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{ "id": 2215871, "url": "http://patchwork.ozlabs.org/api/covers/2215871/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-pci/cover/20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com/", "project": { "id": 28, "url": "http://patchwork.ozlabs.org/api/projects/28/?format=api", "name": "Linux PCI development", "link_name": "linux-pci", "list_id": "linux-pci.vger.kernel.org", "list_email": "linux-pci@vger.kernel.org", "web_url": null, "scm_url": null, "webscm_url": null, "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>", "list_archive_url": null, "date": "2026-03-25T13:31:22", "name": "[v8,0/3] vfio/pci: Introduce vfio_pci driver for ISM devices", "submitter": { "id": 91782, "url": "http://patchwork.ozlabs.org/api/people/91782/?format=api", "name": "Julian Ruess", "email": "julianr@linux.ibm.com" }, "mbox": "http://patchwork.ozlabs.org/project/linux-pci/cover/20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com/mbox/", "series": [ { "id": 497446, "url": "http://patchwork.ozlabs.org/api/series/497446/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-pci/list/?series=497446", "date": "2026-03-25T13:31:25", "name": "vfio/pci: Introduce vfio_pci driver for ISM devices", "version": 8, "mbox": "http://patchwork.ozlabs.org/series/497446/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2215871/comments/", "headers": { "Return-Path": "\n <linux-pci+bounces-51068-incoming=patchwork.ozlabs.org@vger.kernel.org>", "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=FDOa9F7b;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.234.253.10; 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d=ibm.com; h=cc\n\t:content-transfer-encoding:content-type:date:from:message-id\n\t:mime-version:subject:to; s=pp1; bh=AX4NGUAiA6LuFkInZ2FGwECGSS3f\n\tmHNNp2JM0udvmYU=; b=FDOa9F7bRiSgDo5aXpZ0l4Yk9kiqGRxTlHH8KUvFcfxC\n\tFqjioQ7iffAYnMY1mePmTx8dFh4Pt7eNfqV/K5J+PFjWiG1QX0RONhdaqFnDSezL\n\tQAAq8Ug8J7240GDUYguZo/22rqY62+ykOnFxEN+xF7SFvfpyD6FNOrwthSv/00+y\n\t0NjzSfi5d9K/c08HtuY6NgGof2f3PmR+l+fbsmyyP1K6dOhCYAnXCTGrZsuvql25\n\t0d0mH0Ox7eeyXKtGWPxIot6JUK5uwaaXPhPLRuta91xQmKIheEV8rZXuswHt4yhU\n\tBZBP+4iKD8q/oEqaZ/Yo+ITnf/cG7t6WYJ/ZHWu1BQ==", "From": "Julian Ruess <julianr@linux.ibm.com>", "Subject": "[PATCH v8 0/3] vfio/pci: Introduce vfio_pci driver for ISM devices", "Date": "Wed, 25 Mar 2026 14:31:22 +0100", "Message-Id": "<20260325-vfio_pci_ism-v8-0-ddc504cde914@linux.ibm.com>", "Precedence": "bulk", "X-Mailing-List": "linux-pci@vger.kernel.org", "List-Id": "<linux-pci.vger.kernel.org>", "List-Subscribe": "<mailto:linux-pci+subscribe@vger.kernel.org>", "List-Unsubscribe": "<mailto:linux-pci+unsubscribe@vger.kernel.org>", "MIME-Version": "1.0", "Content-Type": "text/plain; charset=\"utf-8\"", "Content-Transfer-Encoding": "8bit", "X-B4-Tracking": "v=1; b=H4sIAKrjw2kC/32Sy27bMBAAfyXQuQp2l+QumVP+owgMPhMCtR1Yj\n ZDC8L+X8qWqQuW4AmaGFPc6TPlS8zQ8PVyHS57rVM+nNtgfD0N886fXPNbU5oGADBDJOJd6Prz\n HeqjTcYQYI2UtRFqGhrxfcqmfd93Plza/1en3+fLnbp9p+bqIGBDN/6KZRhgje1XYsEmonn/V0\n 8fnYw3Hx3g+Lu472EIdsACC00aJKn4DLqeY1brsNgLVBBgTYvIZBNJOWYHpgYQCwtFicr2yXpV\n