzM+XwuN2jC1t8XpKCcqJtC445WnR2IVzE2AkwLG3UtSzZ0JQZRAr0Uw3R7IvHPDoXyKH90yhhTmWhZ2gJT4qBcM=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774945844; c=relaxed/simple;\n\tbh=lHXKyn0rIPGWYtihxusYrWFI7wDP4RG8DEssesQ7JMM=;\n\th=Message-ID:Subject:From:To:Cc:In-Reply-To:References:Content-Type:\n\t Date:MIME-Version;\n b=UZnjY1HDdPh1gwviEB0FLuRYa3pFLf2AA1ijVoGhUWJPaysZ7R5QH2Gv9Nt+sfVzb6UE5uc1F0/uiTDp3Nik7+5irJ55SmG4RxuwEVhGlNg68NNYOyaXn3N9mzlx3Mo8Tp7m0E0AshD9/2DwAdoyGXV9MuK6XXns4gFAZUZ9TmE=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com;\n spf=pass smtp.mailfrom=linux.ibm.com;\n dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=HXyY125h; arc=none smtp.client-ip=148.163.158.5","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc\n\t:content-transfer-encoding:content-type:date:from:in-reply-to\n\t:message-id:mime-version:references:subject:to; s=pp1; bh=IFfMgu\n\t5WL9hOmQ5pM5pTR61tcKadLN/xaLZW4Ubsqts=; b=HXyY125hQGKb09knH6QIpq\n\ttfi7AITG+9Q3yB99ZT5HGerJ9JqIsfjrKzAdJbuRGFUymR6tdF2LoCG/UpDpxceK\n\t1gEzAXHtIyUXlyuIVje8XtLXKWBzW2NMgi9ySUWgVwB8PaECeu9ZFtK9/OzLVKA1\n\t57OrIMkVqriAwBiJaQHsSAMlaOtWNu4gK1LqBvYwrtW8uYiBPlJGTfg6QEsXXUn+\n\tPseUchpz2tVCu+pJ9lM4aZDpQJjWO+exSRFi9huvrgNTDY+QqCaygN2NsyBolZYD\n\tOLNYQSnMmJvcQggFGVHb9pHRVYwQGgO4kOUl8tDN3Jv6LoBfWxvOekSrSM+FdRzg\n\t==","Message-ID":"<4fb2b835ec81ca0ef24bc1c867d177a7d04b4873.camel@linux.ibm.com>","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","From":"Niklas Schnelle ","To":"Jason Gunthorpe , Alex Williamson ","Cc":"Farhan Ali , Julian Ruess ,\n wintera@linux.ibm.com, ts@linux.ibm.com, oberpar@linux.ibm.com,\n gbayer@linux.ibm.com, Yishai Hadas ,\n Shameer Kolothum\t\n ,\n Kevin Tian , mjrosato@linux.ibm.com,\n raspl@linux.ibm.com, hca@linux.ibm.com, agordeev@linux.ibm.com,\n gor@linux.ibm.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org,\n linux-s390@vger.kernel.org, linux-pci@vger.kernel.org","In-Reply-To":"<20260331000334.GI246076@ziepe.ca>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n\t <4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n\t <3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n\t <64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>\n\t <20260330093646.03b0455f@shazbot.org> <20260330155651.GD246076@ziepe.ca>\n\t <20260330120945.023b2295@shazbot.org> <20260330181645.GE246076@ziepe.ca>\n\t <20260330123925.713edac4@shazbot.org> <20260331000334.GI246076@ziepe.ca>","Autocrypt":"addr=schnelle@linux.ibm.com; prefer-encrypt=mutual;\n keydata=mQINBGHm3M8BEAC+MIQkfoPIAKdjjk84OSQ8erd2OICj98+GdhMQpIjHXn/RJdCZLa58k\n /ay5x0xIHkWzx1JJOm4Lki7WEzRbYDexQEJP0xUia0U+4Yg7PJL4Dg/W4Ho28dRBROoJjgJSLSHwc\n 3/1pjpNlSaX/qg3ZM8+/EiSGc7uEPklLYu3gRGxcWV/944HdUyLcnjrZwCn2+gg9ncVJjsimS0ro/\n 2wU2RPE4ju6NMBn5Go26sAj1owdYQQv9t0d71CmZS9Bh+2+cLjC7HvyTHKFxVGOznUL+j1a45VrVS\n XQ+nhTVjvgvXR84z10bOvLiwxJZ/00pwNi7uCdSYnZFLQ4S/JGMs4lhOiCGJhJ/9FR7JVw/1t1G9a\n UlqVp23AXwzbcoV2fxyE/CsVpHcyOWGDahGLcH7QeitN6cjltf9ymw2spBzpRnfFn80nVxgSYVG1d\n w75ksBAuQ/3e+oTQk4GAa2ShoNVsvR9GYn7rnsDN5pVILDhdPO3J2PGIXa5ipQnvwb3EHvPXyzakY\n tK50fBUPKk3XnkRwRYEbbPEB7YT+ccF/HioCryqDPWUivXF8qf6Jw5T1mhwukUV1i+QyJzJxGPh19\n /N2/GK7/yS5wrt0Lwxzevc5g+jX8RyjzywOZGHTVu9KIQiG8Pqx33UxZvykjaqTMjo7kaAdGEkrHZ\n dVHqoPZwhCsgQARAQABtChOaWtsYXMgU2NobmVsbGUgPHNjaG5lbGxlQGxpbnV4LmlibS5jb20+iQ\n JXBBMBCABBAhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAhkBFiEEnbAAstJ1IDCl9y3cr+Q/Fej\n CYJAFAmmAWs8FCQl6sYAACgkQr+Q/FejCYJAn2g//UKzlXOgizdk0wudLooRbGzDo23ktGSPK5Oj9\n 9o5z6v4Jz5+qOHo5835683cqkMLM9//udA1ZcKV88LVwyfmoHChPW24cWBmOEy7RJOWCR4WeEINaO\n pZUGF5YOx7oKTkPs511ky2FR0Heg35754pgTuTMEpYzRXr5pNMPS8mHXcXSARFPDPaCF+uBJ9BafO\n L7XbpSwKRttePsWAlPHbSbloeDApBfHUhcF/pbuM9GNs+c/8V9NK+SwwqNK214t7jaSq9k+19/hfE\n jvU45nbiYQM4VqGCelxVFRWol93JnwPFp/JaMgxgV1VYFH9Ijtgh+qNVVBqO8bbTjioFKy1bHdprN\n 9GyPLDxoaI/lBg+5CwKewzazUjFd0xaqZbTXSgNK4ev/IuNI3qZV8tpvZZWwIgZU1K0Bhplt8Sku+\n O9Yl2H54erq9zuzwXjqBJtoW0+MaKbe+1gZ/v2/AVE2VeQMugPUWDg+2bpJaApRkeA4xQ9XfeW6Bp\n It7xYrwwbVhQtWRC0sRh+QNlU9HI28wPSnLWn7HFBeWupaIrxSp4IEL3eHUn8xv4aA8lpdNsHXD/X\n vqOSUwy5jlTPTlemvwaC9mNHagNdVXng8C6+hxiDLhZ6xH2P4qNHTKmjW61NsdF6Y/HfWP+lmbi8/\n 474UNCltDt/fP01ajqogfWZKFymoH0O0KU5pa2xhcyBTY2huZWxsZSA8bmlrbGFzLnNjaG5lbGxlQ\n GlibS5jb20+iQJUBBMBCAA+AhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEEnbAAstJ1IDCl9y\n 3cr+Q/FejCYJAFAmmAWusFCQl6sYAACgkQr+Q/FejCYJAtIw//WmQW/Z+SLdfrlDH5J2bvixzFNnO\n TOvp8uM8vcNZsxZwPXem4AeCXHayCqipxpa0iXWufEIvdMxkBxWvvM//V+rTUgQnJe6nhDxfLGklx\n 5Mb2H+K/ndS73ElCuA30MPYq7mHr8i3gEmi2ZFX1W47JecJ8hno/DQxhHRG7bd+GFsiKCbsjLWXNq\n s/VaAK9uyOTQx7m6/2nR8L+Mvl1BrRXwkj7Qp0qxfQSd4r+IVNBzNFOcrGagBqsyHrN7Is7IICktH\n 9VFl/G8P+hfviHQLnlxw9ltzpM1Dy6N1+BM3kbqD59gX+L6wqiLJI42eh+SHCiy35FvD3AFlYx4jZ\n MWE6qIgFnbwcL1kvcA7nnwfr3ZizCYPm8e334xXxslXBoRGsvjXSbAeAyZo2dvJXffNHdcDdUbJSl\n CfOixNGGKiQvs00X9ekfq9WmmRFvmYHu/m3lg1OXnMjFFIO41O51ZdhbEYJiqZEki7jA8Hd9xuWwQ\n nFDHhacU3xxivZ4BKQGQc+4XZ3yp/q6+7ux9prepRy/LeRyoaAmE67oxEsAgj+qyA3Tfy5nRTDdRQ\n E//gpaIt9H1VEx+68dRWHroxBQeozpnFPi25AlX3k4/EtVZjcItPWgE9iru1qT4DH3BBrz7Kd1zUw\n