[PATCH v2 24/32] drm/xe: Allow CPU address mirror VMA unbind with gpu bindings for madvise
Ghimiray, Himal Prasad
himal.prasad.ghimiray at intel.com
Tue May 20 10:21:26 UTC 2025
On 15-05-2025 00:50, Matthew Brost wrote:
> On Mon, Apr 07, 2025 at 03:47:11PM +0530, Himal Prasad Ghimiray wrote:
>> In the case of the MADVISE ioctl, if the start or end addresses fall
>> within a VMA and existing SVM ranges are present, remove the existing
>> SVM mappings. Then, continue with ops_parse to create new VMAs by REMAP
>> unmapping of old one.
>>
>
> I'm quite confused why this patch is needed. Why is invalidating the
> ranges not sufficient?
how the madvise is supposed to behave if start or end of input range is
within existing svm range ?
for example lets assume :
svm_range of 2 MiB exists in offset and offset + SZ_2M, madvise is
called with offset as start and offset + SZ_1M as end, in this scenario
vma boundaries will change and previous svm_ranges needs to be removed.
>
> Matt
>
>> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
>> ---
>> drivers/gpu/drm/xe/xe_svm.c | 25 +++++++++++++++++++++++++
>> drivers/gpu/drm/xe/xe_svm.h | 7 +++++++
>> drivers/gpu/drm/xe/xe_vm.c | 18 +++++++++++++++++-
>> 3 files changed, 49 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
>> index 7ec7ecd7eb1f..efcba4b77250 100644
>> --- a/drivers/gpu/drm/xe/xe_svm.c
>> +++ b/drivers/gpu/drm/xe/xe_svm.c
>> @@ -903,6 +903,31 @@ bool xe_svm_has_mapping(struct xe_vm *vm, u64 start, u64 end)
>> return drm_gpusvm_has_mapping(&vm->svm.gpusvm, start, end);
>> }
>>
>> +/**
>> + * xe_svm_range_clean_if_addr_within - Clean SVM mappings and ranges
>> + * @start: start addr
>> + * @end: end addr
>> + *
>> + * This function cleans up svm ranges if start or end address are inside them.
>> + */
>> +void xe_svm_range_clean_if_addr_within(struct xe_vm *vm, u64 start, u64 end)
>> +{
>> + struct drm_gpusvm_notifier *notifier, *next;
>> +
>> + drm_gpusvm_for_each_notifier_safe(notifier, next, &vm->svm.gpusvm, start, end) {
>> + struct drm_gpusvm_range *range, *__next;
>> +
>> + drm_gpusvm_for_each_range_safe(range, __next, notifier, start, end) {
>> + if (start > drm_gpusvm_range_start(range) ||
>> + end < drm_gpusvm_range_end(range)) {
>> + if (IS_DGFX(vm->xe) && xe_svm_range_in_vram(to_xe_range(range)))
>> + drm_gpusvm_range_evict(&vm->svm.gpusvm, range);
>> + __xe_svm_garbage_collector(vm, to_xe_range(range));
>> + }
>> + }
>> + }
>> +}
>> +
>> /**
>> * xe_svm_bo_evict() - SVM evict BO to system memory
>> * @bo: BO to evict
>> diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
>> index d5be8229ca7e..d00ba6d6ba53 100644
>> --- a/drivers/gpu/drm/xe/xe_svm.h
>> +++ b/drivers/gpu/drm/xe/xe_svm.h
>> @@ -98,6 +98,8 @@ int xe_svm_range_get_pages(struct xe_vm *vm, struct xe_svm_range *range,
>> bool xe_svm_range_needs_migrate_to_vram(struct xe_svm_range *range, struct xe_vma *vma,
>> u32 region);
>>
>> +void xe_svm_range_clean_if_addr_within(struct xe_vm *vm, u64 start, u64 end);
>> +
>> /**
>> * xe_svm_range_has_dma_mapping() - SVM range has DMA mapping
>> * @range: SVM range
>> @@ -291,6 +293,11 @@ bool xe_svm_range_needs_migrate_to_vram(struct xe_svm_range *range, struct xe_vm
>> return false;
>> }
>>
>> +static inline
>> +void xe_svm_range_clean_if_addr_within(struct xe_vm *vm, u64 start, u64 end)
>> +{
>> +}
>> +
>> #define xe_svm_assert_in_notifier(...) do {} while (0)
>> #define xe_svm_range_has_dma_mapping(...) false
>>
>> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
>> index c7c012afe9eb..92b8e0cac063 100644
>> --- a/drivers/gpu/drm/xe/xe_vm.c
>> +++ b/drivers/gpu/drm/xe/xe_vm.c
>> @@ -2362,6 +2362,22 @@ vm_bind_ioctl_ops_create(struct xe_vm *vm, struct xe_vma_ops *vops,
>> op->map.pat_index = pat_index;
>> op->map.invalidate_on_bind =
>> __xe_vm_needs_clear_scratch_pages(vm, flags);
>> + } else if (__op->op == DRM_GPUVA_OP_REMAP) {
>> + struct xe_vma *old =
>> + gpuva_to_vma(op->base.remap.unmap->va);
>> + u64 start = xe_vma_start(old), end = xe_vma_end(old);
>> +
>> + if (op->base.remap.prev)
>> + start = op->base.remap.prev->va.addr +
>> + op->base.remap.prev->va.range;
>> + if (op->base.remap.next)
>> + end = op->base.remap.next->va.addr;
>> +
>> + if (xe_vma_is_cpu_addr_mirror(old) &&
>> + xe_svm_has_mapping(vm, start, end)) {
>> + drm_gpuva_ops_free(&vm->gpuvm, ops);
>> + return ERR_PTR(-EBUSY);
>> + }
>> } else if (__op->op == DRM_GPUVA_OP_PREFETCH) {
>> struct xe_vma *vma = gpuva_to_vma(op->base.prefetch.va);
>>
>> @@ -2653,7 +2669,7 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
>>
>> if (xe_vma_is_cpu_addr_mirror(old) &&
>> xe_svm_has_mapping(vm, start, end))
>> - return -EBUSY;
>> + xe_svm_range_clean_if_addr_within(vm, start, end);
>>
>> op->remap.start = xe_vma_start(old);
>> op->remap.range = xe_vma_size(old);
>> --
>> 2.34.1
>>
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