kernel/linux.git/drivers/virtio, branch v6.1.168

mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize()

2026-01-11T14:19:21+00:00

[ Upstream commit 15504b1163007bbfbd9a63460d5c14737c16e96d ] Let's move the removal of the page from the balloon list into the single caller, to remove the dependency on the PG_isolated flag and clarify locking requirements. Note that for now, balloon_page_delete() was used on two paths: (1) Removing a page from the balloon for deflation through balloon_page_list_dequeue() (2) Removing an isolated page from the balloon for migration in the per-driver migration handlers. Isolated pages were already removed from the balloon list during isolation. So instead of relying on the flag, we can just distinguish both cases directly and handle it accordingly in the caller. We'll shuffle the operations a bit such that they logically make more sense (e.g., remove from the list before clearing flags). In balloon migration functions we can now move the balloon_page_finalize() out of the balloon lock and perform the finalization just before dropping the balloon reference. Document that the page lock is currently required when modifying the movability aspects of a page; hopefully we can soon decouple this from the page lock. Link: https://lkml.kernel.org/r/20250704102524.326966-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Brendan Jackman Cc: Byungchul Park Cc: Chengming Zhou Cc: Christian Brauner Cc: Christophe Leroy Cc: Eugenio Pé rez Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Wang Cc: Jerrin Shaji George Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Sergey Senozhatsky Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: xu xin Cc: Zi Yan Signed-off-by: Andrew Morton Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

virtio_vdpa: fix misleading return in void function

2026-01-11T14:18:31+00:00

[ Upstream commit e40b6abe0b1247d43bc61942aa7534fca7209e44 ] virtio_vdpa_set_status() is declared as returning void, but it used "return vdpa_set_status()" Since vdpa_set_status() also returns void, the return statement is unnecessary and misleading. Remove it. Fixes: c043b4a8cf3b ("virtio: introduce a vDPA based transport") Signed-off-by: Alok Tiwari Message-Id: <20251001191653.1713923-1-alok.a.tiwari@oracle.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin

virtio_ring: Fix data race by tagging event_triggered as racy for KCSAN

2025-06-04T12:40:01+00:00

[ Upstream commit 2e2f925fe737576df2373931c95e1a2b66efdfef ] syzbot reports a data-race when accessing the event_triggered, here is the simplified stack when the issue occurred: ================================================================== BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_enable_cb_delayed write to 0xffff8881025bc452 of 1 bytes by task 3288 on cpu 0: virtqueue_enable_cb_delayed+0x42/0x3c0 drivers/virtio/virtio_ring.c:2653 start_xmit+0x230/0x1310 drivers/net/virtio_net.c:3264 __netdev_start_xmit include/linux/netdevice.h:5151 [inline] netdev_start_xmit include/linux/netdevice.h:5160 [inline] xmit_one net/core/dev.c:3800 [inline] read to 0xffff8881025bc452 of 1 bytes by interrupt on cpu 1: virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:880 [inline] virtqueue_disable_cb+0x92/0x180 drivers/virtio/virtio_ring.c:2566 skb_xmit_done+0x5f/0x140 drivers/net/virtio_net.c:777 vring_interrupt+0x161/0x190 drivers/virtio/virtio_ring.c:2715 __handle_irq_event_percpu+0x95/0x490 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] value changed: 0x01 -> 0x00 ================================================================== When the data race occurs, the function virtqueue_enable_cb_delayed() sets event_triggered to false, and virtqueue_disable_cb_split/packed() reads it as false due to the race condition. Since event_triggered is an unreliable hint used for optimization, this should only cause the driver temporarily suggest that the device not send an interrupt notification when the event index is used. Fix this KCSAN reported data-race issue by explicitly tagging the access as data_racy. Reported-by: syzbot+efe683d57990864b8c8e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67c7761a.050a0220.15b4b9.0018.GAE@google.com/ Signed-off-by: Zhongqiu Han Message-Id: <20250312130412.3516307-1-quic_zhonhan@quicinc.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin

