On 7/8/24 17:21, Thomas Zimmermann wrote:
> Add qxl_bo_pin_and_vmap() that pins and vmaps a buffer object in one
> step. Update callers of the regular qxl_bo_vmap(). Fixes a bug where
> qxl accesses an unpinned buffer object while it is being moved; such
> as with the monitor-description BO. An typical error is shown below.
>
> [ 4.303586] [drm:drm_atomic_helper_commit_planes] *ERROR* head 1 wrong: 65376256x16777216+0+0
> [ 4.586883] [drm:drm_atomic_helper_commit_planes] *ERROR* head 1 wrong: 65376256x16777216+0+0
> [ 4.904036] [drm:drm_atomic_helper_commit_planes] *ERROR* head 1 wrong: 65335296x16777216+0+0
> [ 5.374347] [drm:qxl_release_from_id_locked] *ERROR* failed to find id in release_idr
>
> Commit b33651a5c98d ("drm/qxl: Do not pin buffer objects for vmap")
> removed the implicit pin operation from qxl's vmap code. This is the
> correct behavior for GEM and PRIME interfaces, but the pin is still
> needed for qxl internal operation.
>
> Also add a corresponding function qxl_bo_vunmap_and_unpin() and remove
> the old qxl_bo_vmap() helpers.
>
> Future directions: BOs should not be pinned or vmapped unnecessarily.
> The pin-and-vmap operation should be removed from the driver and a
> temporary mapping should be established with a vmap_local-like helper.
> See the client helper drm_client_buffer_vmap_local() for semantics.
>
> v2:
> - unreserve BO on errors in qxl_bo_pin_and_vmap() (Dmitry)
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Fixes: b33651a5c98d ("drm/qxl: Do not pin buffer objects for vmap")
> Reported-by: David Kaplan <david.kaplan@xxxxxxx>
> Closes: https://lore.kernel.org/dri-devel/ab0fb17d-0f96-4ee6-8b21-65d02bb02655@xxxxxxx/
> Tested-by: David Kaplan <david.kaplan@xxxxxxx>
> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> Cc: Christian König <christian.koenig@xxxxxxx>
> Cc: Zack Rusin <zack.rusin@xxxxxxxxxxxx>
> Cc: Dave Airlie <airlied@xxxxxxxxxx>
> Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> Cc: virtualization@xxxxxxxxxxxxxxx
> Cc: spice-devel@xxxxxxxxxxxxxxxxxxxxx
> ---
> drivers/gpu/drm/qxl/qxl_display.c | 14 +++++++-------
> drivers/gpu/drm/qxl/qxl_object.c | 13 +++++++++++--
> drivers/gpu/drm/qxl/qxl_object.h | 4 ++--
> 3 files changed, 20 insertions(+), 11 deletions(-)
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
--
Best regards,
Dmitry