On 12/10/2024 4:38 PM, Lucas De Marchi wrote: > On Thu, Dec 05, 2024 at 03:33:46PM +0100, Nirmoy Das wrote: >> >> On 12/5/2024 1:40 PM, Matthew Auld wrote: >>> 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? >> Yes, this exactly what is happening for this issue. >>> >>> Maybe add some more info to the commit message? >> >> I will add more details. > > Are you going to send a new version? Was waiting for more reviews. Sent out v3 with updated commit message. > Once this is fixed, please also > send a revert MR to the kconfig workaround > 3940181b1bad @ gitlab.freedesktop.org/drm/xe/ci.git I will do that. Thanks, Nirmoy > > Lucas De Marchi > >> >> >>> 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> >> >> >> Thanks, >> >> Nirmoy >> >>> >>>> --- >>>> 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; >>>> } >>>
