Re: [PATCH 04/16] drm/xe/multi_queue: Add multi queue priority property

[Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>]

On Sat, Nov 01, 2025 at 04:59:03PM -0700, Matthew Brost wrote:
>On Fri, Oct 31, 2025 at 11:29:24AM -0700, Niranjana Vishwanathapura wrote:
>> Add support for queues of a multi queue group to set
>> their priority within the queue group by adding property
>> DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_QUEUE_PRIORITY.
>> This is the only other property supported by secondary
>> queues of a multi queue group, other than
>> DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_QUEUE.
>>
>> Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
>> ---
>>  drivers/gpu/drm/xe/xe_exec_queue.c       | 17 ++++++++++++-
>>  drivers/gpu/drm/xe/xe_exec_queue_types.h |  8 ++++++
>>  drivers/gpu/drm/xe/xe_guc_submit.c       |  1 +
>>  drivers/gpu/drm/xe/xe_lrc.c              | 32 ++++++++++++++++++++++++
>>  drivers/gpu/drm/xe/xe_lrc.h              |  5 ++++
>>  include/uapi/drm/xe_drm.h                |  3 +++
>>  6 files changed, 65 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
>> index 86404a7c9fe4..0da256428916 100644
>> --- a/drivers/gpu/drm/xe/xe_exec_queue.c
>> +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
>> @@ -177,6 +177,7 @@ static struct xe_exec_queue *__xe_exec_queue_alloc(struct xe_device *xe,
>>  	INIT_LIST_HEAD(&q->multi_gt_link);
>>  	INIT_LIST_HEAD(&q->hw_engine_group_link);
>>  	INIT_LIST_HEAD(&q->pxp.link);
>> +	q->multi_queue.priority = XE_MULTI_QUEUE_PRIORITY_NORMAL;
>>
>>  	q->sched_props.timeslice_us = hwe->eclass->sched_props.timeslice_us;
>>  	q->sched_props.preempt_timeout_us =
>> @@ -722,6 +723,17 @@ static int exec_queue_set_multi_group(struct xe_device *xe, struct xe_exec_queue
>>  	return xe_exec_queue_group_validate(xe, q, value);
>>  }
>>
>> +static int exec_queue_set_multi_queue_priority(struct xe_device *xe, struct xe_exec_queue *q,
>> +					       u64 value)
>> +{
>> +	if (XE_IOCTL_DBG(xe, value > XE_MULTI_QUEUE_PRIORITY_HIGH))
>> +		return -EINVAL;
>> +
>> +	q->multi_queue.priority = value;
>> +
>> +	return 0;
>> +}
>> +
>>  typedef int (*xe_exec_queue_set_property_fn)(struct xe_device *xe,
>>  					     struct xe_exec_queue *q,
>>  					     u64 value);
>> @@ -731,6 +743,8 @@ static const xe_exec_queue_set_property_fn exec_queue_set_property_funcs[] = {
>>  	[DRM_XE_EXEC_QUEUE_SET_PROPERTY_TIMESLICE] = exec_queue_set_timeslice,
>>  	[DRM_XE_EXEC_QUEUE_SET_PROPERTY_PXP_TYPE] = exec_queue_set_pxp_type,
>>  	[DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_GROUP] = exec_queue_set_multi_group,
>> +	[DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_QUEUE_PRIORITY] =
>> +							exec_queue_set_multi_queue_priority,
>>  };
>>
>>  static int exec_queue_user_ext_set_property(struct xe_device *xe,
>> @@ -752,7 +766,8 @@ static int exec_queue_user_ext_set_property(struct xe_device *xe,
>>  	    XE_IOCTL_DBG(xe, ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_PRIORITY &&
>>  			 ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_TIMESLICE &&
>>  			 ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_PXP_TYPE &&
>> -			 ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_GROUP))
>> +			 ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_GROUP &&
>> +			 ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_QUEUE_PRIORITY))
>>  		return -EINVAL;
>>
>>  	idx = array_index_nospec(ext.property, ARRAY_SIZE(exec_queue_set_property_funcs));
>> diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
>> index 38e47b003259..964a0e6654c7 100644
>> --- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
>> +++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
>> @@ -31,6 +31,12 @@ enum xe_exec_queue_priority {
>>  	XE_EXEC_QUEUE_PRIORITY_COUNT
>>  };
>>
>> +enum xe_multi_queue_priority {
>> +	XE_MULTI_QUEUE_PRIORITY_LOW = 0,
>> +	XE_MULTI_QUEUE_PRIORITY_NORMAL,
>> +	XE_MULTI_QUEUE_PRIORITY_HIGH,
>> +};
>
>Kernel doc.

