Commit ec671737 authored by Christian König's avatar Christian König Committed by Alex Deucher

drm/amdgpu: add graceful VM fault handling v3

Next step towards HMM support. For now just silence the retry fault and
optionally redirect the request to the dummy page.

v2: make sure the VM is not destroyed while we handle the fault.
v3: fix VM destroy check, cleanup comments
Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent b65709a9
......@@ -3126,3 +3126,76 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
}
}
}
/**
* amdgpu_vm_handle_fault - graceful handling of VM faults.
* @adev: amdgpu device pointer
* @pasid: PASID of the VM
* @addr: Address of the fault
*
* Try to gracefully handle a VM fault. Return true if the fault was handled and
* shouldn't be reported any more.
*/
bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, unsigned int pasid,
uint64_t addr)
{
struct amdgpu_bo *root;
uint64_t value, flags;
struct amdgpu_vm *vm;
long r;
spin_lock(&adev->vm_manager.pasid_lock);
vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
if (vm)
root = amdgpu_bo_ref(vm->root.base.bo);
else
root = NULL;
spin_unlock(&adev->vm_manager.pasid_lock);
if (!root)
return false;
r = amdgpu_bo_reserve(root, true);
if (r)
goto error_unref;
/* Double check that the VM still exists */
spin_lock(&adev->vm_manager.pasid_lock);
vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
if (vm && vm->root.base.bo != root)
vm = NULL;
spin_unlock(&adev->vm_manager.pasid_lock);
if (!vm)
goto error_unlock;
addr /= AMDGPU_GPU_PAGE_SIZE;
flags = AMDGPU_PTE_VALID | AMDGPU_PTE_SNOOPED |
AMDGPU_PTE_SYSTEM;
if (amdgpu_vm_fault_stop == AMDGPU_VM_FAULT_STOP_NEVER) {
/* Redirect the access to the dummy page */
value = adev->dummy_page_addr;
flags |= AMDGPU_PTE_EXECUTABLE | AMDGPU_PTE_READABLE |
AMDGPU_PTE_WRITEABLE;
} else {
/* Let the hw retry silently on the PTE */
value = 0;
}
r = amdgpu_vm_bo_update_mapping(adev, vm, true, NULL, addr, addr + 1,
flags, value, NULL, NULL);
if (r)
goto error_unlock;
r = amdgpu_vm_update_pdes(adev, vm, true);
error_unlock:
amdgpu_bo_unreserve(root);
if (r < 0)
DRM_ERROR("Can't handle page fault (%ld)\n", r);
error_unref:
amdgpu_bo_unref(&root);
return false;
}
......@@ -413,6 +413,8 @@ void amdgpu_vm_check_compute_bug(struct amdgpu_device *adev);
void amdgpu_vm_get_task_info(struct amdgpu_device *adev, unsigned int pasid,
struct amdgpu_task_info *task_info);
bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, unsigned int pasid,
uint64_t addr);
void amdgpu_vm_set_task_info(struct amdgpu_vm *vm);
......
......@@ -380,6 +380,10 @@ static int gmc_v9_0_process_interrupt(struct amdgpu_device *adev,
}
/* If it's the first fault for this address, process it normally */
if (retry_fault && !in_interrupt() &&
amdgpu_vm_handle_fault(adev, entry->pasid, addr))
return 1; /* This also prevents sending it to KFD */
if (!amdgpu_sriov_vf(adev)) {
/*
* Issue a dummy read to wait for the status register to
......
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