Re: [PATCH v5 2/6] drm/xe/vf: Split submission config query helpers

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

On 8/10/2026 12:14 PM, Satyanarayana K V P wrote:
> Refactor vf_get_submission_cfg() into separate vf_get_ctxs_cfg()
> and vf_get_dbs_cfg() functions which allows independent error
> handling and validation for each resource, and improves testability.
> 
> Signed-off-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>

with small nit below

> ---
> V4 -> V5:
> - Allow zero DBs are valid configuration (Michal W).
> 
> V3 -> V4:
> - Removed coverage for more error scenarios. (Michal W).
> - Updated fucntion names. (Michal W)
> - Added error scenarios in new commit.
> - Updated commit message.
> 
> V2 -> V3:
> - Added coverage for more error scenarios.
> ---
>  drivers/gpu/drm/xe/xe_gt_sriov_vf.c | 49 +++++++++++++++++++++++------
>  1 file changed, 40 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
> index 37899fcf5b22..339ea0d3344c 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
> @@ -568,11 +568,11 @@ static int vf_get_lmem_info(struct xe_gt *gt)
>  	return size ? 0 : -ENODATA;
>  }
>  
> -static int vf_get_submission_cfg(struct xe_gt *gt)
> +static int vf_get_ctxs_cfg(struct xe_gt *gt)
>  {
>  	struct xe_gt_sriov_vf_selfconfig *config = &gt->sriov.vf.self_config;
>  	struct xe_guc *guc = &gt->uc.guc;
> -	u32 num_ctxs, num_dbs;
> +	u32 num_ctxs;
>  	int err;
>  
>  	xe_gt_assert(gt, IS_SRIOV_VF(gt_to_xe(gt)));
> @@ -581,27 +581,58 @@ static int vf_get_submission_cfg(struct xe_gt *gt)
>  	if (unlikely(err))
>  		return err;
>  
> -	err = guc_action_query_single_klv32(guc, GUC_KLV_VF_CFG_NUM_DOORBELLS_KEY, &num_dbs);
> -	if (unlikely(err))
> -		return err;
> -
>  	if (config->num_ctxs && config->num_ctxs != num_ctxs) {
>  		xe_gt_sriov_err(gt, "Unexpected CTXs reassignment: %u != %u\n",
>  				num_ctxs, config->num_ctxs);
>  		return -EREMCHG;
>  	}
> +
> +	xe_gt_sriov_dbg_verbose(gt, "CTXs %u\n", num_ctxs);
> +
> +	config->num_ctxs = num_ctxs;
> +
> +	return config->num_ctxs ? 0 : -ENODATA;

nit: we can now code all this as:

	if (!num_ctxs) {
		xe_gt_sriov_err(gt, "No CTXs assigned!\n");
		return -ENODATA;
	}
	xe_gt_sriov_dbg_verbose(gt, "CTXs %u\n", num_ctxs);
	config->num_ctxs = num_ctxs;
	return 0;

but we can postpone that until we will be forced to switch to SIGID
> +}
> +
> +static int vf_get_dbs_cfg(struct xe_gt *gt)
> +{
> +	struct xe_gt_sriov_vf_selfconfig *config = &gt->sriov.vf.self_config;
> +	struct xe_guc *guc = &gt->uc.guc;
> +	u32 num_dbs;
> +	int err;
> +
> +	xe_gt_assert(gt, IS_SRIOV_VF(gt_to_xe(gt)));
> +
> +	err = guc_action_query_single_klv32(guc, GUC_KLV_VF_CFG_NUM_DOORBELLS_KEY, &num_dbs);
> +	if (unlikely(err))
> +		return err;
> +
>  	if (config->num_dbs && config->num_dbs != num_dbs) {
>  		xe_gt_sriov_err(gt, "Unexpected DBs reassignment: %u != %u\n",
>  				num_dbs, config->num_dbs);
>  		return -EREMCHG;
>  	}
>  
> -	xe_gt_sriov_dbg_verbose(gt, "CTXs %u DBs %u\n", num_ctxs, num_dbs);
> +	xe_gt_sriov_dbg_verbose(gt, "DBs %u\n", num_dbs);
>  
> -	config->num_ctxs = num_ctxs;
>  	config->num_dbs = num_dbs;
>  
> -	return config->num_ctxs ? 0 : -ENODATA;
> +	return 0;
> +}
> +
> +static int vf_get_submission_cfg(struct xe_gt *gt)
> +{
> +	int err;
> +
> +	err = vf_get_ctxs_cfg(gt);
> +	if (unlikely(err))
> +		return err;
> +
> +	err = vf_get_dbs_cfg(gt);
> +	if (unlikely(err))
> +		return err;
> +
> +	return 0;
>  }
>  
>  static void vf_cache_gmdid(struct xe_gt *gt)