kernel/linux.git/drivers/vhost, branch v6.19.11

vhost: move vdpa group bound check to vhost_vdpa

2026-03-04T12:21:29+00:00

[ Upstream commit cd025c1e876b4e262e71398236a1550486a73ede ] Remove duplication by consolidating these here. This reduces the posibility of a parent driver missing them. While we're at it, fix a bug in vdpa_sim where a valid ASID can be assigned to a group equal to ngroups, causing an out of bound write. Cc: stable@vger.kernel.org Fixes: bda324fd037a ("vdpasim: control virtqueue support") Acked-by: Jason Wang Signed-off-by: Eugenio Pérez Signed-off-by: Michael S. Tsirkin Message-Id: <20260119143306.1818855-2-eperezma@redhat.com> Signed-off-by: Sasha Levin

vhost: fix caching attributes of MMIO regions by setting them explicitly

2026-03-04T12:20:35+00:00

[ Upstream commit 5145b277309f3818e2db507f525d19ac3b910922 ] Explicitly set non-cached caching attributes for MMIO regions. Default write-back mode can cause CPU to cache device memory, causing invalid reads and unpredictable behavior. Invalid read and write issues were observed on ARM64 when mapping the notification area to userspace via mmap. Signed-off-by: Kommula Shiva Shankar Acked-by: Jason Wang Reviewed-by: Jason Gunthorpe Signed-off-by: Michael S. Tsirkin Message-Id: <20260102065703.656255-1-kshankar@marvell.com> Signed-off-by: Sasha Levin

vhost/vsock: improve RCU read sections around vhost_vsock_get()

2025-12-24T13:02:57+00:00

vhost_vsock_get() uses hash_for_each_possible_rcu() to find the `vhost_vsock` associated with the `guest_cid`. hash_for_each_possible_rcu() should only be called within an RCU read section, as mentioned in the following comment in include/linux/rculist.h: /** * hlist_for_each_entry_rcu - iterate over rcu list of given type * @pos: the type * to use as a loop cursor. * @head: the head for your list. * @member: the name of the hlist_node within the struct. * @cond: optional lockdep expression if called from non-RCU protection. * * This list-traversal primitive may safely run concurrently with * the _rcu list-mutation primitives such as hlist_add_head_rcu() * as long as the traversal is guarded by rcu_read_lock(). */ Currently, all calls to vhost_vsock_get() are between rcu_read_lock() and rcu_read_unlock() except for calls in vhost_vsock_set_cid() and vhost_vsock_reset_orphans(). In both cases, the current code is safe, but we can make improvements to make it more robust. About vhost_vsock_set_cid(), when building the kernel with CONFIG_PROVE_RCU_LIST enabled, we get the following RCU warning when the user space issues `ioctl(dev, VHOST_VSOCK_SET_GUEST_CID, ...)` : WARNING: suspicious RCU usage 6.18.0-rc7 #62 Not tainted ----------------------------- drivers/vhost/vsock.c:74 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by rpc-libvirtd/3443: #0: ffffffffc05032a8 (vhost_vsock_mutex){+.+.}-{4:4}, at: vhost_vsock_dev_ioctl+0x2ff/0x530 [vhost_vsock] stack backtrace: CPU: 2 UID: 0 PID: 3443 Comm: rpc-libvirtd Not tainted 6.18.0-rc7 #62 PREEMPT(none) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-7.fc42 06/10/2025 Call Trace: dump_stack_lvl+0x75/0xb0 dump_stack+0x14/0x1a lockdep_rcu_suspicious.cold+0x4e/0x97 vhost_vsock_get+0x8f/0xa0 [vhost_vsock] vhost_vsock_dev_ioctl+0x307/0x530 [vhost_vsock] __x64_sys_ioctl+0x4f2/0xa00 x64_sys_call+0xed0/0x1da0 do_syscall_64+0x73/0xfa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ... This is not a real problem, because the vhost_vsock_get() caller, i.e. vhost_vsock_set_cid(), holds the `vhost_vsock_mutex` used by the hash table writers. Anyway, to prevent that warning, add lockdep_is_held() condition to hash_for_each_possible_rcu() to verify that either the caller is in an RCU read section or `vhost_vsock_mutex` is held when CONFIG_PROVE_RCU_LIST is enabled; and also clarify the comment for vhost_vsock_get() to better describe the locking requirements and the scope of the returned pointer validity. About vhost_vsock_reset_orphans(), currently this function is only called via vsock_for_each_connected_socket(), which holds the `vsock_table_lock` spinlock (which is also an RCU read-side critical section). However, add an explicit RCU read lock there to make the code more robust and explicit about the RCU requirements, and to prevent issues if the calling context changes in the future or if vhost_vsock_reset_orphans() is called from other contexts. Fixes: 834e772c8db0 ("vhost/vsock: fix use-after-free in network stack callers") Cc: stefanha@redhat.com Signed-off-by: Stefano Garzarella Reviewed-by: Stefan Hajnoczi Message-Id: <20251126133826.142496-1-sgarzare@redhat.com> Message-ID: <20251126210313.GA499503@fedora> Acked-by: Jason Wang Signed-off-by: Michael S. Tsirkin