vdpa: Add eventfd for the vdpa callback

2024-10-17T13:21:12+00:00

[ Upstream commit 5e68470f4e80a4120e9ecec408f6ab4ad386bd4a ] Add eventfd for the vdpa callback so that user can signal it directly instead of triggering the callback. It will be used for vhost-vdpa case. Signed-off-by: Xie Yongji Message-Id: <20230323053043.35-9-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Stable-dep-of: 02e9e9366fef ("vhost_vdpa: assign irq bypass producer token correctly") Signed-off-by: Sasha Levin

virtio: delete vq in vp_find_vqs_msix() when request_irq() fails

2024-06-12T09:03:52+00:00

[ Upstream commit 89875151fccdd024d571aa884ea97a0128b968b6 ] When request_irq() fails, error path calls vp_del_vqs(). There, as vq is present in the list, free_irq() is called for the same vector. That causes following splat: [ 0.414355] Trying to free already-free IRQ 27 [ 0.414403] WARNING: CPU: 1 PID: 1 at kernel/irq/manage.c:1899 free_irq+0x1a1/0x2d0 [ 0.414510] Modules linked in: [ 0.414540] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc4+ #27 [ 0.414540] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014 [ 0.414540] RIP: 0010:free_irq+0x1a1/0x2d0 [ 0.414540] Code: 1e 00 48 83 c4 08 48 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 90 8b 74 24 04 48 c7 c7 98 80 6c b1 e8 00 c9 f7 ff 90 <0f> 0b 90 90 48 89 ee 4c 89 ef e8 e0 20 b8 00 49 8b 47 40 48 8b 40 [ 0.414540] RSP: 0000:ffffb71480013ae0 EFLAGS: 00010086 [ 0.414540] RAX: 0000000000000000 RBX: ffffa099c2722000 RCX: 0000000000000000 [ 0.414540] RDX: 0000000000000000 RSI: ffffb71480013998 RDI: 0000000000000001 [ 0.414540] RBP: 0000000000000246 R08: 00000000ffffdfff R09: 0000000000000001 [ 0.414540] R10: 00000000ffffdfff R11: ffffffffb18729c0 R12: ffffa099c1c91760 [ 0.414540] R13: ffffa099c1c916a4 R14: ffffa099c1d2f200 R15: ffffa099c1c91600 [ 0.414540] FS: 0000000000000000(0000) GS:ffffa099fec40000(0000) knlGS:0000000000000000 [ 0.414540] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.414540] CR2: 0000000000000000 CR3: 0000000008e3e001 CR4: 0000000000370ef0 [ 0.414540] Call Trace: [ 0.414540] [ 0.414540] ? __warn+0x80/0x120 [ 0.414540] ? free_irq+0x1a1/0x2d0 [ 0.414540] ? report_bug+0x164/0x190 [ 0.414540] ? handle_bug+0x3b/0x70 [ 0.414540] ? exc_invalid_op+0x17/0x70 [ 0.414540] ? asm_exc_invalid_op+0x1a/0x20 [ 0.414540] ? free_irq+0x1a1/0x2d0 [ 0.414540] vp_del_vqs+0xc1/0x220 [ 0.414540] vp_find_vqs_msix+0x305/0x470 [ 0.414540] vp_find_vqs+0x3e/0x1a0 [ 0.414540] vp_modern_find_vqs+0x1b/0x70 [ 0.414540] init_vqs+0x387/0x600 [ 0.414540] virtnet_probe+0x50a/0xc80 [ 0.414540] virtio_dev_probe+0x1e0/0x2b0 [ 0.414540] really_probe+0xc0/0x2c0 [ 0.414540] ? __pfx___driver_attach+0x10/0x10 [ 0.414540] __driver_probe_device+0x73/0x120 [ 0.414540] driver_probe_device+0x1f/0xe0 [ 0.414540] __driver_attach+0x88/0x180 [ 0.414540] bus_for_each_dev+0x85/0xd0 [ 0.414540] bus_add_driver+0xec/0x1f0 [ 0.414540] driver_register+0x59/0x100 [ 0.414540] ? __pfx_virtio_net_driver_init+0x10/0x10 [ 0.414540] virtio_net_driver_init+0x90/0xb0 [ 0.414540] do_one_initcall+0x58/0x230 [ 0.414540] kernel_init_freeable+0x1a3/0x2d0 [ 0.414540] ? __pfx_kernel_init+0x10/0x10 [ 0.414540] kernel_init+0x1a/0x1c0 [ 0.414540] ret_from_fork+0x31/0x50 [ 0.414540] ? __pfx_kernel_init+0x10/0x10 [ 0.414540] ret_from_fork_asm+0x1a/0x30 [ 0.414540] Fix this by calling deleting the current vq when request_irq() fails. Fixes: 0b0f9dc52ed0 ("Revert "virtio_pci: use shared interrupts for virtqueues"") Signed-off-by: Jiri Pirko Message-Id: <20240426150845.3999481-1-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio: reenable config if freezing device failed

