This patch introduced a regression. If you want to backport it, I'd recommend including this fix as well:

commit 9c29282ecbeeb1b43fced3055c6a5bb244b9390b Author: Lang Yu Lang.Yu@amd.com Date: Thu Jan 11 12:27:07 2024 +0800

drm/amdkfd: reserve the BO before validating it

Fix a warning.

v2: Avoid unmapping attachment repeatedly when ERESTARTSYS.

v3: Lock the BO before accessing ttm->sg to avoid race conditions.(Felix)

[ 41.708711] WARNING: CPU: 0 PID: 1463 at drivers/gpu/drm/ttm/ttm_bo.c:846 ttm_bo_validate+0x146/0x1b0 [ttm] [ 41.708989] Call Trace: [ 41.708992] <TASK> [ 41.708996] ? show_regs+0x6c/0x80 [ 41.709000] ? ttm_bo_validate+0x146/0x1b0 [ttm] [ 41.709008] ? __warn+0x93/0x190 [ 41.709014] ? ttm_bo_validate+0x146/0x1b0 [ttm] [ 41.709024] ? report_bug+0x1f9/0x210 [ 41.709035] ? handle_bug+0x46/0x80 [ 41.709041] ? exc_invalid_op+0x1d/0x80 [ 41.709048] ? asm_exc_invalid_op+0x1f/0x30 [ 41.709057] ? amdgpu_amdkfd_gpuvm_dmaunmap_mem+0x2c/0x80 [amdgpu] [ 41.709185] ? ttm_bo_validate+0x146/0x1b0 [ttm] [ 41.709197] ? amdgpu_amdkfd_gpuvm_dmaunmap_mem+0x2c/0x80 [amdgpu] [ 41.709337] ? srso_alias_return_thunk+0x5/0x7f [ 41.709346] kfd_mem_dmaunmap_attachment+0x9e/0x1e0 [amdgpu] [ 41.709467] amdgpu_amdkfd_gpuvm_dmaunmap_mem+0x56/0x80 [amdgpu] [ 41.709586] kfd_ioctl_unmap_memory_from_gpu+0x1b7/0x300 [amdgpu] [ 41.709710] kfd_ioctl+0x1ec/0x650 [amdgpu] [ 41.709822] ? __pfx_kfd_ioctl_unmap_memory_from_gpu+0x10/0x10 [amdgpu] [ 41.709945] ? srso_alias_return_thunk+0x5/0x7f [ 41.709949] ? tomoyo_file_ioctl+0x20/0x30 [ 41.709959] __x64_sys_ioctl+0x9c/0xd0 [ 41.709967] do_syscall_64+0x3f/0x90 [ 41.709973] entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Fixes: 101b8104307e ("drm/amdkfd: Move dma unmapping after TLB flush") Signed-off-by: Lang Yu Lang.Yu@amd.com Reviewed-by: Felix Kuehling Felix.Kuehling@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com

Regards, Felix

On 2024-08-20 8:00, Sasha Levin wrote:

This is a note to let you know that I've just added the patch titled

drm/amdkfd: Move dma unmapping after TLB flush

to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: drm-amdkfd-move-dma-unmapping-after-tlb-flush.patch and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

commit 23f8ef0f6e5deee5814fda6ec2e2ee4c2f19a384 Author: Philip Yang Philip.Yang@amd.com Date: Mon Sep 11 14:44:22 2023 -0400

