Re: [PATCH 18/26] drm/xe/pf: Handle GGTT migration data as part of PF control

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

On 10/11/2025 9:38 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 ++
>  .../gpu/drm/xe/xe_gt_sriov_pf_control_types.h |   1 +
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c | 119 ++++++++++++++++++
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h |   4 +
>  4 files changed, 137 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 f73a3bf40037c..a74f6feca4830 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> @@ -188,6 +188,7 @@ static const char *control_bit_to_string(enum xe_gt_sriov_control_bits bit)
>  	CASE2STR(MIGRATION_DATA_WIP);
>  	CASE2STR(SAVE_WIP);
>  	CASE2STR(SAVE_DATA_GUC);
> +	CASE2STR(SAVE_DATA_GGTT);
>  	CASE2STR(SAVE_FAILED);
>  	CASE2STR(SAVED);
>  	CASE2STR(RESTORE_WIP);
> @@ -803,6 +804,7 @@ void xe_gt_sriov_pf_control_vf_data_eof(struct xe_gt *gt, unsigned int vfid)
>  
>  static void pf_exit_vf_save_wip(struct xe_gt *gt, unsigned int vfid)
>  {
> +	pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_GGTT);
>  	pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_GUC);
>  	pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WIP);
>  }
> @@ -843,6 +845,13 @@ static bool pf_handle_vf_save_wip(struct xe_gt *gt, unsigned int vfid)
>  		return true;
>  	}
>  
> +	if (pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_GGTT)) {
> +		ret = xe_gt_sriov_pf_migration_ggtt_save(gt, vfid);
> +		if (ret)
> +			goto err;
> +		return true;
> +	}
> +
>  	xe_gt_sriov_pf_control_vf_data_eof(gt, vfid);
>  	pf_exit_vf_save_wip(gt, vfid);
>  	pf_enter_vf_saved(gt, vfid);
> @@ -862,6 +871,8 @@ static bool pf_enter_vf_save_wip(struct xe_gt *gt, unsigned int vfid)
>  		pf_enter_vf_wip(gt, vfid);
>  		if (xe_gt_sriov_pf_migration_guc_size(gt, vfid) > 0)
>  			pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_GUC);
> +		if (xe_gt_sriov_pf_migration_ggtt_size(gt, vfid) > 0)
> +			pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_GGTT);
>  		pf_queue_vf(gt, vfid);
>  		return true;
>  	}
> @@ -970,6 +981,8 @@ static int pf_handle_vf_restore_data(struct xe_gt *gt, unsigned int vfid,
>  				     struct xe_sriov_pf_migration_data *data)
>  {
>  	switch (data->type) {
> +	case XE_SRIOV_MIG_DATA_GGTT:
> +		return xe_gt_sriov_pf_migration_ggtt_restore(gt, vfid, data);
>  	case XE_SRIOV_MIG_DATA_GUC:
>  		return xe_gt_sriov_pf_migration_guc_restore(gt, vfid, data);
>  	default:
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> index b9787c425d9f6..c94ff0258306a 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> @@ -72,6 +72,7 @@ enum xe_gt_sriov_control_bits {
>  
>  	XE_GT_SRIOV_STATE_SAVE_WIP,
>  	XE_GT_SRIOV_STATE_SAVE_DATA_GUC,
> +	XE_GT_SRIOV_STATE_SAVE_DATA_GGTT,
>  	XE_GT_SRIOV_STATE_SAVE_FAILED,
>  	XE_GT_SRIOV_STATE_SAVED,
>  
> 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 0c10284f0b09a..92ecf47e71bc7 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 +7,7 @@
>  
>  #include "abi/guc_actions_sriov_abi.h"
>  #include "xe_bo.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"
> @@ -37,6 +38,117 @@ static void pf_dump_mig_data(struct xe_gt *gt, unsigned int vfid,
>  	}
>  }
>  
> +static int pf_save_vf_ggtt_mig_data(struct xe_gt *gt, unsigned int vfid)
> +{
> +	struct xe_sriov_pf_migration_data *data;
> +	size_t size;
> +	int ret;
> +
> +	size = xe_gt_sriov_pf_config_get_ggtt(gt, vfid);
> +	if (size == 0)
> +		return 0;
> +	size = size / XE_PAGE_SIZE * sizeof(u64);

maybe it would be better to avoid reusing the var and have two:

	u64 alloc_size = xe_gt_sriov_pf_config_get_ggtt(...);
	u64 pte_size = xe_ggtt_pte_size(alloc_size);

