On Wed, Jun 03, 2026 at 02:56:18PM +0800, Honglei Huang wrote:
> From: Honglei Huang <[email protected]>
>
> With drm_gpusvm_pages now self contained, make xe stop relying
> on the drm_gpusvm_range pages and take responsibility for the page
> lifecycle on the driver side.
>
> Driver side (xe):
>
> - Embed struct drm_gpusvm_pages in xe_svm_range and route all
> xe accesses through it instead of range->base.pages.
> - Take over the page lifecycle: xe_svm_range_get_pages() calls
> drm_gpusvm_get_pages() directly with &xe->drm; the notifier
> event_end and xe_svm_range_free() paths drive unmap/free on
> the embedded pages object.
> - Switch xe_svm_range_pages_valid() to drm_gpusvm_pages_valid().
>
> Framework side (drm_gpusvm):
>
> - Export drm_gpusvm_pages_valid() to let driver owned pages
> can query mapping state without going through a range.
> - Contract change: drm_gpusvm_range_remove() no longer unmaps or
> frees pages; drivers that own a drm_gpusvm_pages instance must
> do that themselves.
>
> Side effect / contract: drivers that own a drm_gpusvm_pages
> are now responsible for its lifecycle, in particular for calling
> drm_gpusvm_unmap_pages() and drm_gpusvm_free_pages() at the
> appropriate points.
>
> Suggested-by: Matthew Brost <[email protected]>
> Signed-off-by: Honglei Huang <[email protected]>
> ---
> drivers/gpu/drm/drm_gpusvm.c | 9 +++------
> drivers/gpu/drm/xe/xe_pt.c | 2 +-
> drivers/gpu/drm/xe/xe_svm.c | 22 +++++++++++++++-------
> drivers/gpu/drm/xe/xe_svm.h | 9 +++++++--
> include/drm/drm_gpusvm.h | 3 +++
> 5 files changed, 29 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c
> index 3f076178b2a..a4b56cefeb2 100644
> --- a/drivers/gpu/drm/drm_gpusvm.c
> +++ b/drivers/gpu/drm/drm_gpusvm.c
> @@ -1231,8 +1231,6 @@ EXPORT_SYMBOL_GPL(drm_gpusvm_free_pages);
> void drm_gpusvm_range_remove(struct drm_gpusvm *gpusvm,
> struct drm_gpusvm_range *range)
> {
> - unsigned long npages = npages_in_range(drm_gpusvm_range_start(range),
> - drm_gpusvm_range_end(range));
> struct drm_gpusvm_notifier *notifier;
>
> drm_gpusvm_driver_lock_held(gpusvm);
> @@ -1244,8 +1242,6 @@ void drm_gpusvm_range_remove(struct drm_gpusvm *gpusvm,
> return;
>
> drm_gpusvm_notifier_lock(gpusvm);
> - __drm_gpusvm_unmap_pages(gpusvm, &range->pages, npages);
> - __drm_gpusvm_free_pages(gpusvm, &range->pages);
> __drm_gpusvm_range_remove(notifier, range);
> drm_gpusvm_notifier_unlock(gpusvm);
>
> @@ -1324,13 +1320,14 @@ EXPORT_SYMBOL_GPL(drm_gpusvm_range_put);
> *
> * Return: True if GPU SVM range has valid pages, False otherwise
> */
> -static bool drm_gpusvm_pages_valid(struct drm_gpusvm *gpusvm,
> - struct drm_gpusvm_pages *svm_pages)
> +bool drm_gpusvm_pages_valid(struct drm_gpusvm *gpusvm,
> + struct drm_gpusvm_pages *svm_pages)
> {
> lockdep_assert_held(&gpusvm->notifier_lock);
>
> return svm_pages->flags.has_devmem_pages ||
> svm_pages->flags.has_dma_mapping;
> }
> +EXPORT_SYMBOL_GPL(drm_gpusvm_pages_valid);
