linux-stable.git/drivers/virtio, branch v7.2.6 Linux kernel stable tree virtio: rtc: time out alarm requests 2026-09-14T11:40:58+00:00 GuoHan Zhao zhaoguohan@kylinos.cn 2026-07-14T02:43:52+00:00 afbf69d1d691c06d093d7c3f17168ecb608c4977 [ Upstream commit 68e00d9212929805b40dcb9166755610f4f4acee ] RTC class operations run with rtc_device.ops_lock held. The virtio RTC alarm requests currently wait without a timeout for the device to return their requestq buffers. On surprise removal, virtio-pci marks the virtqueues broken before unregistering the virtio device. If an alarm request is waiting when the device stops responding, viortc_remove() blocks in viortc_class_stop() while trying to acquire ops_lock. The request cannot complete and device removal hangs until the waiting task is signalled. Use the same 60-second timeout as clock read requests for alarm reads, alarm programming, and alarm interrupt enable requests. The existing message reference counting keeps a timed-out request alive until a late response or device teardown. Fixes: 9d4f22fd563e ("virtio_rtc: Add RTC class driver") Assisted-by: Codex:gpt-5.6-sol Signed-off-by: GuoHan Zhao <zhaoguohan@kylinos.cn> Reviewed-by: Peter Hilber <peter.hilber@oss.qualcomm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260714024352.71307-1-zhaoguohan@kylinos.cn> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 68e00d9212929805b40dcb9166755610f4f4acee ]

RTC class operations run with rtc_device.ops_lock held. The virtio RTC
alarm requests currently wait without a timeout for the device to return
their requestq buffers.

On surprise removal, virtio-pci marks the virtqueues broken before
unregistering the virtio device. If an alarm request is waiting when the
device stops responding, viortc_remove() blocks in viortc_class_stop()
while trying to acquire ops_lock. The request cannot complete and device
removal hangs until the waiting task is signalled.

Use the same 60-second timeout as clock read requests for alarm reads,
alarm programming, and alarm interrupt enable requests. The existing
message reference counting keeps a timed-out request alive until a late
response or device teardown.

Fixes: 9d4f22fd563e ("virtio_rtc: Add RTC class driver")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: GuoHan Zhao <zhaoguohan@kylinos.cn>
Reviewed-by: Peter Hilber <peter.hilber@oss.qualcomm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260714024352.71307-1-zhaoguohan@kylinos.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_pci: fix wrong queue index for admin vq in intx path 2026-09-14T11:40:58+00:00 Li RongQing lirongqing@baidu.com 2026-06-29T03:35:38+00:00 89b4d033a4b531d8aff55283e26d4ec3e4d945b2 [ Upstream commit dc3f1eef9ab678c396baf5df12aba61db061aa8c ] In vp_find_vqs_intx(), the admin vq was set up using the local queue_idx counter instead of avq->vq_index (the actual queue index obtained from the device). This differs from vp_find_vqs_msix() which correctly uses avq->vq_index. Using the wrong index causes the admin virtqueue to be mapped to an incorrect hardware queue. Fix it by using avq->vq_index consistent with the msix path. Fixes: af22bbe1f4a5 ("virtio: create admin queues alongside other virtqueues") Signed-off-by: Li RongQing <lirongqing@baidu.com> Message-ID: <20260629033538.2476-1-lirongqing@baidu.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit dc3f1eef9ab678c396baf5df12aba61db061aa8c ]

In vp_find_vqs_intx(), the admin vq was set up using the local
queue_idx counter instead of avq->vq_index (the actual queue index
obtained from the device). This differs from vp_find_vqs_msix() which
correctly uses avq->vq_index. Using the wrong index causes the admin
virtqueue to be mapped to an incorrect hardware queue.

Fix it by using avq->vq_index consistent with the msix path.

