Re: [PATCH V15 13/14] drm/xe/uapi: Expose ban reason in EXEC_QUEUE_GET_PROPERTY_BAN

On 11-08-2026 18:10, Tejas Upadhyay wrote:
> 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.
> 
> 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 <[email protected]>
> Acked-by: Michal Mrozek <[email protected]>
> Signed-off-by: Tejas Upadhyay <[email protected]>

Reviewed-by: Himal Prasad Ghimiray <[email protected]>

> ---
>   drivers/gpu/drm/xe/xe_exec_queue_types.h |  7 ++++--
>   drivers/gpu/drm/xe/xe_execlist.c         |  4 +--
>   drivers/gpu/drm/xe/xe_guc_submit.c       | 32 ++++++++++++++++++++----
>   drivers/gpu/drm/xe/xe_ttm_vram_mgr.c     | 10 +++++++-
>   include/uapi/drm/xe_drm.h                | 12 ++++++++-
>   5 files changed, 54 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
> index b2276559c2f6..a21916359e2f 100644
> --- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
> +++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
> @@ -156,6 +156,9 @@ struct xe_exec_queue {
>   	 */
>   	unsigned long flags;
>   
> +	/** @ban_reason: Bitmask of ban reasons (DRM_XE_EXEC_QUEUE_BAN_REASON_*) */
> +	atomic_t ban_reason;
> +
>   	union {
>   		/** @multi_gt_list: list head for VM bind engines if multi-GT */
>   		struct list_head multi_gt_list;
> @@ -350,8 +353,8 @@ struct xe_exec_queue_ops {
>   	 * signalled when this function is called.
>   	 */
>   	void (*resume)(struct xe_exec_queue *q);
> -	/** @reset_status: check exec queue reset status */
> -	bool (*reset_status)(struct xe_exec_queue *q);
> +	/** @reset_status: check exec queue ban status, returns ban reason bitmask */
> +	u64 (*reset_status)(struct xe_exec_queue *q);
>   };
>   
>   #endif
> diff --git a/drivers/gpu/drm/xe/xe_execlist.c b/drivers/gpu/drm/xe/xe_execlist.c
> index cc33ae80e8cf..534e7c4e0099 100644
> --- a/drivers/gpu/drm/xe/xe_execlist.c
> +++ b/drivers/gpu/drm/xe/xe_execlist.c
> @@ -452,10 +452,10 @@ static void execlist_exec_queue_resume(struct xe_exec_queue *q)
>   	/* NIY */
>   }
>   
> -static bool execlist_exec_queue_reset_status(struct xe_exec_queue *q)
> +static u64 execlist_exec_queue_reset_status(struct xe_exec_queue *q)
>   {
>   	/* NIY */
> -	return false;
> +	return 0;
>   }
>   
>   static const struct xe_exec_queue_ops execlist_exec_queue_ops = {
> diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
> index 9036f89dff7d..f52577de1ac2 100644
> --- a/drivers/gpu/drm/xe/xe_guc_submit.c
> +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
> @@ -6,6 +6,7 @@
>   #include "xe_guc_submit.h"
>   
>   #include <linux/bitfield.h>
> +#include <uapi/drm/xe_drm.h>
>   #include <linux/bitmap.h>
>   #include <linux/circ_buf.h>
>   #include <linux/dma-fence-array.h>
> @@ -1593,6 +1594,12 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
>   	if (!exec_queue_killed(q))
>   		wedged = guc_submit_hint_wedged(exec_queue_to_guc(q));
>   
> +	/*
> +	 * Only tag as GPU hang if this is the original timeout, not a
> +	 * consequence of a prior kill (e.g., page-offline).
> +	 */
> +	if (!exec_queue_killed(q))
> +		atomic_or(DRM_XE_EXEC_QUEUE_BAN_REASON_GPU_HANG, &q->ban_reason);
>   	set_exec_queue_banned(q);
>   
>   	/* Kick job / queue off hardware */