>
> /**
> * drm_gpusvm_range_pages_valid() - GPU SVM range pages valid
> diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
> index 2669ff5ee74..e82b0d8fab1 100644
> --- a/drivers/gpu/drm/xe/xe_pt.c
> +++ b/drivers/gpu/drm/xe/xe_pt.c
> @@ -758,7 +758,7 @@ xe_pt_stage_bind(struct xe_tile *tile, struct xe_vma *vma,
> return -EAGAIN;
> }
> if (xe_svm_range_has_dma_mapping(range)) {
> - xe_res_first_dma(range->base.pages.dma_addr, 0,
> + xe_res_first_dma(range->pages.dma_addr, 0,
> xe_svm_range_size(range),
> &curs);
> xe_svm_range_debug(range, "BIND PREPARE - MIXED");
> diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
> index 3acfddb7c5b..33c26df5111 100644
> --- a/drivers/gpu/drm/xe/xe_svm.c
> +++ b/drivers/gpu/drm/xe/xe_svm.c
> @@ -66,7 +66,7 @@ static bool xe_svm_range_in_vram(struct xe_svm_range *range)
>
> struct drm_gpusvm_pages_flags flags = {
> /* Pairs with WRITE_ONCE in drm_gpusvm.c */
> - .__flags = READ_ONCE(range->base.pages.flags.__flags),
> + .__flags = READ_ONCE(range->pages.flags.__flags),
> };
>
> return flags.has_devmem_pages;
> @@ -96,7 +96,7 @@ static struct xe_vm *range_to_vm(struct drm_gpusvm_range *r)
> (r__)->base.gpusvm, \
> xe_svm_range_in_vram((r__)) ? 1 : 0, \
> xe_svm_range_has_vram_binding((r__)) ? 1 : 0, \
> - (r__)->base.pages.notifier_seq, \
> + (r__)->pages.notifier_seq, \
> xe_svm_range_start((r__)), xe_svm_range_end((r__)), \
> xe_svm_range_size((r__)))
>
> @@ -115,6 +115,7 @@ xe_svm_range_alloc(struct drm_gpusvm *gpusvm)
> return NULL;
>
> INIT_LIST_HEAD(&range->garbage_collector_link);
> + range->pages.notifier_seq = LONG_MAX;
As discussed in the cover-letter let's do a drm_gpusvm_init_pages()
function to set the notifier_seq.
If we want to include 'drm' in the init function as discussed in patch
#2, to fish this out in Xe you can do '&gpusvm_to_vm(gpusvm)->xe->drm'.
> xe_vm_get(gpusvm_to_vm(gpusvm));
>
> return &range->base;
> @@ -122,8 +123,10 @@ xe_svm_range_alloc(struct drm_gpusvm *gpusvm)
>
> static void xe_svm_range_free(struct drm_gpusvm_range *range)
> {
> + drm_gpusvm_free_pages(range->gpusvm, &(to_xe_range(range)->pages),
> + drm_gpusvm_range_size(range) >> PAGE_SHIFT);
> xe_vm_put(range_to_vm(range));
> - kfree(range);
> + kfree(to_xe_range(range));
> }
>
> static void
> @@ -208,7 +211,8 @@ xe_svm_range_notifier_event_end(struct xe_vm *vm, struct
> drm_gpusvm_range *r,
>
> xe_svm_assert_in_notifier(vm);
>
> - drm_gpusvm_range_unmap_pages(&vm->svm.gpusvm, r, &ctx);
> + drm_gpusvm_unmap_pages(&vm->svm.gpusvm, &(to_xe_range(r)->pages),
> + drm_gpusvm_range_size(r) >> PAGE_SHIFT, &ctx);
> if (!xe_vm_is_closed(vm) && mmu_range->event == MMU_NOTIFY_UNMAP)
> xe_svm_garbage_collector_add_range(vm, to_xe_range(r),
> mmu_range);
> @@ -952,7 +956,7 @@ void xe_svm_fini(struct xe_vm *vm)
> static bool xe_svm_range_has_pagemap_locked(const struct xe_svm_range *range,
> const struct drm_pagemap *dpagemap)
> {
