On Wed, Nov 05, 2025 at 10:45:47PM +0100, Michal Wajdeczko wrote:
>
>
> On 11/5/2025 4:10 PM, Michał Winiarski wrote:
> > In an upcoming change, the VF GGTT migration data will be handled as
> > part of VF control state machine. Add the necessary helpers to allow the
> > migration data transfer to/from the HW GGTT resource.
> >
> > Signed-off-by: Michał Winiarski <[email protected]>
> > ---
> > drivers/gpu/drm/xe/xe_ggtt.c | 104 +++++++++++++++++++++
> > drivers/gpu/drm/xe/xe_ggtt.h | 4 +
> > drivers/gpu/drm/xe/xe_ggtt_types.h | 2 +
> > drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c | 52 +++++++++++
> > drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h | 5 +
> > 5 files changed, 167 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c
> > index 20d226d90c50f..2c4f752d76996 100644
> > --- a/drivers/gpu/drm/xe/xe_ggtt.c
> > +++ b/drivers/gpu/drm/xe/xe_ggtt.c
> > @@ -151,6 +151,14 @@ static void xe_ggtt_set_pte_and_flush(struct xe_ggtt
> > *ggtt, u64 addr, u64 pte)
> > ggtt_update_access_counter(ggtt);
> > }
> >
> > +static u64 xe_ggtt_get_pte(struct xe_ggtt *ggtt, u64 addr)
> > +{
> > + xe_tile_assert(ggtt->tile, !(addr & XE_PTE_MASK));
> > + xe_tile_assert(ggtt->tile, addr < ggtt->size);
> > +
> > + return readq(&ggtt->gsm[addr >> XE_PTE_SHIFT]);
> > +}
> > +
> > static void xe_ggtt_clear(struct xe_ggtt *ggtt, u64 start, u64 size)
> > {
> > u16 pat_index = tile_to_xe(ggtt->tile)->pat.idx[XE_CACHE_WB];
> > @@ -233,16 +241,19 @@ void xe_ggtt_might_lock(struct xe_ggtt *ggtt)
> > static const struct xe_ggtt_pt_ops xelp_pt_ops = {
> > .pte_encode_flags = xelp_ggtt_pte_flags,
> > .ggtt_set_pte = xe_ggtt_set_pte,
> > + .ggtt_get_pte = xe_ggtt_get_pte,
> > };
> >
> > static const struct xe_ggtt_pt_ops xelpg_pt_ops = {
> > .pte_encode_flags = xelpg_ggtt_pte_flags,
> > .ggtt_set_pte = xe_ggtt_set_pte,
> > + .ggtt_get_pte = xe_ggtt_get_pte,
> > };
> >
> > static const struct xe_ggtt_pt_ops xelpg_pt_wa_ops = {
> > .pte_encode_flags = xelpg_ggtt_pte_flags,
> > .ggtt_set_pte = xe_ggtt_set_pte_and_flush,
> > + .ggtt_get_pte = xe_ggtt_get_pte,
> > };
> >
> > static void __xe_ggtt_init_early(struct xe_ggtt *ggtt, u32 reserved)
> > @@ -889,6 +900,20 @@ u64 xe_ggtt_largest_hole(struct xe_ggtt *ggtt, u64
> > alignment, u64 *spare)
> > return max_hole;
> > }
> >
> > +/**
> > + * xe_ggtt_node_pt_size() - Convert GGTT node size to its page table
> > entries size.
> > + * @node: the &xe_ggtt_node
> > + *
> > + * Return: GGTT node page table entries size in bytes.
> > + */
> > +size_t xe_ggtt_node_pt_size(const struct xe_ggtt_node *node)
> > +{
> > + if (!node)
> > + return 0;
> > +
> > + return node->base.size / XE_PAGE_SIZE * sizeof(u64);
> > +}
> > +
> > #ifdef CONFIG_PCI_IOV
> > static u64 xe_encode_vfid_pte(u16 vfid)
> > {
> > @@ -930,6 +955,85 @@ void xe_ggtt_assign(const struct xe_ggtt_node *node,
> > u16 vfid)
> > xe_ggtt_assign_locked(node->ggtt, &node->base, vfid);
> > mutex_unlock(&node->ggtt->lock);
> > }
> > +
> > +/**
> > + * xe_ggtt_node_save() - Save a &xe_ggtt_node to a buffer.
