Re: [PATCH v8 05/10] drm/xe/exec_queue: Introduce xe_exec_queue_reinit()

[Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>]

On 6/3/2026 3:17 AM, Raag Jadav wrote:
> In preparation of usecases which require re-initializing exec queue
> after PCIe FLR, introduce xe_exec_queue_reinit() helper. All the exec
> queue LCRs already exist but the context is lost on PCIe FLR and needs
> re-initialization.
>
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> Tested-by: Lukasz Laguna <lukasz.laguna@intel.com>
> ---
> v2: Re-initialize migrate context (Matthew Brost)
> v6: Add IS_DGFX() and EXEC_QUEUE_FLAG_KERNEL asserts (Daniele)
> ---
>   drivers/gpu/drm/xe/xe_exec_queue.c | 42 +++++++++++++++++++++++++++---
>   drivers/gpu/drm/xe/xe_exec_queue.h |  1 +
>   drivers/gpu/drm/xe/xe_lrc.c        | 17 ++++++++++++
>   drivers/gpu/drm/xe/xe_lrc.h        |  2 ++
>   4 files changed, 58 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
> index 1b5ca3ce578a..91b241a7ab24 100644
> --- a/drivers/gpu/drm/xe/xe_exec_queue.c
> +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
> @@ -335,9 +335,8 @@ static void __xe_exec_queue_fini(struct xe_exec_queue *q)
>   		xe_lrc_put(q->lrc[i]);
>   }
>   
> -static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
> +static u32 xe_lrc_init_flags(struct xe_exec_queue *q, u32 exec_queue_flags)
>   {
> -	int i, err;
>   	u32 flags = 0;
>   
>   	/*
> @@ -360,6 +359,13 @@ static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
>   	if (q->flags & EXEC_QUEUE_FLAG_DISABLE_STATE_CACHE_PERF_FIX)
>   		flags |= XE_LRC_DISABLE_STATE_CACHE_PERF_FIX;
>   
> +	return flags;
> +}
> +
> +static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
> +{
> +	int i, err;
> +
>   	err = q->ops->init(q);
>   	if (err)
>   		return err;
> @@ -383,8 +389,8 @@ static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
>   
>   			marker = xe_gt_sriov_vf_wait_valid_ggtt(q->gt);
>   
> -			lrc = xe_lrc_create(q->hwe, q->vm, q->replay_state,
> -					    xe_lrc_ring_size(), q->msix_vec, flags);
> +			lrc = xe_lrc_create(q->hwe, q->vm, q->replay_state, xe_lrc_ring_size(),
> +					    q->msix_vec, xe_lrc_init_flags(q, exec_queue_flags));
>   			if (IS_ERR(lrc)) {
>   				err = PTR_ERR(lrc);
>   				goto err_lrc;
> @@ -406,6 +412,34 @@ static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
>   	return err;
>   }
>   
> +/**
> + * xe_exec_queue_reinit() - Re-initialize exec queue
> + * @q: exec queue to re-initialize
> + *
> + * Returns: 0 on success, negative error code otherwise.
> + */
> +int xe_exec_queue_reinit(struct xe_exec_queue *q)
> +{
> +	int i, err;
> +
> +	/* TODO: Re-initialize GSC and PXP queues */
> +	xe_assert(gt_to_xe(q->gt), IS_DGFX(gt_to_xe(q->gt)));
You can use xe_gt_assert here. Also, note that us not supporting GSC and 
PXP on discrete is a choice, not a generic requirement, so IMO for 
PXP/GSC checking it'd be better to add:

xe_gt_assert(q->gt, !xe_uc_fw_is_loadable(&gt->uc.gsc.fw));

xe_gt_assert(q->gt, !xe_pxp_is_enabled(gt_to_xe(q->gt)->pxp));


> +	/* Re-initialization only allowed for kernel queues */
> +	xe_assert(gt_to_xe(q->gt), q->flags & EXEC_QUEUE_FLAG_KERNEL);
> +
> +	/* Re-initialize submission backend */
> +	q->ops->reinit_kernel(q);

Thinking about it, the xe_sched_reinit() call from patch 2 could be 
moved here since that's not back-end specific.
I won't ask you to re-spin just for this, so I'm ok with it being 
considered as a follow-up, but if you need to do a re-spin anyway it 
might be worth doing it now.

