From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C0839C677C4 for ; Wed, 11 Jun 2025 15:07:40 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uPN2k-00053b-FJ; Wed, 11 Jun 2025 11:07:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uPN2i-0004sb-BC for qemu-devel@nongnu.org; Wed, 11 Jun 2025 11:07:08 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uPN2f-00078q-P3 for qemu-devel@nongnu.org; Wed, 11 Jun 2025 11:07:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749654425; 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=krTSwMcwgTojtoWqP6DWRFs5VyrJ3ZJrofXJEj1Rfkw=; b=bKrgKExbg0x/mp0TN5b5myPO4Ym9Kq/m6unl1+dUsY4xOQXJZaOl5AKraV7q9OuNCC1ctN RSCBWaexmplilt8qjvnOamwnz09frvvILuNcIr3HeFn9U+L8Xwq+oZ1oXbVSLjwrB4xupd pgGMefn+yhMIBEiTwtiXRyGCQZbKbms= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-152-vrMyL2tdPNWwOjrcqMsDCg-1; Wed, 11 Jun 2025 11:06:59 -0400 X-MC-Unique: vrMyL2tdPNWwOjrcqMsDCg-1 X-Mimecast-MFC-AGG-ID: vrMyL2tdPNWwOjrcqMsDCg_1749654418 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 39956195608B; Wed, 11 Jun 2025 15:06:58 +0000 (UTC) Received: from corto.redhat.com (unknown [10.45.225.191]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D228D180045C; Wed, 11 Jun 2025 15:06:55 +0000 (UTC) From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= To: qemu-devel@nongnu.org Cc: Alex Williamson , Steve Sistare , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , Zhenzhong Duan Subject: [PULL 13/27] vfio/container: preserve descriptors Date: Wed, 11 Jun 2025 17:06:05 +0200 Message-ID: <20250611150620.701903-14-clg@redhat.com> In-Reply-To: <20250611150620.701903-1-clg@redhat.com> References: <20250611150620.701903-1-clg@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=clg@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Steve Sistare At vfio creation time, save the value of vfio container, group, and device descriptors in CPR state. On qemu restart, vfio_realize() finds and uses the saved descriptors. During reuse, device and iommu state is already configured, so operations in vfio_realize that would modify the configuration, such as vfio ioctl's, are skipped. The result is that vfio_realize constructs qemu data structures that reflect the current state of the device. Signed-off-by: Steve Sistare Reviewed-by: Cédric Le Goater Reviewed-by: Zhenzhong Duan Link: https://lore.kernel.org/qemu-devel/1749569991-25171-5-git-send-email-steven.sistare@oracle.com Signed-off-by: Cédric Le Goater --- include/hw/vfio/vfio-cpr.h | 6 ++++ hw/vfio/container.c | 67 +++++++++++++++++++++++++++++--------- hw/vfio/cpr-legacy.c | 42 ++++++++++++++++++++++++ 3 files changed, 100 insertions(+), 15 deletions(-) diff --git a/include/hw/vfio/vfio-cpr.h b/include/hw/vfio/vfio-cpr.h index d4e0bd53c98f39a01f1d40fdc8bfe1690166e9c8..5a2e5f6b21e690cf91fd731ff9aa21a569f92f61 100644 --- a/include/hw/vfio/vfio-cpr.h +++ b/include/hw/vfio/vfio-cpr.h @@ -13,6 +13,7 @@ struct VFIOContainer; struct VFIOContainerBase; +struct VFIOGroup; typedef struct VFIOContainerCPR { Error *blocker; @@ -30,4 +31,9 @@ bool vfio_cpr_register_container(struct VFIOContainerBase *bcontainer, Error **errp); void vfio_cpr_unregister_container(struct VFIOContainerBase *bcontainer); +int vfio_cpr_group_get_device_fd(int d, const char *name); + +bool vfio_cpr_container_match(struct VFIOContainer *container, + struct VFIOGroup *group, int fd); + #endif /* HW_VFIO_VFIO_CPR_H */ diff --git a/hw/vfio/container.c b/hw/vfio/container.c index 