kernel/git/stable/linux-stable.git/drivers/virtio, branch linux-rolling-lts

virtio: rtc: time out alarm requests

2026-09-14T11:36:04+00:00

[ 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 Reviewed-by: Peter Hilber Signed-off-by: Michael S. Tsirkin Message-ID: <20260714024352.71307-1-zhaoguohan@kylinos.cn> Signed-off-by: Sasha Levin

virtio_pci: fix wrong queue index for admin vq in intx path

2026-09-14T11:36:03+00:00

[ 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 Message-ID: <20260629033538.2476-1-lirongqing@baidu.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio_balloon: quiesce balloon work before device shutdown

2026-09-14T11:36:03+00:00

[ 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 Reviewed-by: David Hildenbrand (Arm) Signed-off-by: Michael S. Tsirkin Message-ID: <20260624140846.2616797-4-den@openvz.org> Signed-off-by: Sasha Levin

virtio_balloon: factor out virtballoon_quiesce()

2026-09-14T11:36:03+00:00

[ 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 Reviewed-by: David Hildenbrand (Arm) Signed-off-by: Michael S. Tsirkin 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

virtio: add virtio_device_shutdown() helper

2026-09-14T11:36:03+00:00

[ 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 Reviewed-by: David Hildenbrand (Arm) Signed-off-by: Michael S. Tsirkin 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

virtio_balloon: disable indirect descriptors

2026-09-14T11:36:03+00:00

[ 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) Signed-off-by: Michael S. Tsirkin Message-ID: <73fac8a629fd9aca7bb3265ac243a769c28af25d.1783232420.git.mst@redhat.com> Signed-off-by: Sasha Levin

virtio: rtc: tear down old virtqueues before restore

2026-07-24T14:16:07+00:00

[ Upstream commit 548d2208455f14e6121404c6e30e997bfe0cd264 ] virtio_device_restore() resets the device and restores the negotiated features before calling ->restore(). viortc_freeze() intentionally leaves the existing virtqueues in place so the alarm queue can still wake the system, but viortc_restore() immediately calls viortc_init_vqs() without first deleting those old queues. If virtqueue reinitialization fails on virtio-pci, the transport error path can run vp_del_vqs() against a newly allocated vp_dev->vqs array while vdev->vqs still contains the old virtqueues. vp_del_vqs() then looks up queue state through the new array and can dereference a NULL info pointer in vp_del_vq(), crashing the guest kernel during restore. This can also happen during a non-faulty reinitialization, when one of the vp_find_vqs_msix() attempts is unsuccessful before a later attempt would succeed. Delete the stale virtqueues before rebuilding them. If restore fails before virtio_device_ready(), reuse the remove path to stop the device. Once the device is ready, return errors directly instead of deleting the virtqueues again. Fixes: 0623c7592768 ("virtio_rtc: Add module and driver core") Signed-off-by: Jia Jia Reviewed-by: Peter Hilber Signed-off-by: Michael S. Tsirkin Message-ID: <20260507120801.3677552-1-physicalmtea@gmail.com> Signed-off-by: Sasha Levin

virtio-mmio: fix device release warning on module unload

2026-07-18T14:53:13+00:00

commit c687bc35694698ec4c7f92bf929c3d659f0cecb8 upstream. Driver core expects devices to be allocated dynamically and complains loudly when a device that lacks a release function is freed. Use __root_device_register() to allocate and register the root device instead of open coding using a static device. Note that root_device_register(), which also creates a link to the module, cannot be used as the device is registered when parsing the module parameters which happens before the module kobject has been set up. Fixes: 81a054ce0b46 ("virtio-mmio: Devices parameter parsing") Cc: stable@vger.kernel.org # 3.5 Cc: Pawel Moll Signed-off-by: Johan Hovold Signed-off-by: Michael S. Tsirkin Message-ID: <20260427143710.14702-1-johan@kernel.org> Signed-off-by: Greg Kroah-Hartman

virtio_pci: fix vq info pointer lookup via wrong index

2026-07-18T14:53:13+00:00

commit f7d380fb525c13bdd114369a1979c80c346e6abc upstream. Unbinding a virtio balloon device: echo virtio0 > /sys/bus/virtio/drivers/virtio_balloon/unbind triggers a NULL pointer dereference. The dmesg says: BUG: kernel NULL pointer dereference, address: 0000000000000008 [...] RIP: 0010:__list_del_entry_valid_or_report+0x5/0xf0 Call Trace: vp_del_vqs+0x121/0x230 remove_common+0x135/0x150 virtballoon_remove+0xee/0x100 virtio_dev_remove+0x3b/0x80 device_release_driver_internal+0x187/0x2c0 unbind_store+0xb9/0xe0 kernfs_fop_write_iter.llvm.11660790530567441834+0xf6/0x180 vfs_write+0x2a9/0x3b0 ksys_write+0x5c/0xd0 do_syscall_64+0x54/0x230 entry_SYSCALL_64_after_hwframe+0x29/0x31 [...] The virtio_balloon device registers 5 queues (inflate, deflate, stats, free_page, reporting) but only the first two are unconditional. The stats, free_page and reporting queues are each conditional on their respective feature bits. When any of these features are absent, the corresponding vqs_info entry has name == NULL, creating holes in the array. The root cause is an indexing mismatch introduced when vq info storage was changed to be passed as an argument. vp_find_vqs_msix() and vp_find_vqs_intx() store the info pointer at vp_dev->vqs[i], where 'i' is the caller's sparse array index. However, the virtqueue itself gets vq->index assigned from queue_idx, a dense index that skips NULL entries. When holes exist, 'i' and queue_idx diverge. Later, vp_del_vqs() looks up info via vp_dev->vqs[vq->index] using the dense index into the sparsely-populated array, and hits NULL. Fix this by storing info at vp_dev->vqs[queue_idx] instead of vp_dev->vqs[i], so the store index matches the lookup index (vq->index). Apply the fix to both the MSIX and INTX paths. Cc: Yichun Zhang Cc: Jiri Pirko Cc: stable@vger.kernel.org # v6.11+ Tested-by: Yuka Fixes: 89a1c435aec2 ("virtio_pci: pass vq info as an argument to vp_setup_vq()") Signed-off-by: Ammar Faizi Message-Id: <20260315141808.547081-1-ammarfaizi2@openresty.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio: clean up features qword/dword terms

2025-12-18T13:03:24+00:00

[ Upstream commit 9513f25056b22100ddffe24898c587873b0d022c ] virtio pci uses word to mean "16 bits". mmio uses it to mean "32 bits". To avoid confusion, let's avoid the term in core virtio altogether. Just say U64 to mean "64 bit". Fixes: e7d4c1c5a546 ("virtio: introduce extended features") Cc: Paolo Abeni Acked-by: Jason Wang Message-ID: Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin