Re: [PATCH v8 10/24] drm/xe: Update GuC submission backend to run PT jobs

["Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>]

On 26-09-2026 01:45, Matthew Brost wrote:
> PT jobs bypass GPU execution for the final step of a bind job, using the
> CPU to program the required page tables. Teach the GuC submission backend
> how to execute these jobs.
> 
> PT job submission is implemented in the GuC backend for simplicity. A
> follow-up patch could introduce a dedicated backend for PT jobs.
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> Reviewed-by: Maarten Lankhorst <dev@lankhorst.se>
> ---
>   drivers/gpu/drm/xe/xe_guc_submit.c | 31 +++++++++++++++++++++++++++---
>   drivers/gpu/drm/xe/xe_migrate.c    | 20 +++++++++++++++----
>   drivers/gpu/drm/xe/xe_migrate.h    |  7 +++++++
>   3 files changed, 51 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
> index 4bd1ead57efa..9faddb7c6407 100644
> --- a/drivers/gpu/drm/xe/xe_guc_submit.c
> +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
> @@ -39,9 +39,11 @@
>   #include "xe_lrc.h"
>   #include "xe_macros.h"
>   #include "xe_map.h"
> +#include "xe_migrate.h"
>   #include "xe_mocs.h"
>   #include "xe_module.h"
>   #include "xe_pm.h"
> +#include "xe_pt.h"
>   #include "xe_ring_ops_types.h"
>   #include "xe_sched_job.h"
>   #include "xe_sleep.h"
> @@ -1238,21 +1240,44 @@ static void submit_exec_queue(struct xe_exec_queue *q, struct xe_sched_job *job)
>   	}
>   }
>   
> +static bool is_pt_job(struct xe_sched_job *job)
> +{
> +	return job->is_pt_job;
> +}
> +
> +static void run_pt_job(struct xe_sched_job *job, bool force_clear)
> +{
> +	xe_migrate_update_pgtables_cpu_execute(job->pt_update[0].vm,
> +					       job->pt_update[0].tile,
> +					       job->pt_update[0].ops,
> +					       job->pt_update[0].pt_job_ops->ops,
> +					       job->pt_update[0].pt_job_ops->current_op,
> +					       force_clear);
> +}
> +
>   static struct dma_fence *
>   guc_exec_queue_run_job(struct drm_sched_job *drm_job)
>   {
>   	struct xe_sched_job *job = to_xe_sched_job(drm_job);
>   	struct xe_exec_queue *q = job->q;
>   	struct xe_guc *guc = exec_queue_to_guc(q);
> -	bool killed_or_banned_or_wedged =
> -		exec_queue_killed_or_banned_or_wedged(q);
> +	bool killed_or_banned_or_wedged_or_error  =
> +		exec_queue_killed_or_banned_or_wedged(q) ||
> +		xe_sched_job_is_error(job);

Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

>   
>   	xe_gt_assert(guc_to_gt(guc), !(exec_queue_destroyed(q) || exec_queue_pending_disable(q)) ||
>   		     exec_queue_banned(q) || exec_queue_suspended(q));
>   
>   	trace_xe_sched_job_run(job);
>   
> -	if (!killed_or_banned_or_wedged && !xe_sched_job_is_error(job)) {
> +	if (is_pt_job(job)) {
> +		xe_gt_assert(guc_to_gt(guc), !exec_queue_registered(q));
> +		run_pt_job(job, killed_or_banned_or_wedged_or_error);
> +		xe_pt_job_ops_put(job->pt_update[0].pt_job_ops);
> +		dma_fence_put(job->fence);	/* Drop ref from xe_sched_job_arm */
> +
> +		return NULL;
> +	} else if (!killed_or_banned_or_wedged_or_error) {
>   		if (xe_exec_queue_is_multi_queue_secondary(q)) {
>   			struct xe_exec_queue *primary = xe_exec_queue_multi_queue_primary(q);
>   
> diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
> index d7f35aa91c1c..3007fe0b8535 100644
> --- a/drivers/gpu/drm/xe/xe_migrate.c
> +++ b/drivers/gpu/drm/xe/xe_migrate.c
> @@ -1819,11 +1819,23 @@ struct migrate_test_params {
>   	container_of(_priv, struct migrate_test_params, base)
>   #endif
>   
> -static void
> +/**
> + * xe_migrate_update_pgtables_cpu_execute() - Update a VM's PTEs via the CPU
> + * @vm: The VM being updated
> + * @tile: The tile being updated
> + * @ops: The migrate PT update ops
> + * @pt_ops: The VM PT update ops
> + * @num_ops: The number of The VM PT update ops
> + * @force_clear: Force clear
> + *
> + * Execute the VM PT update ops array which results in a VM's PTEs being updated
> + * via the CPU.
> + */
> +void
>   xe_migrate_update_pgtables_cpu_execute(struct xe_vm *vm, struct xe_tile *tile,
>   				       const struct xe_migrate_pt_update_ops *ops,
>   				       struct xe_vm_pgtable_update_op *pt_op,
> -				       u32 num_ops)
> +				       u32 num_ops, bool force_clear)
>   {
>   	u32 j, i;
>   
> @@ -1834,7 +1846,7 @@ xe_migrate_update_pgtables_cpu_execute(struct xe_vm *vm, struct xe_tile *tile,
>   
>   			xe_tile_assert(tile, !iosys_map_is_null(&update->pt_bo->vmap));
>   
> -			if (pt_op->bind)
> +			if (pt_op->bind && !force_clear)
>   				ops->populate(tile, &update->pt_bo->vmap,
>   					      NULL, update->ofs, update->qwords,
>   					      update);
> @@ -1874,7 +1886,7 @@ xe_migrate_update_pgtables_cpu(struct xe_migrate *m,
>   
>   	xe_migrate_update_pgtables_cpu_execute(vm, m->tile, ops,
>   					       pt_update_ops->pt_job_ops->ops,
> -					       pt_update_ops->num_ops);
> +					       pt_update_ops->num_ops, false);
>   
>   	return dma_fence_get_stub();
>   }
> diff --git a/drivers/gpu/drm/xe/xe_migrate.h b/drivers/gpu/drm/xe/xe_migrate.h
> index 2ec9de896dfe..c41f6e3ca2c6 100644
> --- a/drivers/gpu/drm/xe/xe_migrate.h
> +++ b/drivers/gpu/drm/xe/xe_migrate.h
> @@ -24,6 +24,7 @@ struct xe_pt;
>   struct xe_tile;
>   struct xe_vm;
>   struct xe_vm_pgtable_update;
> +struct xe_vm_pgtable_update_op;
>   struct xe_vma;
>   
>   enum xe_sriov_vf_ccs_rw_ctxs;
> @@ -163,6 +164,12 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>   
>   struct xe_vm *xe_migrate_get_vm(struct xe_migrate *m);
>   
> +void
> +xe_migrate_update_pgtables_cpu_execute(struct xe_vm *vm, struct xe_tile *tile,
> +				       const struct xe_migrate_pt_update_ops *ops,
> +				       struct xe_vm_pgtable_update_op *pt_op,
> +				       u32 num_ops, bool force_clear);
> +
>   struct dma_fence *
>   xe_migrate_update_pgtables(struct xe_migrate *m,
>   			   struct xe_migrate_pt_update *pt_update);