> +
> +	for (i = 0; i < q->width; i++) {
> +		err = xe_lrc_reinit(q->lrc[i], q->hwe, q->vm, q->replay_state,
> +				    q->msix_vec, xe_lrc_init_flags(q, q->flags));
> +		if (err)
> +			return err;
> +	}
> +
> +	return 0;
> +}
> +
>   /**
>    * xe_exec_queue_create() - Create an exec queue
>    * @xe: Xe device
> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.h b/drivers/gpu/drm/xe/xe_exec_queue.h
> index a82d99bd77bc..445867d4da26 100644
> --- a/drivers/gpu/drm/xe/xe_exec_queue.h
> +++ b/drivers/gpu/drm/xe/xe_exec_queue.h
> @@ -34,6 +34,7 @@ struct xe_exec_queue *xe_exec_queue_create_bind(struct xe_device *xe,
>   void xe_exec_queue_fini(struct xe_exec_queue *q);
>   void xe_exec_queue_destroy(struct kref *ref);
>   void xe_exec_queue_assign_name(struct xe_exec_queue *q, u32 instance);
> +int xe_exec_queue_reinit(struct xe_exec_queue *q);
>   
>   static inline struct xe_exec_queue *
>   xe_exec_queue_get_unless_zero(struct xe_exec_queue *q)
> diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
> index a4292a11391d..c425269893fe 100644
> --- a/drivers/gpu/drm/xe/xe_lrc.c
> +++ b/drivers/gpu/drm/xe/xe_lrc.c
> @@ -1629,6 +1629,23 @@ static int xe_lrc_ctx_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe, struct
>   	return err;
>   }
>   
> +/**
> + * xe_lrc_reinit() - Re-initialize LRC
> + * @lrc: Pointer to the LRC
> + * @hwe: Hardware Engine
> + * @vm: The VM (address space)
> + * @replay_state: GPU hang replay state
> + * @msix_vec: MSI-X interrupt vector (for platforms that support it)
> + * @init_flags: LRC initialization flags
> + *
> + * Returns: 0 on success, negative error code otherwise.
> + */
> +int xe_lrc_reinit(struct xe_lrc *lrc, struct xe_hw_engine *hwe, struct xe_vm *vm,
> +		  void *replay_state, u16 msix_vec, u32 init_flags)
> +{
> +	return xe_lrc_ctx_init(lrc, hwe, vm, replay_state, msix_vec, init_flags);

nit: I wonder if it 'd just be easier to just export xe_lrc_ctx_init 
instead of creating xe_lrc_reinit. Not a blocker, so with the asserts fixed:

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>

Daniele

> +}
> +
>   static int xe_lrc_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe, struct xe_vm *vm,
>   		       void *replay_state, u32 ring_size, u16 msix_vec, u32 init_flags)
>   {
> diff --git a/drivers/gpu/drm/xe/xe_lrc.h b/drivers/gpu/drm/xe/xe_lrc.h
> index 0a3a611391ee..333b11f739ea 100644
> --- a/drivers/gpu/drm/xe/xe_lrc.h
> +++ b/drivers/gpu/drm/xe/xe_lrc.h
> @@ -56,6 +56,8 @@ struct xe_lrc_snapshot {
>   
>   struct xe_lrc *xe_lrc_create(struct xe_hw_engine *hwe, struct xe_vm *vm,
>   			     void *replay_state, u32 ring_size, u16 msix_vec, u32 flags);
> +int xe_lrc_reinit(struct xe_lrc *lrc, struct xe_hw_engine *hwe, struct xe_vm *vm,
> +		  void *replay_state, u16 msix_vec, u32 init_flags);
>   void xe_lrc_destroy(struct kref *ref);
>   
>   /**