Re: [PATCH v3 18/28] drm/xe/pf: Handle GGTT migration data as part of PF control

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

On 10/30/2025 9:31 PM, Michał Winiarski wrote:
> Connect the helpers to allow save and restore of GGTT migration data in
> stop_copy / resume device state.
> 
> Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c   |  13 ++
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c | 113 ++++++++++++++++++
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h |   3 +
>  3 files changed, 129 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> index cb45e97f4c4d9..e7ea9b88fd246 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> @@ -860,6 +860,16 @@ static int pf_handle_vf_save_data(struct xe_gt *gt, unsigned int vfid)
>  		return -EAGAIN;
>  	}
>  
> +	if (xe_gt_sriov_pf_migration_save_test(gt, vfid, XE_SRIOV_MIGRATION_DATA_TYPE_GGTT)) {
> +		ret = xe_gt_sriov_pf_migration_ggtt_save(gt, vfid);
> +		if (ret)
> +			return ret;
> +
> +		xe_gt_sriov_pf_migration_save_clear(gt, vfid, XE_SRIOV_MIGRATION_DATA_TYPE_GGTT);
> +
> +		return -EAGAIN;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -1066,6 +1076,9 @@ static int pf_handle_vf_restore_data(struct xe_gt *gt, unsigned int vfid)
>  	xe_gt_assert(gt, data);
>  
>  	switch (data->type) {
> +	case XE_SRIOV_MIGRATION_DATA_TYPE_GGTT:
> +		ret = xe_gt_sriov_pf_migration_ggtt_restore(gt, vfid, data);
> +		break;
>  	case XE_SRIOV_MIGRATION_DATA_TYPE_GUC:
>  		ret = xe_gt_sriov_pf_migration_guc_restore(gt, vfid, data);
>  		break;
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> index fbb451767712a..6f2ee5820bdd4 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> @@ -7,6 +7,9 @@
>  
>  #include "abi/guc_actions_sriov_abi.h"
>  #include "xe_bo.h"
> +#include "xe_ggtt.h"
> +#include "xe_gt.h"
> +#include "xe_gt_sriov_pf_config.h"
>  #include "xe_gt_sriov_pf_control.h"
>  #include "xe_gt_sriov_pf_helpers.h"
>  #include "xe_gt_sriov_pf_migration.h"
> @@ -39,6 +42,106 @@ static void pf_dump_mig_data(struct xe_gt *gt, unsigned int vfid,
>  	}
>  }
>  
> +static ssize_t pf_migration_ggtt_size(struct xe_gt *gt, unsigned int vfid)
> +{
> +	if (!xe_gt_is_main_type(gt))
> +		return 0;
> +
> +	return xe_gt_sriov_pf_config_ggtt_save(gt, vfid, NULL, 0);
> +}
> +
> +static int pf_save_vf_ggtt_mig_data(struct xe_gt *gt, unsigned int vfid)
> +{
> +	struct xe_sriov_migration_data *data;
> +	size_t size;
> +	int ret;
> +
> +	size = pf_migration_ggtt_size(gt, vfid);
> +	xe_gt_assert(gt, size);
> +
> +	data = xe_sriov_migration_data_alloc(gt_to_xe(gt));
> +	if (!data)
> +		return -ENOMEM;
> +
> +	ret = xe_sriov_migration_data_init(data, gt->tile->id, gt->info.id,
> +					   XE_SRIOV_MIGRATION_DATA_TYPE_GGTT, 0, size);
> +	if (ret)
> +		goto fail;
> +
> +	ret = xe_gt_sriov_pf_config_ggtt_save(gt, vfid, data->vaddr, size);
> +	if (ret)
> +		goto fail;
> +
> +	xe_gt_sriov_dbg_verbose(gt, "VF%u GGTT data save (%zu bytes)\n", vfid, size);
> +	pf_dump_mig_data(gt, vfid, data);
> +
> +	ret = xe_gt_sriov_pf_migration_save_produce(gt, vfid, data);
> +	if (ret)
> +		goto fail;
> +
> +	return 0;
> +
> +fail:
> +	xe_sriov_migration_data_free(data);
> +	xe_gt_sriov_err(gt, "Failed to save VF%u GGTT data (%pe)\n", vfid, ERR_PTR(ret));
> +	return ret;
> +}
> +
> +static int pf_restore_vf_ggtt_mig_data(struct xe_gt *gt, unsigned int vfid,
> +				       struct xe_sriov_migration_data *data)
> +{
> +	int ret;