NnQC77zDJyZD2WUj1E+5bftO0aeE+7HZXj3tM/ea0K05pa2xhcyBTY2huZWxsZSA8bmlrbGFzLnNj\n aG5lbGxlQGdtYWlsLmNvbT6JAlQEEwEIAD4CGwEFCwkIBwIGFQoJCAsCBBYCAwECHgECF4AWIQSds\n ACy0nUgMKX3Ldyv5D8V6MJgkAUCaYBa6wUJCXqxgAAKCRCv5D8V6MJgkF/TEACOY2kL4NGFIbWeM5\n TUhatxqe8c3RT6jvNjq32CkvaK/cSZzBkS0smddyOzxt2WnsvMgkr9cM7P+CevoMwhT3e0lgQbqBD\n /vXZJjWKddC+iKXeqWkjMVcgCOsWNZ7PWEzRUT5X1AEFq2zzxQAQ/bCWEYNqIbHN4b6G1Wk+2Y598\n +KypZ3FS0bwiItnPQOWzOOqJCGxDxaEUuXFx4ah8HtVdtIev8jPS/5uzQO9iG2vZQUWeMEYZtfMHW\n sbFWqo2A3lxB+KPzNIYFhul4Lyx1CwvKUAGSHOx7FZuc2xI5DYt/Wdh2QyKFYr7xVzv3uwJjeS1+3\n 6gvyB7DJaQuY+PziNPv4GPr5wy0cRkJ6Ps15fgC6y6wNwoNdNXKlwiuclIsBzJKa7A0pZMIfpCpIJ\n bEHP7oy3drBRAhIrBx7Lx1lyqqodDqc+ok5IQ5WcKG/TOrH732mTmJX6fxYTiCVxcU4WLJSNZbrZ/\n pjF0AWXs7E+onAkQy6RLg/XU1iiU5QdMvug+fTA6TpPSUMdujWtGWUt3/4nC+69AVc8tXtRQTZ7gP\n t7uIcQFwPqUuJGS26vl0w/6dIABQAyU9acvE3adCZra+/PBKFZi/yxT1WgV1T2mexKSWwQgLcR57J\n Yp5oWnQRgi/S6fAoskIWkp9UVcfAQPY0p45NwO5cZR9/g06JZmyrQhTmlrbGFzIFNjaG5lbGxlIDx\n uaWtzQGtlcm5lbC5vcmc+iQJUBBMBCAA+AhsBBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEEnbAA\n stJ1IDCl9y3cr+Q/FejCYJAFAmmAWusFCQl6sYAACgkQr+Q/FejCYJAz4A/9F+dMhzu7YonagL4qh\n WDz5IpRD4vzYKOBZ+qwYp1ugJz1BIUppN9i68HKoS4ARfgP97Sv9GpOy9g7L0lymH2MPF8hRPK0Yn\n 7DKIkeu/r28YWEoWfoVm5reC+gpxMgmxBz4JScE4f6xfa7+Nw0bbTDl+nxftJD7lf/dTiruNJsXph\n HQnZ5wPXmxeH6XVJikfpyrGe8iJZALbtHtjlx6Omu7NvRGikenB8trrWS5W0F60ZdbqH1HdmDDcrZ\n pDq6LtAARHK5tGRm0SK6sZpKe3nULFeeCt7T/edk2FC6KVh4sL1jw1kyceX4DjiMffqYBPrhK5gz5\n cDIixLBF9C6Wt1ObvuDBrIQf1/3q6EZrUrUuf6qtaXDMuC6cSlShm47qaPEvVYh67O9JZQ7vzvaea\n UI74DJUb8Pjnz7mTOmMOzsS1gUhCue4n2YSSM6ythioCGb/3bgMGTpuer3JhvZG5s5uKD9yyj8s8x\n 35qJkCFfjmjVx9s3vSUS48X+cUpYcMispErKzFu7C0YgKoxvJ4XTfXlDBiMFMPYcN67hsb2jeYHVJ\n wzE+fIZiDx9JLh1oQW2krwjweisE+3glOaKXZKi0fBtkxyH41iemLtLNYZRJopv6ykdl3hiI+Nh+a\n 3FZJPTo/OpqchMm8XIeDxC4NFFiPMpyLeYzIxO7eZpiGrAjVTE=","Content-Type":"text/plain; charset=\"UTF-8\"","Content-Transfer-Encoding":"quoted-printable","Date":"Tue, 31 Mar 2026 10:29:31 +0200","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","User-Agent":"Evolution 3.58.3 (3.58.3-1.fc43) ","X-TM-AS-GCONF":"00","X-Authority-Analysis":"v=2.4 cv=J6enLQnS c=1 sm=1 tr=0 ts=69cb862d cx=c_pps\n a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17\n a=IkcTkHD0fZMA:10 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22\n a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=NEAV23lmAAAA:8\n a=eic7ZF46ImWAZUYm3ecA:9 a=QEXdDO2ut3YA:10","X-Proofpoint-Spam-Details-Enc":"AW1haW4tMjYwMzMxMDA3OCBTYWx0ZWRfX8yuY0RA5lt8o\n 8rslq/FMUqDNmBM8KrV+Rh+yp1Dc5HzYMsfAoZ+0whoI0UN1WEVxr3tF9fEV+38irmqoynfw8Ty\n tT/MqXorMR3cjsEOoVy6nfhWsJqTKMiRIdLmWWVRZKbNSdNNzOgMXy83rm4vBusK+OR2q6ZKFGX\n rlONXxR7riwKaUSNp1CSu+fY5Y+BgmO5rwAxsjDJGVvPoQMt1+CHrCbKLikxR4utcFOqYreGXvu\n pqAF+CxjX3ZuL4xqUNdtGoUymGyANJzBwQYjXWCS3/8w67YLraNEFof5vSrZ0X1lIPgXnu6khVf\n lB6eJgKE18piGlQPBbbL7Y92ihEdyc5kMJj3n3BZI6cRNVDGOmE17O0A520TYn0v5Seg/+/azqN\n fxtImW+91ivhuSUNxnQR4t1yA5mol9ugHDxQxZ9nprWCxxwtDjmjtE6Cla8v9JFJO99+EVjzam5\n 9dIBL+Lv+N2I+OtZcSA==","X-Proofpoint-GUID":"tk1974_lsb68QMwYxrWQJxpZl794BysI","X-Proofpoint-ORIG-GUID":"tk1974_lsb68QMwYxrWQJxpZl794BysI","X-Proofpoint-Virus-Version":"vendor=baseguard\n engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49\n definitions=2026-03-31_02,2026-03-28_01,2025-10-01_01","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n suspectscore=0 clxscore=1015 adultscore=0 priorityscore=1501 bulkscore=0\n phishscore=0 malwarescore=0 lowpriorityscore=0 spamscore=0 impostorscore=0\n classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0\n reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603310078"}},{"id":3671927,"web_url":"http://patchwork.ozlabs.org/comment/3671927/","msgid":"<20260331144415.33f3414b@shazbot.org>","list_archive_url":null,"date":"2026-03-31T20:44:15","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":91887,"url":"http://patchwork.ozlabs.org/api/people/91887/","name":"Alex Williamson","email":"alex@shazbot.org"},"content":"On Tue, 31 Mar 2026 10:29:31 +0200\nNiklas Schnelle wrote:\n\n> On Mon, 2026-03-30 at 21:03 -0300, Jason Gunthorpe wrote:\n> > On Mon, Mar 30, 2026 at 12:39:25PM -0600, Alex Williamson wrote: \n> > > Yes, that would be the ideal balance of enabling larger BARs while\n> > > retaining compatibility for existing devices. Sounds like we'll\n> > > continue down the variant driver path for this one-off device for\n> > > now. It remains fairly self contained so long as we don't add more\n> > > regions for vfio-pci-core to manage.\n> > > \n> > > This could be a good project if someone is looking though, especially\n> > > if it had a build-time config option to set the minimum region size so\n> > > we can exercise it before we hit 1TB BARs. Thanks, \n> > \n> > Well, it took claude an hour to vibe code a draft from a four sentence\n> > prompt.. I see many things that need changing/cleaning in here, but\n> > the patch strategy and general idea looks sound.\n> > \n> > I guess another day of effort would probably get things into something\n> > presentable. We are not so far away - maybe the variant driver path is\n> > not necessary?