Re: [PATCH v3 19/28] drm/xe/pf: Handle MMIO migration data as part of PF control

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

On 10/30/2025 9:31 PM, Michał Winiarski wrote:
> Implement the helpers and use them for save and restore of MMIO
> 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.h           |   2 +
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c   |  13 ++
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c | 158 ++++++++++++++++++
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h |   3 +
>  4 files changed, 176 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf.h
> index e7fde3f9937af..c0dcbb1054e4d 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf.h
> @@ -6,6 +6,8 @@
>  #ifndef _XE_GT_SRIOV_PF_H_
>  #define _XE_GT_SRIOV_PF_H_
>  
> +#include <linux/types.h>

?

> +
>  struct xe_gt;
>  
>  #ifdef CONFIG_PCI_IOV
> 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 e7ea9b88fd246..7cd7cae950bc7 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> @@ -870,6 +870,16 @@ 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_MMIO)) {
> +		ret = xe_gt_sriov_pf_migration_mmio_save(gt, vfid);
> +		if (ret)
> +			return ret;
> +
> +		xe_gt_sriov_pf_migration_save_clear(gt, vfid, XE_SRIOV_MIGRATION_DATA_TYPE_MMIO);
> +
> +		return -EAGAIN;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -1079,6 +1089,9 @@ static int pf_handle_vf_restore_data(struct xe_gt *gt, unsigned int vfid)
>  	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_MMIO:
> +		ret = xe_gt_sriov_pf_migration_mmio_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 6f2ee5820bdd4..5e90aeafeeb41 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> @@ -5,10 +5,13 @@
>  
>  #include <drm/drm_managed.h>
>  
> +#include "regs/xe_guc_regs.h"
> +
>  #include "abi/guc_actions_sriov_abi.h"
>  #include "xe_bo.h"
>  #include "xe_ggtt.h"
>  #include "xe_gt.h"
> +#include "xe_gt_sriov_pf.h"
>  #include "xe_gt_sriov_pf_config.h"
>  #include "xe_gt_sriov_pf_control.h"
>  #include "xe_gt_sriov_pf_helpers.h"
> @@ -16,6 +19,7 @@
>  #include "xe_gt_sriov_printk.h"
>  #include "xe_guc_buf.h"
>  #include "xe_guc_ct.h"
> +#include "xe_mmio.h"
>  #include "xe_sriov.h"
>  #include "xe_sriov_migration_data.h"
>  #include "xe_sriov_pf_migration.h"
> @@ -357,6 +361,150 @@ int xe_gt_sriov_pf_migration_guc_restore(struct xe_gt *gt, unsigned int vfid,
>  	return pf_restore_vf_guc_state(gt, vfid, data);
>  }
>  
> +static ssize_t pf_migration_mmio_size(struct xe_gt *gt, unsigned int vfid)
> +{
> +	if (xe_gt_is_media_type(gt))
> +		return MED_VF_SW_FLAG_COUNT * sizeof(u32);
> +	else
> +		return VF_SW_FLAG_COUNT * sizeof(u32);
> +}
> +
> +static int pf_migration_mmio_save(struct xe_gt *gt, unsigned int vfid, void *buf, size_t size)
> +{
> +	struct xe_mmio mmio;
> +	u32 *regs = buf;
> +	int n;
> +
> +	xe_mmio_init_vf_view(&mmio, &gt->mmio, vfid);
> +
> +	if (size != pf_migration_mmio_size(gt, vfid))
> +		return -EINVAL;

you may want to check that first (before init vf view)

> +
> +	if (xe_gt_is_media_type(gt))
> +		for (n = 0; n < MED_VF_SW_FLAG_COUNT; n++)
> +			regs[n] = xe_mmio_read32(&gt->mmio, MED_VF_SW_FLAG(n));
> +	else
> +		for (n = 0; n < VF_SW_FLAG_COUNT; n++)
> +			regs[n] = xe_mmio_read32(&gt->mmio, VF_SW_FLAG(n));
> +
> +	return 0;
> +}
> +
> +static int pf_migration_mmio_restore(struct xe_gt *gt, unsigned int vfid,
> +				     const void *buf, size_t size)
> +{
> +	const u32 *regs = buf;
> +	struct xe_mmio mmio;
> +	int n;
> +
> +	xe_mmio_init_vf_view(&mmio, &gt->mmio, vfid);
> +
> +	if (size != pf_migration_mmio_size(gt, vfid))
> +		return -EINVAL;

