Am 21.05.20 um 19:06 schrieb Felix Kuehling:
Am 2020-05-21 um 9:50 a.m. schrieb Christian König:
Am 21.05.20 um 00:51 schrieb Felix Kuehling:
This fixes an intermittent bug where a root PD clear operation still in
progress could overwrite a PDE update done by the CPU, resulting in a
VM fault.
Mhm, maybe better add this to amdgpu_vm_cpu_prepare().
This way we could (in theory) switch between CPU and SDMA based
updates on the fly elsewhere as well.
That won't work. I want to wait for FENCE_OWNER_VM fences, so I need to
use FENCE_OWNER_UNDEFINED. But then I would also end up waiting for
FENCE_OWNER_KFD eviction fences, which would trigger unwanted evictions.
This works OK in amdgpu_vm_make_compute because it runs before the
eviction fence is attached to the VM.
Ok, in this case the patch is Reviewed-by: Christian König
<christian.koenig@xxxxxxx>.
Regards,
Felix
Christian.
Fixes: 108b4d928c03 ("drm/amd/amdgpu: Update VM function pointer")
Reported-by: Jay Cornwall <Jay.Cornwall@xxxxxxx>
Tested-by: Jay Cornwall <Jay.Cornwall@xxxxxxx>
Signed-off-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 414a0b1c2e5a..7417754e9141 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -3000,10 +3000,17 @@ int amdgpu_vm_make_compute(struct
amdgpu_device *adev, struct amdgpu_vm *vm,
!amdgpu_gmc_vram_full_visible(&adev->gmc)),
"CPU update of VM recommended only for large BAR system\n");
- if (vm->use_cpu_for_update)
+ if (vm->use_cpu_for_update) {
+ /* Sync with last SDMA update/clear before switching to CPU */
+ r = amdgpu_bo_sync_wait(vm->root.base.bo,
+ AMDGPU_FENCE_OWNER_UNDEFINED, true);
+ if (r)
+ goto free_idr;
+
vm->update_funcs = &amdgpu_vm_cpu_funcs;
- else
+ } else {
vm->update_funcs = &amdgpu_vm_sdma_funcs;
+ }
dma_fence_put(vm->last_update);
vm->last_update = NULL;
vm->is_compute_context = true;
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