JbQR6uXOwRYknR8HulbEHamHTDmy4CPbKZl3e3tk0gRR24pUO2uNuWTpgEEXaBp2NcK/M/8oEv\n BFwE6TkRGlwnMXtll0HjBx8YDEhQved5buyLD+Ng9WpeHaY98pfnmkBfShtvdCABtsr21UZcSO\n wTWCMBh9dIPtlw+4CXAtoI8AmUEoRk09tR/VWcLvd/gJ/V0IUyQMAAA==", "X-Change-ID": "20250227-vfio_pci_ism-0ccc2e472247", "To": "schnelle@linux.ibm.com, wintera@linux.ibm.com, ts@linux.ibm.com,\n oberpar@linux.ibm.com, gbayer@linux.ibm.com,\n Alex Williamson <alex@shazbot.org>, Jason Gunthorpe <jgg@ziepe.ca>,\n Yishai Hadas <yishaih@nvidia.com>,\n Shameer Kolothum <skolothumtho@nvidia.com>,\n Kevin Tian <kevin.tian@intel.com>", "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 julianr@linux.ibm.com, kvm@vger.kernel.org,\n linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,\n linux-pci@vger.kernel.org", "X-Mailer": "b4 0.14.2", "X-TM-AS-GCONF": "00", "X-Proofpoint-ORIG-GUID": "5myxCgrO0ytfx_W2wgjp7fWPh22yLOni", "X-Proofpoint-Spam-Details-Enc": "AW1haW4tMjYwMzI1MDA5NSBTYWx0ZWRfXxvf05h+A/+Z2\n CpviZTRVOHSn4JTLqAekHOjQYNKuhhntwLE4w/f0FLu55KGuCPwDtRoo+Jyje7zEbBeeI4nGuQI\n LBgqSl7dLHf9jrrvqLQt2n9qIWKSbzBRkMK2I+MmW9V2gkcELeQ2gs+JDy8bCxtEm4XGQbz9VcO\n 7WzShwVsF0cwIyZO7q5QU1bi8WfebPOJVpIqNmrn2QtDAVGBLtYmXP1quy2cTwVoVIEaBe6U2+J\n 4l9HFiHHXlCWWp67OFuMPpx4Z1i98DArXhD+CCrtbIGyvq49GwmDmJ8Sv6vyjznw9QQz8qJjdQN\n vinhVW6c6MhbcJKJvf9GVA/gz7Odin5jvcnIt7IqTYrE2TuEj0Rl/jb8xv+blYQgg54ypRYiar2\n MEXj2eePNsF4mrGw3pqYcEBTr5R5JdY+DzWkQBN99ThT8FkA/zKnlYymIQ+crH6CTXI358WEtF7\n Cn1R5kj6i1ZU8b2EO1g==", "X-Authority-Analysis": "v=2.4 cv=bLEb4f+Z c=1 sm=1 tr=0 ts=69c3e3c2 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=iQ6ETzBq9ecOQQE5vZCe:22 a=VwQbUJbxAAAA:8\n a=VnNF1IyMAAAA:8 a=3XGxXiOqMMHeIvAuhUYA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10", "X-Proofpoint-GUID": "5myxCgrO0ytfx_W2wgjp7fWPh22yLOni", "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=2026-03-25_04,2026-03-24_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-2603250095" }, "content": "Hi all,\n\nThis series adds a vfio_pci variant driver for the s390-specific\nInternal Shared Memory (ISM) devices used for inter-VM communication\nincluding SMC-D.\n\nThis is a prerequisite for an in-development open-source user space\ndriver stack that will allow to use ISM devices to provide remote\nconsole and block device functionality. This stack will be part of\ns390-tools.\n\nThis driver would also allow QEMU to mediate access to an ISM device,\nenabling a form of PCI pass-through even for guests whose hardware\ncannot directly execute PCI accesses, such as nested guests.\n\nOn s390, kernel primitives such as ioread() and iowrite() are switched\nover from function-handle-based PCI load/stores instructions to PCI\nmemory-I/O (MIO) loads/stores when these are available and not\nexplicitly disabled. Since these instructions cannot be used with ISM\ndevices, ensure that classic function-handle-based PCI instructions are\nused instead.\n\nThe driver is still required even when MIO instructions are disabled, as\nthe ISM device relies on the PCI store‑block (PCISTB) instruction to\nperform write operations.