ditto

> +
> +	if (xe_gt_is_media_type(gt))
> +		for (n = 0; n < MED_VF_SW_FLAG_COUNT; n++)
> +			xe_mmio_write32(&gt->mmio, MED_VF_SW_FLAG(n), regs[n]);
> +	else
> +		for (n = 0; n < VF_SW_FLAG_COUNT; n++)
> +			xe_mmio_write32(&gt->mmio, VF_SW_FLAG(n), regs[n]);
> +
> +	return 0;
> +}
> +
> +static int pf_save_vf_mmio_mig_data(struct xe_gt *gt, unsigned int vfid)
> +{
> +	struct xe_sriov_migration_data *data;
> +	size_t size;
> +	int ret;
> +
> +	size = pf_migration_mmio_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_MMIO, 0, size);
> +	if (ret)
> +		goto fail;
> +
> +	ret = pf_migration_mmio_save(gt, vfid, data->vaddr, size);
> +	if (ret)
> +		goto fail;
> +
> +	xe_gt_sriov_dbg_verbose(gt, "VF%u MMIO data save (%zu bytes)\n", vfid, size);

maybe make it part of the pf_dump_mig_data() ?

	pf_dump_mig_data(gt, vfid, data, "MMIO saved");

> +	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 MMIO data (%pe)\n", vfid, ERR_PTR(ret));
> +	return ret;
> +}
> +
> +static int pf_restore_vf_mmio_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 MMIO data restore (%llu bytes)\n", vfid, data->size);

and here:

	pf_dump_mig_data(gt, vfid, data, "restoring MMIO");
> +	pf_dump_mig_data(gt, vfid, data);
> +
> +	ret = pf_migration_mmio_restore(gt, vfid, data->vaddr, data->size);
> +	if (ret) {
> +		xe_gt_sriov_err(gt, "Failed to restore VF%u MMIO data (%pe)\n",
> +				vfid, ERR_PTR(ret));
> +
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * xe_gt_sriov_pf_migration_mmio_save() - Save VF MMIO 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_mmio_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_mmio_mig_data(gt, vfid);
> +}
> +
> +/**
> + * xe_gt_sriov_pf_migration_mmio_restore() - Restore VF MMIO 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_mmio_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_mmio_mig_data(gt, vfid, data);
> +}
> +
>  /**
>   * xe_gt_sriov_pf_migration_size() - Total size of migration data from all components within a GT.
>   * @gt: the &xe_gt
> @@ -389,6 +537,13 @@ 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_mmio_size(gt, vfid);
> +	if (size < 0)
> +		return size;
> +	if (size > 0)
> +		size += sizeof(struct xe_sriov_pf_migration_hdr);
> +	total += size;
> +
>  	return total;
>  }
>  
> @@ -453,6 +608,9 @@ void xe_gt_sriov_pf_migration_save_init(struct xe_gt *gt, unsigned int vfid)
>  
>  	if (pf_migration_ggtt_size(gt, vfid) > 0)
>  		set_bit(XE_SRIOV_MIGRATION_DATA_TYPE_GGTT, &migration->save.data_remaining);
> +
> +	xe_gt_assert(gt, pf_migration_mmio_size(gt, vfid) > 0);
> +	set_bit(XE_SRIOV_MIGRATION_DATA_TYPE_MMIO, &migration->save.data_remaining);
>  }
>  
>  /**
> 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 bc201d8f3147a..b0eec94fea3a6 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
> @@ -22,6 +22,9 @@ int xe_gt_sriov_pf_migration_guc_restore(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_migration_data *data);
> +int xe_gt_sriov_pf_migration_mmio_save(struct xe_gt *gt, unsigned int vfid);
> +int xe_gt_sriov_pf_migration_mmio_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);
>  

but patch looks ok, so with #include fixed (and maybe with better dump helper),

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