> +
> +	data = xe_sriov_pf_migration_data_alloc(gt_to_xe(gt));
> +	if (!data)
> +		return -ENOMEM;
> +
> +	ret = xe_sriov_pf_migration_data_init(data, gt->tile->id, gt->info.id,
> +					      XE_SRIOV_MIG_DATA_GGTT, 0, size);
> +	if (ret)
> +		goto fail;
> +
> +	ret = xe_gt_sriov_pf_config_ggtt_save(gt, vfid, data->vaddr, size);
> +	if (ret)
> +		goto fail;
> +
> +	pf_dump_mig_data(gt, vfid, data);
> +
> +	ret = xe_gt_sriov_pf_migration_ring_produce(gt, vfid, data);
> +	if (ret)
> +		goto fail;
> +
> +	return 0;
> +
> +fail:
> +	xe_sriov_pf_migration_data_free(data);
> +	xe_gt_sriov_err(gt, "Unable to save VF%u GGTT data (%d)\n", vfid, ret);

use %pe for errors

> +	return ret;
> +}
> +
> +static int pf_restore_vf_ggtt_mig_data(struct xe_gt *gt, unsigned int vfid,
> +				       struct xe_sriov_pf_migration_data *data)
> +{
> +	size_t size;
> +	int ret;
> +
> +	size = xe_gt_sriov_pf_config_get_ggtt(gt, vfid) / XE_PAGE_SIZE * sizeof(u64);
> +	if (size != data->hdr.size)
> +		return -EINVAL;

do we need this ?

there seems to be similar check in xe_ggtt_node_load() called by restore() below

> +
> +	pf_dump_mig_data(gt, vfid, data);
> +
> +	ret = xe_gt_sriov_pf_config_ggtt_restore(gt, vfid, data->vaddr, size);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +/**
> + * xe_gt_sriov_pf_migration_ggtt_size() - Get the size of VF GGTT migration data.
> + * @gt: the &struct xe_gt
> + * @vfid: the VF identifier
> + *
> + * This function is for PF only.
> + *
> + * Return: size in bytes or a negative error code on failure.
> + */
> +ssize_t xe_gt_sriov_pf_migration_ggtt_size(struct xe_gt *gt, unsigned int vfid)
> +{
> +	if (gt != xe_root_mmio_gt(gt_to_xe(gt)))
> +		return 0;
> +
> +	return xe_gt_sriov_pf_config_get_ggtt(gt, vfid) / XE_PAGE_SIZE * sizeof(u64);

this conversion logic should be done by xe_ggtt layer helper
> +}
> +
> +/**
> + * xe_gt_sriov_pf_migration_ggtt_save() - Save VF GGTT migration data.
> + * @gt: the &struct xe_gt
> + * @vfid: the VF identifier

since there is assert, probably you should also say: "(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 &struct xe_gt
> + * @vfid: the VF identifier
> + *
> + * 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_pf_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)
> @@ -290,6 +402,13 @@ 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 = xe_gt_sriov_pf_migration_ggtt_size(gt, vfid);
> +	if (size < 0)
> +		return size;
> +	else if (size > 0)
> +		size += sizeof(struct xe_sriov_pf_migration_hdr);
> +	total += size;
> +
>  	return total;
>  }
>  
> 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 5df64449232bc..5bb8cba2ea0cb 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> @@ -16,6 +16,10 @@ ssize_t xe_gt_sriov_pf_migration_guc_size(struct xe_gt *gt, unsigned int vfid);
>  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_pf_migration_data *data);
> +ssize_t xe_gt_sriov_pf_migration_ggtt_size(struct xe_gt *gt, unsigned int vfid);
> +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_pf_migration_data *data);
>  
>  ssize_t xe_gt_sriov_pf_migration_size(struct xe_gt *gt, unsigned int vfid);
>