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* [PATCH] drm/xe/guc: Reset GuC before unmapping its post-hwconfig buffers
@ 2026-10-19 10:04 Sujaritha Sundaresan
  2026-10-19  9:26 ` ✓ CI.KUnit: success for " Patchwork
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Sujaritha Sundaresan @ 2026-10-19 10:04 UTC (permalink / raw)
  To: intel-xe
  Cc: Tangudu Tilak Tirumalesh, Matthew Brost, Stuart Summers,
	Sujaritha Sundaresan

guc_fini_hw() resets the GuC on teardown, but it is registered before
xe_guc_init_post_hwconfig() (re)allocates most of the GuC buffers. As
devm actions run in reverse order, these buffers get unmapped from the
GGTT while the GuC is still running and may still access them. When
unmapped GGTT entries are left invalid, this results in a GuC page
fault on unbind or probe failure.

Re-register guc_fini_hw() after all the GuC buffer allocations, so the
GuC is reset before any of them is unmapped. Keep GuC submit and RC
teardown running before the reset, as they still need to stop or talk
to the GuC.

Assisted-by: LLM
Signed-off-by: Sujaritha Sundaresan <sujaritha.sundaresan@intel.com>
---
 drivers/gpu/drm/xe/xe_guc.c | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
index 6c35474ab843..14ae73844d76 100644
--- a/drivers/gpu/drm/xe/xe_guc.c
+++ b/drivers/gpu/drm/xe/xe_guc.c
@@ -882,9 +882,10 @@ static u32 guc_additional_cache_size(struct xe_device *xe)
  */
 int xe_guc_init_post_hwconfig(struct xe_guc *guc)
 {
+	struct xe_device *xe = guc_to_xe(guc);
 	int ret;
 
-	if (IS_SRIOV_VF(guc_to_xe(guc)))
+	if (IS_SRIOV_VF(xe))
 		return vf_guc_init_post_hwconfig(guc);
 
 	ret = xe_guc_realloc_post_hwconfig(guc);
@@ -897,28 +898,41 @@ int xe_guc_init_post_hwconfig(struct xe_guc *guc)
 
 	guc_init_params_post_hwconfig(guc);
 
-	ret = xe_guc_submit_init(guc);
+	ret = xe_guc_pc_init(&guc->pc);
 	if (ret)
 		return ret;
 
-	ret = xe_guc_db_mgr_init(&guc->dbm, ~0);
+	ret = xe_guc_engine_activity_init(guc);
 	if (ret)
 		return ret;
 
-	ret = xe_guc_pc_init(&guc->pc);
+	ret = xe_guc_buf_cache_init_with_size(&guc->buf,
+					      guc_additional_cache_size(xe));
 	if (ret)
 		return ret;
 
-	ret = xe_guc_rc_init(guc);
+	/*
+	 * The GuC keeps accessing its GGTT-mapped buffers until it is reset,
+	 * so move guc_fini_hw() after all GuC allocations above to have the
+	 * reset done before any of them is unpinned and its GGTT PTEs cleared.
+	 * Teardown actions that must run before the reset, either because they
+	 * still talk to the GuC (like GuC RC) or because they stop the CT and
+	 * submission (like GuC submit), must be registered after this point.
+	 */
+	devm_remove_action(xe->drm.dev, guc_fini_hw, guc);
+	ret = devm_add_action_or_reset(xe->drm.dev, guc_fini_hw, guc);
 	if (ret)
 		return ret;
 
-	ret = xe_guc_engine_activity_init(guc);
+	ret = xe_guc_submit_init(guc);
 	if (ret)
 		return ret;
 
-	ret = xe_guc_buf_cache_init_with_size(&guc->buf,
-					      guc_additional_cache_size(guc_to_xe(guc)));
+	ret = xe_guc_db_mgr_init(&guc->dbm, ~0);
+	if (ret)
+		return ret;
+
+	ret = xe_guc_rc_init(guc);
 	if (ret)
 		return ret;
 

base-commit: 5bc00022b24f8a7bc6630609e9fd93dd977a87d3
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-10-26 14:09 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2026-10-19 10:04 [PATCH] drm/xe/guc: Reset GuC before unmapping its post-hwconfig buffers Sujaritha Sundaresan
2026-10-19  9:26 ` ✓ CI.KUnit: success for " Patchwork
2026-10-19 10:17 ` ✓ Xe.CI.BAT: " Patchwork
2026-10-19 12:08 ` ✗ Xe.CI.FULL: failure " Patchwork
2026-10-26 14:07 ` [PATCH] " Vivekanandan, Balasubramani

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