> @@ -1676,6 +1683,9 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
>   		if (timeout_needs_gt_reset(q, job, skip_timeout_check)) {
>   			if (!xe_sched_invalidate_job(job, 2)) {
>   				clear_exec_queue_banned(q);
> +				/* protect concurrent page offline reasons */
> +				atomic_andnot(DRM_XE_EXEC_QUEUE_BAN_REASON_GPU_HANG,
> +					      &q->ban_reason);
>   				xe_gt_reset_async(q->gt);
>   				goto rearm;
>   			}
> @@ -2570,13 +2580,25 @@ static void guc_exec_queue_multi_queue_drop_suspend(struct xe_exec_queue *q)
>   	}
>   }
>   
> -static bool guc_exec_queue_reset_status(struct xe_exec_queue *q)
> +static u64 guc_exec_queue_reset_status(struct xe_exec_queue *q)
>   {
> -	if (xe_exec_queue_is_multi_queue_secondary(q) &&
> -	    guc_exec_queue_reset_status(xe_exec_queue_multi_queue_primary(q)))
> -		return true;
> +	if (xe_exec_queue_is_multi_queue_secondary(q)) {
> +		u64 status = guc_exec_queue_reset_status(xe_exec_queue_multi_queue_primary(q));
>   
> -	return exec_queue_reset(q) || exec_queue_killed_or_banned_or_wedged(q);
> +		if (status)
> +			return status;
> +	}
> +
> +	if (exec_queue_reset(q) || exec_queue_killed_or_banned_or_wedged(q)) {
> +		u64 reason = atomic_read_acquire(&q->ban_reason);
> +
> +		/* If no specific reason was recorded, default to GPU hang */
> +		if (!reason)
> +			reason = DRM_XE_EXEC_QUEUE_BAN_REASON_GPU_HANG;
> +		return reason;
> +	}
> +
> +	return 0;
>   }
>   
>   /*
> diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> index c22669955147..5bb66c7b5505 100644
> --- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> +++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> @@ -7,6 +7,7 @@
>   #include <drm/drm_managed.h>
>   #include <drm/drm_drv.h>
>   #include <drm/drm_buddy.h>
> +#include <uapi/drm/xe_drm.h>
>   
>   #include <drm/ttm/ttm_placement.h>
>   #include <drm/ttm/ttm_range_manager.h>
> @@ -541,7 +542,12 @@ static int xe_ttm_vram_purge_page(struct xe_device *xe, struct xe_bo *bo)
>   	xe_bo_unlock(bo);
>   	/*  Ban VM if BO is PPGTT */
>   	if (vm && (flags & XE_BO_FLAG_PAGETABLE)) {
> +		struct xe_exec_queue *eq;
> +
>   		down_write(&vm->lock);
> +		list_for_each_entry(eq, &vm->preempt.exec_queues, lr.link)
> +			atomic_or(DRM_XE_EXEC_QUEUE_BAN_REASON_PAGE_OFFLINE, &eq->ban_reason);
> +		smp_wmb(); /* Force all queue bits to be visible before killing the VM */
>   		xe_vm_kill(vm, true);
>   		up_write(&vm->lock);
>   	}
> @@ -553,7 +559,9 @@ static int xe_ttm_vram_purge_page(struct xe_device *xe, struct xe_bo *bo)
>   	/*  Ban exec queue if BO is lrc */
>   	if (q && xe_exec_queue_get_unless_zero(q)) {
>   		/* ban queue */
> -		q_to_put = q;
> +                atomic_or(DRM_XE_EXEC_QUEUE_BAN_REASON_PAGE_OFFLINE, &q->ban_reason);
> +                smp_wmb(); /* Force bit change to finish before state change triggers */
> +                q_to_put = q;
>   	}
>   
>   	if (bo->purgeable.state == XE_MADV_PURGEABLE_PURGED) {
> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> index 509202a7b13e..1600e8f0885a 100644
> --- a/include/uapi/drm/xe_drm.h
> +++ b/include/uapi/drm/xe_drm.h
> @@ -1503,7 +1503,17 @@ 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 */