drm/amdkfd: Move dma unmapping after TLB flush

[ Upstream commit 101b8104307eac734f2dfa4d3511430b0b631c73 ] Otherwise GPU may access the stale mapping and generate IOMMU IO_PAGE_FAULT. Move this to inside p->mutex to prevent multiple threads mapping and unmapping concurrently race condition. After kfd_mem_dmaunmap_attachment is removed from unmap_bo_from_gpuvm, kfd_mem_dmaunmap_attachment is called if failed to map to GPUs, and before free the mem attachment in case failed to unmap from GPUs. Signed-off-by: Philip Yang Philip.Yang@amd.com Reviewed-by: Felix Kuehling Felix.Kuehling@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h index 2fe9860725bd9..5e4fb33b97351 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h @@ -303,6 +303,7 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu(struct amdgpu_device *adev, struct kgd_mem *mem, void *drm_priv); int amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu( struct amdgpu_device *adev, struct kgd_mem *mem, void *drm_priv); +void amdgpu_amdkfd_gpuvm_dmaunmap_mem(struct kgd_mem *mem, void *drm_priv); int amdgpu_amdkfd_gpuvm_sync_memory( struct amdgpu_device *adev, struct kgd_mem *mem, bool intr); int amdgpu_amdkfd_gpuvm_map_gtt_bo_to_kernel(struct kgd_mem *mem, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index 62c1dc9510a41..c2d1d57a6c668 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -733,7 +733,7 @@ kfd_mem_dmaunmap_sg_bo(struct kgd_mem *mem, enum dma_data_direction dir; if (unlikely(!ttm->sg)) {

• pr_err("SG Table of BO is UNEXPECTEDLY NULL");
  

• pr_debug("SG Table of BO is NULL");
  

  return; }

@@ -1202,8 +1202,6 @@ static void unmap_bo_from_gpuvm(struct kgd_mem *mem, amdgpu_vm_clear_freed(adev, vm, &bo_va->last_pt_update); amdgpu_sync_fence(sync, bo_va->last_pt_update);

• kfd_mem_dmaunmap_attachment(mem, entry);

} static int update_gpuvm_pte(struct kgd_mem *mem, @@ -1258,6 +1256,7 @@ static int map_bo_to_gpuvm(struct kgd_mem *mem, update_gpuvm_pte_failed: unmap_bo_from_gpuvm(mem, entry, sync);

• kfd_mem_dmaunmap_attachment(mem, entry); return ret;

} @@ -1862,8 +1861,10 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu( mem->va + bo_size * (1 + mem->aql_queue)); /* Remove from VM internal data structures */

• list_for_each_entry_safe(entry, tmp, &mem->attachments, list)

• list_for_each_entry_safe(entry, tmp, &mem->attachments, list) {

• kfd_mem_dmaunmap_attachment(mem, entry);
  

  kfd_mem_detach(entry);
• }

ret = unreserve_bo_and_vms(&ctx, false, false); @@ -2037,6 +2038,23 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu( return ret; } +void amdgpu_amdkfd_gpuvm_dmaunmap_mem(struct kgd_mem *mem, void *drm_priv) +{

• struct kfd_mem_attachment *entry;
• struct amdgpu_vm *vm;
• vm = drm_priv_to_vm(drm_priv);
• mutex_lock(&mem->lock);
• list_for_each_entry(entry, &mem->attachments, list) {

• if (entry->bo_va->base.vm == vm)
  

• 	kfd_mem_dmaunmap_attachment(mem, entry);
  

• }
• mutex_unlock(&mem->lock);

+}

int amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu( struct amdgpu_device *adev, struct kgd_mem *mem, void *drm_priv) { diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c index d33ba4fe9ad5b..045280c2b607c 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c @@ -1432,17 +1432,21 @@ static int kfd_ioctl_unmap_memory_from_gpu(struct file *filep, goto sync_memory_failed; } }

• mutex_unlock(&p->mutex);

• if (flush_tlb) {

• /* Flush TLBs after waiting for the page table updates to complete */
  

• for (i = 0; i < args->n_devices; i++) {
  

• 	peer_pdd = kfd_process_device_data_by_id(p, devices_arr[i]);
  

• 	if (WARN_ON_ONCE(!peer_pdd))
  

• 		continue;
  

• /* Flush TLBs after waiting for the page table updates to complete */
• for (i = 0; i < args->n_devices; i++) {

• peer_pdd = kfd_process_device_data_by_id(p, devices_arr[i]);
  

• if (WARN_ON_ONCE(!peer_pdd))
  

• 	continue;
  

• if (flush_tlb)
  kfd_flush_tlb(peer_pdd, TLB_FLUSH_HEAVYWEIGHT);
  

• }
  

• /* Remove dma mapping after tlb flush to avoid IO_PAGE_FAULT */
  

• amdgpu_amdkfd_gpuvm_dmaunmap_mem(mem, peer_pdd->drm_priv);
  

  }
• mutex_unlock(&p->mutex);
• kfree(devices_arr);

return 0;