Re: [PATCH v5 3/5] drm/pagemap: Drop source_peer_migrates flag and assume true

[Francois Dugast <francois.dugast@intel.com>]

On Thu, Feb 19, 2026 at 12:53:13PM -0800, Matthew Brost wrote:
> On Thu, Feb 19, 2026 at 12:10:55PM -0800, Matthew Brost wrote:
> > All current users of DRM pagemap set source_peer_migrates to true during
> > migration, and it is unclear whether any user would ever want to disable
> > this for performance reasons or for features such as compression. It is
> > also questionable whether this flag could be made to work with
> > high-speed fabric mapping APIs.
> > 
> > Drop the flag and make DRM pagemap unconditionally assume that
> > source_peer_migrates is true.
> > 
> > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> > ---
> >  drivers/gpu/drm/drm_pagemap.c | 10 ++++------
> >  drivers/gpu/drm/xe/xe_svm.c   |  1 -
> >  include/drm/drm_pagemap.h     |  8 ++------
> >  3 files changed, 6 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
> > index 01a06d1fd1a0..32535ab01c0f 100644
> > --- a/drivers/gpu/drm/drm_pagemap.c
> > +++ b/drivers/gpu/drm/drm_pagemap.c
> > @@ -602,12 +602,10 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> >  				own_pages++;
> >  				continue;
> >  			}
> > -			if (mdetails->source_peer_migrates) {
> > -				cur.dpagemap = src_zdd->dpagemap;
> > -				cur.ops = src_zdd->devmem_allocation->ops;
> > -				cur.device = cur.dpagemap->drm->dev;
> > -				pages[i] = src_page;
> > -			}
> > +			cur.dpagemap = src_zdd->dpagemap;
> > +			cur.ops = src_zdd->devmem_allocation->ops;
> > +			cur.device = cur.dpagemap->drm->dev;
> > +			pages[i] = src_page;
> >  		}
> >  		if (!pages[i]) {
> >  			cur.dpagemap = NULL;
> > diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
> > index c96ed760c077..e86e69087c7e 100644
> > --- a/drivers/gpu/drm/xe/xe_svm.c
> > +++ b/drivers/gpu/drm/xe/xe_svm.c
> > @@ -1027,7 +1027,6 @@ static int xe_drm_pagemap_populate_mm(struct drm_pagemap *dpagemap,
> >  	struct xe_pagemap *xpagemap = container_of(dpagemap, typeof(*xpagemap), dpagemap);
> >  	struct drm_pagemap_migrate_details mdetails = {
> >  		.timeslice_ms = timeslice_ms,
> > -		.source_peer_migrates = 1,
> >  	};
> >  	struct xe_vram_region *vr = xe_pagemap_to_vr(xpagemap);
> >  	struct dma_fence *pre_migrate_fence = NULL;
> > diff --git a/include/drm/drm_pagemap.h b/include/drm/drm_pagemap.h
> > index 72f6828f2604..5c33982141c2 100644
> > --- a/include/drm/drm_pagemap.h
> > +++ b/include/drm/drm_pagemap.h
> > @@ -329,12 +329,8 @@ struct drm_pagemap_devmem {
> >   * struct drm_pagemap_migrate_details - Details to govern migration.
> >   * @timeslice_ms: The time requested for the migrated pagemap pages to
> >   * be present in @mm before being allowed to be migrated back.
> > - * @can_migrate_same_pagemap: Whether the copy function as indicated by
> > - * the @source_peer_migrates flag, can migrate device pages within a
> > - * single drm_pagemap.
> > - * @source_peer_migrates: Whether on p2p migration, The source drm_pagemap
> > - * should use the copy_to_ram() callback rather than the destination
> > - * drm_pagemap should use the copy_to_devmem() callback.
> > + * @can_migrate_same_pagemap: Whether the copy function can migrate
> > + * device pages within a single drm_pagemap.
> 
> I forgot to delete this variable, in effort to save CI cycles, will fix
> this in next rev or when merging.

With source_peer_migrates removed:

    Reviewed-by: Francois Dugast <francois.dugast@intel.com>

> 
> Matt 
> 
> >   */
> >  struct drm_pagemap_migrate_details {
> >  	unsigned long timeslice_ms;
> > -- 
> > 2.34.1
> >