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2025-12-05T02:59:21+00:00

Pull virtio updates from Michael Tsirkin: "Just a bunch of fixes and cleanups, mostly very simple. Several features were merged through net-next this time around" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio_pci: drop kernel.h vhost: switch to arrays of feature bits vhost/test: add test specific macro for features virtio: clean up features qword/dword terms vduse: add WQ_PERCPU to alloc_workqueue users virtio_balloon: add WQ_PERCPU to alloc_workqueue users vdpa/pds: use %pe for ERR_PTR() in event handler registration vhost: Fix kthread worker cgroup failure handling virtio: vdpa: Fix reference count leak in octep_sriov_enable() vdpa/mlx5: Fix incorrect error code reporting in query_virtqueues virtio: fix map ops comment virtio: fix virtqueue_set_affinity() docs virtio: standardize Returns documentation style virtio: fix grammar in virtio_map_ops docs virtio: fix grammar in virtio_queue_info docs virtio: fix whitespace in virtio_config_ops virtio: fix typo in virtio_device_ready() comment virtio: fix kernel-doc for mapping/free_coherent functions virtio_vdpa: fix misleading return in void function

vhost: switch to arrays of feature bits

2025-11-30T23:02:43+00:00

The current interface where caller has to know in which 64 bit chunk each bit is, is inelegant and fragile. Let's simply use arrays of bits. By using unroll macros text size grows only slightly. Message-ID: <637e182e139980e5930d50b928ba5ac072d628a9.1764225384.git.mst@redhat.com> Signed-off-by: Michael S. Tsirkin

vhost/test: add test specific macro for features

2025-11-27T07:03:07+00:00

test just uses vhost features with no change, but people tend to copy/paste code, so let's add our own define. Message-ID: <23ca04512a800ee8b3594482492e536020931340.1764225384.git.mst@redhat.com> Signed-off-by: Michael S. Tsirkin

virtio: clean up features qword/dword terms

2025-11-27T07:03:07+00:00

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

vhost: Fix kthread worker cgroup failure handling

2025-11-27T07:03:06+00:00

If we fail to attach to a cgroup we are leaking the id. This adds a new goto to free the id. Fixes: 7d9896e9f6d0 ("vhost: Reintroduce kthread API and add mode selection") Signed-off-by: Mike Christie Acked-by: Jason Wang Reviewed-by: Chaitanya Kulkarni Signed-off-by: Michael S. Tsirkin Message-Id: <20251101194358.13605-1-michael.christie@oracle.com>

vhost: rewind next_avail_head while discarding descriptors

2025-11-26T22:44:58+00:00

When discarding descriptors with IN_ORDER, we should rewind next_avail_head otherwise it would run out of sync with last_avail_idx. This would cause driver to report "id X is not a head". Fixing this by returning the number of descriptors that is used for each buffer via vhost_get_vq_desc_n() so caller can use the value while discarding descriptors. Fixes: 67a873df0c41 ("vhost: basic in order support") Cc: stable@vger.kernel.org Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Link: https://patch.msgid.link/20251120022950.10117-1-jasowang@redhat.com Signed-off-by: Jakub Kicinski

vdpa: support virtio_map

2025-10-01T11:24:43+00:00

Virtio core switches from DMA device to virtio_map, let's do that as well for vDPA. Signed-off-by: Jason Wang Message-Id: <20250821064641.5025-8-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin Tested-by: Lei Yang Reviewed-by: Eugenio Pérez