Fixes: af22bbe1f4a5 ("virtio: create admin queues alongside other virtqueues")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Message-ID: <20260629033538.2476-1-lirongqing@baidu.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_balloon: quiesce balloon work before device shutdown 2026-09-14T11:40:57+00:00 Denis V. Lunev den@openvz.org 2026-06-24T14:08:45+00:00 bdef50a8226fc04899ef6815dd08a002247d47d5 [ Upstream commit 7e17eef04600c399c7e0f5ce765da5cf9d40d8e1 ] Commit 8bd2fa086a04 ("virtio: break and reset virtio devices on device_shutdown()") added a generic virtio bus .shutdown handler that breaks and resets every virtio device during device_shutdown(), i.e. on reboot and kexec. virtio_balloon provides no .shutdown of its own, so that generic path runs while the balloon's asynchronous work is still armed. Once the device has been broken, virtqueue_add_inbuf() in virtballoon_free_page_report() returns -EIO and trips its WARN_ON_ONCE(). On a kernel booted with panic_on_warn that turns an ordinary reboot, for example a kexec based upgrade, into a fatal panic in the middle of device_shutdown(), so the machine never reaches the new kernel. Relaxing that single WARN_ON_ONCE() would only hide the symptom: the inflate/deflate and OOM paths do not warn, they call wait_event(vb->acked, ...) and would instead block forever on a broken queue that can no longer complete. The device has to be quiesced, not just kept quiet. Add a .shutdown handler that quiesces the balloon via the shared virtballoon_quiesce() helper while the device is still alive, and only then breaks and resets it via virtio_device_shutdown(). Unlike virtballoon_remove() the balloon workqueue is not destroyed, as shutdown does not free the device and cancel_work_sync() together with stop_update already prevent any further work from being queued. Fixes: 8bd2fa086a04 ("virtio: break and reset virtio devices on device_shutdown()") Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260624140846.2616797-4-den@openvz.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7e17eef04600c399c7e0f5ce765da5cf9d40d8e1 ]

Commit 8bd2fa086a04 ("virtio: break and reset virtio devices on
device_shutdown()") added a generic virtio bus .shutdown handler that
breaks and resets every virtio device during device_shutdown(), i.e. on
reboot and kexec.

virtio_balloon provides no .shutdown of its own, so that generic path
runs while the balloon's asynchronous work is still armed. Once the
device has been broken, virtqueue_add_inbuf() in
virtballoon_free_page_report() returns -EIO and trips its
WARN_ON_ONCE(). On a kernel booted with panic_on_warn that turns an
ordinary reboot, for example a kexec based upgrade, into a fatal panic
in the middle of device_shutdown(), so the machine never reaches the
new kernel.

Relaxing that single WARN_ON_ONCE() would only hide the symptom: the
inflate/deflate and OOM paths do not warn, they call
wait_event(vb->acked, ...) and would instead block forever on a broken
queue that can no longer complete. The device has to be quiesced, not
just kept quiet.

Add a .shutdown handler that quiesces the balloon via the shared
virtballoon_quiesce() helper while the device is still alive, and only
then breaks and resets it via virtio_device_shutdown(). Unlike
virtballoon_remove() the balloon workqueue is not destroyed, as shutdown
does not free the device and cancel_work_sync() together with stop_update
already prevent any further work from being queued.

Fixes: 8bd2fa086a04 ("virtio: break and reset virtio devices on device_shutdown()")
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260624140846.2616797-4-den@openvz.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_balloon: factor out virtballoon_quiesce() 2026-09-14T11:40:57+00:00 Denis V. Lunev den@openvz.org 2026-06-24T14:08:44+00:00 1ac4c32198b83f93ee72ad793f6353f8e8c90ea5 [ Upstream commit 29536a923a9412812eb3e378258019b54538a220 ] virtballoon_remove() stops all of the balloon's asynchronous work (the free page reporting worker, the inflate/deflate and stats workers, the OOM notifier and the free page shrinker) before tearing the device down. A following change needs the same teardown from a .shutdown handler, so move it into a virtballoon_quiesce() helper. No functional change. Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260624140846.2616797-3-den@openvz.org> Stable-dep-of: 7e17eef04600 ("virtio_balloon: quiesce balloon work before device shutdown") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 29536a923a9412812eb3e378258019b54538a220 ]

virtballoon_remove() stops all of the balloon's asynchronous work (the
free page reporting worker, the inflate/deflate and stats workers, the
OOM notifier and the free page shrinker) before tearing the device
down. A following change needs the same teardown from a .shutdown
handler, so move it into a virtballoon_quiesce() helper.

No functional change.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260624140846.2616797-3-den@openvz.org>
Stable-dep-of: 7e17eef04600 ("virtio_balloon: quiesce balloon work before device shutdown")
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio: add virtio_device_shutdown() helper 2026-09-14T11:40:57+00:00 Denis V. Lunev den@openvz.org 2026-06-24T14:08:43+00:00 fcbba617b38cb368519681bda6426e2c09cf172f [ Upstream commit 0d8aebe089b4ba887e792884cf041ce9f1040ff4 ] The generic virtio bus .shutdown handler, virtio_dev_shutdown(), breaks and resets a device once it has established that the driver has no .shutdown of its own. A driver that does implement .shutdown, to quiesce its own activity first, still needs the same break and reset afterwards and would otherwise have to open code it. Factor the break + synchronize_cbs + reset sequence out of virtio_dev_shutdown() into an exported virtio_device_shutdown() helper so such drivers can reuse it instead of duplicating the core logic. No functional change. Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260624140846.2616797-2-den@openvz.org> Stable-dep-of: 7e17eef04600 ("virtio_balloon: quiesce balloon work before device shutdown") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0d8aebe089b4ba887e792884cf041ce9f1040ff4 ]

The generic virtio bus .shutdown handler, virtio_dev_shutdown(), breaks
and resets a device once it has established that the driver has no
.shutdown of its own. A driver that does implement .shutdown, to quiesce
its own activity first, still needs the same break and reset afterwards
and would otherwise have to open code it.

Factor the break + synchronize_cbs + reset sequence out of
virtio_dev_shutdown() into an exported virtio_device_shutdown() helper so
such drivers can reuse it instead of duplicating the core logic.

No functional change.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260624140846.2616797-2-den@openvz.org>
Stable-dep-of: 7e17eef04600 ("virtio_balloon: quiesce balloon work before device shutdown")
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_balloon: disable indirect descriptors 2026-09-14T11:40:57+00:00 Michael S. Tsirkin mst@redhat.com 2026-07-05T06:24:18+00:00 2ee4d24c88c488a34a6ef6618d7ac2d6b379b7a2 [ Upstream commit 281eb4732aae5473141b84e106fe906c69b2ff3d ] The page reporting callback submits an sg list to the reporting virtqueue. With VIRTIO_RING_F_INDIRECT_DESC negotiated and total_sg > 1 (which it typically is), virtqueue_add reports it to the host by allocating an indirect descriptor via kmalloc(GFP_KERNEL). This is not pretty: the reporting worker isolates potentially hundreds of MB of free pages from the buddy allocator (reported pages are at least pageblock_order, and the sg can contain up to PAGE_REPORTING_CAPACITY entries of varying orders). As the result, very theoretically, the kmalloc might trigger OOM when we have in fact a ton of free memory. Clear VIRTIO_RING_F_INDIRECT_DESC, to avoid using indirect descriptors. Fixes: b0c504f15471 ("virtio-balloon: add support for providing free page reports to host") Assisted-by: Claude:claude-opus-4-6 Acked-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <73fac8a629fd9aca7bb3265ac243a769c28af25d.1783232420.git.mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 281eb4732aae5473141b84e106fe906c69b2ff3d ]

The page reporting callback submits an sg list to the reporting
virtqueue.  With VIRTIO_RING_F_INDIRECT_DESC negotiated and
total_sg > 1 (which it typically is), virtqueue_add reports it to the
host by allocating an indirect descriptor via kmalloc(GFP_KERNEL).

This is not pretty: the reporting worker isolates potentially hundreds
of MB of free pages from the buddy allocator (reported pages are at
least pageblock_order, and the sg can contain up to
PAGE_REPORTING_CAPACITY entries of varying orders).  As the result,
very theoretically, the kmalloc might trigger OOM when we have in fact a
ton of free memory.

Clear VIRTIO_RING_F_INDIRECT_DESC, to avoid using indirect descriptors.

