Am 29.08.2018 um 04:52 schrieb Zhang, Jerry (Junwei):
On 08/28/2018 08:40 PM, Emily Deng wrote:
Fix the VMC page fault when the running sequence is as below:
1.amdgpu_gem_create_ioctl
2.ttm_bo_swapout->amdgpu_vm_bo_invalidate, as not called
amdgpu_vm_bo_base_init, so won't called
list_add_tail(&base->bo_list, &bo->va). Even the bo was evicted,
it won't set the bo_base->moved.
IMO, the evicted bo should be created previously.
On BO creation we will add it to the bo->va as below:
amdgpu_gem_create_ioctl
drm_gem_handle_create
amdgpu_gem_object_open
And here is the problem. Between creating the BO and opening it in the
client the BO can be evicted.
That's what Emily's patch is handling here.
Christian.
amdgpu_vm_bo_add
amdgpu_vm_bo_base_init
list_add_tail(&base->bo_list, &bo->va)
Then it could be set moved in bo invalidate when evicting.
could you provide a bit more backgroud about the issue?
looks a per vm bo is evicted and a new same bo created.
Jerry
3.drm_gem_open_ioctl->amdgpu_vm_bo_base_init, here only called
list_move_tail(&base->vm_status, &vm->evicted), but not set the
bo_base->moved.
4.amdgpu_vm_bo_map->amdgpu_vm_bo_insert_map, as the bo_base->moved is
not set true, the function amdgpu_vm_bo_insert_map will call
list_move(&bo_va->base.vm_status, &vm->moved)
5.amdgpu_cs_ioctl won't validate the swapout bo, as it is only in the
moved list, not in the evict list. So VMC page fault occurs.
Signed-off-by: Emily Deng <[email protected]>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 1f4b8df..015e20e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -172,6 +172,7 @@ static void amdgpu_vm_bo_base_init(struct
amdgpu_vm_bo_base *base,
* is validated on next vm use to avoid fault.
* */
list_move_tail(&base->vm_status, &vm->evicted);
+ base->moved = true;
}
/**
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