\n> > \n> > https://github.com/jgunthorpe/linux/commits/vfio_maple_tree/\n> > \n> > Jason \n> \n> I'm in no way against changing the offset handling in general but for\n> what it's worth, we need a variant driver for ISM regardless, though it\n> would be smaller with large offset support. This is because besides the\n> large BAR we also have to use our classic function handle based PCI\n> instructions to access that BAR instead of the newer memory-I/O (MIO)\n> PCI instructions. And sadly the way the ISM device uses the PCI Store\n> Block instruction there is no straight forward way to enable the newer\n> instructions even if we changed the device implementation. This also\n> means that we would want to keep the no-mmap() restriction.\n\nIt feels a bit late in the cycle for an untested maple tree conversion\nanyway, though I am interested in it for v7.2. So I think we're agreed\nin the variant driver here to handle the excessively large BAR with no\ncurrently foreseeable need for additional regions, and maybe it gets\nsimplified when that conversion occurs later. Thanks,\n\nAlex","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=shazbot.org header.i=@shazbot.org header.a=rsa-sha256\n header.s=fm1 header.b=VBMvaleZ;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=messagingengine.com header.i=@messagingengine.com\n header.a=rsa-sha256 header.s=fm2 header.b=tqbvb7P5;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=104.64.211.4; helo=sin.lore.kernel.org;\n envelope-from=linux-pci+bounces-51628-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=\"VBMvaleZ\";\n\tdkim=pass (2048-bit key) header.d=messagingengine.com\n header.i=@messagingengine.com header.b=\"tqbvb7P5\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=202.12.124.149","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=shazbot.org"],"Received":["from sin.lore.kernel.org (sin.lore.kernel.org [104.64.211.4])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4flg8W5k5Jz1yCp\n\tfor ; Wed, 01 Apr 2026 07:44:27 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sin.lore.kernel.org (Postfix) with ESMTP id B2EC03008098\n\tfor ; Tue, 31 Mar 2026 20:44:25 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id ED9FF44E045;\n\tTue, 31 Mar 2026 20:44:23 +0000 (UTC)","from fout-b6-smtp.messagingengine.com\n (fout-b6-smtp.messagingengine.com [202.12.124.149])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id E261A274FE9;\n\tTue, 31 Mar 2026 20:44:20 +0000 (UTC)","from phl-compute-01.internal (phl-compute-01.internal [10.202.2.41])\n\tby mailfout.stl.internal (Postfix) with ESMTP id 351F01D00157;\n\tTue, 31 Mar 2026 16:44:19 -0400 (EDT)","from phl-frontend-04 ([10.202.2.163])\n by phl-compute-01.internal (MEProxy); Tue, 31 Mar 2026 16:44:20 -0400","by mail.messagingengine.com (Postfix) with ESMTPA; Tue,\n 31 Mar 2026 16:44:17 -0400 (EDT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1774989863; cv=none;\n b=DJY35KNgYIghbm6AZWqaalSScKhgjyT3/KPnKi0CI9S51VjZz9Aib8e0hIDjiajP9hk4GVevoJjYEA0CqkR3WWO3Wl6xBf762LPaW/7Krqv9HsWqm7ME2lePzvCm4z1VZgMAFtBwIYC+iunBf4gzpoms2mS84jFqSR6tJXSGxNs=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1774989863; c=relaxed/simple;\n\tbh=9JiShWLzsMfEIFKmmLnX3lKHoUsByhcPPiUx3sx9ljc=;\n\th=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:\n\t MIME-Version:Content-Type;\n b=rBq6d7iE6tLdpmKcPk/GLQwt8LUxhRbkUhWng9oy5r/ldZSndEZuCbMMG21hlBUr8baIEAWja9CLEoJwEJGo0AEBxteZ/44dycMPnRncggnp6WN82Y3OnK3I1AqCuGFcMWK64ErJtd+2xaC2RXfBOfNlj5s6wezeZDp+nHvPI3s=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org;\n spf=pass smtp.mailfrom=shazbot.org;\n dkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=VBMvaleZ;\n dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com\n header.b=tqbvb7P5; arc=none smtp.client-ip=202.12.124.149","DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/relaxed; d=shazbot.org; h=\n\tcc:cc:content-transfer-encoding:content-type:content-type:date\n\t:date:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to; s=fm1; t=1774989858;\n\t x=1775076258; bh=2naYgeCqp4JHbxNG5hbN+LbC6Dsxev/Fv44jf/ivh80=; b=\n\tVBMvaleZt+xdbRoJyYB18VABz+FxWi5/91aNae+7rgz1BX7PhajEbbuasS3ij4DC\n\thuNWU9C8s2HgnV1dR5Q8WOziXdzFdclCqr66L+YwjQvOpCKzGhHbwQHJx3LJBWrv\n\tP4chF+s7ESahKXNCRl7o1AjyaZY+s+m2CiDWyB66XPt5b1J1gkClWOPk42htFW+F\n\tWkFRi3Hj1dWTCIOEONw7bKiPhc/+3d90vj1UWLKz9Mlc4N5gH9cS17ru5HoxFTAp\n\t6X8W0IyFewnU5kxfy5S/Cye7goWBgY7qju0OeiKqr/Ud9YYppINfjjxIuNqiY8vT\n\tH5sNi0jZRbbuxxe7eqdTng==","v=1; a=rsa-sha256; c=relaxed/relaxed; d=\n\tmessagingengine.com; h=cc:cc:content-transfer-encoding\n\t:content-type:content-type:date:date:feedback-id:feedback-id\n\t:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to:x-me-proxy\n\t:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1774989858; x=\n\t1775076258; bh=2naYgeCqp4JHbxNG5hbN+LbC6Dsxev/Fv44jf/ivh80=; b=t\n\tqbvb7P5NAclNR0cZUBetzKGIU/7IELKS2xk1k1jYuzZfkFMw9cJXJ0BaRq6BTV9K\n\tUnlvjVeugDQlaVgODJBCMnm6855GbY43OZrut7Wuv565ZuPeByyWklx2MRnpGJMg\n\tLUi6JKaKlVGsD6sd0jeMnO7ltOK/uxUaNcIX3tGGX5PhiyisNQcazkOw/whg8vI3\n\tb5+0bVyz1ejTL0FjPtr1t3NcShfolO93Uxfs1GhN8GUc7CHYkrSfoUTDhd0OyKkD\n\t0xtGzdveLUa10B182NEX0F7TqYcwozl7GnUJJ10s1dWPDTCAIDCLul488BcNtyOr\n\tHyGfIYxS8xzzKy5cJTFCA=="],"X-ME-Sender":"\n ","X-ME-Received":"\n ","X-ME-Proxy-Cause":"\n gggruggvucftvghtrhhoucdtuddrgeefhedrtddtgdduudelucetufdoteggodetrfdotf\n fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceurghi\n lhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurh\n epfffhvfevuffkjghfofggtgfgsehtjeertdertddvnecuhfhrohhmpeetlhgvgicuhghi\n lhhlihgrmhhsohhnuceorghlvgigsehshhgriigsohhtrdhorhhgqeenucggtffrrghtth\n gvrhhnpeejteekhedvleehjefhgfdvteetudevieeiuefhhfevjeduleefiedvueegudeu\n hfenucffohhmrghinhepghhithhhuhgsrdgtohhmnecuvehluhhsthgvrhfuihiivgeptd\n enucfrrghrrghmpehmrghilhhfrhhomheprghlvgigsehshhgriigsohhtrdhorhhgpdhn\n sggprhgtphhtthhopedvuddpmhhouggvpehsmhhtphhouhhtpdhrtghpthhtohepshgthh\n hnvghllhgvsehlihhnuhigrdhisghmrdgtohhmpdhrtghpthhtohepjhhgghesiihivghp\n vgdrtggrpdhrtghpthhtoheprghlihhfmheslhhinhhugidrihgsmhdrtghomhdprhgtph\n htthhopehjuhhlihgrnhhrsehlihhnuhigrdhisghmrdgtohhmpdhrtghpthhtohepfihi\n nhhtvghrrgeslhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopehtsheslhhinhhugi\n drihgsmhdrtghomhdprhgtphhtthhopehosggvrhhprghrsehlihhnuhigrdhisghmrdgt\n ohhmpdhrtghpthhtohepghgsrgihvghrsehlihhnuhigrdhisghmrdgtohhmpdhrtghpth\n htohephihishhhrghihhesnhhvihguihgrrdgtohhm","X-ME-Proxy":"\n \n \n \n ","Feedback-ID":"i03f14258:Fastmail","Date":"Tue, 31 Mar 2026 14:44:15 -0600","From":"Alex Williamson ","To":"Niklas Schnelle ","Cc":"Jason Gunthorpe , Farhan Ali , Julian\n Ruess , wintera@linux.ibm.com, ts@linux.ibm.com,\n oberpar@linux.ibm.com, gbayer@linux.ibm.com, Yishai Hadas\n , Shameer Kolothum\t , Kevin\n Tian , mjrosato@linux.ibm.com, raspl@linux.ibm.com,\n hca@linux.ibm.com, agordeev@linux.ibm.com, gor@linux.ibm.com,\n kvm@vger.kernel.org, linux-kernel@vger.kernel.org,\n linux-s390@vger.kernel.org, linux-pci@vger.kernel.org, alex@shazbot.org","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","Message-ID":"<20260331144415.33f3414b@shazbot.org>","In-Reply-To":"<4fb2b835ec81ca0ef24bc1c867d177a7d04b4873.camel@linux.ibm.com>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n\t<4096cb9d402b1aabc9667d450221cb0922e78d90.camel@linux.ibm.com>\n\t<3d6457b9-715a-4cbb-9c69-d8a7e7473c89@linux.ibm.com>\n\t<64e3158a441c79c55febead9aac956c31f034fb9.camel@linux.ibm.com>\n\t<20260330093646.03b0455f@shazbot.org>\n\t<20260330155651.GD246076@ziepe.ca>\n\t<20260330120945.023b2295@shazbot.org>\n\t<20260330181645.GE246076@ziepe.ca>\n\t<20260330123925.713edac4@shazbot.org>\n\t<20260331000334.GI246076@ziepe.ca>\n\t<4fb2b835ec81ca0ef24bc1c867d177a7d04b4873.camel@linux.ibm.com>","X-Mailer":"Claws Mail 4.3.1 (GTK 3.24.51; x86_64-pc-linux-gnu)","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=US-ASCII","Content-Transfer-Encoding":"7bit"}},{"id":3672363,"web_url":"http://patchwork.ozlabs.org/comment/3672363/","msgid":"","list_archive_url":null,"date":"2026-04-01T16:28:57","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":73785,"url":"http://patchwork.ozlabs.org/api/people/73785/","name":"Farhan Ali","email":"alifm@linux.ibm.com"},"content":"On 3/25/2026 6:31 AM, Julian Ruess wrote:\n> Add a vfio_pci variant driver for the s390-specific Internal Shared\n> Memory (ISM) devices used for inter-VM communication.\n>\n> This enables the development of vfio-pci-based user space drivers for\n> ISM devices.\n>\n> On s390, kernel primitives such as ioread() and iowrite() are switched\n> over from function-handle-based PCI load/stores instructions to PCI\n> memory-I/O (MIO) loads/stores when these are available and not\n> explicitly disabled. Since these instructions cannot be used with ISM\n> devices, ensure that classic function-handle-based PCI instructions are\n> used instead.\n>\n> The driver is still required even when MIO instructions are disabled, as\n> the ISM device relies on the PCI store block (PCISTB) instruction to\n> perform write operations.\n>\n> Stores are not fragmented, therefore one ioctl corresponds to exactly\n> one PCISTB instruction. User space must ensure to not write more than\n> 4096 bytes at once to an ISM BAR which is the maximum payload of the\n> PCISTB instruction.\n>\n> Reviewed-by: Alexandra Winter\n> Reviewed-by: Niklas Schnelle\n> Signed-off-by: Julian Ruess\n> ---\n\nI think we have decided to not support any additional regions with this \npatch. Feel free to add\n\nReviewed-by: Farhan Ali","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256\n header.s=pp1 header.b=VYq58tWi;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=linux-pci+bounces-51689-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=\"VYq58tWi\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=148.163.158.5","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=linux.ibm.com"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fmB2N5XZ3z1xtJ\n\tfor ; Thu, 02 Apr 2026 03:55:56 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id 300DC317B4A7\n\tfor ; Wed, 1 Apr 2026 16:30:29 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 9DC0F43DA40;\n\tWed, 1 Apr 2026 16:29:11 +0000 (UTC)","from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com\n [148.163.158.5])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 31E393F1669;\n\tWed, 1 Apr 2026 16:29:09 +0000 (UTC)","from pps.filterd (m0356516.