> - return range->base.pages.dpagemap == dpagemap;
> + return range->pages.dpagemap == dpagemap;
> }
>
> static bool xe_svm_range_has_pagemap(struct xe_svm_range *range,
> @@ -1017,7 +1021,7 @@ bool xe_svm_range_validate(struct xe_vm *vm,
> if (dpagemap)
> ret = ret && xe_svm_range_has_pagemap_locked(range, dpagemap);
> else
> - ret = ret && !range->base.pages.dpagemap;
> + ret = ret && !range->pages.dpagemap;
>
> xe_svm_notifier_unlock(vm);
>
> @@ -1510,7 +1514,11 @@ int xe_svm_range_get_pages(struct xe_vm *vm, struct
> xe_svm_range *range,
> if (READ_ONCE(range->base.flags.unmapped))
> return -EFAULT;
>
> - err = drm_gpusvm_range_get_pages(&vm->svm.gpusvm, &range->base, ctx);
> + err = drm_gpusvm_get_pages(&vm->svm.gpusvm, &range->pages,
> + &vm->xe->drm, vm->svm.gpusvm.mm,
> + &range->base.notifier->notifier,
> + drm_gpusvm_range_start(&range->base),
> + drm_gpusvm_range_end(&range->base), ctx);
> if (err == -EOPNOTSUPP) {
> range_debug(range, "PAGE FAULT - EVICT PAGES");
> drm_gpusvm_range_evict(&vm->svm.gpusvm, &range->base);
> diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
> index b7b8eeacf19..ea73241d3d9 100644
> --- a/drivers/gpu/drm/xe/xe_svm.h
> +++ b/drivers/gpu/drm/xe/xe_svm.h
> @@ -31,6 +31,11 @@ struct xe_vram_region;
> struct xe_svm_range {
> /** @base: base drm_gpusvm_range */
> struct drm_gpusvm_range base;
> + /**
> + * @pages: Per-device DMA mapping state; single instance since
> + * xe svm is 1 svm : 1 drm_device.
s/xe/Xe
Matt
> + */
> + struct drm_gpusvm_pages pages;
> /**
> * @garbage_collector_link: Link into VM's garbage collect SVM range
> * list. Protected by VM's garbage collect lock.
> @@ -74,7 +79,7 @@ struct xe_pagemap {
> */
> static inline bool xe_svm_range_pages_valid(struct xe_svm_range *range)
> {
> - return drm_gpusvm_range_pages_valid(range->base.gpusvm, &range->base);
> + return drm_gpusvm_pages_valid(range->base.gpusvm, &range->pages);
> }
>
> int xe_devm_add(struct xe_tile *tile, struct xe_vram_region *vr);
> @@ -132,7 +137,7 @@ void *xe_svm_private_page_owner(struct xe_vm *vm, bool
> force_smem);
> static inline bool xe_svm_range_has_dma_mapping(struct xe_svm_range *range)
> {
> lockdep_assert_held(&range->base.gpusvm->notifier_lock);
> - return range->base.pages.flags.has_dma_mapping;
> + return range->pages.flags.has_dma_mapping;
> }
>
> /**
> diff --git a/include/drm/drm_gpusvm.h b/include/drm/drm_gpusvm.h
> index ed228d9ff6b..21baf91ec7e 100644
> --- a/include/drm/drm_gpusvm.h
> +++ b/include/drm/drm_gpusvm.h
> @@ -306,6 +306,9 @@ void drm_gpusvm_range_put(struct drm_gpusvm_range *range);
> bool drm_gpusvm_range_pages_valid(struct drm_gpusvm *gpusvm,
> struct drm_gpusvm_range *range);
>
> +bool drm_gpusvm_pages_valid(struct drm_gpusvm *gpusvm,
> + struct drm_gpusvm_pages *svm_pages);
> +
> int drm_gpusvm_range_get_pages(struct drm_gpusvm *gpusvm,
> struct drm_gpusvm_range *range,
> const struct drm_gpusvm_ctx *ctx);
> --
> 2.34.1
>