Fixes: b0c504f15471 ("virtio-balloon: add support for providing free page reports to host")
Assisted-by: Claude:claude-opus-4-6
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <73fac8a629fd9aca7bb3265ac243a769c28af25d.1783232420.git.mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mm: page_reporting: allow driver to set batch capacity 2026-07-09T22:48:56+00:00 Michael S. Tsirkin mst@redhat.com 2026-07-05T06:25:13+00:00 47c81dadb704cdf07bb8f9f43b4fbe758a351e08 At the moment, if a virtio balloon device has a page reporting vq but its size is < PAGE_REPORTING_CAPACITY (32), the balloon driver fails probe. But, there's no way for host to know this value, so it can easily create a smaller vq and suddenly adding the reporting capability to the device makes all of the driver fail. Not pretty. Add a capacity field to page_reporting_dev_info so drivers can control the maximum number of pages per report batch. In virtio-balloon, set the capacity to the reporting virtqueue size, letting page_reporting adapt to whatever the device provides. Capacity need not be a power of two. Code previously called out division by PAGE_REPORTING_CAPACITY as cheap since it was a power of 2, but no performance difference was observed with non-power-of-2 values. If capacity is 0 or exceeds PAGE_REPORTING_CAPACITY, it defaults to PAGE_REPORTING_CAPACITY. The 0 check and the clamping is done in page_reporting_register(), before the reporting work is scheduled, so we never get division by 0. Link: https://lore.kernel.org/444c24cf39f3f3620fc90ef4695bd6b0979f4c4b.1783232420.git.mst@redhat.com Fixes: b0c504f15471 ("virtio-balloon: add support for providing free page reports to host") Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Assisted-by: Claude:claude-opus-4-6 Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Gregory Price <gourry@gourry.net> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
At the moment, if a virtio balloon device has a page reporting vq but its
size is < PAGE_REPORTING_CAPACITY (32), the balloon driver fails probe.

But, there's no way for host to know this value, so it can easily create a
smaller vq and suddenly adding the reporting capability to the device
makes all of the driver fail.  Not pretty.

Add a capacity field to page_reporting_dev_info so drivers can control the
maximum number of pages per report batch.

In virtio-balloon, set the capacity to the reporting virtqueue size,
letting page_reporting adapt to whatever the device provides.

Capacity need not be a power of two.  Code previously called out division
by PAGE_REPORTING_CAPACITY as cheap since it was a power of 2, but no
performance difference was observed with non-power-of-2 values.

If capacity is 0 or exceeds PAGE_REPORTING_CAPACITY, it defaults to
PAGE_REPORTING_CAPACITY.  The 0 check and the clamping is done in
page_reporting_register(), before the reporting work is scheduled, so we
never get division by 0.

Link: https://lore.kernel.org/444c24cf39f3f3620fc90ef4695bd6b0979f4c4b.1783232420.git.mst@redhat.com
Fixes: b0c504f15471 ("virtio-balloon: add support for providing free page reports to host")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Assisted-by: Claude:claude-opus-4-6
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Gregory Price <gourry@gourry.net>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Eugenio Pérez <eperezma@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost 2026-06-17T18:49:00+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-06-17T18:49:00+00:00 d44ade05aa21468bd30652bc4492891b854a400a Pull virtio updates from Michael Tsirkin: - new virtio CAN driver - support for LoongArch architecture in fw_cfg - support for firmware notifications in vdpa/octeon_ep - support for VFs in virtio core - fixes, cleanups all over the place, notably: - vhost: fix vhost_get_avail_idx for a non empty ring fixing an significant old perf regression - READ_ONCE() annotations mean virtio ring is now free of KCSAN warnings * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (37 commits) can: virtio: Fix comment in UAPI header can: virtio: Add virtio CAN driver virtio: add num_vf callback to virtio_bus fw_cfg: Add support for LoongArch architecture vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler vdpa/octeon_ep: Add vDPA device event handling for firmware notifications vdpa/octeon_ep: Use 4 bytes for mailbox signature vdpa/octeon_ep: Fix PF->VF mailbox data address calculation vhost_task_create: kill unnecessary .exit_signal initialization vhost: remove unnecessary module_init/exit functions vdpa/mlx5: Use kvzalloc_flex() for MTT command memory vdpa_sim_net: switch to dynamic root device vdpa_sim_blk: switch to dynamic root device virtio-mem: Destroy mutex before freeing virtio_mem virtio-balloon: Destroy mutex before freeing virtio_balloon tools/virtio: fix build for kmalloc_obj API and missing stubs virtio_ring: Add READ_ONCE annotations for device-writable fields vduse: fix compat handling for VDUSE_IOTLB_GET_FD/VDUSE_VQ_GET_INFO tools/virtio: check mmap return value in vringh_test vhost/net: complete zerocopy ubufs only once ... 
Pull virtio updates from Michael Tsirkin:

 - new virtio CAN driver

 - support for LoongArch architecture in fw_cfg

 - support for firmware notifications in vdpa/octeon_ep

 - support for VFs in virtio core

 - fixes, cleanups all over the place, notably:

    - vhost: fix vhost_get_avail_idx for a non empty ring
      fixing an significant old perf regression