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id\n 6316tLV03728917;\n\tWed, 1 Apr 2026 16:29:02 GMT","from ppma13.dal12v.mail.ibm.com\n (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221])\n\tby mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4d64dgrh93-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tWed, 01 Apr 2026 16:29:02 +0000 (GMT)","from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1])\n\tby ppma13.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id\n 631G4Eeb031034;\n\tWed, 1 Apr 2026 16:29:01 GMT","from smtprelay06.dal12v.mail.ibm.com ([172.16.1.8])\n\tby ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 4d6uhjx91e-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tWed, 01 Apr 2026 16:29:01 +0000","from smtpav01.wdc07v.mail.ibm.com (smtpav01.wdc07v.mail.ibm.com\n [10.39.53.228])\n\tby smtprelay06.dal12v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id\n 631GT0NI33620568\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK);\n\tWed, 1 Apr 2026 16:29:00 GMT","from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 3E0C958055;\n\tWed, 1 Apr 2026 16:29:00 +0000 (GMT)","from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 3D9265804B;\n\tWed, 1 Apr 2026 16:28:58 +0000 (GMT)","from [9.61.244.25] (unknown [9.61.244.25])\n\tby smtpav01.wdc07v.mail.ibm.com (Postfix) with ESMTP;\n\tWed, 1 Apr 2026 16:28:58 +0000 (GMT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1775060951; cv=none;\n b=f7UpGjOAnMKGP3igFiaOrLMk+PS4vYAYEeldiKix0FSuAYp4lrRc2FFLM7+T7WcQmd4PO4Jl4fez8fNM+ipAtJvrHn1mDRYA7CBUoObyj0kt+9oiCefq7ak4U5PJK83MSD9XxM1kkG5UsC68OITEoVlWyS9kHZc8357nYGcoIQI=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1775060951; c=relaxed/simple;\n\tbh=lpKRatsiKjme51mt1hfc1a4RLa4UswyEdIlbv0MRluU=;\n\th=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:\n\t In-Reply-To:Content-Type;\n b=MASU5BiplAAC4r2ojV9Qe3Ns3K++vHV4NrXFHG1JrzA63avVfoBZJ8wGwRxlo5MmNvthP6p517ScUeaEMfmqsSZ1iLw/zqc6wARJ8ddFpehkLqdMuTyNhkhAdCg5G7QsZuqu8aOkAEFhSCFVgQzGRuFdNBrczauOeUC20SNp824=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com;\n spf=pass smtp.mailfrom=linux.ibm.com;\n dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=VYq58tWi; arc=none smtp.client-ip=148.163.158.5","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc\n\t:content-transfer-encoding:content-type:date:from:in-reply-to\n\t:message-id:mime-version:references:subject:to; s=pp1; bh=8QC9Fk\n\t+OLA7N5EuWutkyWpfjvL6o15fl0W8VJ8R99rw=; b=VYq58tWiWVgFmhF0JU2Amg\n\tXunKj9wOkBfJN6cR2hHSh3kPylzwj88drIvV0y9jdm6KgpQTbFF7iUZ8vV1RuBgS\n\tYFzk5gIxmicF3mVtpE3wuHTKVgl0uMnSnegOkOVm5fEGLYPiHheOjwSb6eRPTumN\n\tufRvel/rGzmarRPGLlBlV6mHhrALus9ZfZjmbcr2dO9J6Anf38c8SCSvkdkBvja1\n\tlW650OYe+pmIamhEWRReaf4y18pyssf9KNHIjLKnyT92TRA+RoYs1sSjsWf2tFd+\n\tWlmSxgXQB0rUsdrKID6vMgrN2mUjk5YsfrG1ruJKyPR2auBs/LEnOknZMT/Cqp8g\n\t==","Message-ID":"","Date":"Wed, 1 Apr 2026 09:28:57 -0700","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","To":"Julian Ruess , schnelle@linux.ibm.com,\n wintera@linux.ibm.com, ts@linux.ibm.com, oberpar@linux.ibm.com,\n gbayer@linux.ibm.com, Alex Williamson ,\n Jason Gunthorpe , Yishai Hadas ,\n Shameer Kolothum ,\n Kevin Tian ","Cc":"mjrosato@linux.ibm.com, raspl@linux.ibm.com, hca@linux.ibm.com,\n agordeev@linux.ibm.com, gor@linux.ibm.com, kvm@vger.kernel.org,\n linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n linux-pci@vger.kernel.org","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>","Content-Language":"en-US","From":"Farhan Ali ","In-Reply-To":"<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>","Content-Type":"text/plain; charset=UTF-8; format=flowed","Content-Transfer-Encoding":"7bit","X-TM-AS-GCONF":"00","X-Proofpoint-Spam-Details-Enc":"AW1haW4tMjYwNDAxMDE1MiBTYWx0ZWRfXwiDqhZdR7r2b\n 2NeRzSts7j1FXaM+q1fLgqbT48zd1+k7VdnOq6xA8kmwEkPOLLBFCW+pGCs0iHDJmzvDU39055k\n LXkfSexkVXZyhAq6cj2j0LLh49DYV7Q6pegGgoQ2nwrsrLtYcawtydTxd4brFfhv83WTQkPKsyW\n ifA8IrS+X8WnsShS9kBnKY4fpbpGI+7DdJDKoxpmRk9n0SHXUyMdmGrwN4WxisHttBPRo/WCSE/\n Q0EETLleHswEmgOZgIWrqZJ8QmSfxs1mMap4F94rKazS3pa65uC9WtOOKwFmO4CEqSTX7sVtFgS\n KIQ70MVUnPlHZgXIEOKO76EhZpwP5kr92aR1rPT2JP521uN6g2ardtuWMMe7wLNnLtdpYDngxMr\n 4N8/kVtRn4J6ludMUCM/dt74Haaktb57cwKBieYoZGt9uBfM+u8aUkTVg231s+keiphQCJzio98\n DAP/J2od+V1BV6RPawg==","X-Authority-Analysis":"v=2.4 cv=QKZlhwLL c=1 sm=1 tr=0 ts=69cd47ce cx=c_pps\n a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17\n a=IkcTkHD0fZMA:10 a=A5OVakUREuEA:10 a=VkNPw1HP01LnGYTKEx00:22\n a=RnoormkPH1_aCDwRdu11:22 a=Y2IxJ9c9Rs8Kov3niI8_:22 a=VnNF1IyMAAAA:8\n a=akap8JHnbm7pTVdsz3UA:9 