kernel/linux.git/drivers/gpu/drm/amd/amdkfd/kfd_process.c, branch linux-6.9.y

drm/amdkfd: Flush the process wq before creating a kfd_process

2024-05-01T01:59:16+00:00

There is a race condition when re-creating a kfd_process for a process. This has been observed when a process under the debugger executes exec(3). In this scenario: - The process executes exec. - This will eventually release the process's mm, which will cause the kfd_process object associated with the process to be freed (kfd_process_free_notifier decrements the reference count to the kfd_process to 0). This causes kfd_process_ref_release to enqueue kfd_process_wq_release to the kfd_process_wq. - The debugger receives the PTRACE_EVENT_EXEC notification, and tries to re-enable AMDGPU traps (KFD_IOC_DBG_TRAP_ENABLE). - When handling this request, KFD tries to re-create a kfd_process. This eventually calls kfd_create_process and kobject_init_and_add. At this point the call to kobject_init_and_add can fail because the old kfd_process.kobj has not been freed yet by kfd_process_wq_release. This patch proposes to avoid this race by making sure to drain kfd_process_wq before creating a new kfd_process object. This way, we know that any cleanup task is done executing when we reach kobject_init_and_add. Signed-off-by: Lancelot SIX Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher

drm/amdkfd: Fix rescheduling of restore worker

2024-04-24T03:23:28+00:00

Handle the case that the restore worker was already scheduled by another eviction while the restore was in progress. Fixes: 9a1c1339abf9 ("drm/amdkfd: Run restore_workers on freezable WQs") Signed-off-by: Felix Kuehling Reviewed-by: Philip Yang Tested-by: Yunxiang Li Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org

drm/amdkfd: Fix eviction fence handling

2024-04-24T03:17:30+00:00

Handle case that dma_fence_get_rcu_safe returns NULL. If restore work is already scheduled, only update its timer. The same work item cannot be queued twice, so undo the extra queue eviction. Fixes: 9a1c1339abf9 ("drm/amdkfd: Run restore_workers on freezable WQs") Signed-off-by: Felix Kuehling Reviewed-by: Philip Yang Tested-by: Gang BA Reviewed-by: Gang BA Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org

drm/amdkfd: Fix memory leak in create_process failure

2024-04-17T15:05:09+00:00

Fix memory leak due to a leaked mmget reference on an error handling code path that is triggered when attempting to create KFD processes while a GPU reset is in progress. Fixes: 0ab2d7532b05 ("drm/amdkfd: prepare per-process debug enable and disable") CC: Xiaogang Chen Signed-off-by: Felix Kuehling Tested-by: Harish Kasiviswanthan Reviewed-by: Mukul Joshi Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org

drm/amdkfd: Fix sparse __rcu annotation warnings

2024-01-09T20:44:13+00:00

Properly mark kfd_process->ef as __rcu and consistently use the right accessor functions. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202312052245.yFpBSgNH-lkp@intel.com/ Signed-off-by: Felix Kuehling Reviewed-by: Christian König Signed-off-by: Alex Deucher

drm/amdkfd: Run restore_workers on freezable WQs

2023-11-29T21:49:23+00:00

Make restore workers freezable so we don't have to explicitly flush them in suspend and GPU reset code paths, and we don't accidentally try to restore BOs while the GPU is suspended. Not having to flush restore_work also helps avoid lock/fence dependencies in the GPU reset case where we're not allowed to wait for fences. A side effect of this is, that we can now have multiple concurrent threads trying to signal the same eviction fence. Rework eviction fence signaling and replacement to account for that. The GPU reset path can no longer rely on restore_process_worker to resume queues because evict/restore workers can run independently of it. Instead call a new restore_process_helper directly. This is an RFC and request for testing. v2: - Reworked eviction fence signaling - Introduced restore_process_helper v3: - Handle unsignaled eviction fences in restore_process_bos Signed-off-by: Felix Kuehling Acked-by: Christian König Tested-by: Emily Deng Signed-off-by: Alex Deucher

drm/amdkfd: Move TLB flushing logic into amdgpu

2023-11-17T14:29:53+00:00

This will make it possible for amdgpu GEM ioctls to flush TLBs on compute VMs. This removes VMID-based TLB flushing and always uses PASID-based flushing. This still works because it scans the VMID-PASID mapping registers to find the right VMID. It's only slightly less efficient. This is not a production use case. Signed-off-by: Felix Kuehling Reviewed-by: Christian König Signed-off-by: Alex Deucher

drm/amd: Disable XNACK on SRIOV environment

2023-11-07T16:15:37+00:00

The purpose of this patch is to disable XNACK or set XNACK OFF mode on SRIOV platform which doesn't support it. This will prevent user-space application to fail or result into unexpected behaviour whenever the application need to run test-case in XNACK ON mode. Signed-off-by: Surbhi Kakarya Reviewed-by: Shaoyun Liu Signed-off-by: Alex Deucher

drm/amdkfd: drop IOMMUv2 support

2023-08-11T18:47:25+00:00

Now that we use the dGPU path for all APUs, drop the IOMMUv2 support. v2: drop the now unused queue manager functions for gfx7/8 APUs Reviewed-by: Felix Kuehling Acked-by: Christian König Tested-by: Mike Lothian Signed-off-by: Alex Deucher

drm/amdgpu: use doorbell mgr for kfd process doorbells

2023-08-07T21:14:07+00:00

This patch: - adds a doorbell object in kfd pdd structure. - allocates doorbells for a process while creating its queue. - frees the doorbells with pdd destroy. - moves doorbell bitmap init function to kfd_doorbell.c PS: This patch ensures that we don't break the existing KFD functionality, but now KFD userspace library should also create doorbell pages as AMDGPU GEM objects using libdrm functions in userspace. The reference code for the same is available with AMDGPU Usermode queue libdrm MR. Once this is done, we will not need to create process doorbells in kernel. V2: - Do not use doorbell wrapper API, use amdgpu_bo_create_kernel instead (Alex). - Do not use custom doorbell structure, instead use separate variables for bo and doorbell_bitmap (Alex) V3: - Do not allocate doorbell page with PDD, delay doorbell process page allocation until really needed (Felix) Cc: Alex Deucher Cc: Christian Koenig Cc: Felix Kuehling Acked-by: Christian König Reviewed-by: Felix Kuehling Signed-off-by: Shashank Sharma Signed-off-by: Alex Deucher