On Wed, 2025-01-29 at 11:52 -0800, Matthew Brost wrote:
> Add some useful SVM debug logging fro SVM range which prints the
> range's
> state.
>
> v2:
> - Upadte logging with latest structure layout
NIT: Update
> v3:
> - Better commit message (Thomas)
> - New range structure (Thomas)
> - s/COLLECTOT/s/COLLECTOR (Thomas)
> v4:
> - Drop partial evict message (Thomas)
> - Use %p for pointers print (Thomas)
>
> Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/xe/xe_pt.c | 8 ++++
> drivers/gpu/drm/xe/xe_svm.c | 91 +++++++++++++++++++++++++++++++++--
> --
> drivers/gpu/drm/xe/xe_svm.h | 2 +
> 3 files changed, 93 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
> index f8d06c70f77d..29ade504e1c1 100644
> --- a/drivers/gpu/drm/xe/xe_pt.c
> +++ b/drivers/gpu/drm/xe/xe_pt.c
> @@ -647,6 +647,7 @@ xe_pt_stage_bind(struct xe_tile *tile, struct
> xe_vma *vma,
> /* Move this entire thing to xe_svm.c? */
> xe_svm_notifier_lock(xe_vma_vm(vma));
> if (!xe_svm_range_pages_valid(range)) {
> + xe_svm_range_debug(range, "BIND PREPARE -
> RETRY");
> xe_svm_notifier_unlock(xe_vma_vm(vma));
> return -EAGAIN;
> }
> @@ -655,6 +656,10 @@ xe_pt_stage_bind(struct xe_tile *tile, struct
> xe_vma *vma,
> range->base.itree.last + 1
> - range->base.itree.start,
> &curs);
> is_devmem = xe_res_is_vram(&curs);
> + if (is_devmem)
> + xe_svm_range_debug(range, "BIND
> PREPARE - DMA VRAM");
> + else
> + xe_svm_range_debug(range, "BIND
> PREPARE - DMA");
> } else {
> xe_assert(xe, false);
> }
> @@ -1429,10 +1434,13 @@ static int xe_pt_svm_pre_commit(struct
> xe_migrate_pt_update *pt_update)
> if (op->subop == XE_VMA_SUBOP_UNMAP_RANGE)
> continue;
>
> + xe_svm_range_debug(range, "PRE-COMMIT");
> +
> xe_assert(vm->xe, xe_vma_is_cpu_addr_mirror(op-
> >map_range.vma));
> xe_assert(vm->xe, op->subop ==
> XE_VMA_SUBOP_MAP_RANGE);
>
> if (!xe_svm_range_pages_valid(range)) {
> + xe_svm_range_debug(range, "PRE-COMMIT -
> RETRY");
> xe_svm_notifier_unlock(vm);
> return -EAGAIN;
> }
> diff --git a/drivers/gpu/drm/xe/xe_svm.c
> b/drivers/gpu/drm/xe/xe_svm.c
> index dafc5061eb42..0df924ca8ed1 100644
> --- a/drivers/gpu/drm/xe/xe_svm.c
> +++ b/drivers/gpu/drm/xe/xe_svm.c
> @@ -12,6 +12,18 @@
> #include "xe_vm.h"
> #include "xe_vm_types.h"
>
> +static bool xe_svm_range_in_vram(struct xe_svm_range *range)
> +{
> + /* Not reliable without notifier lock */
> + return range->base.flags.has_devmem_pages;
> +}
> +
> +static bool xe_svm_range_has_vram_binding(struct xe_svm_range
> *range)
> +{
> + /* Not reliable without notifier lock */
> + return xe_svm_range_in_vram(range) && range->tile_present;
> +}
> +
> static struct xe_vm *gpusvm_to_vm(struct drm_gpusvm *gpusvm)
> {
> return container_of(gpusvm, struct xe_vm, svm.gpusvm);
> @@ -22,6 +34,23 @@ static struct xe_vm *range_to_vm(struct
> drm_gpusvm_range *r)
> return gpusvm_to_vm(r->gpusvm);
> }
>
> +#define range_debug(r__,
> operaton__) \
> + vm_dbg(&range_to_vm(&(r__)->base)->xe-
> >drm, \
> + "%s: asid=%u, gpusvm=%p, vram=%d,%d, seqno=%lu, " \
> + "start=0x%014lx, end=0x%014lx,
> size=%lu", \
> + (operaton__), range_to_vm(&(r__)->base)-
> >usm.asid, \
> + (r__)-
> >base.gpusvm, \
> + xe_svm_range_in_vram((r__)) ? 1 :
> 0, \
> + xe_svm_range_has_vram_binding((r__)) ? 1 :
> 0, \
> + (r__)-
> >base.notifier_seq, \
> + (r__)->base.itree.start, (r__)->base.itree.last +
> 1, \