a=QEXdDO2ut3YA:10","X-Proofpoint-GUID":"bfWW_YluBv6JnohcvqC4Kb3bOE2DEqql","X-Proofpoint-ORIG-GUID":"bfWW_YluBv6JnohcvqC4Kb3bOE2DEqql","X-Proofpoint-Virus-Version":"vendor=baseguard\n engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49\n definitions=2026-04-01_04,2026-04-01_02,2025-10-01_01","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n lowpriorityscore=0 phishscore=0 adultscore=0 impostorscore=0 clxscore=1015\n spamscore=0 bulkscore=0 priorityscore=1501 suspectscore=0 malwarescore=0\n classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0\n reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2604010152"}},{"id":3672453,"web_url":"http://patchwork.ozlabs.org/comment/3672453/","msgid":"<20260401160441.406fe25a@shazbot.org>","list_archive_url":null,"date":"2026-04-01T22:04:41","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":91887,"url":"http://patchwork.ozlabs.org/api/people/91887/","name":"Alex Williamson","email":"alex@shazbot.org"},"content":"On Wed, 25 Mar 2026 14:31:24 +0100\nJulian Ruess wrote:\n> diff --git a/drivers/vfio/pci/ism/main.c b/drivers/vfio/pci/ism/main.c\n> new file mode 100644\n> index 0000000000000000000000000000000000000000..00bc81f7225f806eac1b99c4520ab5a68137885e\n> --- /dev/null\n> +++ b/drivers/vfio/pci/ism/main.c\n> @@ -0,0 +1,408 @@\n> +// SPDX-License-Identifier: GPL-2.0\n> +/*\n> + * vfio-ISM driver for s390\n> + *\n> + * Copyright IBM Corp.\n> + */\n> +\n> +#include \"../vfio_pci_priv.h\"\n> +#include \"linux/slab.h\"\n\nConvention says this should be:\n\n+#include \n #include \"../vfio_pci_priv.h\"\n-#include \"linux/slab.h\"\n \nWithout objection, I'll make the change and push this to next tomorrow.\nThanks,\n\nAlex","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=shazbot.org header.i=@shazbot.org header.a=rsa-sha256\n header.s=fm1 header.b=nZyhmzjl;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=messagingengine.com header.i=@messagingengine.com\n header.a=rsa-sha256 header.s=fm2 header.b=uXaTuolM;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=linux-pci+bounces-51698-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=\"nZyhmzjl\";\n\tdkim=pass (2048-bit key) header.d=messagingengine.com\n header.i=@messagingengine.com header.b=\"uXaTuolM\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=103.168.172.148","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=shazbot.org"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fmJzx1zLYz1yGY\n\tfor ; Thu, 02 Apr 2026 09:09:17 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id AE9FF3009B21\n\tfor ; Wed, 1 Apr 2026 22:04:50 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id F008030DECE;\n\tWed, 1 Apr 2026 22:04:48 +0000 (UTC)","from fout-a5-smtp.messagingengine.com\n (fout-a5-smtp.messagingengine.com [103.168.172.148])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id B442BA932;\n\tWed, 1 Apr 2026 22:04:45 +0000 (UTC)","from phl-compute-04.internal (phl-compute-04.internal [10.202.2.44])\n\tby mailfout.phl.internal (Postfix) with ESMTP id CE307EC0283;\n\tWed, 1 Apr 2026 18:04:44 -0400 (EDT)","from phl-frontend-03 ([10.202.2.162])\n by phl-compute-04.internal (MEProxy); Wed, 01 Apr 2026 18:04:44 -0400","by mail.messagingengine.com (Postfix) with ESMTPA; Wed,\n 1 Apr 2026 18:04:43 -0400 (EDT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1775081088; cv=none;\n b=s5+YQuVo+6eJQgEorBJiR3z7NSjkAn8KTp2D3zZrwENH1SaauBogTWXy9gvvoty7IJsQuuLOs7nLBhRkPQjXNoeoye275y09f9RMJBE8BAphIrXHlGQNWGkElQnZt+DLbhzaxk8nmTQp59sn0MXtcCycGdH2/h+glWUQnxjNK3U=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1775081088; c=relaxed/simple;\n\tbh=nJOvaNy7j6rvTOxcVafJpBYJp/0tPwEzuBoNXIR/zRA=;\n\th=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:\n\t MIME-Version:Content-Type;\n b=UFBPUPTDEHafi8TncxxvscEQjexFp3tHr0dFmlPomLxFUNuklaTQbpnYm8sOUYMFfAcUkr2YOTVtsoVhxWUqGn3KarSXXH5Tyx4y2njDhg0aYA5klNphVxAcAObWikde+ChzKPtrGHojm66Gm085L3wZEtlmShec0AI1DHwENrg=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=shazbot.org;\n spf=pass smtp.mailfrom=shazbot.org;\n dkim=pass (2048-bit key) header.d=shazbot.org header.i=@shazbot.org\n header.b=nZyhmzjl;\n dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com\n header.b=uXaTuolM; arc=none smtp.client-ip=103.168.172.148","DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/relaxed; d=shazbot.org; h=\n\tcc:cc:content-transfer-encoding:content-type:content-type:date\n\t:date:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to; s=fm1; t=1775081084;\n\t