[PATCH v5 20/23] drm/xe: Reset VMA attributes to default in SVM garbage collector
Ghimiray, Himal Prasad
himal.prasad.ghimiray at intel.com
Wed Jul 30 06:09:11 UTC 2025
On 25-07-2025 03:20, Matthew Brost wrote:
> On Tue, Jul 22, 2025 at 07:05:23PM +0530, Himal Prasad Ghimiray wrote:
>> Restore default memory attributes for VMAs during garbage collection
>> if they were modified by madvise. Reuse existing VMA if fully overlapping;
>> otherwise, allocate a new mirror VMA.
>>
>> Suggested-by: Matthew Brost <matthew.brost at intel.com>
>> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
>> ---
>> drivers/gpu/drm/xe/xe_svm.c | 34 +++++++++
>> drivers/gpu/drm/xe/xe_vm.c | 140 +++++++++++++++++++++++++-----------
>> drivers/gpu/drm/xe/xe_vm.h | 2 +
>> 3 files changed, 135 insertions(+), 41 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
>> index ba1233d0d5a2..79709dc066b9 100644
>> --- a/drivers/gpu/drm/xe/xe_svm.c
>> +++ b/drivers/gpu/drm/xe/xe_svm.c
>> @@ -255,7 +255,18 @@ static int __xe_svm_garbage_collector(struct xe_vm *vm,
>> static int xe_svm_garbage_collector(struct xe_vm *vm)
>> {
>> struct xe_svm_range *range;
>> + struct xe_vma *vma;
>> + u64 range_start;
>> + u64 range_size;
>> + u64 range_end;
>> int err;
>> + struct xe_vma_mem_attr default_attr = {
>> + .preferred_loc = {
>> + .devmem_fd = DRM_XE_PREFERRED_LOC_DEFAULT_DEVICE,
>> + .migration_policy = DRM_XE_MIGRATE_ALL_PAGES,
>> + },
>> + .atomic_access = DRM_XE_ATOMIC_UNDEFINED,
>> + };
>>
>> lockdep_assert_held_write(&vm->lock);
>>
>> @@ -270,6 +281,12 @@ static int xe_svm_garbage_collector(struct xe_vm *vm)
>> if (!range)
>> break;
>>
>> + range_start = xe_svm_range_start(range);
>> + range_size = xe_svm_range_size(range);
>> + range_end = xe_svm_range_end(range);
>> +
>> + vma = xe_vm_find_vma_by_addr(vm, xe_svm_range_start(range));
>> +
>
> I'd find the VMA outside of the svm.garbage_collector.lock.
Sure.
>
>> list_del(&range->garbage_collector_link);
>> spin_unlock(&vm->svm.garbage_collector.lock);
>>
>> @@ -282,7 +299,24 @@ static int xe_svm_garbage_collector(struct xe_vm *vm)
>> return err;
>> }
>>
>> + if (!xe_vma_has_default_mem_attrs(vma)) {
>
> It seems possible the VMA could be NULL in error cases. I'd check for
> NULL and error out.
>
> Also could this code be moved to a helper? Internal SVM seems ok, in
> that case xe_vm_find_vma_by_addr could also be in the helper.
Sure
>
>> + vm_dbg(&vm->xe->drm, "Existing VMA start=0x%016llx, vma_end=0x%016llx",
>> + xe_vma_start(vma), xe_vma_end(vma));
>> +
>> + if (xe_vma_start(vma) == range_start && xe_vma_end(vma) == range_end) {
>> + default_attr.pat_index = vma->attr.default_pat_index;
>> + default_attr.default_pat_index = vma->attr.default_pat_index;
>> + vma->attr = default_attr;
>> + } else {
>> + vm_dbg(&vm->xe->drm, "Split VMA start=0x%016llx, vma_end=0x%016llx",
>> + range_start, range_end);
>> + err = xe_vm_alloc_cpu_addr_mirror_vma(vm, range_start, range_size);
>> + if (err)
>
> On error, I'd print a message and kill the VM as it shouldn't be
> possible to fail aside from a memory allocation failure and we can't
> code with errors given this can be inside a worker.
Sure
>
> I'll circle back to the rest of the patch a bit later.
