Re: [PATCH 02/26] drm/xe: Move migration support to device-level struct

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

On 10/11/2025 9:38 PM, Michał Winiarski wrote:
> Upcoming changes will allow users to control VF state and obtain its
> migration data with a device-level granularity (not tile/gt).
> Change the data structures to reflect that and move the GT-level
> migration init to happen after device-level init.
> 
> Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
> ---
>  drivers/gpu/drm/xe/Makefile                   |  1 +
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c | 12 +-----
>  .../drm/xe/xe_gt_sriov_pf_migration_types.h   |  3 --
>  drivers/gpu/drm/xe/xe_sriov_pf.c              |  5 +++
>  drivers/gpu/drm/xe/xe_sriov_pf_migration.c    | 43 +++++++++++++++++++
>  drivers/gpu/drm/xe/xe_sriov_pf_migration.h    | 27 ++++++++++++
>  .../gpu/drm/xe/xe_sriov_pf_migration_types.h  |  0
>  drivers/gpu/drm/xe/xe_sriov_pf_types.h        |  5 +++
>  8 files changed, 83 insertions(+), 13 deletions(-)
>  create mode 100644 drivers/gpu/drm/xe/xe_sriov_pf_migration.c
>  create mode 100644 drivers/gpu/drm/xe/xe_sriov_pf_migration.h
>  create mode 100644 drivers/gpu/drm/xe/xe_sriov_pf_migration_types.h
> 
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index 84321fad32658..71f685a315dca 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -176,6 +176,7 @@ xe-$(CONFIG_PCI_IOV) += \
>  	xe_sriov_pf.o \
>  	xe_sriov_pf_control.o \
>  	xe_sriov_pf_debugfs.o \
> +	xe_sriov_pf_migration.o \
>  	xe_sriov_pf_service.o \
>  	xe_tile_sriov_pf_debugfs.o
>  
> 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 a5bf327ef8889..ca28f45aaf481 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> @@ -13,6 +13,7 @@
>  #include "xe_guc.h"
>  #include "xe_guc_ct.h"
>  #include "xe_sriov.h"
> +#include "xe_sriov_pf_migration.h"
>  
>  /* 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,
> @@ -115,8 +116,7 @@ static int pf_send_guc_restore_vf_state(struct xe_gt *gt, unsigned int vfid,
>  
>  static bool pf_migration_supported(struct xe_gt *gt)
>  {
> -	xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
> -	return gt->sriov.pf.migration.supported;
> +	return xe_sriov_pf_migration_supported(gt_to_xe(gt));
>  }
>  
>  static struct mutex *pf_migration_mutex(struct xe_gt *gt)
> @@ -382,12 +382,6 @@ ssize_t xe_gt_sriov_pf_migration_write_guc_state(struct xe_gt *gt, unsigned int
>  }
>  #endif /* CONFIG_DEBUG_FS */
>  
> -static bool pf_check_migration_support(struct xe_gt *gt)
> -{
> -	/* XXX: for now this is for feature enabling only */
> -	return IS_ENABLED(CONFIG_DRM_XE_DEBUG);
> -}
> -
>  /**
>   * xe_gt_sriov_pf_migration_init() - Initialize support for VF migration.
>   * @gt: the &xe_gt
> @@ -403,8 +397,6 @@ int xe_gt_sriov_pf_migration_init(struct xe_gt *gt)
>  
>  	xe_gt_assert(gt, IS_SRIOV_PF(xe));
>  
> -	gt->sriov.pf.migration.supported = pf_check_migration_support(gt);
> -
>  	if (!pf_migration_supported(gt))
>  		return 0;
>  
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration_types.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration_types.h
> index 1f3110b6d44fa..9d672feac5f04 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration_types.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration_types.h
> @@ -30,9 +30,6 @@ struct xe_gt_sriov_state_snapshot {
>   * Used by the PF driver to maintain non-VF specific per-GT data.
>   */
>  struct xe_gt_sriov_pf_migration {
> -	/** @supported: indicates whether the feature is supported */
> -	bool supported;
> -
>  	/** @snapshot_lock: protects all VFs snapshots */
>  	struct mutex snapshot_lock;
>  };
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf.c b/drivers/gpu/drm/xe/xe_sriov_pf.c
> index bc1ab9ee31d92..95743c7af8050 100644
> --- a/drivers/gpu/drm/xe/xe_sriov_pf.c
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf.c
> @@ -15,6 +15,7 @@
>  #include "xe_sriov.h"
>  #include "xe_sriov_pf.h"
>  #include "xe_sriov_pf_helpers.h"
> +#include "xe_sriov_pf_migration.h"
>  #include "xe_sriov_pf_service.h"
>  #include "xe_sriov_printk.h"
>  
> @@ -101,6 +102,10 @@ int xe_sriov_pf_init_early(struct xe_device *xe)
>  	if (err)
>  		return err;
>  
> +	err = xe_sriov_pf_migration_init(xe);
> +	if (err)
> +		return err;
> +
>  	xe_sriov_pf_service_init(xe);
>  
>  	return 0;
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_migration.c b/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
> new file mode 100644
> index 0000000000000..cf6a210d5597a
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
> @@ -0,0 +1,43 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#include "xe_sriov.h"
> +#include "xe_sriov_pf_migration.h"
> +
> +/**
> + * xe_sriov_pf_migration_supported() - Check if SR-IOV VF migration is supported by the device
> + * @xe: the &struct xe_device

