drm/amdkfd: Allow access for mmapping KFD BOs

DRM render node file handles are used for CPU mapping of BOs using mmap
by the Thunk. It uses the DRM render node of the GPU where the BO was
allocated.

DRM allows mmap access automatically when it creates a GEM handle for a
BO. KFD BOs don't have GEM handles, so KFD needs to manage access
manually. Use drm_vma_node_allow to allow user mode to mmap BOs allocated
with kfd_ioctl_alloc_memory_of_gpu through the DRM render node that was
used in the kfd_ioctl_acquire_vm call for the same GPU.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Philip Yang <philip.yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index dc86faa03b88..f96c331c9b6d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1229,6 +1229,11 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
 			 domain_string(alloc_domain), ret);
 		goto err_bo_create;
 	}
+	ret = drm_vma_node_allow(&gobj->vma_node, drm_priv);
+	if (ret) {
+		pr_debug("Failed to allow vma node access. ret %d\n", ret);
+		goto err_node_allow;
+	}
 	bo = gem_to_amdgpu_bo(gobj);
 	if (bo_type == ttm_bo_type_sg) {
 		bo->tbo.sg = sg;
@@ -1258,6 +1263,8 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
 
 allocate_init_user_pages_failed:
 	remove_kgd_mem_from_kfd_bo_list(*mem, avm->process_info);
+	drm_vma_node_revoke(&gobj->vma_node, drm_priv);
+err_node_allow:
 	amdgpu_bo_unref(&bo);
 	/* Don't unreserve system mem limit twice */
 	goto err_reserve_limit;
@@ -1275,7 +1282,8 @@ err:
 }
 
 int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
-		struct kgd_dev *kgd, struct kgd_mem *mem, uint64_t *size)
+		struct kgd_dev *kgd, struct kgd_mem *mem, void *drm_priv,
+		uint64_t *size)
 {
 	struct amdkfd_process_info *process_info = mem->process_info;
 	unsigned long bo_size = mem->bo->tbo.base.size;
@@ -1352,6 +1360,7 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
 	}
 
 	/* Free the BO*/
+	drm_vma_node_revoke(&mem->bo->tbo.base.vma_node, drm_priv);
 	drm_gem_object_put(&mem->bo->tbo.base);
 	mutex_destroy(&mem->lock);
 	kfree(mem);
@@ -1663,6 +1672,7 @@ int amdgpu_amdkfd_gpuvm_import_dmabuf(struct kgd_dev *kgd,
 	struct amdgpu_vm *avm = drm_priv_to_vm(drm_priv);
 	struct drm_gem_object *obj;
 	struct amdgpu_bo *bo;
+	int ret;
 
 	if (dma_buf->ops != &amdgpu_dmabuf_ops)
 		/* Can't handle non-graphics buffers */
@@ -1683,6 +1693,12 @@ int amdgpu_amdkfd_gpuvm_import_dmabuf(struct kgd_dev *kgd,
 	if (!*mem)
 		return -ENOMEM;
 
+	ret = drm_vma_node_allow(&obj->vma_node, drm_priv);
+	if (ret) {
+		kfree(mem);
+		return ret;
+	}
+
 	if (size)
 		*size = amdgpu_bo_size(bo);