x=1775167484; bh=9IL6MYddNSgjsTDnmWtOw+9dnQBGMdnLa6tOppVniio=; b=\n\tnZyhmzjlzYpN31Sb53GozZK7YfFnFNK719ZxNlGQpgQLDoI4RRoI8M339F5zBIgP\n\tDGPmSvmLWrglk3g8lJVWJUSs94/QAkYpMwo77H54Nt/fezDHc1/2+oyo29mkrfEs\n\tl2bsZfBqayxh+z8V8ucQHXw1wY5Vvmy24jT9FNKoWitx+3abeisvjQ0mpjMxSvA+\n\tpl7oGOsFmkMcNMcIuIJ8H5aF/CFS3wgp4eHadqWA0LmBVC3vU8jpPQjgbrGju75Z\n\tZXaEI10pr96bbPqSeIWw5d6gw2qVPFNWSCex6tGfXeF1im5lLYKdktpdxsJKVex0\n\teNfvRJBbGZPM2RnxLi9TJg==","v=1; a=rsa-sha256; c=relaxed/relaxed; d=\n\tmessagingengine.com; h=cc:cc:content-transfer-encoding\n\t:content-type:content-type:date:date:feedback-id:feedback-id\n\t:from:from:in-reply-to:in-reply-to:message-id:mime-version\n\t:references:reply-to:subject:subject:to:to:x-me-proxy\n\t:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1775081084; x=\n\t1775167484; bh=9IL6MYddNSgjsTDnmWtOw+9dnQBGMdnLa6tOppVniio=; b=u\n\tXaTuolMv4eO5R6eaSVldRiUT6ZufrCvo6UXZLk7JsR7OA+ZNLv1GgS43j344H0gB\n\taez5B8w950iz7ehmhTYx1YzmvVWwKRfBEqp+YeYX4cnTrCjsL4pTZYMpVW9eafU4\n\tvq057RlDFfrMpgCVv/Uf7EJpMM6yK2N+gNr3RutaMt9SZq8VhLWPiApovSpExdgH\n\t6pM4MISBIofo4qRC82ZqWFOz5qluF6kPoRcZ2UNK4PZO9xo2PD9d7erzL0diDdrP\n\t68Ns7TP40GBZ22AvFzvWT15d5IpMYwwf7O/khQCqYKhOl25GqxSt4cwUjllQfEAd\n\tk8unY8cW200lxENP0iFZg=="],"X-ME-Sender":"\n ","X-ME-Received":"\n ","X-ME-Proxy-Cause":"\n gggruggvucftvghtrhhoucdtuddrgeefhedrtddtgdegvdekucetufdoteggodetrfdotf\n fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceurghi\n lhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurh\n epfffhvfevuffkjghfofggtgfgsehtjeertdertddvnecuhfhrohhmpeetlhgvgicuhghi\n lhhlihgrmhhsohhnuceorghlvgigsehshhgriigsohhtrdhorhhgqeenucggtffrrghtth\n gvrhhnpedvkeefjeekvdduhfduhfetkedugfduieettedvueekvdehtedvkefgudegveeu\n ueenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegrlh\n gvgiesshhhrgiisghothdrohhrghdpnhgspghrtghpthhtohepvddupdhmohguvgepshhm\n thhpohhuthdprhgtphhtthhopehjuhhlihgrnhhrsehlihhnuhigrdhisghmrdgtohhmpd\n hrtghpthhtohepshgthhhnvghllhgvsehlihhnuhigrdhisghmrdgtohhmpdhrtghpthht\n ohepfihinhhtvghrrgeslhhinhhugidrihgsmhdrtghomhdprhgtphhtthhopehtsheslh\n hinhhugidrihgsmhdrtghomhdprhgtphhtthhopehosggvrhhprghrsehlihhnuhigrdhi\n sghmrdgtohhmpdhrtghpthhtohepghgsrgihvghrsehlihhnuhigrdhisghmrdgtohhmpd\n hrtghpthhtohepjhhgghesiihivghpvgdrtggrpdhrtghpthhtohephihishhhrghihhes\n nhhvihguihgrrdgtohhmpdhrtghpthhtohepshhkohhlohhthhhumhhthhhosehnvhhiug\n hirgdrtghomh","X-ME-Proxy":"\n \n \n \n ","Feedback-ID":"i03f14258:Fastmail","Date":"Wed, 1 Apr 2026 16:04:41 -0600","From":"Alex Williamson ","To":"Julian Ruess ","Cc":"schnelle@linux.ibm.com, wintera@linux.ibm.com, ts@linux.ibm.com,\n oberpar@linux.ibm.com, gbayer@linux.ibm.com, Jason Gunthorpe\n , Yishai Hadas , Shameer Kolothum\n , Kevin Tian ,\n mjrosato@linux.ibm.com, alifm@linux.ibm.com, raspl@linux.ibm.com,\n hca@linux.ibm.com, agordeev@linux.ibm.com, gor@linux.ibm.com,\n kvm@vger.kernel.org, linux-kernel@vger.kernel.org,\n linux-s390@vger.kernel.org, linux-pci@vger.kernel.org, alex@shazbot.org","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","Message-ID":"<20260401160441.406fe25a@shazbot.org>","In-Reply-To":"<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n\t<20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>","X-Mailer":"Claws Mail 4.3.1 (GTK 3.24.51; x86_64-pc-linux-gnu)","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=US-ASCII","Content-Transfer-Encoding":"7bit"}},{"id":3672569,"web_url":"http://patchwork.ozlabs.org/comment/3672569/","msgid":"","list_archive_url":null,"date":"2026-04-02T09:06:28","subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","submitter":{"id":91782,"url":"http://patchwork.ozlabs.org/api/people/91782/","name":"Julian Ruess","email":"julianr@linux.ibm.com"},"content":"On Thu Apr 2, 2026 at 12:04 AM CEST, Alex Williamson wrote:\n> On Wed, 25 Mar 2026 14:31:24 +0100\n> Julian Ruess wrote:\n>> diff --git a/drivers/vfio/pci/ism/main.c b/drivers/vfio/pci/ism/main.c\n>> new file mode 100644\n>> index 0000000000000000000000000000000000000000..00bc81f7225f806eac1b99c4520ab5a68137885e\n>> --- /dev/null\n>> +++ b/drivers/vfio/pci/ism/main.c\n>> @@ -0,0 +1,408 @@\n>> +// SPDX-License-Identifier: GPL-2.0\n>> +/*\n>> + * vfio-ISM driver for s390\n>> + *\n>> + * Copyright IBM Corp.\n>> + */\n>> +\n>> +#include \"../vfio_pci_priv.h\"\n>> +#include \"linux/slab.h\"\n>\n> Convention says this should be:\n>\n> +#include \n> #include \"../vfio_pci_priv.h\"\n> -#include \"linux/slab.h\"\n> \n> Without objection, I'll make the change and push this to next tomorrow.\n> Thanks,\n>\n> Alex\n\nThank you very much!! \n\nJulian","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256\n header.s=pp1 header.b=CGpTdZoF;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=linux-pci+bounces-51709-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=\"CGpTdZoF\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=148.163.158.5","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=linux.ibm.com"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fmY301jz7z1yCs\n\tfor ; Thu, 02 Apr 2026 18:12:44 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id 8F6C9307784C\n\tfor ; Thu, 2 Apr 2026 07:07:19 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id E23CF388E55;\n\tThu, 2 Apr 2026 07:06:55 +0000 (UTC)","from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com\n [148.163.158.5])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 2470337F734;\n\tThu, 2 Apr 2026 07:06:52 +0000 (UTC)","from pps.filterd (m0353725.