nit: this will render better:

	@xe: the struct &xe_device

but in other places we just use:

	@xe: the &xe_device

> + *
> + * Return: true if migration is supported, false otherwise
> + */
> +bool xe_sriov_pf_migration_supported(struct xe_device *xe)
> +{
> +	xe_assert(xe, IS_SRIOV_PF(xe));
> +
> +	return xe->sriov.pf.migration.supported;
> +}
> +
> +static bool pf_check_migration_support(struct xe_device *xe)
> +{
> +	xe_assert(xe, IS_SRIOV_PF(xe));

we don't need this here for now

> +
> +	/* XXX: for now this is for feature enabling only */
> +	return IS_ENABLED(CONFIG_DRM_XE_DEBUG);
> +}
> +
> +/**
> + * xe_sriov_pf_migration_init() - Initialize support for SR-IOV VF migration.
> + * @xe: the &struct xe_device
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int xe_sriov_pf_migration_init(struct xe_device *xe)
> +{
> +	xe_assert(xe, IS_SRIOV_PF(xe));
> +
> +	xe->sriov.pf.migration.supported = pf_check_migration_support(xe);
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_migration.h b/drivers/gpu/drm/xe/xe_sriov_pf_migration.h
> new file mode 100644
> index 0000000000000..d3058b6682192
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf_migration.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#ifndef _XE_SRIOV_PF_MIGRATION_H_
> +#define _XE_SRIOV_PF_MIGRATION_H_
> +
> +#include <linux/types.h>
> +
> +struct xe_device;
> +
> +#ifdef CONFIG_PCI_IOV
> +int xe_sriov_pf_migration_init(struct xe_device *xe);
> +bool xe_sriov_pf_migration_supported(struct xe_device *xe);
> +#else
> +static inline int xe_sriov_pf_migration_init(struct xe_device *xe)
> +{
> +	return 0;
> +}
> +static inline bool xe_sriov_pf_migration_supported(struct xe_device *xe)
> +{
> +	return false;
> +}
> +#endif
> +
> +#endif
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_migration_types.h b/drivers/gpu/drm/xe/xe_sriov_pf_migration_types.h
> new file mode 100644
> index 0000000000000..e69de29bb2d1d
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_types.h b/drivers/gpu/drm/xe/xe_sriov_pf_types.h
> index 956a88f9f213d..2d2fcc0a2f258 100644
> --- a/drivers/gpu/drm/xe/xe_sriov_pf_types.h
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf_types.h
> @@ -32,6 +32,11 @@ struct xe_device_pf {
>  	/** @driver_max_vfs: Maximum number of VFs supported by the driver. */
>  	u16 driver_max_vfs;
>  

I guess you need to document @migration too to make it work

> +	struct {
> +		/** @migration.supported: indicates whether VF migration feature is supported */
> +		bool supported;
> +	} migration;

also can you move that closer to other sub-component "service" below ?

> +
>  	/** @master_lock: protects all VFs configurations across GTs */
>  	struct mutex master_lock;
>  

but otherwise LGTM, so with above fixed,

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