From patchwork Thu Jan 21 11:05:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 1429742 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=VSxfopTK; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4DM09M13Psz9sTD for ; Thu, 21 Jan 2021 22:12:39 +1100 (AEDT) Received: from localhost ([::1]:46660 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l2XtE-00054h-Ty for incoming@patchwork.ozlabs.org; Thu, 21 Jan 2021 06:12:36 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47690) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l2Xov-0008Da-Nd for qemu-devel@nongnu.org; Thu, 21 Jan 2021 06:08:09 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:59389) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l2Xot-0007Gz-2m for qemu-devel@nongnu.org; Thu, 21 Jan 2021 06:08:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611227286; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=orjsB6TcWdqyjGGjz0hvUzG8Dx0x8loB58RR7CA2C0M=; b=VSxfopTK4FHJcmuFd1WsoJU5Ip/ifb6iRwPwdA0FvA9vpqEn4hkENpIGDMA7g1IRZZCwS3 3B4rfnFkWE0fqGBVbSgKE9eHlxQIvV/QQODcT7c+2+NWsXMGcB2RhGtC9iwIlxHVNhZUnb RzwJCJk2t5SKzlgGxgm5CVl3LV6uj0o= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-404-TAkuVSFIOJOcHxuzJ3jxzQ-1; Thu, 21 Jan 2021 06:08:04 -0500 X-MC-Unique: TAkuVSFIOJOcHxuzJ3jxzQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CCDFF800D55; Thu, 21 Jan 2021 11:08:02 +0000 (UTC) Received: from t480s.redhat.com (ovpn-115-70.ams2.redhat.com [10.36.115.70]) by smtp.corp.redhat.com (Postfix) with ESMTP id 79AA110013BD; Thu, 21 Jan 2021 11:07:54 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v5 11/11] vfio: Disable only uncoordinated discards for VFIO_TYPE1 iommus Date: Thu, 21 Jan 2021 12:05:40 +0100 Message-Id: <20210121110540.33704-12-david@redhat.com> In-Reply-To: <20210121110540.33704-1-david@redhat.com> References: <20210121110540.33704-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=63.128.21.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.167, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pankaj Gupta , Wei Yang , David Hildenbrand , "Michael S. Tsirkin" , "Dr . David Alan Gilbert" , Peter Xu , Marek Kedzierski , Auger Eric , Alex Williamson , teawater , Jonathan Cameron , Paolo Bonzini , Igor Mammedov Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" We support coordinated discarding of RAM using the RamDiscardMgr for the VFIO_TYPE1 iommus. Let's unlock support for coordinated discards, keeping uncoordinated discards (e.g., via virtio-balloon) disabled if possible. This unlocks virtio-mem + vfio on x86-64. Note that vfio used via "nvme://" by the block layer has to be implemented/unlocked separately. For now, virtio-mem only supports x86-64; we don't restrict RamDiscardMgr to x86-64, though: arm64 and s390x are supposed to work as well, and we'll test once unlocking virtio-mem support. The spapr IOMMUs will need special care, to be tackled later, e.g.., once supporting virtio-mem. Note: The block size of a virtio-mem device has to be set to sane sizes, depending on the maximum hotplug size - to not run out of vfio mappings. The default virtio-mem block size is usually in the range of a couple of MBs. The maximum number of mapping is 64k, shared with other users. Assume you want to hotplug 256GB using virtio-mem - the block size would have to be set to at least 8 MiB (resulting in 32768 separate mappings). Cc: Paolo Bonzini Cc: "Michael S. Tsirkin" Cc: Alex Williamson Cc: Dr. David Alan Gilbert Cc: Igor Mammedov Cc: Pankaj Gupta Cc: Peter Xu Cc: Auger Eric Cc: Wei Yang Cc: teawater Cc: Marek Kedzierski Signed-off-by: David Hildenbrand Acked-by: Alex Williamson Reviewed-by: Alex Williamson --- hw/vfio/common.c | 63 +++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 51 insertions(+), 12 deletions(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 15ecd05a4b..d879b8ab92 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -135,6 +135,27 @@ static const char *index_to_str(VFIODevice *vbasedev, int index) } } +static int vfio_ram_block_discard_disable(VFIOContainer *container, bool state) +{ + switch (container->iommu_type) { + case VFIO_TYPE1v2_IOMMU: + case VFIO_TYPE1_IOMMU: + /* We support coordinated discarding of RAM via the RamDiscardMgr. */ + return ram_block_uncoordinated_discard_disable(state); + default: + /* + * VFIO_SPAPR_TCE_IOMMU most probably works just fine with + * RamDiscardMgr, however, it is completely untested. + * + * VFIO_SPAPR_TCE_v2_IOMMU with "DMA memory preregistering" does + * completely the opposite of managing mapping/pinning dynamically as + * required by RamDiscardMgr. We would have to special-case sections + * with a RamDiscardMgr. + */ + return ram_block_discard_disable(state); + } +} + int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex, int action, int fd, Error **errp) { @@ -1979,15 +2000,25 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, * new memory, it will not yet set ram_block_discard_set_required() and * therefore, neither stops us here or deals with the sudden memory * consumption of inflated memory. + * + * We do support discarding of memory coordinated via the RamDiscardMgr + * with some IOMMU types. vfio_ram_block_discard_disable() handles the + * details once we know which type of IOMMU we are using. */ - ret = ram_block_discard_disable(true); - if (ret) { - error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken"); - return ret; - } QLIST_FOREACH(container, &space->containers, next) { if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) { + ret = vfio_ram_block_discard_disable(container, true); + if (ret) { + error_setg_errno(errp, -ret, + "Cannot set discarding of RAM broken"); + if (ioctl(group->fd, VFIO_GROUP_UNSET_CONTAINER, + &container->fd)) { + error_report("vfio: error disconnecting group %d from" + " container", group->groupid); + } + return ret; + } group->container = container; QLIST_INSERT_HEAD(&container->group_list, group, container_next); vfio_kvm_device_add_group(group); @@ -2025,6 +2056,12 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, goto free_container_exit; } + ret = vfio_ram_block_discard_disable(container, true); + if (ret) { + error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken"); + goto free_container_exit; + } + switch (container->iommu_type) { case VFIO_TYPE1v2_IOMMU: case VFIO_TYPE1_IOMMU: @@ -2072,7 +2109,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, if (ret) { error_setg_errno(errp, errno, "failed to enable container"); ret = -errno; - goto free_container_exit; + goto enable_discards_exit; } } else { container->prereg_listener = vfio_prereg_listener; @@ -2084,7 +2121,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, ret = -1; error_propagate_prepend(errp, container->error, "RAM memory listener initialization failed: "); - goto free_container_exit; + goto enable_discards_exit; } } @@ -2097,7 +2134,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, if (v2) { memory_listener_unregister(&container->prereg_listener); } - goto free_container_exit; + goto enable_discards_exit; } if (v2) { @@ -2112,7 +2149,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, if (ret) { error_setg_errno(errp, -ret, "failed to remove existing window"); - goto free_container_exit; + goto enable_discards_exit; } } else { /* The default table uses 4K pages */ @@ -2153,6 +2190,9 @@ listener_release_exit: vfio_kvm_device_del_group(group); vfio_listener_release(container); +enable_discards_exit: + vfio_ram_block_discard_disable(container, false); + free_container_exit: g_free(container); @@ -2160,7 +2200,6 @@ close_fd_exit: close(fd); put_space_exit: - ram_block_discard_disable(false); vfio_put_address_space(space); return ret; @@ -2282,7 +2321,7 @@ void vfio_put_group(VFIOGroup *group) } if (!group->ram_block_discard_allowed) { - ram_block_discard_disable(false); + vfio_ram_block_discard_disable(group->container, false); } vfio_kvm_device_del_group(group); vfio_disconnect_container(group); @@ -2336,7 +2375,7 @@ int vfio_get_device(VFIOGroup *group, const char *name, if (!group->ram_block_discard_allowed) { group->ram_block_discard_allowed = true; - ram_block_discard_disable(false); + vfio_ram_block_discard_disable(group->container, false); } }