\n\nThank you,\nJulian\n\nSigned-off-by: Julian Ruess <julianr@linux.ibm.com>\n---\nChanges in v8:\n- Format vfio_pci_config_rw_single().\n- Add () around the off macro argument in ISM_VFIO_PCI_OFFSET_TO_INDEX.\n- Use function-handle-based wording consistently.\n- Return -EINVAL in default case in ism_vfio_pci_ioctl_get_region_info().\n- Change ssize_t to size_t in ISM_READ macro.\n- Use kmem_cache_args with with kmem_cache_create() to prevent kernel\n panic when using HARDENED_USERCOPY.\n- Link to v7: https://lore.kernel.org/r/20260323-vfio_pci_ism-v7-0-abf537150408@linux.ibm.com\n\nChanges in v7:\n- Add 4k alignment and to kmem_cache_create() to do not cross the integral\n boundary.\n- Add SLAB_RECLAIM_ACCOUNT ans SLAB_ACCOUNT to kmem_cache_create() for memcg accounting.\n- Link to v6: https://lore.kernel.org/r/20260319-vfio_pci_ism-v6-0-c6bab675bc0a@linux.ibm.com\n\nChanges in v6:\n- Introduce ism_vfio_pci_init_dev() and ism_vfio_pci_release_dev().\n- Add early return for __zpci_load().\n- Use kmem_cache_alloc() instead of kmem_cache_zalloc().\n- Rename ivdev to ivpcd for consistency.\n- Rename ism_pci_open_device() to ism_vfio_pci_open_device().\n- Link to v5: https://lore.kernel.org/r/20260317-vfio_pci_ism-v5-0-b73248b4e576@linux.ibm.com\n\nChanges in v5:\n- Support reads < 8 bytes.\n- Link to v4: https://lore.kernel.org/r/20260313-vfio_pci_ism-v4-0-4765ae056f71@linux.ibm.com\n\nChanges in v4:\n- Fix bug with < 8 byte reads. For code simplicity, only support 8 byte reads.\n- Fix leak of ivpcd.\n- Fix cache replacement by implementing a per-device kmem_cache.\n- Link to v3: https://lore.kernel.org/r/20260305-vfio_pci_ism-v3-0-1217076c81d9@linux.ibm.com\n\nChanges in v3:\n- Add comments to ism_vfio_pci_do_io_r() and ism_vfio_pci_do_io_w().\n- Format Kconfig.\n- Add 4k boundary check to ism_vfio_pci_do_io_w().\n- Use kmem_cache instead of kzalloc in ism_vfio_pci_do_io_w().\n- Add error handler to struct ism_vfio_pci_driver.\n- Link to v2: https://lore.kernel.org/r/20260224-vfio_pci_ism-v2-0-f010945373fa@linux.ibm.com\n\nChanges in v2:\n- Remove common code patch that sets VFIO_PCI_OFFSET_SHIFT to 48.\n- Implement ism_vfio_pci_ioctl_get_region_info() to have own region\n offsets.\n- For config space accesses, rename vfio_config_do_rw() to\n vfio_pci_config_rw_single() and export it.\n- Use zdev->maxstbl instead of ZPCI_BOUNDARY_SIZE.\n- Add comment that zPCI must not use MIO instructions for config space\n access.\n- Rework patch descriptions.\n- Update license info.\n- Link to v1: https://lore.kernel.org/r/20260212-vfio_pci_ism-v1-0-333262ade074@linux.ibm.com\n\n---\nJulian Ruess (3):\n vfio/pci: Rename vfio_config_do_rw() to vfio_pci_config_rw_single() and export it\n vfio/ism: Implement vfio_pci driver for ISM devices\n MAINTAINERS: add VFIO ISM PCI DRIVER section\n\n MAINTAINERS | 6 +\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 drivers/vfio/pci/vfio_pci_config.c | 8 +-\n drivers/vfio/pci/vfio_pci_priv.h | 4 +\n 8 files changed, 440 insertions(+), 3 deletions(-)\n---\nbase-commit: c369299895a591d96745d6492d4888259b004a9e\nchange-id: 20250227-vfio_pci_ism-0ccc2e472247\n\nBest regards," }