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id\n 6321QLLE108580;\n\tThu, 2 Apr 2026 07:06:47 GMT","from ppma23.wdc07v.mail.ibm.com\n (5d.69.3da9.ip4.static.sl-reverse.com [169.61.105.93])\n\tby mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4d65dcjuw4-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tThu, 02 Apr 2026 07:06:47 +0000 (GMT)","from pps.filterd (ppma23.wdc07v.mail.ibm.com [127.0.0.1])\n\tby ppma23.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id\n 63271VQD013897;\n\tThu, 2 Apr 2026 07:06:46 GMT","from smtprelay07.fra02v.mail.ibm.com ([9.218.2.229])\n\tby ppma23.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4d6ttkryfs-1\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT);\n\tThu, 02 Apr 2026 07:06:46 +0000","from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com\n [10.20.54.104])\n\tby smtprelay07.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id\n 63276g0246268730\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK);\n\tThu, 2 Apr 2026 07:06:42 GMT","from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 6BDEE20043;\n\tThu, 2 Apr 2026 07:06:42 +0000 (GMT)","from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 046462004D;\n\tThu, 2 Apr 2026 07:06:41 +0000 (GMT)","from localhost (unknown [9.111.23.196])\n\tby smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP;\n\tThu, 2 Apr 2026 07:06:40 +0000 (GMT)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1775113615; cv=none;\n b=Gt9idfSULal+2RVt25tOnurL6xfpOJEdBW5Y2Xlthd3DMSkfcjJKzKG936mIZt/byUKb59mqBUMpqbNKd7YRbeGy+kFd40bF/ZshxK5AXnMzOmqy5+Srp4267iE2p3VrhU+bj5q0o8RdDwhR7bLEWGl9EQvCD7ivxx/NaE2ueCY=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1775113615; c=relaxed/simple;\n\tbh=YOfWV0b+1yPsva8LgjO/aKzz5PWMLP1G/zmXa15zYV0=;\n\th=Mime-Version:Content-Type:Date:Message-Id:Cc:Subject:From:To:\n\t References:In-Reply-To;\n b=OsRQGH6IeBrsHZYaWcZ+JbiluBJ5S9J2uFTgSCTaCHKW1ovYUYZxFnP9iPMmIemF1UipyDC3qAbwAqbxtoWRBUCgbhvdPuG2jTXp+arFKUE8xSGzrTsI3jgNKJsmRt72sfETarBZUC4p/wrtHfW9v0fMlt12IFpod5vBCu3j7lw=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.ibm.com;\n spf=pass smtp.mailfrom=linux.ibm.com;\n dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com\n header.b=CGpTdZoF; arc=none smtp.client-ip=148.163.158.5","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc\n\t:content-transfer-encoding:content-type:date:from:in-reply-to\n\t:message-id:mime-version:references:subject:to; s=pp1; bh=KTjfrj\n\tTpSK0fVT+D/0wqDCWvFcR2XqlkR0GvUIEpVUw=; b=CGpTdZoFMBa/fEnF5reNfY\n\tdODnCk+uRojGVPZLfxBWWuz6PFqwL8pgdPTjIOnLMJ+7RPB9oRdo1VFHX6FXOS/r\n\tqkqdbTkIBQ+4+uG/izb9FRAmncrH09Jc3jRpTG9Ly10wb8d8QbsJNmq4DpcEVbtW\n\tmZbCGST+40gJqyu8BdKYNMRQXXBTNl4IVqreFuMjOestuFRgNfTyWamnhNzoqE5G\n\tfl6fmu1h5BPq4M3YfMKzOP6H04E2LnFJuMqxfBOMs/W3CzpXB6DzHm9595ZHhYxc\n\tFC1bonybXZ/8R7Sm7VFdlpPZww/gGQ4ERE7afZP5ts0gkmUGjISrd05KS2/JzBMw\n\t==","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","Mime-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","Content-Type":"text/plain; charset=UTF-8","Date":"Thu, 02 Apr 2026 11:06:28 +0200","Message-Id":"","Cc":", , ,\n , ,\n \"Jason Gunthorpe\"\n , \"Yishai Hadas\" ,\n \"Shameer Kolothum\"\n ,\n \"Kevin Tian\" , ,\n , , ,\n , , ,\n , ,\n ","Subject":"Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM\n devices","From":"\"Julian Ruess\" ","To":"\"Alex Williamson\" ,\n \"Julian Ruess\"\n ","X-Mailer":"aerc 0.21.0-0-g5549850facc2","References":"<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>\n <20260325-vfio_pci_ism-v8-2-ddc504cde914@linux.ibm.com>\n <20260401160441.406fe25a@shazbot.org>","In-Reply-To":"<20260401160441.406fe25a@shazbot.org>","X-TM-AS-GCONF":"00","X-Authority-Analysis":"v=2.4 cv=RsjI7SmK c=1 sm=1 tr=0 ts=69ce1587 cx=c_pps\n a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17\n a=IkcTkHD0fZMA:10 a=A5OVakUREuEA:10 a=VkNPw1HP01LnGYTKEx00:22\n a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=VnNF1IyMAAAA:8\n a=ZDiVSpLLCKoyWu1YpPgA:9 a=QEXdDO2ut3YA:10","X-Proofpoint-GUID":"EVxx1ZDovUSM0yfp_nhhPsUDtEZ_Wy6P","X-Proofpoint-Spam-Details-Enc":"AW1haW4tMjYwNDAyMDA1OSBTYWx0ZWRfX3ovWCpFFYroV\n 1u2j4sTkKDo8LEOTApw/T0oDUX5BdWaECIRsmc1xWCqEozVjpZc31HooRqiOe38iy52SB1oDLdV\n F7U2y5RRikbE3jfEkcAZqS1kZwS7KryD0Qt0v1WtlIUgam3OmlFcdjb+BCu64Z/TJvo+/8GkhXi\n /x6lXxblxnE9NCJ3NNeefU0Po74S2Y5KZ9OXQF9SG/BAjadxGLGjg93x5r7kTlsL0p+rSGO2svw\n CWM0h6xtpr2h3jbf7Mq+s8rrHktr91XtLderXamWboubb9j165q3IXNud6Q2gaIJZQ8VL9fbd9c\n k5Nk2ElAKHi0V1Sg5vgRmGYkIgdNv7kpWL6MjhYZtqLCTb5qyni8Ohx0p9GJUUyr9S4jKZR2WzS\n tIBFcuiLkqC0lDo1NX59grUX/USYn2Faj89d0SIK5Y8nYFY7PypUIEA0LPnnuwe907+6iYiA8rQ\n z+hM7aVPaJi8N/G5DIA==","X-Proofpoint-ORIG-GUID":"EVxx1ZDovUSM0yfp_nhhPsUDtEZ_Wy6P","X-Proofpoint-Virus-Version":"vendor=baseguard\n engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49\n definitions=2026-04-02_01,2026-04-01_02,2025-10-01_01","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n impostorscore=0 bulkscore=0 priorityscore=1501 lowpriorityscore=0\n suspectscore=0 malwarescore=0 spamscore=0 clxscore=1015 phishscore=0\n adultscore=0 classifier=typeunknown authscore=0 authtc= authcc=\n route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001\n definitions=main-2604020059"}}]