>
> Matt
>
>> + return err;
>> + }
>> + }
>> spin_lock(&vm->svm.garbage_collector.lock);
>> +
>> }
>> spin_unlock(&vm->svm.garbage_collector.lock);
>>
>> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
>> index d3f08bf9a3ee..003c8209f8bd 100644
>> --- a/drivers/gpu/drm/xe/xe_vm.c
>> +++ b/drivers/gpu/drm/xe/xe_vm.c
>> @@ -4254,34 +4254,24 @@ bool xe_vma_need_vram_for_atomic(struct xe_device *xe, struct xe_vma *vma, bool
>> }
>> }
>>
>> -/**
>> - * xe_vm_alloc_madvise_vma - Allocate VMA's with madvise ops
>> - * @vm: Pointer to the xe_vm structure
>> - * @start: Starting input address
>> - * @range: Size of the input range
>> - *
>> - * This function splits existing vma to create new vma for user provided input range
>> - *
>> - * Return: 0 if success
>> - */
>> -int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t start, uint64_t range)
>> +static int xe_vm_alloc_vma(struct xe_vm *vm,
>> + u64 start, u64 range,
>> + enum drm_gpuvm_sm_map_ops_flags flags)
>> {
>> struct xe_vma_ops vops;
>> struct drm_gpuva_ops *ops = NULL;
>> struct drm_gpuva_op *__op;
>> bool is_cpu_addr_mirror = false;
>> bool remap_op = false;
>> + bool is_madvise = flags == DRM_GPUVM_SKIP_GEM_OBJ_VA_SPLIT_MADVISE;
>> struct xe_vma_mem_attr tmp_attr;
>> + u16 default_pat;
>> int err;
>>
>> - vm_dbg(&vm->xe->drm, "MADVISE IN: addr=0x%016llx, size=0x%016llx", start, range);
>> -
>> lockdep_assert_held_write(&vm->lock);
>>
>> - vm_dbg(&vm->xe->drm, "MADVISE_OPS_CREATE: addr=0x%016llx, size=0x%016llx", start, range);
>> ops = drm_gpuvm_sm_map_ops_create(&vm->gpuvm, start, range,
>> - DRM_GPUVM_SKIP_GEM_OBJ_VA_SPLIT_MADVISE,
>> - NULL, start);
>> + flags, NULL, start);
>> if (IS_ERR(ops))
>> return PTR_ERR(ops);
>>
>> @@ -4292,33 +4282,56 @@ int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t start, uint64_t range)
>>
>> drm_gpuva_for_each_op(__op, ops) {
>> struct xe_vma_op *op = gpuva_op_to_vma_op(__op);
>> + struct xe_vma *vma = NULL;
>>
>> - if (__op->op == DRM_GPUVA_OP_REMAP) {
>> - xe_assert(vm->xe, !remap_op);
>> - remap_op = true;
>> + if (!is_madvise) {
>> + if (__op->op == DRM_GPUVA_OP_UNMAP) {
>> + vma = gpuva_to_vma(op->base.unmap.va);
>> + XE_WARN_ON(!xe_vma_has_default_mem_attrs(vma));
>> + default_pat = vma->attr.default_pat_index;
>> + }
>>
>> - if (xe_vma_is_cpu_addr_mirror(gpuva_to_vma(op->base.remap.unmap->va)))
>> - is_cpu_addr_mirror = true;
>> - else
>> - is_cpu_addr_mirror = false;
>> - }
>> + if (__op->op == DRM_GPUVA_OP_REMAP) {
>> + vma = gpuva_to_vma(op->base.remap.unmap->va);
>> + default_pat = vma->attr.default_pat_index;
>> + }
>>
>> - if (__op->op == DRM_GPUVA_OP_MAP) {
>> - xe_assert(vm->xe, remap_op);
>> - remap_op = false;
>> + if (__op->op == DRM_GPUVA_OP_MAP) {
>> + op->map.is_cpu_addr_mirror = true;
>> + op->map.pat_index = default_pat;
>> + }
>> + } else {
>> + if (__op->op == DRM_GPUVA_OP_REMAP) {
>> + vma = gpuva_to_vma(op->base.remap.unmap->va);
>> + xe_assert(vm->xe, !remap_op);
>> + remap_op = true;
>>
>> - /* In case of madvise ops DRM_GPUVA_OP_MAP is always after
>> - * DRM_GPUVA_OP_REMAP, so ensure we assign op->map.is_cpu_addr_mirror true
>> - * if REMAP is for xe_vma_is_cpu_addr_mirror vma
>> - */
>> - op->map.is_cpu_addr_mirror = is_cpu_addr_mirror;
>> - }
>> + if (xe_vma_is_cpu_addr_mirror(vma))
>> + is_cpu_addr_mirror = true;
>> + else
>> + is_cpu_addr_mirror = false;
>> + }
>>
>> + if (__op->op == DRM_GPUVA_OP_MAP) {
>> + xe_assert(vm->xe, remap_op);
>> + remap_op = false;
>> + /*
>> + * In case of madvise ops DRM_GPUVA_OP_MAP is
>> + * always after DRM_GPUVA_OP_REMAP, so ensure
>> + * we assign op->map.is_cpu_addr_mirror true
>> + * if REMAP is for xe_vma_is_cpu_addr_mirror vma
>> + */
>> + op->map.is_cpu_addr_mirror = is_cpu_addr_mirror;
>> + }
>> + }
>> print_op(vm->xe, __op);
>> }
>>
>> xe_vma_ops_init(&vops, vm, NULL, NULL, 0);
>> - vops.flags |= XE_VMA_OPS_FLAG_MADVISE;
>> +
>> + if (is_madvise)
>> + vops.flags |= XE_VMA_OPS_FLAG_MADVISE;
>> +
>> err = vm_bind_ioctl_ops_parse(vm, ops, &vops);
>> if (err)
>> goto unwind_ops;
>> @@ -4330,15 +4343,20 @@ int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t start, uint64_t range)
>> struct xe_vma *vma;
>>
>> if (__op->op == DRM_GPUVA_OP_UNMAP) {
>> - /* There should be no unmap */
>> - XE_WARN_ON("UNEXPECTED UNMAP");
>> - xe_vma_destroy(gpuva_to_vma(op->base.unmap.va), NULL);
>> + vma = gpuva_to_vma(op->base.unmap.va);
>> + /* There should be no unmap for madvise */
>> + if (is_madvise)
>> + XE_WARN_ON("UNEXPECTED UNMAP");
>> +
>> + xe_vma_destroy(vma, NULL);
>> } else if (__op->op == DRM_GPUVA_OP_REMAP) {
>> vma = gpuva_to_vma(op->base.remap.unmap->va);
>> - /* Store attributes for REMAP UNMAPPED VMA, so they can be assigned
>> - * to newly MAP created vma.