    - READ_ONCE() annotations mean virtio ring is now
      free of KCSAN warnings

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (37 commits)
  can: virtio: Fix comment in UAPI header
  can: virtio: Add virtio CAN driver
  virtio: add num_vf callback to virtio_bus
  fw_cfg: Add support for LoongArch architecture
  vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler
  vdpa/octeon_ep: Add vDPA device event handling for firmware notifications
  vdpa/octeon_ep: Use 4 bytes for mailbox signature
  vdpa/octeon_ep: Fix PF->VF mailbox data address calculation
  vhost_task_create: kill unnecessary .exit_signal initialization
  vhost: remove unnecessary module_init/exit functions
  vdpa/mlx5: Use kvzalloc_flex() for MTT command memory
  vdpa_sim_net: switch to dynamic root device
  vdpa_sim_blk: switch to dynamic root device
  virtio-mem: Destroy mutex before freeing virtio_mem
  virtio-balloon: Destroy mutex before freeing virtio_balloon
  tools/virtio: fix build for kmalloc_obj API and missing stubs
  virtio_ring: Add READ_ONCE annotations for device-writable fields
  vduse: fix compat handling for VDUSE_IOTLB_GET_FD/VDUSE_VQ_GET_INFO
  tools/virtio: check mmap return value in vringh_test
  vhost/net: complete zerocopy ubufs only once
  ...
virtio: add num_vf callback to virtio_bus 2026-06-10T06:17:00+00:00 Yui Washizu yui.washidu@gmail.com 2026-03-10T06:14:52+00:00 82da84282c0746ae7c6d87dad7b8daba88f0d091 Recent QEMU versions added support for virtio SR-IOV emulation, allowing virtio devices to expose SR-IOV VFs to the guest. However, virtio_bus does not implement the num_vf callback of bus_type, causing dev_num_vf() to return 0 for virtio devices even when SR-IOV VFs are active. net/core/rtnetlink.c calls dev_num_vf(dev->dev.parent) to populate IFLA_NUM_VF in RTM_GETLINK responses. For a virtio-net device, dev.parent points to the virtio_device, whose busis virtio_bus. Without num_vf, SR-IOV VF information is silently omitted from tools that rely on rtnetlink, such as 'ip link show'. Add a num_vf callback that delegates to dev_num_vf(dev->parent), which in turn reaches the underlying transport (pci_bus_type for virtio-pci) where the actual VF count is tracked. Non-PCI transports are unaffected as dev_num_vf() returns 0 when no num_vf callback is present. Signed-off-by: Yui Washizu <yui.washidu@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260310061454.683894-1-yui.washidu@gmail.com> 
Recent QEMU versions added support for virtio SR-IOV emulation,
allowing virtio devices to expose SR-IOV VFs to the guest.
However, virtio_bus does not implement the num_vf callback of bus_type,
causing dev_num_vf() to return 0 for virtio devices even when
SR-IOV VFs are active.

net/core/rtnetlink.c calls dev_num_vf(dev->dev.parent) to populate
IFLA_NUM_VF in RTM_GETLINK responses.  For a virtio-net device,
dev.parent points to the virtio_device, whose busis virtio_bus.
Without num_vf, SR-IOV VF information is silently
omitted from tools that rely on rtnetlink, such as 'ip link show'.

Add a num_vf callback that delegates to dev_num_vf(dev->parent),
which in turn reaches the underlying transport (pci_bus_type for
virtio-pci) where the actual VF count is tracked.  Non-PCI transports
are unaffected as dev_num_vf() returns 0 when no num_vf callback is
present.

Signed-off-by: Yui Washizu <yui.washidu@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260310061454.683894-1-yui.washidu@gmail.com>
virtio-mem: Destroy mutex before freeing virtio_mem 2026-06-10T06:16:59+00:00 Maurice Hieronymus mhi@mailbox.org 2025-11-23T17:57:49+00:00 7cdaeef19bc87bb93f3083b11dda92e3e9ff855c Add a call to mutex_destroy in the error code path as well as in the virtio_mem_remove code path. Signed-off-by: Maurice Hieronymus <mhi@mailbox.org> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20251123175750.445461-3-mhi@mailbox.org> 
Add a call to mutex_destroy in the error code path as well as in the
virtio_mem_remove code path.

Signed-off-by: Maurice Hieronymus <mhi@mailbox.org>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20251123175750.445461-3-mhi@mailbox.org>