> > + * @node: the &xe_ggtt_node to be saved
> > + * @dst: destination buffer
> > + * @size: destination buffer size in bytes
> > + * @vfid: VF identifier
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +int xe_ggtt_node_save(struct xe_ggtt_node *node, void *dst, size_t size,
> > u16 vfid)
> > +{
> > + struct xe_ggtt *ggtt;
> > + u64 start, end;
> > + u64 *buf = dst;
> > + u64 pte;
> > +
> > + if (!node)
> > + return -ENOENT;
> > +
> > + guard(mutex)(&node->ggtt->lock);
> > +
> > + if (xe_ggtt_node_pt_size(node) != size)
> > + return -EINVAL;
> > +
> > + ggtt = node->ggtt;
> > + start = node->base.start;
> > + end = start + node->base.size - 1;
> > +
> > + while (start < end) {
> > + pte = ggtt->pt_ops->ggtt_get_pte(ggtt, start);
> > + if (vfid != u64_get_bits(pte, GGTT_PTE_VFID))
> > + return -EPERM;
> > +
> > + *buf++ = u64_replace_bits(pte, 0, GGTT_PTE_VFID);
> > + start += XE_PAGE_SIZE;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * xe_ggtt_node_load() - Load a &xe_ggtt_node from a buffer.
> > + * @node: the &xe_ggtt_node to be loaded
> > + * @src: source buffer
> > + * @size: source buffer size in bytes
> > + * @vfid: VF identifier
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +int xe_ggtt_node_load(struct xe_ggtt_node *node, const void *src, size_t
> > size, u16 vfid)
> > +{
> > + u64 vfid_pte = xe_encode_vfid_pte(vfid);
> > + const u64 *buf = src;
> > + struct xe_ggtt *ggtt;
> > + u64 start, end;
> > +
> > + if (!node)
> > + return -ENOENT;
> > +
> > + guard(mutex)(&node->ggtt->lock);
> > +
> > + if (xe_ggtt_node_pt_size(node) != size)
> > + return -EINVAL;
> > +
> > + ggtt = node->ggtt;
> > + start = node->base.start;
> > + end = start + node->base.size - 1;
> > +
> > + while (start < end) {
> > + vfid_pte = u64_replace_bits(*buf++, vfid, GGTT_PTE_VFID);
> > + ggtt->pt_ops->ggtt_set_pte(ggtt, start, vfid_pte);
> > + start += XE_PAGE_SIZE;
> > + }
> > + xe_ggtt_invalidate(ggtt);
> > +
> > + return 0;
> > +}
> > +
> > #endif
> >
> > /**
> > diff --git a/drivers/gpu/drm/xe/xe_ggtt.h b/drivers/gpu/drm/xe/xe_ggtt.h
> > index 75fc7a1efea76..1edf27608d39a 100644
> > --- a/drivers/gpu/drm/xe/xe_ggtt.h
> > +++ b/drivers/gpu/drm/xe/xe_ggtt.h
> > @@ -41,8 +41,12 @@ u64 xe_ggtt_largest_hole(struct xe_ggtt *ggtt, u64
> > alignment, u64 *spare);
> > int xe_ggtt_dump(struct xe_ggtt *ggtt, struct drm_printer *p);
> > u64 xe_ggtt_print_holes(struct xe_ggtt *ggtt, u64 alignment, struct
> > drm_printer *p);
> >
> > +size_t xe_ggtt_node_pt_size(const struct xe_ggtt_node *node);
>
> nit: maybe it should be placed near other "node" related functions
Ok.