2024-04-13T11:05:25+00:00

commit 310227f42882c52356b523e2f4e11690eebcd2ab upstream. Currently, we don't reenable the config if freezing the device failed. For example, virtio-mem currently doesn't support suspend+resume, and trying to freeze the device will always fail. Afterwards, the device will no longer respond to resize requests, because it won't get notified about config changes. Let's fix this by re-enabling the config if freezing fails. Fixes: 22b7050a024d ("virtio: defer config changed notifications") Cc: Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Xuan Zhuo Signed-off-by: David Hildenbrand Message-Id: <20240213135425.795001-1-david@redhat.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio_pci: fix the common cfg map size

2023-11-02T08:35:23+00:00

commit 061b39fdfe7fd98946e67637213bcbb10a318cca upstream. The function vp_modern_map_capability() takes the size parameter, which corresponds to the size of virtio_pci_common_cfg. As a result, this indicates the size of memory area to map. Now the size is the size of virtio_pci_common_cfg, but some feature(such as the _F_RING_RESET) needs the virtio_pci_modern_common_cfg, so this commit changes the size to the size of virtio_pci_modern_common_cfg. Cc: stable@vger.kernel.org Fixes: 0b50cece0b78 ("virtio_pci: introduce helper to get/set queue reset") Signed-off-by: Xuan Zhuo Message-Id: <20231010031120.81272-3-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Greg Kroah-Hartman

virtio-mmio: fix memory leak of vm_dev

2023-11-02T08:35:23+00:00

commit fab7f259227b8f70aa6d54e1de1a1f5f4729041c upstream. With the recent removal of vm_dev from devres its memory is only freed via the callback virtio_mmio_release_dev. However, this only takes effect after device_add is called by register_virtio_device. Until then it's an unmanaged resource and must be explicitly freed on error exit. This bug was discovered and resolved using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc. Cc: stable@vger.kernel.org Fixes: 55c91fedd03d ("virtio-mmio: don't break lifecycle of vm_dev") Signed-off-by: Maximilian Heyne Reviewed-by: Catalin Marinas Tested-by: Catalin Marinas Reviewed-by: Xuan Zhuo Signed-off-by: Greg Kroah-Hartman Message-Id: <20230911090328.40538-1-mheyne@amazon.de> Signed-off-by: Michael S. Tsirkin Reviewed-by: Wolfram Sang

