kernel/linux.git/drivers/gpu/drm/virtio, branch v6.12.92

drm/virtio: use uninterruptible resv lock for plane updates

2026-06-01T15:46:21+00:00

commit 9af1b6e175c82daf4b423da339a722d8e67a735a upstream. virtio_gpu_cursor_plane_update() and virtio_gpu_resource_flush() lock the framebuffer BO's dma_resv via virtio_gpu_array_lock_resv() and ignore its return value. The function can fail with -EINTR from dma_resv_lock_interruptible() (signal during lock wait) or with -ENOMEM from dma_resv_reserve_fences() (fence slot allocation), leaving the resv lock not held. The queue path then walks the object array and calls dma_resv_add_fence(), which requires the lock held; with lockdep enabled this trips dma_resv_assert_held(): WARNING: drivers/dma-buf/dma-resv.c:296 at dma_resv_add_fence+0x71e/0x840 Call Trace: virtio_gpu_array_add_fence virtio_gpu_queue_ctrl_sgs virtio_gpu_queue_fenced_ctrl_buffer virtio_gpu_cursor_plane_update drm_atomic_helper_commit_planes drm_atomic_helper_commit_tail commit_tail drm_atomic_helper_commit drm_atomic_commit drm_atomic_helper_update_plane __setplane_atomic drm_mode_cursor_universal drm_mode_cursor_common drm_mode_cursor_ioctl drm_ioctl __x64_sys_ioctl Beyond the WARN, mutating the dma_resv fence list without the lock races with concurrent readers/writers and can corrupt the list. Both call sites run inside the .atomic_update plane callback, which DRM atomic helpers do not allow to fail (by the time it runs, the commit has been signed off to userspace and there is no clean rollback path). Moving the lock acquisition to .prepare_fb was rejected because the broader lock scope deadlocks against other BO locking paths in the same atomic commit. Introduce virtio_gpu_lock_one_resv_uninterruptible() that uses dma_resv_lock() instead of dma_resv_lock_interruptible(). This eliminates the -EINTR failure mode -- the realistic syzbot trigger -- without extending the lock hold across the commit. The helper locks a single BO and rejects nents > 1 with -EINVAL; both fix sites lock exactly one BO. Use it from virtio_gpu_cursor_plane_update() and virtio_gpu_resource_flush(); check the return value to handle the remaining -ENOMEM case from dma_resv_reserve_fences() by freeing the objs and skipping the plane update for that frame. The framebuffer BOs touched here are not shared with other contexts and lock contention is expected to be brief, so the loss of signal-interruptibility is acceptable. Other callers of virtio_gpu_array_lock_resv() (the ioctl paths) continue to use the interruptible variant. The bug was reported by syzbot, triggered via fault injection (fail_nth) on the DRM_IOCTL_MODE_CURSOR path, which forces the -ENOMEM branch in dma_resv_reserve_fences(). Reported-by: syzbot+72bd3dd3a5d5f39a0271@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=72bd3dd3a5d5f39a0271 Fixes: 5cfd31c5b3a3 ("drm/virtio: fix virtio_gpu_cursor_plane_update().") Cc: stable@vger.kernel.org Signed-off-by: Deepanshu Kartikey Signed-off-by: Dmitry Osipenko Link: https://patch.msgid.link/20260519082247.34470-1-kartikey406@gmail.com Signed-off-by: Greg Kroah-Hartman

drm/virtio: New fence for every plane update

2025-02-17T09:04:44+00:00

[ Upstream commit d3c55b8ab6fe5fa2e7ab02efd36d09c39ee5022f ] Having a fence linked to a virtio_gpu_framebuffer in the plane update sequence would cause conflict when several planes referencing the same framebuffer (e.g. Xorg screen covering multi-displays configured for an extended mode) and those planes are updated concurrently. So it is needed to allocate a fence for every plane state instead of the framebuffer. Signed-off-by: Dongwon Kim [dmitry.osipenko@collabora.com: rebase, fix up, edit commit message] Signed-off-by: Dmitry Osipenko Acked-by: Vivek Kasireddy Reviewed-by: Rob Clark Link: https://patchwork.freedesktop.org/patch/msgid/20241020230803.247419-2-dmitry.osipenko@collabora.com Signed-off-by: Sasha Levin

Merge drm/drm-fixes into drm-misc-fixes

2024-07-30T07:09:23+00:00

Let's start the new drm-misc-fixes cycle by bringing in 6.11-rc1. Signed-off-by: Maxime Ripard

drm/virtio: Fix type of dma-fence context variable

2024-07-24T17:42:19+00:00

Type of DMA fence context is u64. Fence-waiting code uses u32 for the context variable, fix it. Fixes: e4812ab8e6b1 ("drm/virtio: Refactor and optimize job submission code path") Cc: # v6.4+ Signed-off-by: Dmitry Osipenko Reviewed-by: Rob Clark Link: https://patchwork.freedesktop.org/patch/msgid/20240714205009.3408298-1-dmitry.osipenko@collabora.com

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

2024-07-19T18:57:55+00:00

Pull virtio updates from Michael Tsirkin: "Several new features here: - Virtio find vqs API has been reworked (required to fix the scalability issue we have with adminq, which I hope to merge later in the cycle) - vDPA driver for Marvell OCTEON - virtio fs performance improvement - mlx5 migration speedups Fixes, cleanups all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (56 commits) virtio: rename virtio_find_vqs_info() to virtio_find_vqs() virtio: remove unused virtio_find_vqs() and virtio_find_vqs_ctx() helpers virtio: convert the rest virtio_find_vqs() users to virtio_find_vqs_info() virtio_balloon: convert to use virtio_find_vqs_info() virtiofs: convert to use virtio_find_vqs_info() scsi: virtio_scsi: convert to use virtio_find_vqs_info() virtio_net: convert to use virtio_find_vqs_info() virtio_crypto: convert to use virtio_find_vqs_info() virtio_console: convert to use virtio_find_vqs_info() virtio_blk: convert to use virtio_find_vqs_info() virtio: rename find_vqs_info() op to find_vqs() virtio: remove the original find_vqs() op virtio: call virtio_find_vqs_info() from virtio_find_single_vq() directly virtio: convert find_vqs() op implementations to find_vqs_info() virtio_pci: convert vp_*find_vqs() ops to find_vqs_info() virtio: introduce virtio_queue_info struct and find_vqs_info() config op virtio: make virtio_find_single_vq() call virtio_find_vqs() virtio: make virtio_find_vqs() call virtio_find_vqs_ctx() caif_virtio: use virtio_find_single_vq() for single virtqueue finding vdpa/mlx5: Don't enable non-active VQs in .set_vq_ready() ...

virtio: rename virtio_find_vqs_info() to virtio_find_vqs()

2024-07-17T09:20:58+00:00

Since the original virtio_find_vqs() is no longer present, rename virtio_find_vqs_info() back to virtio_find_vqs(). Signed-off-by: Jiri Pirko Message-Id: <20240708074814.1739223-20-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin

virtio: convert the rest virtio_find_vqs() users to virtio_find_vqs_info()

2024-07-17T09:20:58+00:00

Instead of passing separate names and callbacks arrays to virtio_find_vqs(), have one of virtual_queue_info structs and pass it to virtio_find_vqs_info(). Suggested-by: Xuan Zhuo Signed-off-by: Jiri Pirko Message-Id: <20240708074814.1739223-18-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin

Merge drm/drm-next into drm-misc-next

2024-05-27T09:08:31+00:00

Let's start the new release cycle. Signed-off-by: Maxime Ripard

Merge tag 'trace-assign-str-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2024-05-23T19:28:01+00:00

Pull tracing cleanup from Steven Rostedt: "Remove second argument of __assign_str() The __assign_str() macro logic of the TRACE_EVENT() macro was optimized so that it no longer needs the second argument. The __assign_str() is always matched with __string() field that takes a field name and the source for that field: __string(field, source) The TRACE_EVENT() macro logic will save off the source value and then use that value to copy into the ring buffer via the __assign_str(). Before commit c1fa617caeb0 ("tracing: Rework __assign_str() and __string() to not duplicate getting the string"), the __assign_str() needed the second argument which would perform the same logic as the __string() source parameter did. Not only would this add overhead, but it was error prone as if the __assign_str() source produced something different, it may not have allocated enough for the string in the ring buffer (as the __string() source was used to determine how much to allocate) Now that the __assign_str() just uses the same string that was used in __string() it no longer needs the source parameter. It can now be removed" * tag 'trace-assign-str-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/treewide: Remove second parameter of __assign_str()

tracing/treewide: Remove second parameter of __assign_str()

2024-05-23T00:14:47+00:00

With the rework of how the __string() handles dynamic strings where it saves off the source string in field in the helper structure[1], the assignment of that value to the trace event field is stored in the helper value and does not need to be passed in again. This means that with: __string(field, mystring) Which use to be assigned with __assign_str(field, mystring), no longer needs the second parameter and it is unused. With this, __assign_str() will now only get a single parameter. There's over 700 users of __assign_str() and because coccinelle does not handle the TRACE_EVENT() macro I ended up using the following sed script: git grep -l __assign_str | while read a ; do sed -e 's/$__assign_str([^,]*[^ ,]$ *,[^;]*/\1)/' $a > /tmp/test-file; mv /tmp/test-file $a; done I then searched for __assign_str() that did not end with ';' as those were multi line assignments that the sed script above would fail to catch. Note, the same updates will need to be done for: __assign_str_len() __assign_rel_str() __assign_rel_str_len() I tested this with both an allmodconfig and an allyesconfig (build only for both). [1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/ Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Linus Torvalds Cc: Julia Lawall Signed-off-by: Steven Rostedt (Google) Acked-by: Jani Nikula Acked-by: Christian König for the amdgpu parts. Acked-by: Thomas Hellström #for Acked-by: Rafael J. Wysocki # for thermal Acked-by: Takashi Iwai Acked-by: Darrick J. Wong # xfs Tested-by: Guenter Roeck