> +
> +	xe_gt_sriov_dbg_verbose(gt, "VF%u GGTT data restore (%llu bytes)\n", vfid, data->size);
> +	pf_dump_mig_data(gt, vfid, data);
> +
> +	ret = xe_gt_sriov_pf_config_ggtt_restore(gt, vfid, data->vaddr, data->size);
> +	if (ret) {
> +		xe_gt_sriov_err(gt, "Failed to restore VF%u GGTT data (%pe)\n",
> +				vfid, ERR_PTR(ret));
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * xe_gt_sriov_pf_migration_ggtt_save() - Save VF GGTT migration data.
> + * @gt: the &xe_gt
> + * @vfid: the VF identifier (can't be 0)
> + *
> + * This function is for PF only.
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int xe_gt_sriov_pf_migration_ggtt_save(struct xe_gt *gt, unsigned int vfid)
> +{
> +	xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
> +	xe_gt_assert(gt, vfid != PFID);
> +	xe_gt_assert(gt, vfid <= xe_sriov_pf_get_totalvfs(gt_to_xe(gt)));
> +
> +	return pf_save_vf_ggtt_mig_data(gt, vfid);
> +}
> +
> +/**
> + * xe_gt_sriov_pf_migration_ggtt_restore() - Restore VF GGTT migration data.
> + * @gt: the &xe_gt
> + * @vfid: the VF identifier (can't be 0)
> + *
> + * This function is for PF only.
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int xe_gt_sriov_pf_migration_ggtt_restore(struct xe_gt *gt, unsigned int vfid,
> +					  struct xe_sriov_migration_data *data)
> +{
> +	xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
> +	xe_gt_assert(gt, vfid != PFID);
> +	xe_gt_assert(gt, vfid <= xe_sriov_pf_get_totalvfs(gt_to_xe(gt)));
> +
> +	return pf_restore_vf_ggtt_mig_data(gt, vfid, data);
> +}
> +
>  /* Return: number of dwords saved/restored/required or a negative error code on failure */
>  static int guc_action_vf_save_restore(struct xe_guc *guc, u32 vfid, u32 opcode,
>  				      u64 addr, u32 ndwords)
> @@ -279,6 +382,13 @@ ssize_t xe_gt_sriov_pf_migration_size(struct xe_gt *gt, unsigned int vfid)
>  		size += sizeof(struct xe_sriov_pf_migration_hdr);
>  	total += size;
>  
> +	size = pf_migration_ggtt_size(gt, vfid);
> +	if (size < 0)
> +		return size;
> +	if (size > 0)
> +		size += sizeof(struct xe_sriov_pf_migration_hdr);
> +	total += size;
> +
>  	return total;
>  }
>  
> @@ -340,6 +450,9 @@ void xe_gt_sriov_pf_migration_save_init(struct xe_gt *gt, unsigned int vfid)
>  
>  	xe_gt_assert(gt, pf_migration_guc_size(gt, vfid) > 0);
>  	set_bit(XE_SRIOV_MIGRATION_DATA_TYPE_GUC, &migration->save.data_remaining);
> +
> +	if (pf_migration_ggtt_size(gt, vfid) > 0)
> +		set_bit(XE_SRIOV_MIGRATION_DATA_TYPE_GGTT, &migration->save.data_remaining);

btw, does it make sense to save GuC data if there is no GGTT data on the main GT?

>  }
>  
>  /**
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> index 66a45d6234245..bc201d8f3147a 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> @@ -19,6 +19,9 @@ int xe_gt_sriov_pf_migration_init(struct xe_gt *gt);
>  int xe_gt_sriov_pf_migration_guc_save(struct xe_gt *gt, unsigned int vfid);
>  int xe_gt_sriov_pf_migration_guc_restore(struct xe_gt *gt, unsigned int vfid,
>  					 struct xe_sriov_migration_data *data);
> +int xe_gt_sriov_pf_migration_ggtt_save(struct xe_gt *gt, unsigned int vfid);
> +int xe_gt_sriov_pf_migration_ggtt_restore(struct xe_gt *gt, unsigned int vfid,
> +					  struct xe_sriov_migration_data *data);
>  
>  ssize_t xe_gt_sriov_pf_migration_size(struct xe_gt *gt, unsigned int vfid);
>  

only one nit question about corner case, so

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