Re: [PATCH v3] drm/amdkfd: simplify vm_validate_pt_pd_bos

[Christian König]

Am 14.06.22 um 11:03 schrieb Lang Yu:

We don't need to validate and map root PD specially here,
it would be validated and mapped by amdgpu_vm_validate_pt_bos
if it is evicted.

The special case is when turning a GFX VM to a compute VM,
if vm_update_mode changed, we should make sure root PD gets
mapped. So just map root PD after updating vm->update_funcs
in amdgpu_vm_make_compute whether the vm_update_mode changed
or not.

v3:
  - Add some comments suggested by Christian.

v2:
  - Don't rename vm_validate_pt_pd_bos and make it public.

Signed-off-by: Lang Yu <lang...@amd.com>

I can't judge the kfd part, but the VM stuff looks good to me now.

Acked-by: Christian König <christian.koe...@amd.com>

---
  drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 14 --------------
  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c           |  8 ++++++++
  2 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 50bb590c3306..c9ef242177e2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -439,22 +439,8 @@ static int vm_validate_pt_pd_bos(struct amdgpu_vm *vm)
                return ret;
        }

- ret = amdgpu_amdkfd_validate_vm_bo(NULL, pd);

-       if (ret) {
-               pr_err("failed to validate PD\n");
-               return ret;
-       }
-
        vm->pd_phys_addr = amdgpu_gmc_pd_addr(vm->root.bo);

- if (vm->use_cpu_for_update) {

-               ret = amdgpu_bo_kmap(pd, NULL);
-               if (ret) {
-                       pr_err("failed to kmap PD, ret=%d\n", ret);
-                       return ret;
-               }
-       }
-
        return 0;
  }

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

index 703552f9a6d7..3a6b827e540c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2225,6 +2225,14 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, 
struct amdgpu_vm *vm)
        } else {
                vm->update_funcs = &amdgpu_vm_sdma_funcs;
        }
+       /*
+        * Make sure root PD gets mapped. As vm_update_mode could be changed
+        * when turning a GFX VM into a compute VM.
+        */
+       r = vm->update_funcs->map_table(to_amdgpu_bo_vm(vm->root.bo));
+       if (r)
+               goto unreserve_bo;
+
        dma_fence_put(vm->last_update);
        vm->last_update = NULL;
        vm->is_compute_context = true;