Ok

>
>> +
>>  /**
>>   * struct xe_exec_queue_group - Execution multi queue group
>>   *
>> @@ -134,6 +140,8 @@ struct xe_exec_queue {
>>  	struct {
>>  		/** @multi_queue.group: Queue group information */
>>  		struct xe_exec_queue_group *group;
>> +		/** @multi_queue.priority: Queue priority within the multi-queue group */
>> +		enum xe_multi_queue_priority priority;
>>  		/** @multi_queue.pos: Position of queue within the multi-queue group */
>>  		u8 pos;
>>  		/** @multi_queue.valid: Queue belongs to a multi queue group */
>> diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
>> index d2aa9a2524e7..5ec144c1c2dc 100644
>> --- a/drivers/gpu/drm/xe/xe_guc_submit.c
>> +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
>> @@ -634,6 +634,7 @@ static void xe_guc_exec_queue_group_cgp_sync(struct xe_guc *guc,
>>  		return;
>>  	}
>>
>> +	xe_lrc_set_multi_queue_priority(q->lrc[0], q->multi_queue.priority);
>>  	xe_guc_exec_queue_group_cgp_update(xe, q);
>>
>>  	WRITE_ONCE(group->sync_pending, true);
>> diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
>> index b5083c99dd50..45fc5bc5de5c 100644
>> --- a/drivers/gpu/drm/xe/xe_lrc.c
>> +++ b/drivers/gpu/drm/xe/xe_lrc.c
>> @@ -44,6 +44,11 @@
>>  #define LRC_INDIRECT_CTX_BO_SIZE		SZ_4K
>>  #define LRC_INDIRECT_RING_STATE_SIZE		SZ_4K
>>
>> +#define LRC_PRIORITY				GENMASK_ULL(10, 9)
>> +#define LRC_PRIORITY_LOW			0
>> +#define LRC_PRIORITY_NORMAL			1
>> +#define LRC_PRIORITY_HIGH			2
>> +
>>  /*
>>   * Layout of the LRC and associated data allocated as
>>   * lrc->bo:
>> @@ -1386,6 +1391,33 @@ setup_indirect_ctx(struct xe_lrc *lrc, struct xe_hw_engine *hwe)
>>  	return 0;
>>  }
>>
>> +static u8 xe_multi_queue_prio_to_lrc(struct xe_lrc *lrc, enum xe_multi_queue_priority priority)
>> +{
>> +	struct xe_device *xe = gt_to_xe(lrc->gt);
>> +
>> +	/* xe_multi_queue_priority is directly mapped to LRC priority values */
>> +	if (priority >= XE_MULTI_QUEUE_PRIORITY_LOW &&
>> +	    priority <= XE_MULTI_QUEUE_PRIORITY_HIGH)
>> +		return priority;
>
>You santize at the IOCTL layer, so an assert here would be preferred.
>

