On 05/12/2024 12:02, Nirmoy Das wrote:
There could be still migration job going on while doing
xe_tt_unmap_sg() which could trigger GPU page faults. Fix this by
waiting for the migration job to finish.
v2: Use intr=false(Matt A)
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3466
Fixes: 75521e8b56e8 ("drm/xe: Perform dma_map when moving system buffer objects to TT")
Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v6.11+
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
Ok, so this is something like ttm_bo_move_to_ghost() doing a pipeline
move for tt -> system, but we then do xe_tt_unmap_sg() too early which
tears down the IOMMU (if enabled) mappings whilst the job is in progress?
Maybe add some more info to the commit message? I think this for sure
fixes it. Just wondering if it's somehow possible to keep the mapping
until the job is done, since all tt -> sys moves are now synced here?
Unless Thomas has a better idea here,
Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx>
---
drivers/gpu/drm/xe/xe_bo.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index b2aa368a23f8..c906a5529db0 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -857,8 +857,16 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
out:
if ((!ttm_bo->resource || ttm_bo->resource->mem_type == XE_PL_SYSTEM) &&
- ttm_bo->ttm)
+ ttm_bo->ttm) {
+ long timeout = dma_resv_wait_timeout(ttm_bo->base.resv,
+ DMA_RESV_USAGE_BOOKKEEP,
+ false,
+ MAX_SCHEDULE_TIMEOUT);
+ if (timeout < 0)
+ ret = timeout;
+
xe_tt_unmap_sg(ttm_bo->ttm);
+ }
return ret;
}
