On Tue, Aug 18, 2026 at 10:40 PM Jesse Zhang <[email protected]> wrote: > > On resume, amdgpu_userq_vm_validate_and_restore_queue() updates each queue's > wptr GPU address via amdgpu_bo_gpu_offset(). > > WPTR BOs are VM-mapped, but each BO has its own reservation object and is not > implicitly covered by the VM validation path here. This can leave offset reads > without proper BO locking/placement state and trigger WARN_ONs. > ------------[ cut here ]------------ > WARNING: amdgpu_object.c:1486 at amdgpu_bo_gpu_offset+0x75/0xa0 [amdgpu], > CPU#3: kworker/3:1/116 > Workqueue: events amdgpu_userq_restore_worker [amdgpu] > RIP: 0010:amdgpu_bo_gpu_offset+0x75/0xa0 [amdgpu] > Call Trace: > <TASK> > amdgpu_userq_vm_validate_and_restore_queue+0x629/0x960 [amdgpu] > amdgpu_userq_restore_worker+0xa6/0x180 [amdgpu] > process_scheduled_works+0xa6/0x460 > worker_thread+0x13c/0x290 > kthread+0xfb/0x140 > ret_from_fork+0x1b6/0x2b0 > ret_from_fork_asm+0x1a/0x30 > </TASK> > ---[ end trace 0000000000000000 ]--- > ------------[ cut here ]------------ > WARNING: amdgpu_object.c:1485 at amdgpu_bo_gpu_offset+0x9a/0xa0 [amdgpu], > CPU#2: kworker/2:1/127 > Workqueue: events amdgpu_userq_restore_worker [amdgpu] > RIP: 0010:amdgpu_bo_gpu_offset+0x9a/0xa0 [amdgpu] > > Add each queue's WPTR BO to the drm_exec ww context and validate it to its > allowed placement before the later offset update. > > v2: > - Clarify that WPTR BOs are VM-mapped (fix incorrect "not part of VM" > wording). (Christian) > - Describe both parts of the fix: lock BO reservations in drm_exec and > validate BO placement before offset reads. > > Signed-off-by: Jesse Zhang <[email protected]>
Acked-by: Alex Deucher <[email protected]> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 24 +++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c > index 17cc48d87c4d..ab8fc14a235b 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c > @@ -1054,6 +1054,30 @@ amdgpu_userq_vm_validate_and_restore_queue(struct > amdgpu_userq_mgr *uq_mgr) > drm_exec_retry_on_contention(&exec); > if (unlikely(ret)) > goto unlock_all; > + > + /* > + * WPTR BOs are VM-mapped, but each BO has its own reservation > + * object. Lock them into this drm_exec ww context so the > later > + * amdgpu_bo_gpu_offset() reads are done with the BO resv > locked. > + */ > + xa_for_each(&uq_mgr->userq_xa, tmp_key, queue) { > + struct ttm_operation_ctx wptr_ctx = { false, false }; > + > + bo = queue->wptr_obj.obj; > + if (!bo) > + continue; > + > + ret = drm_exec_prepare_obj(&exec, &bo->tbo.base, > + TTM_NUM_MOVE_FENCES + 1); > + drm_exec_retry_on_contention(&exec); > + if (unlikely(ret)) > + goto unlock_all; > + > + amdgpu_bo_placement_from_domain(bo, > bo->allowed_domains); > + ret = ttm_bo_validate(&bo->tbo, &bo->placement, > &wptr_ctx); > + if (unlikely(ret)) > + goto unlock_all; > + } > } > > if (invalidated) { > -- > 2.49.0 >