> > +
> > #ifdef CONFIG_PCI_IOV
> > void xe_ggtt_assign(const struct xe_ggtt_node *node, u16 vfid);
> > +int xe_ggtt_node_save(struct xe_ggtt_node *node, void *dst, size_t size,
> > u16 vfid);
> > +int xe_ggtt_node_load(struct xe_ggtt_node *node, const void *src, size_t
> > size, u16 vfid);
> > #endif
> >
> > #ifndef CONFIG_LOCKDEP
> > diff --git a/drivers/gpu/drm/xe/xe_ggtt_types.h
> > b/drivers/gpu/drm/xe/xe_ggtt_types.h
> > index c5e999d58ff2a..dacd796f81844 100644
> > --- a/drivers/gpu/drm/xe/xe_ggtt_types.h
> > +++ b/drivers/gpu/drm/xe/xe_ggtt_types.h
> > @@ -78,6 +78,8 @@ struct xe_ggtt_pt_ops {
> > u64 (*pte_encode_flags)(struct xe_bo *bo, u16 pat_index);
> > /** @ggtt_set_pte: Directly write into GGTT's PTE */
> > void (*ggtt_set_pte)(struct xe_ggtt *ggtt, u64 addr, u64 pte);
> > + /** @ggtt_get_pte: Directly read from GGTT's PTE */
> > + u64 (*ggtt_get_pte)(struct xe_ggtt *ggtt, u64 addr);
> > };
> >
> > #endif
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> > b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> > index d90261a7ab7ca..2786f516a9440 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> > @@ -726,6 +726,58 @@ int xe_gt_sriov_pf_config_set_fair_ggtt(struct xe_gt
> > *gt, unsigned int vfid,
> > return xe_gt_sriov_pf_config_bulk_set_ggtt(gt, vfid, num_vfs, fair);
> > }
> >
> > +/**
> > + * xe_gt_sriov_pf_config_ggtt_save() - Save a VF provisioned GGTT data
> > into a buffer.
> > + * @gt: the &xe_gt
> > + * @vfid: VF identifier (can't be 0)
> > + * @buf: the GGTT data destination buffer (or NULL to query the buf size)
> > + * @size: the size of the buffer (or 0 to query the buf size)
> > + *
> > + * This function can only be called on PF.
> > + *
> > + * Return: size of the buffer needed to save GGTT data if querying,
> > + * 0 on successful save or a negative error code on failure.
> > + */
> > +ssize_t xe_gt_sriov_pf_config_ggtt_save(struct xe_gt *gt, unsigned int
> > vfid,
> > + void *buf, size_t size)
> > +{
> > + struct xe_ggtt_node *node;
> > +
> > + xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
> > + xe_gt_assert(gt, vfid);
> > + xe_gt_assert(gt, !(!buf ^ !size));
> > +
> > + guard(mutex)(xe_gt_sriov_pf_master_mutex(gt));
>
> new line here wouldn't hurt
Ok.
>
> > + node = pf_pick_vf_config(gt, vfid)->ggtt_region;
> > +
> > + if (!buf)
> > + return xe_ggtt_node_pt_size(node);
> > +
> > + return xe_ggtt_node_save(node, buf, size, vfid);
> > +}
> > +
> > +/**
> > + * xe_gt_sriov_pf_config_ggtt_restore() - Restore a VF provisioned GGTT
> > data from a buffer.
> > + * @gt: the &xe_gt
> > + * @vfid: VF identifier (can't be 0)
> > + * @buf: the GGTT data source buffer
> > + * @size: the size of the buffer
> > + *
> > + * This function can only be called on PF.
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +int xe_gt_sriov_pf_config_ggtt_restore(struct xe_gt *gt, unsigned int vfid,
> > + const void *buf, size_t size)
> > +{
> > + xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
> > + xe_gt_assert(gt, vfid);
> > +
> > + guard(mutex)(xe_gt_sriov_pf_master_mutex(gt));
> > +
> > + return xe_ggtt_node_load(pf_pick_vf_config(gt, vfid)->ggtt_region, buf,
> > size, vfid);
>
> nit: not very clear, better to have node* var
Ok.
>
> > +}
> > +
> > static u32 pf_get_min_spare_ctxs(struct xe_gt *gt)
> > {
> > /* XXX: preliminary */
> > diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
> > b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
> > index 14d036790695d..66223c0e948db 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
> > +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
> > @@ -71,6 +71,11 @@ ssize_t xe_gt_sriov_pf_config_save(struct xe_gt *gt,
> > unsigned int vfid, void *bu
> > int xe_gt_sriov_pf_config_restore(struct xe_gt *gt, unsigned int vfid,
> > const void *buf, size_t size);
> >
> > +ssize_t xe_gt_sriov_pf_config_ggtt_save(struct xe_gt *gt, unsigned int
> > vfid,
> > + void *buf, size_t size);
> > +int xe_gt_sriov_pf_config_ggtt_restore(struct xe_gt *gt, unsigned int vfid,
> > + const void *buf, size_t size);
> > +
> > bool xe_gt_sriov_pf_config_is_empty(struct xe_gt *gt, unsigned int vfid);
> >
> > int xe_gt_sriov_pf_config_init(struct xe_gt *gt);
>
> few nits, but LGTM
>
> Reviewed-by: Michal Wajdeczko <[email protected]>
>
Thanks,
-Michał
