Can we change the flags if needed. E.g. see what
amdgpu_bo_pin_restricted does:
if (!(bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS))
bo->flags |= AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
amdgpu_bo_placement_from_domain(bo, domain);
This shouldn't really change anything about the BO placement because we
only enable CPU page table updates on large-BAR GPUs by default.
Alternatively, we could create VM BOs with
AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED on large-BAR GPUs to make it
possible to switch to CPU page table updates for compute VMs.
Regards,
Felix
Am 2023-06-21 um 05:46 schrieb YuBiao Wang:
If a same GPU VM is shared by kfd and graphic operations, we must align
the vm update mode to sdma, or cpu kmap will fail and cause null pointer
issue.
Signed-off-by: YuBiao Wang <YuBiao.Wang@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 291977b93b1d..e105ff9e8041 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2239,6 +2239,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm)
int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
{
bool pte_support_ats = (adev->asic_type == CHIP_RAVEN);
+ struct amdgpu_bo *bo = vm->root.bo;
int r;
r = amdgpu_bo_reserve(vm->root.bo, true);
@@ -2265,6 +2266,10 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
/* Update VM state */
vm->use_cpu_for_update = !!(adev->vm_manager.vm_update_mode &
AMDGPU_VM_USE_CPU_FOR_COMPUTE);
+
+ if (bo && !(bo->flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED))
+ vm->use_cpu_for_update = false;
+
DRM_DEBUG_DRIVER("VM update mode is %s\n",
vm->use_cpu_for_update ? "CPU" : "SDMA");
WARN_ONCE((vm->use_cpu_for_update &&