virtio_balloon: Fix endless deflation and inflation on arm64

2023-11-02T08:35:23+00:00

commit 07622bd415639e9709579f400afd19e7e9866e5e upstream. The deflation request to the target, which isn't unaligned to the guest page size causes endless deflation and inflation actions. For example, we receive the flooding QMP events for the changes on memory balloon's size after a deflation request to the unaligned target is sent for the ARM64 guest, where we have 64KB base page size. /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \ -accel kvm -machine virt,gic-version=host -cpu host \ -smp maxcpus=8,cpus=8,sockets=2,clusters=2,cores=2,threads=1 \ -m 1024M,slots=16,maxmem=64G \ -object memory-backend-ram,id=mem0,size=512M \ -object memory-backend-ram,id=mem1,size=512M \ -numa node,nodeid=0,memdev=mem0,cpus=0-3 \ -numa node,nodeid=1,memdev=mem1,cpus=4-7 \ : \ -device virtio-balloon-pci,id=balloon0,bus=pcie.10 { "execute" : "balloon", "arguments": { "value" : 1073672192 } } {"return": {}} {"timestamp": {"seconds": 1693272173, "microseconds": 88667}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272174, "microseconds": 89704}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272175, "microseconds": 90819}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272176, "microseconds": 91961}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272177, "microseconds": 93040}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} {"timestamp": {"seconds": 1693272178, "microseconds": 94117}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} {"timestamp": {"seconds": 1693272179, "microseconds": 95337}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272180, "microseconds": 96615}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} {"timestamp": {"seconds": 1693272181, "microseconds": 97626}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272182, "microseconds": 98693}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} {"timestamp": {"seconds": 1693272183, "microseconds": 99698}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272184, "microseconds": 100727}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272185, "microseconds": 90430}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} {"timestamp": {"seconds": 1693272186, "microseconds": 102999}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073676288}} : Fix it by aligning the target up to the guest page size, 64KB in this specific case. With this applied, no flooding QMP events are observed and the memory balloon's size can be stablizied to 0x3ffe0000 soon after the deflation request is sent. { "execute" : "balloon", "arguments": { "value" : 1073672192 } } {"return": {}} {"timestamp": {"seconds": 1693273328, "microseconds": 793075}, \ "event": "BALLOON_CHANGE", "data": {"actual": 1073610752}} { "execute" : "query-balloon" } {"return": {"actual": 1073610752}} Cc: stable@vger.kernel.org Signed-off-by: Gavin Shan Tested-by: Zhenyu Zhang Message-Id: <20230831011007.1032822-1-gshan@redhat.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: David Hildenbrand Signed-off-by: Greg Kroah-Hartman

virtio_ring: fix avail_wrap_counter in virtqueue_add_packed

2023-09-13T07:42:59+00:00

[ Upstream commit 1acfe2c1225899eab5ab724c91b7e1eb2881b9ab ] In current packed virtqueue implementation, the avail_wrap_counter won't flip, in the case when the driver supplies a descriptor chain with a length equals to the queue size; total_sg == vq->packed.vring.num. Let’s assume the following situation: vq->packed.vring.num=4 vq->packed.next_avail_idx: 1 vq->packed.avail_wrap_counter: 0 Then the driver adds a descriptor chain containing 4 descriptors. We expect the following result with avail_wrap_counter flipped: vq->packed.next_avail_idx: 1 vq->packed.avail_wrap_counter: 1 But, the current implementation gives the following result: vq->packed.next_avail_idx: 1 vq->packed.avail_wrap_counter: 0 To reproduce the bug, you can set a packed queue size as small as possible, so that the driver is more likely to provide a descriptor chain with a length equal to the packed queue size. For example, in qemu run following commands: sudo qemu-system-x86_64 \ -enable-kvm \ -nographic \ -kernel "path/to/kernel_image" \ -m 1G \ -drive file="path/to/rootfs",if=none,id=disk \ -device virtio-blk,drive=disk \ -drive file="path/to/disk_image",if=none,id=rwdisk \ -device virtio-blk,drive=rwdisk,packed=on,queue-size=4,\ indirect_desc=off \ -append "console=ttyS0 root=/dev/vda rw init=/bin/bash" Inside the VM, create a directory and mount the rwdisk device on it. The rwdisk will hang and mount operation will not complete. This commit fixes the wrap counter error by flipping the packed.avail_wrap_counter, when start of descriptor chain equals to the end of descriptor chain (head == i). Fixes: 1ce9e6055fa0 ("virtio_ring: introduce packed ring support") Signed-off-by: Yuan Yao Message-Id: <20230808051110.3492693-1-yuanyaogoog@chromium.org> Acked-by: Jason Wang Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin