Commit ffa88b00 authored by Xiaogang Chen's avatar Xiaogang Chen Committed by Alex Deucher
Browse files

drm/amdgpu: Correctly use bo_va->ref_count in compute VMs 



This is needed to correctly handle BOs imported into compute VM from gfx.
Both kfd and gfx should use same bo_va and set bo_va->ref_count correctly
when map the Bos into same VM, otherwise we may trigger kernel general
protection when iterate mappings over bo_va's valids or invalids list.

Signed-off-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: default avatarXiaogang Chen <Xiaogang.Chen@amd.com>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarRamesh Errabolu <Ramesh.Errabolu@amd.com>
Tested-by: default avatarXiaogang Chen <Xiaogang.Chen@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent f20f3b0d

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c

+11 −3
Original line number Diff line number Diff line
@@ -834,6 +834,7 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem, 
	uint64_t va = mem->va;

	struct kfd_mem_attachment *attachment[2] = {NULL, NULL};

	struct amdgpu_bo *bo[2] = {NULL, NULL};

	struct amdgpu_bo_va *bo_va;

	bool same_hive = false;

	int i, ret;
@@ -921,7 +922,12 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem, 
			pr_debug("Unable to reserve BO during memory attach");

			goto unwind;

		}

		attachment[i]->bo_va = amdgpu_vm_bo_add(adev, vm, bo[i]);

		bo_va = amdgpu_vm_bo_find(vm, bo[i]);

		if (!bo_va)

			bo_va = amdgpu_vm_bo_add(adev, vm, bo[i]);

		else

			++bo_va->ref_count;

		attachment[i]->bo_va = bo_va;

		amdgpu_bo_unreserve(bo[i]);

		if (unlikely(!attachment[i]->bo_va)) {

			ret = -ENOMEM;
@@ -945,6 +951,7 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem, 
			continue;

		if (attachment[i]->bo_va) {

			amdgpu_bo_reserve(bo[i], true);

			if (--attachment[i]->bo_va->ref_count == 0)

				amdgpu_vm_bo_del(adev, attachment[i]->bo_va);

			amdgpu_bo_unreserve(bo[i]);

			list_del(&attachment[i]->list);
@@ -962,6 +969,7 @@ static void kfd_mem_detach(struct kfd_mem_attachment *attachment) 


	pr_debug("\t remove VA 0x%llx in entry %p\n",

			attachment->va, attachment);

	if (--attachment->bo_va->ref_count == 0)

		amdgpu_vm_bo_del(attachment->adev, attachment->bo_va);

	drm_gem_object_put(&bo->tbo.base);

	list_del(&attachment->list);