[PATCH v4 5/9] drm/xe: Add cpu_caching to properties line in VM snapshot capture

Matthew Brost matthew.brost at intel.com
Wed May 7 20:15:35 UTC 2025


Add CPU caching to properties line in VM snapshot capture indicating
the BO caching properites. This is useful information for debug and
will help build a robust GPU hang replay tool.

The current format is:

[<vma address>]: <permissions>|<type>|mem_region=0x%x|pat_index=%d|cpu_caching=%d

Permissions has two options, either "read_only" or "read_write".

Type has three options, either "userptr", "null_sparse", or "bo".

Memory region is a bit mask of where the memory is located.

Pat index corresponds to the value setup upon VM bind.

CPU caching corresponds to the value of BO setup upon creation.

v2:
 - Save off cpu_caching value rather than looking at BO (Carlos)
v4:
 - Fix NULL ptr dereference (Carlos)

Cc: José Roberto de Souza <jose.souza at intel.com>
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
---
 drivers/gpu/drm/xe/xe_vm.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 0675c46b7c63..5af2e79ae34e 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -3733,6 +3733,7 @@ struct xe_vm_snapshot {
 		unsigned long flags;
 		int uapi_mem_region;
 		int pat_index;
+		int cpu_caching;
 		struct xe_bo *bo;
 		void *data;
 		struct mm_struct *mm;
@@ -3777,6 +3778,7 @@ struct xe_vm_snapshot *xe_vm_snapshot_capture(struct xe_vm *vm)
 			XE_VM_SNAP_FLAG_READ_ONLY : 0;
 		snap->snap[i].pat_index = vma->pat_index;
 		if (bo) {
+			snap->snap[i].cpu_caching = bo->cpu_caching;
 			snap->snap[i].bo = xe_bo_get(bo);
 			snap->snap[i].bo_ofs = xe_vma_bo_offset(vma);
 			switch (bo->ttm.resource->mem_type) {
@@ -3877,7 +3879,7 @@ void xe_vm_snapshot_print(struct xe_vm_snapshot *snap, struct drm_printer *p)
 	for (i = 0; i < snap->num_snaps; i++) {
 		drm_printf(p, "[%llx].length: 0x%lx\n", snap->snap[i].ofs, snap->snap[i].len);
 
-		drm_printf(p, "[%llx].properties: %s|%s|mem_region=0x%lx|pat_index=%d\n",
+		drm_printf(p, "[%llx].properties: %s|%s|mem_region=0x%lx|pat_index=%d|cpu_caching=%d\n",
 			   snap->snap[i].ofs,
 			   snap->snap[i].flags & XE_VM_SNAP_FLAG_READ_ONLY ?
 			   "read_only" : "read_write",
@@ -3887,7 +3889,8 @@ void xe_vm_snapshot_print(struct xe_vm_snapshot *snap, struct drm_printer *p)
 			   "userptr" : "bo",
 			   snap->snap[i].uapi_mem_region == -1 ? 0 :
 			   BIT(snap->snap[i].uapi_mem_region),
-			   snap->snap[i].pat_index);
+			   snap->snap[i].pat_index,
+			   snap->snap[i].cpu_caching);
 
 		if (IS_ERR(snap->snap[i].data)) {
 			drm_printf(p, "[%llx].error: %li\n", snap->snap[i].ofs,
-- 
2.34.1



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