Ok

>> +
>> +	/* Fallback to NORMAL if out of range */
>> +	drm_warn(&xe->drm, "Unknown multi queue priority: %d, defaulting to NORMAL\n", priority);
>> +	return LRC_PRIORITY_NORMAL;
>> +}
>> +
>> +/**
>> + * xe_lrc_set_multi_queue_priority() - Set multi queue priority in LRC
>> + * @lrc: Logical Ring Context
>> + * @priority: Multi queue priority of the exec queue
>> + *
>> + * Convert @priority to LRC multi queue priority and update the @lrc descriptor
>> + */
>> +void xe_lrc_set_multi_queue_priority(struct xe_lrc *lrc, enum xe_multi_queue_priority priority)
>> +{
>> +	lrc->desc &= ~LRC_PRIORITY;
>> +	lrc->desc |= FIELD_PREP(LRC_PRIORITY, xe_multi_queue_prio_to_lrc(lrc, priority));
>> +}
>> +
>>  static int xe_lrc_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe,
>>  		       struct xe_vm *vm, 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 2fb628da5c43..3e6b356e0d1c 100644
>> --- a/drivers/gpu/drm/xe/xe_lrc.h
>> +++ b/drivers/gpu/drm/xe/xe_lrc.h
>> @@ -8,11 +8,14 @@
>>  #include <linux/types.h>
>>
>>  #include "xe_lrc_types.h"
>> +#include "xe_exec_queue_types.h"
>>
>>  struct drm_printer;
>>  struct xe_bb;
>>  struct xe_device;
>>  struct xe_exec_queue;
>> +enum xe_exec_queue_priority;
>
>Never needed in this file.
>

Ok

>> +enum xe_multi_queue_priority;
>
>No need to forward declare if xe_exec_queue_types.h is included. If this
>compiles without "xe_exec_queue_types.h", please drop that include. If
>it doesn't compile, drop this forward declaration.
>

Ok

>>  enum xe_engine_class;
>>  struct xe_gt;
>>  struct xe_hw_engine;
>> @@ -133,6 +136,8 @@ void xe_lrc_dump_default(struct drm_printer *p,
>>
>>  u32 *xe_lrc_emit_hwe_state_instructions(struct xe_exec_queue *q, u32 *cs);
>>
>> +void xe_lrc_set_multi_queue_priority(struct xe_lrc *lrc, enum xe_multi_queue_priority priority);
>> +
>>  struct xe_lrc_snapshot *xe_lrc_snapshot_capture(struct xe_lrc *lrc);
>>  void xe_lrc_snapshot_capture_delayed(struct xe_lrc_snapshot *snapshot);
>>  void xe_lrc_snapshot_print(struct xe_lrc_snapshot *snapshot, struct drm_printer *p);
>> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
>> index d903b3a55ec1..8ab44413646a 100644
>> --- a/include/uapi/drm/xe_drm.h
>> +++ b/include/uapi/drm/xe_drm.h
>> @@ -1258,6 +1258,8 @@ struct drm_xe_vm_bind {
>>   *    then a new multi-queue group is created with this queue as the primary queue
>>   *    (Q0). Otherwise, the queue gets added to the multi-queue group whose primary
>>   *    queue id is specified in the 'value' field.
>> + *  - %DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_QUEUE_PRIORITY - Set the queue
>> + *    priority within the multi-queue group.
>
>Should the valid values be in uAPI as defines? At the minimum the valid
>values should be mentioned in the kernel doc.
>

It is defined below. Also mentioned in the kernel-doc.

Niranjana

>Matt
>
>>   *
>>   * The example below shows how to use @drm_xe_exec_queue_create to create
>>   * a simple exec_queue (no parallel submission) of class
>> @@ -1300,6 +1302,7 @@ struct drm_xe_exec_queue_create {
>>  #define   DRM_XE_EXEC_QUEUE_SET_PROPERTY_PXP_TYPE		2
>>  #define   DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_GROUP		3
>>  #define     DRM_XE_MULTI_GROUP_CREATE				(1ull << 63)
>> +#define   DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_QUEUE_PRIORITY	4
>>  	/** @extensions: Pointer to the first extension struct, if any */
>>  	__u64 extensions;
>>
>> --
>> 2.43.0
>>