From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= <thomas.hellstrom@linux.intel.com>
To: intel-xe@lists.freedesktop.org
Cc: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= <thomas.hellstrom@linux.intel.com>,
	Matthew Brost <matthew.brost@intel.com>,
	Matthew Auld <matthew.auld@intel.com>,
	stable@vger.kernel.org
Subject: [PATCH] drm/xe: Fix incorrect migration of backed-up object to VRAM
Date: Thu, 28 Aug 2025 15:48:37 +0200
Message-ID: <20250828134837.5709-1-thomas.hellstrom@linux.intel.com>
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If an object is backed up to shmem it is incorrectly identified
as not having valid data by the move code. This means moving
to VRAM skips the -EMULTIHOP step and the bo is cleared. This
causes all sorts of weird behaviour on DGFX if an already evicted
object is targeted by the shrinker.

Fix this by using ttm_tt_is_swapped() to identify backed-up
objects.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/5996
Fixes: 00c8efc3180f ("drm/xe: Add a shrinker for xe bos")
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: <stable@vger.kernel.org> # v6.15+
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
---
 drivers/gpu/drm/xe/xe_bo.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 7d1ff642b02a..4faf15d5fa6d 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -823,8 +823,7 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
 		return ret;
 	}
 
-	tt_has_data = ttm && (ttm_tt_is_populated(ttm) ||
-			      (ttm->page_flags & TTM_TT_FLAG_SWAPPED));
+	tt_has_data = ttm && (ttm_tt_is_populated(ttm) || ttm_tt_is_swapped(ttm));
 
 	move_lacks_source = !old_mem || (handle_system_ccs ? (!bo->ccs_cleared) :
 					 (!mem_type_is_vram(old_mem_type) && !tt_has_data));
-- 
2.50.1