Re: [PATCH v6 1/4] drm/xe/pf: Enable SR-IOV VF migration

[Michał Winiarski]

On Tue, Nov 25, 2025 at 03:26:38PM +0100, Michal Wajdeczko wrote:
> 
> 
> On 11/25/2025 12:08 AM, Michał Winiarski wrote:
> > All of the necessary building blocks are now in place to support SR-IOV
> > VF migration.
> > Flip the enable/disable logic to match VF code and disable the feature
> > only for platforms that don't meet the necessary prerequisites.
> > 
> 
> I guess you should mention that "to allow more testing and experiments,
> on DEBUG builds any missing prerequisites will be ignored"

Sure, let's add it.

> 
> > Signed-off-by: Michał Winiarski <michal.winiarski@xxxxxxxxx>
> > ---
> >  drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c |  9 +++++
> >  drivers/gpu/drm/xe/xe_sriov_pf_migration.c    | 35 ++++++++++++++++---
> >  drivers/gpu/drm/xe/xe_sriov_pf_migration.h    |  1 +
> >  .../gpu/drm/xe/xe_sriov_pf_migration_types.h  |  4 +--
> >  4 files changed, 42 insertions(+), 7 deletions(-)
> > 
> > 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 d5d918ddce4fe..3174a8dee779e 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
> > @@ -17,6 +17,7 @@
> >  #include "xe_gt_sriov_pf_helpers.h"
> >  #include "xe_gt_sriov_pf_migration.h"
> >  #include "xe_gt_sriov_printk.h"
> > +#include "xe_guc.h"
> >  #include "xe_guc_buf.h"
> >  #include "xe_guc_ct.h"
> >  #include "xe_migrate.h"
> > @@ -1023,6 +1024,12 @@ static void action_ring_cleanup(void *arg)
> >  	ptr_ring_cleanup(r, destroy_pf_packet);
> >  }
> >  
> > +static void pf_gt_migration_check_support(struct xe_gt *gt)
> > +{
> > +	if (GUC_FIRMWARE_VER(&gt->uc.guc) < MAKE_GUC_VER(70, 54, 0))
> > +		xe_sriov_pf_migration_disable(gt_to_xe(gt), "requires GuC version >= 70.54.0");
> > +}
> > +
> >  /**
> >   * xe_gt_sriov_pf_migration_init() - Initialize support for VF migration.
> >   * @gt: the &xe_gt
> > @@ -1039,6 +1046,8 @@ int xe_gt_sriov_pf_migration_init(struct xe_gt *gt)
> >  
> >  	xe_gt_assert(gt, IS_SRIOV_PF(xe));
> >  
> > +	pf_gt_migration_check_support(gt);
> > +
> >  	if (!pf_migration_supported(gt))
> >  		return 0;
> >  
> > diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_migration.c b/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
> > index de06cc690fc81..6c4b16409cc9a 100644
> > --- a/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
> > +++ b/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
> > @@ -46,13 +46,37 @@ bool xe_sriov_pf_migration_supported(struct xe_device *xe)
> >  {
> >  	xe_assert(xe, IS_SRIOV_PF(xe));
> >  
> > -	return xe->sriov.pf.migration.supported;
> > +	return IS_ENABLED(CONFIG_DRM_XE_DEBUG) || !xe->sriov.pf.migration.disabled;
> >  }
> >  
> > -static bool pf_check_migration_support(struct xe_device *xe)
> > +/**
> > + * xe_sriov_pf_migration_disable() - Turn off SR-IOV VF migration support on PF.
> > + * @xe: the &xe_device instance.
> > + * @fmt: format string for the log message, to be combined with following VAs.
> > + */
> > +void xe_sriov_pf_migration_disable(struct xe_device *xe, const char *fmt, ...)
> > +{
> > +	struct va_format vaf;
> > +	va_list va_args;
> > +
> > +	xe_assert(xe, IS_SRIOV_PF(xe));
> > +
> > +	va_start(va_args, fmt);
> > +	vaf.fmt = fmt;
> > +	vaf.va  = &va_args;
> > +	xe_sriov_notice(xe, "migration %s: %pV\n",
> > +			IS_ENABLED(CONFIG_DRM_XE_DEBUG) ?
> > +			"missing prerequisite" : "disabled",
> > +			&vaf);
> > +	va_end(va_args);
> > +
> > +	xe->sriov.pf.migration.disabled = true;
> > +}
> > +
> > +static void pf_migration_check_support(struct xe_device *xe)
> >  {
> > -	/* XXX: for now this is for feature enabling only */
> > -	return IS_ENABLED(CONFIG_DRM_XE_DEBUG);
> > +	if (!xe_device_has_memirq(xe))
> > +		xe_sriov_pf_migration_disable(xe, "requires memory-based IRQ support");
> >  }
> >  
> >  static void pf_migration_cleanup(void *arg)
> > @@ -77,7 +101,8 @@ 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);
> > +	pf_migration_check_support(xe);
> > +
> >  	if (!xe_sriov_pf_migration_supported(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
> > index b806298a0bb62..f8f408df84813 100644
> > --- a/drivers/gpu/drm/xe/xe_sriov_pf_migration.h
> > +++ b/drivers/gpu/drm/xe/xe_sriov_pf_migration.h
> > @@ -14,6 +14,7 @@ struct xe_sriov_packet;
> >  
> >  int xe_sriov_pf_migration_init(struct xe_device *xe);
> >  bool xe_sriov_pf_migration_supported(struct xe_device *xe);
> > +void xe_sriov_pf_migration_disable(struct xe_device *xe, const char *fmt, ...);
> >  int xe_sriov_pf_migration_restore_produce(struct xe_device *xe, unsigned int vfid,
> >  					  struct xe_sriov_packet *data);
> >  struct xe_sriov_packet *
> > diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_migration_types.h b/drivers/gpu/drm/xe/xe_sriov_pf_migration_types.h
> > index 363d673ee1dd5..7d9a8a278d915 100644
> > --- a/drivers/gpu/drm/xe/xe_sriov_pf_migration_types.h
> > +++ b/drivers/gpu/drm/xe/xe_sriov_pf_migration_types.h
> > @@ -14,8 +14,8 @@
> >   * struct xe_sriov_pf_migration - Xe device level VF migration data
> >   */
> >  struct xe_sriov_pf_migration {
> > -	/** @supported: indicates whether VF migration feature is supported */
> > -	bool supported;
> > +	/** @disabled: indicates whether VF migration feature is disabled */
> > +	bool disabled;
> >  };
> >  
> >  /**
> 
> otherwise lgtm,
> 
> Reviewed-by: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
> 

Thanks,
-Michał