drm/xe/uapi: Expose ban reason in EXEC_QUEUE_GET_PROPERTY_BAN

Extend DRM_XE_EXEC_QUEUE_GET_PROPERTY_BAN to return a bitmask indicating
the reason for the ban, rather than a simple boolean. This allows
userspace to distinguish between different ban causes:

- DRM_XE_EXEC_QUEUE_BAN_REASON_GPU_HANG (bit 0): exec queue was banned
  due to a GPU hang or job timeout detected by the TDR.
- DRM_XE_EXEC_QUEUE_BAN_REASON_PAGE_OFFLINE (bit 1): exec queue was
  banned because a VRAM page backing its resources was taken offline.

The ban_reason field is added to struct xe_exec_queue and set at the
point where the ban is triggered:
- In guc_exec_queue_timedout_job() for GPU hang.
- In xe_ttm_vram_purge_page() for memory page offline, before calling
  xe_exec_queue_kill() or xe_vm_kill().

The reset_status op is updated to return u64 with the reason bitmask.
When a queue is banned but no explicit reason was recorded (e.g., from a
generic CAT error), it defaults to GPU_HANG for backward compatibility.
A value of 0 means the exec queue is not banned.

v5 (Sashiko/MattB):
- Take the write lock for the traversal to tag ban_reason
v4(Sashiko):
- Add ban reason for non-LR exec queues
- Add TODO for multiqueue
v3(Rodrigo):
- Add doc in xe_drm.h
v2(Sashiko):
- Use atomic_t for ban_reason to fix concurrent updates from TDR and
  page-offline
- Guard GPU_HANG bit with !exec_queue_killed to avoid masking
  page-offline reason
- Clear ban_reason on queue recovery (clear_exec_queue_banned path)
- Use atomic_read in guc_exec_queue_reset_status for lockless read

Assisted-by: Copilot:claude-opus-4.6
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Michal Mrozek <michal.mrozek@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260903161553.528932-31-tejas.upadhyay@intel.com

1 files changed, 17 insertions, 1 deletions

diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
index 8c852abcacf0..578f0c1eb43e 100644
--- a/include/uapi/drm/xe_drm.h
+++ b/include/uapi/drm/xe_drm.h
@@ -1491,6 +1491,12 @@ struct drm_xe_exec_queue_destroy {
  *
  * The @property can be:
  *  - %DRM_XE_EXEC_QUEUE_GET_PROPERTY_BAN
+ *
+ * For %DRM_XE_EXEC_QUEUE_GET_PROPERTY_BAN, @value is a bitmask of ban reasons:
+ *  - %DRM_XE_EXEC_QUEUE_BAN_REASON_GPU_HANG - banned due to GPU hang/timeout
+ *  - %DRM_XE_EXEC_QUEUE_BAN_REASON_PAGE_OFFLINE - banned due to memory page offline
+ *
+ * A @value of 0 means the exec queue is not banned.
  */
 struct drm_xe_exec_queue_get_property {
 	/** @extensions: Pointer to the first extension struct, if any */
@@ -1503,7 +1509,17 @@ struct drm_xe_exec_queue_get_property {
 	/** @property: property to get */
 	__u32 property;
 
-	/** @value: property value */
+	/**
+	 * @value: property value
+	 *
+	 * For %DRM_XE_EXEC_QUEUE_GET_PROPERTY_BAN, this is a bitmask of:
+	 *  - %DRM_XE_EXEC_QUEUE_BAN_REASON_GPU_HANG - banned due to GPU hang/timeout
+	 *  - %DRM_XE_EXEC_QUEUE_BAN_REASON_PAGE_OFFLINE - banned due to memory page offline
+	 *
+	 * Value of 0 means the exec queue is not banned.
+	 */
+#define DRM_XE_EXEC_QUEUE_BAN_REASON_GPU_HANG		(1 << 0)
+#define DRM_XE_EXEC_QUEUE_BAN_REASON_PAGE_OFFLINE	(1 << 1)
 	__u64 value;
 
 	/** @reserved: Reserved */