Re: [PATCH i-g-t 4/6] lib/xe/xe_sriov_admin: Add bulk scheduling params setter

["Laguna, Lukasz" <lukasz.laguna@intel.com>]

On 8/18/2026 14:39, Marcin Bernatowicz wrote:
> Provisioning execution quantum, preemption timeout and priority is not
> order independent. Priority above LOW combined with infinite timeslicing
> is a risky state, which can be left via PAUSE/FLR, so timeslicing has to
> be programmed before priority is raised.
>
> Add struct xe_sriov_sched_params and a bulk setter that enforces that
> order, and that rejects infinite execution quantum or preemption timeout.
> Together with xe_sriov_admin_bulk_restore_sched_defaults(), which now
> lowers priority first, callers get a safe setup and cleanup pair without
> having to open code the sequence.
>
> Assisted-by: Copilot:Claude-Opus-5
> Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
> Cc: Adam Miszczak <adam.miszczak@linux.intel.com>
> Cc: Jakub Kolakowski <jakub1.kolakowski@intel.com>
> Cc: Lukasz Laguna <lukasz.laguna@intel.com>

Reviewed-by: Lukasz Laguna <lukasz.laguna@intel.com>

> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
> ---
>   lib/xe/xe_sriov_admin.c | 53 +++++++++++++++++++++++++++++++++++++++++
>   lib/xe/xe_sriov_admin.h | 20 ++++++++++++++++
>   2 files changed, 73 insertions(+)
>
> diff --git a/lib/xe/xe_sriov_admin.c b/lib/xe/xe_sriov_admin.c
> index 0433ddcfc..2f47d0965 100644
> --- a/lib/xe/xe_sriov_admin.c
> +++ b/lib/xe/xe_sriov_admin.c
> @@ -505,6 +505,59 @@ void xe_sriov_admin_bulk_set_sched_priority(int pf_fd,
>   	igt_assert_eq(0, __xe_sriov_admin_bulk_set_sched_priority(pf_fd, prio));
>   }
>   
> +/**
> + * __xe_sriov_admin_bulk_set_sched_params - Set scheduling parameters for PF and all VFs
> + * @pf_fd:  PF device file descriptor.
> + * @params: Scheduling parameters to apply.
> + *
> + * Applies execution quantum and preemption timeout before priority, so that a
> + * priority above LOW is never active while timeslicing is still infinite.
> + *
> + * Both &xe_sriov_sched_params.exec_quantum_ms and
> + * &xe_sriov_sched_params.preempt_timeout_us must be non-zero. Use
> + * __xe_sriov_admin_bulk_restore_sched_defaults() to restore infinite timeslicing.
> + *
> + * Returns: 0 on success or negative errno on error.
> + */
> +int __xe_sriov_admin_bulk_set_sched_params(int pf_fd,
> +					   const struct xe_sriov_sched_params *params)
> +{
> +	int ret;
> +
> +	if (igt_warn_on_f(!params->exec_quantum_ms || !params->preempt_timeout_us,
> +			  "Infinite timeslicing requires restoring defaults: eq=%u pt=%u\n",
> +			  params->exec_quantum_ms, params->preempt_timeout_us))
> +		return -EINVAL;
> +
> +	ret = __xe_sriov_admin_bulk_set_exec_quantum_ms(pf_fd, params->exec_quantum_ms);
> +	if (igt_warn_on_f(ret, "Failed to bulk set exec quantum=%u: %d\n",
> +			  params->exec_quantum_ms, ret))
> +		return ret;
> +
> +	ret = __xe_sriov_admin_bulk_set_preempt_timeout_us(pf_fd, params->preempt_timeout_us);
> +	if (igt_warn_on_f(ret, "Failed to bulk set preempt timeout=%u: %d\n",
> +			  params->preempt_timeout_us, ret))
> +		return ret;
> +
> +	ret = __xe_sriov_admin_bulk_set_sched_priority(pf_fd, params->priority);
> +	if (igt_warn_on_f(ret, "Failed to bulk set sched priority=%d: %d\n",
> +			  params->priority, ret))
> +		return ret;
> +
> +	return 0;
> +}
> +
> +/**
> + * xe_sriov_admin_bulk_set_sched_params - Assert wrapper for bulk scheduling params update
> + * @pf_fd:  PF device file descriptor.
> + * @params: Scheduling parameters to apply.
> + */
> +void xe_sriov_admin_bulk_set_sched_params(int pf_fd,
> +					  const struct xe_sriov_sched_params *params)
> +{
> +	igt_assert_eq(0, __xe_sriov_admin_bulk_set_sched_params(pf_fd, params));
> +}
> +
>   /**
>    * __xe_sriov_admin_vf_stop - Issue stop command for a VF
>    * @pf_fd:  PF device file descriptor.
> diff --git a/lib/xe/xe_sriov_admin.h b/lib/xe/xe_sriov_admin.h
> index 4eb9c83a6..6d482f8bf 100644
> --- a/lib/xe/xe_sriov_admin.h
> +++ b/lib/xe/xe_sriov_admin.h
> @@ -13,6 +13,22 @@
>   
>   struct igt_sysfs_choice;
>   
> +/**
> + * struct xe_sriov_sched_params - Scheduling parameters for a function
> + * @exec_quantum_ms: Execution quantum in milliseconds
> + * @preempt_timeout_us: Preemption timeout in microseconds
> + * @priority: Scheduling priority
> + *
> + * Zero @exec_quantum_ms or zero @preempt_timeout_us means infinity, which is
> + * only valid together with %XE_SRIOV_SCHED_PRIORITY_LOW. Use
> + * xe_sriov_admin_bulk_restore_sched_defaults() to return to that state.
> + */
> +struct xe_sriov_sched_params {
> +	uint32_t exec_quantum_ms;
> +	uint32_t preempt_timeout_us;
> +	enum xe_sriov_sched_priority priority;
> +};
> +
>   bool xe_sriov_admin_is_present(int pf_fd);
>   
>   int  __xe_sriov_admin_set_exec_quantum_ms(int pf_fd, unsigned int vf_num, uint32_t eq_ms);
> @@ -48,6 +64,10 @@ int __xe_sriov_admin_bulk_set_sched_priority(int pf_fd,
>   					     enum xe_sriov_sched_priority prio);
>   void xe_sriov_admin_bulk_set_sched_priority(int pf_fd,
>   					    enum xe_sriov_sched_priority prio);
> +int __xe_sriov_admin_bulk_set_sched_params(int pf_fd,
> +					   const struct xe_sriov_sched_params *params);
> +void xe_sriov_admin_bulk_set_sched_params(int pf_fd,
> +					  const struct xe_sriov_sched_params *params);
>   
>   int  __xe_sriov_admin_vf_stop(int pf_fd, unsigned int vf_num);
>   void  xe_sriov_admin_vf_stop(int pf_fd, unsigned int vf_num);