drm/amdkfd: pages_addr offset must be 0 for system range

prange->offset is for VRAM range mm_nodes, if multiple ranges share same
mm_nodes, migrate range back to VRAM will reuse the VRAM at offset of
the same mm_nodes. For system memory pages_addr array, the offset is
always 0, otherwise, update GPU mapping will use incorrect system memory
page, and cause system memory corruption.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_svm.c

@@ -1153,7 +1153,7 @@ svm_range_map_to_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 
 	prange->mapping.start = prange->start;
 	prange->mapping.last = prange->last;
-	prange->mapping.offset = prange->offset;
+	prange->mapping.offset = prange->ttm_res ? prange->offset : 0;
 	pte_flags = svm_range_get_pte_flags(adev, prange);
 
 	r = amdgpu_vm_bo_update_mapping(adev, bo_adev, vm, false, false, NULL,