> + (r__)->base.itree.last + 1 - (r__)->base.itree.start)
> +
> +void xe_svm_range_debug(struct xe_svm_range *range, const char
> *operation)
> +{
> + range_debug(range, operation);
> +}
> +
> static void *xe_svm_devm_owner(struct xe_device *xe)
> {
> return xe;
> @@ -59,6 +88,8 @@ xe_svm_garbage_collector_add_range(struct xe_vm
> *vm, struct xe_svm_range *range,
> {
> struct xe_device *xe = vm->xe;
>
> + range_debug(range, "GARBAGE COLLECTOR ADD");
> +
> drm_gpusvm_range_set_unmapped(&range->base, mmu_range);
>
> spin_lock(&vm->svm.garbage_collector.lock);
> @@ -84,10 +115,14 @@ xe_svm_range_notifier_event_begin(struct xe_vm
> *vm, struct drm_gpusvm_range *r,
>
> xe_svm_assert_in_notifier(vm);
>
> + range_debug(range, "NOTIFIER");
> +
> /* Skip if already unmapped or if no binding exist */
> if (range->base.flags.unmapped || !range->tile_present)
> return 0;
>
> + range_debug(range, "NOTIFIER - EXECUTE");
> +
> /* Adjust invalidation to range boundaries */
> if (range->base.itree.start < mmu_range->start)
> *adj_start = range->base.itree.start;
> @@ -140,6 +175,11 @@ static void xe_svm_invalidate(struct drm_gpusvm
> *gpusvm,
>
> xe_svm_assert_in_notifier(vm);
>
> + vm_dbg(&gpusvm_to_vm(gpusvm)->xe->drm,
> + "INVALIDATE: asid=%u, gpusvm=%p, seqno=%lu,
> start=0x%016lx, end=0x%016lx, event=%d",
> + vm->usm.asid, gpusvm, notifier-
> >notifier.invalidate_seq,
> + mmu_range->start, mmu_range->end, mmu_range->event);
> +
> /* Adjust invalidation to notifier boundaries */
> if (adj_start < notifier->itree.start)
> adj_start = notifier->itree.start;
> @@ -226,6 +266,8 @@ static int __xe_svm_garbage_collector(struct
> xe_vm *vm,
> {
> struct dma_fence *fence;
>
> + range_debug(range, "GARBAGE COLLECTOR");
> +
> xe_vm_lock(vm, false);
> fence = xe_vm_range_unbind(vm, range);
> xe_vm_unlock(vm);
> @@ -385,16 +427,23 @@ static int xe_svm_copy(struct page **pages,
> dma_addr_t *dma_addr,
> int incr = (match && last) ? 1 : 0;
>
> if (vram_addr != XE_VRAM_ADDR_INVALID) {
> - if (sram)
> + if (sram) {
> + vm_dbg(&tile->xe->drm,
> + "COPY TO SRAM -
> 0x%016llx -> 0x%016llx, NPAGES=%ld",
> + vram_addr,
> dma_addr[pos], i - pos + incr);
> __fence =
> xe_migrate_from_vram(tile->migrate,
>
> i - pos + incr,
>
> vram_addr,
>
> dma_addr + pos);
> - else
> + } else {
> + vm_dbg(&tile->xe->drm,
> + "COPY TO VRAM -
> 0x%016llx -> 0x%016llx, NPAGES=%ld",
> + dma_addr[pos],
> vram_addr, i - pos + incr);
> __fence =
> xe_migrate_to_vram(tile->migrate,
>
> i - pos + incr,
>
> dma_addr + pos,
>
> vram_addr);
> + }
> if (IS_ERR(__fence)) {
> err = PTR_ERR(__fence);
> goto err_out;
> @@ -414,14 +463,21 @@ static int xe_svm_copy(struct page **pages,
> dma_addr_t *dma_addr,
>
> /* Extra mismatched device page, copy it */
> if (!match && last && vram_addr !=
> XE_VRAM_ADDR_INVALID) {
> - if (sram)
> + if (sram) {
> + vm_dbg(&tile->xe->drm,
> + "COPY TO SRAM -
> 0x%016llx -> 0x%016llx, NPAGES=%d",
> + vram_addr,
> dma_addr[pos], 1);
> __fence =
> xe_migrate_from_vram(tile->migrate, 1,
>
> vram_addr,
>
> dma_addr + pos);
> - else
> + } else {
> + vm_dbg(&tile->xe->drm,
> + "COPY TO VRAM -
> 0x%016llx -> 0x%016llx, NPAGES=%d",
> + dma_addr[pos],
> vram_addr, 1);
> __fence =
> xe_migrate_to_vram(tile->migrate, 1,
>
> dma_addr + pos,
>
> vram_addr);
> + }
> if (IS_ERR(__fence)) {
> err = PTR_ERR(__fence);
> goto err_out;