93cdf80e13df8cc6f7a66a410b5273519af77280..5caae4ccae59bf114f37a49019c40bb125ed4ba1 100644 --- a/hw/vfio/container.c +++ b/hw/vfio/container.c @@ -31,6 +31,8 @@ #include "system/reset.h" #include "trace.h" #include "qapi/error.h" +#include "migration/cpr.h" +#include "migration/blocker.h" #include "pci.h" #include "hw/vfio/vfio-container.h" #include "vfio-helpers.h" @@ -425,7 +427,12 @@ static VFIOContainer *vfio_create_container(int fd, VFIOGroup *group, return NULL; } - if (!vfio_set_iommu(fd, group->fd, &iommu_type, errp)) { + /* + * During CPR, just set the container type and skip the ioctls, as the + * container and group are already configured in the kernel. + */ + if (!cpr_is_incoming() && + !vfio_set_iommu(fd, group->fd, &iommu_type, errp)) { return NULL; } @@ -592,6 +599,11 @@ static bool vfio_container_group_add(VFIOContainer *container, VFIOGroup *group, group->container = container; QLIST_INSERT_HEAD(&container->group_list, group, container_next); vfio_group_add_kvm_device(group); + /* + * Remember the container fd for each group, so we can attach to the same + * container after CPR. + */ + cpr_resave_fd("vfio_container_for_group", group->groupid, container->fd); return true; } @@ -601,6 +613,7 @@ static void vfio_container_group_del(VFIOContainer *container, VFIOGroup *group) group->container = NULL; vfio_group_del_kvm_device(group); vfio_ram_block_discard_disable(container, false); + cpr_delete_fd("vfio_container_for_group", group->groupid); } static bool vfio_container_connect(VFIOGroup *group, AddressSpace *as, @@ -615,17 +628,34 @@ static bool vfio_container_connect(VFIOGroup *group, AddressSpace *as, bool group_was_added = false; space = vfio_address_space_get(as); + fd = cpr_find_fd("vfio_container_for_group", group->groupid); - QLIST_FOREACH(bcontainer, &space->containers, next) { - container = container_of(bcontainer, VFIOContainer, bcontainer); - if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) { - return vfio_container_group_add(container, group, errp); + if (!cpr_is_incoming()) { + QLIST_FOREACH(bcontainer, &space->containers, next) { + container = container_of(bcontainer, VFIOContainer, bcontainer); + if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) { + return vfio_container_group_add(container, group, errp); + } } - } - fd = qemu_open("/dev/vfio/vfio", O_RDWR, errp); - if (fd < 0) { - goto fail; + fd = qemu_open("/dev/vfio/vfio", O_RDWR, errp); + if (fd < 0) { + goto fail; + } + } else { + /* + * For incoming CPR, the group is already attached in the kernel. + * If a container with matching fd is found, then update the + * userland group list and return. If not, then after the loop, + * create the container struct and group list. + */ + QLIST_FOREACH(bcontainer, &space->containers, next) { + container = container_of(bcontainer, VFIOContainer, bcontainer); + + if (vfio_cpr_container_match(container, group, fd)) { + return vfio_container_group_add(container, group, errp); + } + } } ret = ioctl(fd, VFIO_GET_API_VERSION); @@ -697,6 +727,7 @@ static void vfio_container_disconnect(VFIOGroup *group) QLIST_REMOVE(group, container_next); group->container = NULL; + cpr_delete_fd("vfio_container_for_group", group->groupid); /* * Explicitly release the listener first before unset container, @@ -750,7 +781,7 @@ static VFIOGroup *vfio_group_get(int groupid, AddressSpace *as, Error **errp) group = g_malloc0(sizeof(*group)); snprintf(path, sizeof(path), "/dev/vfio/%d", groupid); - group->fd = qemu_open(path, O_RDWR, errp); + group->fd = cpr_open_fd(path, O_RDWR, "vfio_group", groupid, errp); if (group->fd < 0) { goto free_group_exit; } @@ -782,6 +813,7 @@ static VFIOGroup *vfio_group_get(int groupid, AddressSpace *as, Error **errp) return group; close_fd_exit: + cpr_delete_fd("vfio_group", groupid); close(group->fd); free_group_exit: @@ -803,6 +835,7 @@ static void vfio_group_put(VFIOGroup *group) vfio_container_disconnect(group); QLIST_REMOVE(group, next); trace_vfio_group_put(group->fd); + cpr_delete_fd("vfio_group", group->groupid); close(group->fd); g_free(group); } @@ -813,7 +846,7 @@ static bool vfio_device_get(VFIOGroup *group, const char *name, g_autofree struct vfio_device_info *info = NULL; int fd; - fd = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name); + fd = vfio_cpr_group_get_device_fd(group->fd, name); if (fd < 0) { error_setg_errno(errp, errno, "error getting device from group %d", group->groupid); @@ -826,8 +859,7 @@ static bool vfio_device_get(VFIOGroup *group, const char *name, info = vfio_get_device_info(fd); if (!info) { error_setg_errno(errp, errno, "error getting device info"); - close(fd); - return false; + goto fail; } /* @@ -841,8 +873,7 @@ static bool vfio_device_get(VFIOGroup *group, const char *name, if (!QLIST_EMPTY(&group->device_list)) { error_setg(errp, "Inconsistent setting of support for discarding " "RAM (e.g., balloon) within group"); - close(fd); - return false; + goto fail; } if (!group->ram_block_discard_allowed) { @@ -860,6 +891,11 @@ static bool vfio_device_get(VFIOGroup *group, const char *name, trace_vfio_device_get(name, info->flags, info->num_regions, info->num_irqs); return true; + +fail: + close(fd); + cpr_delete_fd(name, 0); + return false; } static void vfio_device_put(VFIODevice *vbasedev) @@ -870,6 +906,7 @@ static void vfio_device_put(VFIODevice *vbasedev) QLIST_REMOVE(vbasedev, next); vbasedev->group = NULL; trace_vfio_device_put(vbasedev->fd); + cpr_delete_fd(vbasedev->name, 0); close(vbasedev->fd); } diff --git a/hw/vfio/cpr-legacy.c b/hw/vfio/cpr-legacy.c index dd7ac84074c6fb12fb26e236263bc1a0b865f06e..ac4a9ab315eab515607fb2405032ddc1ab980cf0 100644 --- a/hw/vfio/cpr-legacy.c +++ b/hw/vfio/cpr-legacy.c @@ -8,6 +8,7 @@ #include #include "qemu/osdep.h" #include "hw/vfio/vfio-container.h" +#include "hw/vfio/vfio-device.h" #include "migration/blocker.h" #include "migration/cpr.h" #include "migration/migration.h" @@ -66,3 +67,44 @@ void vfio_legacy_cpr_unregister_container(VFIOContainer *container) migrate_del_blocker(&container->cpr.blocker); vmstate_unregister(NULL, &vfio_container_vmstate, container); } + +int vfio_cpr_group_get_device_fd(int d, const char *name) +{ + const int id = 0; + int fd = cpr_find_fd(name, id); + + if (fd < 0) { + fd = ioctl(d, VFIO_GROUP_GET_DEVICE_FD, name); + if (fd >= 0) { + cpr_save_fd(name, id, fd); + } + } + return fd; +} + +static bool same_device(int fd1, int fd2) +{ + struct stat st1, st2; + + return !fstat(fd1, &st1) && !fstat(fd2, &st2) && st1.st_dev == st2.st_dev; +} + +bool vfio_cpr_container_match(VFIOContainer *container, VFIOGroup *group, + int fd) +{ + if (container->fd == fd) { + return true; + } + if (!same_device(container->fd, fd)) { + return false; + } + /* + * Same device, different fd. This occurs when the container fd is + * cpr_save'd multiple times, once for each groupid, so SCM_RIGHTS + * produces duplicates. De-dup it. + */ + cpr_delete_fd("vfio_container_for_group", group->groupid); + close(fd); + cpr_save_fd("vfio_container_for_group", group->groupid, container->fd); + return true; +} -- 2.49.0