>> + /* In case of madvise ops Store attributes for REMAP UNMAPPED
>> + * VMA, so they can be assigned to newly MAP created vma.
>> */
>> - tmp_attr = vma->attr;
>> + if (is_madvise)
>> + tmp_attr = vma->attr;
>> +
>> xe_vma_destroy(gpuva_to_vma(op->base.remap.unmap->va), NULL);
>> } else if (__op->op == DRM_GPUVA_OP_MAP) {
>> vma = op->map.vma;
>> @@ -4346,7 +4364,8 @@ int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t start, uint64_t range)
>> * Therefore temp_attr will always have sane values, making it safe to
>> * copy them to new vma.
>> */
>> - vma->attr = tmp_attr;
>> + if (is_madvise)
>> + vma->attr = tmp_attr;
>> }
>> }
>>
>> @@ -4360,3 +4379,42 @@ int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t start, uint64_t range)
>> drm_gpuva_ops_free(&vm->gpuvm, ops);
>> return err;
>> }
>> +
>> +/**
>> + * xe_vm_alloc_madvise_vma - Allocate VMA's with madvise ops
>> + * @vm: Pointer to the xe_vm structure
>> + * @start: Starting input address
>> + * @range: Size of the input range
>> + *
>> + * This function splits existing vma to create new vma for user provided input range
>> + *
>> + * Return: 0 if success
>> + */
>> +int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t start, uint64_t range)
>> +{
>> + lockdep_assert_held_write(&vm->lock);
>> +
>> + vm_dbg(&vm->xe->drm, "MADVISE_OPS_CREATE: addr=0x%016llx, size=0x%016llx", start, range);
>> +
>> + return xe_vm_alloc_vma(vm, start, range, DRM_GPUVM_SKIP_GEM_OBJ_VA_SPLIT_MADVISE);
>> +}
>> +
>> +/**
>> + * xe_vm_alloc_cpu_addr_mirror_vma - Allocate CPU addr mirror vma
>> + * @vm: Pointer to the xe_vm structure
>> + * @start: Starting input address
>> + * @range: Size of the input range
>> + *
>> + * This function splits/merges existing vma to create new vma for user provided input range
>> + *
>> + * Return: 0 if success
>> + */
>> +int xe_vm_alloc_cpu_addr_mirror_vma(struct xe_vm *vm, uint64_t start, uint64_t range)
>> +{
>> + lockdep_assert_held_write(&vm->lock);
>> +
>> + vm_dbg(&vm->xe->drm, "CPU_ADDR_MIRROR_VMA_OPS_CREATE: addr=0x%016llx, size=0x%016llx",
>> + start, range);
>> +
>> + return xe_vm_alloc_vma(vm, start, range, DRM_GPUVM_SM_MAP_NOT_MADVISE);
>> +}
>> diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
>> index a4db843de540..f7b9ad83685a 100644
>> --- a/drivers/gpu/drm/xe/xe_vm.h
>> +++ b/drivers/gpu/drm/xe/xe_vm.h
>> @@ -177,6 +177,8 @@ bool xe_vma_need_vram_for_atomic(struct xe_device *xe, struct xe_vma *vma, bool
>>
>> int xe_vm_alloc_madvise_vma(struct xe_vm *vm, uint64_t addr, uint64_t size);
>>
>> +int xe_vm_alloc_cpu_addr_mirror_vma(struct xe_vm *vm, uint64_t addr, uint64_t size);
>> +
>> /**
>> * to_userptr_vma() - Return a pointer to an embedding userptr vma
>> * @vma: Pointer to the embedded struct xe_vma
>> --
>> 2.34.1
>>
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