> @@ -591,12 +647,14 @@ static struct xe_bo *xe_svm_alloc_vram(struct
> xe_vm *vm, struct xe_tile *tile,
> const struct drm_gpusvm_ctx
> *ctx)
> {
> struct xe_mem_region *mr = tile_to_mr(tile);
> + struct drm_buddy *buddy = tile_to_buddy(tile);
> struct drm_buddy_block *block;
> struct list_head *blocks;
> struct xe_bo *bo;
> ktime_t end = 0;
> int err;
>
> + range_debug(range, "ALLOCATE VRAM");
> retry:
> xe_vm_lock(vm, false);
> bo = xe_bo_create(tile_to_xe(tile), tile, vm, range-
> >base.itree.last + 1 -
> @@ -619,8 +677,13 @@ static struct xe_bo *xe_svm_alloc_vram(struct
> xe_vm *vm, struct xe_tile *tile,
> range->base.itree.start);
>
> blocks = &to_xe_ttm_vram_mgr_resource(bo->ttm.resource)-
> >blocks;
> - list_for_each_entry(block, blocks, link)
> + list_for_each_entry(block, blocks, link) {
> + vm_dbg(&vm->xe->drm, "ALLOC VRAM: asid=%u,
> gpusvm=%p, pfn=%llu, npages=%llu",
> + vm->usm.asid, &vm->svm.gpusvm,
> + block_offset_to_pfn(mr,
> drm_buddy_block_offset(block)),
> + drm_buddy_block_size(buddy, block) >>
> PAGE_SHIFT);
> block->private = mr;
> + }
>
> /*
> * Take ref because as soon as drm_gpusvm_migrate_to_devmem
> succeeds the
> @@ -693,6 +756,8 @@ int xe_svm_handle_pagefault(struct xe_vm *vm,
> struct xe_vma *vma,
> if (xe_svm_range_is_valid(range, tile))
> return 0;
>
> + range_debug(range, "PAGE FAULT");
> +
> /* XXX: Add migration policy, for now migrate range once */
> if (!range->migrated && range->base.flags.migrate_devmem &&
> (range->base.itree.last + 1 - range->base.itree.start)
> >= SZ_64K) {
> @@ -708,18 +773,26 @@ int xe_svm_handle_pagefault(struct xe_vm *vm,
> struct xe_vma *vma,
> }
> }
>
> + range_debug(range, "GET PAGES");
> err = drm_gpusvm_range_get_pages(&vm->svm.gpusvm, r, &ctx);
> /* Corner where CPU mappings have changed */
> if (err == -EOPNOTSUPP || err == -EFAULT || err == -EPERM) {
> - if (err == -EOPNOTSUPP)
> + if (err == -EOPNOTSUPP) {
> + range_debug(range, "PAGE FAULT - EVICT
> PAGES");
> drm_gpusvm_range_evict(&vm->svm.gpusvm,
> &range->base);
> + }
> drm_info(&vm->xe->drm,
> "Get pages failed, falling back to
> retrying, asid=%u, gpusvm=%p, errno %pe\n",
> vm->usm.asid, &vm->svm.gpusvm,
> ERR_PTR(err));
> + range_debug(range, "PAGE FAULT - RETRY PAGES");
> goto retry;
> }
> - if (err)
> + if (err) {
> + range_debug(range, "PAGE FAULT - FAIL PAGE
> COLLECT");
> goto err_out;
> + }
> +
> + range_debug(range, "PAGE FAULT - BIND");
>
> retry_bind:
> drm_exec_init(&exec, 0, 0);
> @@ -735,8 +808,10 @@ int xe_svm_handle_pagefault(struct xe_vm *vm,
> struct xe_vma *vma,
> if (IS_ERR(fence)) {
> drm_exec_fini(&exec);
> err = PTR_ERR(fence);
> - if (err == -EAGAIN)
> + if (err == -EAGAIN) {
> + range_debug(range, "PAGE FAULT -
> RETRY BIND");
> goto retry;
> + }
> if (xe_vm_validate_should_retry(&exec, err,
> &end))
> goto retry_bind;
> goto err_out;
> diff --git a/drivers/gpu/drm/xe/xe_svm.h
> b/drivers/gpu/drm/xe/xe_svm.h
> index 77dec5aae0ee..f16b76dcc55b 100644
> --- a/drivers/gpu/drm/xe/xe_svm.h
> +++ b/drivers/gpu/drm/xe/xe_svm.h
> @@ -57,6 +57,8 @@ int xe_svm_handle_pagefault(struct xe_vm *vm,
> struct xe_vma *vma,
>
> bool xe_svm_has_mapping(struct xe_vm *vm, u64 start, u64 end);
>
> +void xe_svm_range_debug(struct xe_svm_range *range, const char
> *operation);
> +
> int xe_svm_bo_evict(struct xe_bo *bo);
>
> static inline bool xe_svm_range_pages_valid(struct xe_svm_range
> *range)
