From 75188605c56d10c1bd3b1cd94f4872f349c3a9c8 Mon Sep 17 00:00:00 2001 From: Matthew Brost Date: Thu, 9 Oct 2025 06:06:29 -0700 Subject: [PATCH] drm/xe: Handle mixed mappings and existing VRAM on atomic faults Moving to VRAM will fail if mixed mappings are present or if the page is already located in VRAM. Atomic faults that require a move to VRAM currently retry without attempting to evict mixed mappings or locate existing VRAM mappings. This patch fixes the issue by attempting to evict mixed mappings or find existing VRAM pages when a move to VRAM fails during atomic fault handling. Fixes: a9ac0fa455b0 ("drm/xe: Strict migration policy for atomic SVM faults") Signed-off-by: Matthew Brost Reviewed-by: Himal Prasad Ghimiray Link: https://lore.kernel.org/r/20251009130629.3531962-1-matthew.brost@intel.com --- drivers/gpu/drm/xe/xe_svm.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c index 7e2db71ff34ee..b268ee0d22710 100644 --- a/drivers/gpu/drm/xe/xe_svm.c +++ b/drivers/gpu/drm/xe/xe_svm.c @@ -1073,7 +1073,17 @@ retry: drm_dbg(&vm->xe->drm, "VRAM allocation failed, falling back to retrying fault, asid=%u, errno=%pe\n", vm->usm.asid, ERR_PTR(err)); - goto retry; + + /* + * In the devmem-only case, mixed mappings may + * be found. The get_pages function will fix + * these up to a single location, allowing the + * page fault handler to make forward progress. + */ + if (ctx.devmem_only) + goto get_pages; + else + goto retry; } else { drm_err(&vm->xe->drm, "VRAM allocation failed, retry count exceeded, asid=%u, errno=%pe\n", @@ -1083,6 +1093,7 @@ retry: } } +get_pages: get_pages_start = xe_svm_stats_ktime_get(); range_debug(range, "GET PAGES"); -- 2.47.3