[PATCH v2 2/2] drm/amdkfd: Update mapping if range attributes changed
Felix Kuehling
felix.kuehling at amd.com
Fri Apr 22 22:05:30 UTC 2022
On 2022-04-22 10:06, Philip Yang wrote:
> Change SVM range mapping flags or access attributes don't trigger
> migration, if range is already mapped on GPUs we should update GPU
> mapping and pass flush_tlb flag true to amdgpu vm.
>
> Change SVM range preferred_loc or migration granularity don't need
> update GPU mapping, skip the validate_and_map.
>
> Signed-off-by: Philip Yang <Philip.Yang at amd.com>
> ---
> drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 46 +++++++++++++++++++---------
> 1 file changed, 32 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index 8a077cd066a1..e740384df9c7 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -686,7 +686,8 @@ svm_range_check_attr(struct kfd_process *p,
>
> static void
> svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
> - uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
> + uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
> + bool *update_mapping)
> {
> uint32_t i;
> int gpuidx;
> @@ -702,6 +703,7 @@ svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
> case KFD_IOCTL_SVM_ATTR_ACCESS:
> case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
> case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
> + *update_mapping = true;
> gpuidx = kfd_process_gpuidx_from_gpuid(p,
> attrs[i].value);
> if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
> @@ -716,9 +718,11 @@ svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
> }
> break;
> case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
> + *update_mapping = true;
> prange->flags |= attrs[i].value;
> break;
> case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
> + *update_mapping = true;
> prange->flags &= ~attrs[i].value;
> break;
> case KFD_IOCTL_SVM_ATTR_GRANULARITY:
> @@ -1254,7 +1258,7 @@ static int
> svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange,
> unsigned long offset, unsigned long npages, bool readonly,
> dma_addr_t *dma_addr, struct amdgpu_device *bo_adev,
> - struct dma_fence **fence)
> + struct dma_fence **fence, bool flush_tlb)
> {
> struct amdgpu_device *adev = pdd->dev->adev;
> struct amdgpu_vm *vm = drm_priv_to_vm(pdd->drm_priv);
> @@ -1292,7 +1296,7 @@ svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange,
> (last_domain == SVM_RANGE_VRAM_DOMAIN) ? 1 : 0,
> pte_flags);
>
> - r = amdgpu_vm_update_range(adev, vm, false, false, false, NULL,
> + r = amdgpu_vm_update_range(adev, vm, false, false, flush_tlb, NULL,
> last_start, prange->start + i,
> pte_flags,
> last_start - prange->start,
> @@ -1326,7 +1330,7 @@ svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange,
> static int
> svm_range_map_to_gpus(struct svm_range *prange, unsigned long offset,
> unsigned long npages, bool readonly,
> - unsigned long *bitmap, bool wait)
> + unsigned long *bitmap, bool wait, bool flush_tlb)
> {
> struct kfd_process_device *pdd;
> struct amdgpu_device *bo_adev;
> @@ -1361,7 +1365,8 @@ svm_range_map_to_gpus(struct svm_range *prange, unsigned long offset,
>
> r = svm_range_map_to_gpu(pdd, prange, offset, npages, readonly,
> prange->dma_addr[gpuidx],
> - bo_adev, wait ? &fence : NULL);
> + bo_adev, wait ? &fence : NULL,
> + flush_tlb);
> if (r)
> break;
>
> @@ -1482,8 +1487,8 @@ static void *kfd_svm_page_owner(struct kfd_process *p, int32_t gpuidx)
> * 5. Release page table (and SVM BO) reservation
> */
> static int svm_range_validate_and_map(struct mm_struct *mm,
> - struct svm_range *prange,
> - int32_t gpuidx, bool intr, bool wait)
> + struct svm_range *prange, int32_t gpuidx,
> + bool intr, bool wait, bool flush_tlb)
> {
> struct svm_validate_context ctx;
> unsigned long start, end, addr;
> @@ -1522,8 +1527,12 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
> prange->bitmap_aip, MAX_GPU_INSTANCE);
> }
>
> - if (bitmap_empty(ctx.bitmap, MAX_GPU_INSTANCE))
> - return 0;
> + if (bitmap_empty(ctx.bitmap, MAX_GPU_INSTANCE)) {
> + if (!prange->mapped_to_gpu)
> + return 0;
> +
> + bitmap_copy(ctx.bitmap, prange->bitmap_access, MAX_GPU_INSTANCE);
> + }
>
> if (prange->actual_loc && !prange->ttm_res) {
> /* This should never happen. actual_loc gets set by
> @@ -1595,7 +1604,7 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
> }
>
> r = svm_range_map_to_gpus(prange, offset, npages, readonly,
> - ctx.bitmap, wait);
> + ctx.bitmap, wait, flush_tlb);
>
> unlock_out:
> svm_range_unlock(prange);
> @@ -1691,7 +1700,7 @@ static void svm_range_restore_work(struct work_struct *work)
> mutex_lock(&prange->migrate_mutex);
>
> r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
> - false, true);
> + false, true, false);
> if (r)
> pr_debug("failed %d to map 0x%lx to gpus\n", r,
> prange->start);
> @@ -2847,7 +2856,7 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
> }
> }
>
> - r = svm_range_validate_and_map(mm, prange, gpuidx, false, false);
> + r = svm_range_validate_and_map(mm, prange, gpuidx, false, false, false);
> if (r)
> pr_debug("failed %d to map svms 0x%p [0x%lx 0x%lx] to gpus\n",
> r, svms, prange->start, prange->last);
> @@ -3264,6 +3273,8 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
> struct svm_range_list *svms;
> struct svm_range *prange;
> struct svm_range *next;
> + bool update_mapping = false;
> + bool flush_tlb;
> int r = 0;
>
> pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] pages 0x%llx\n",
> @@ -3302,7 +3313,7 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
> svm_range_add_notifier_locked(mm, prange);
> }
> list_for_each_entry(prange, &update_list, update_list) {
> - svm_range_apply_attrs(p, prange, nattr, attrs);
> + svm_range_apply_attrs(p, prange, nattr, attrs, &update_mapping);
> /* TODO: unmap ranges from GPU that lost access */
> }
> list_for_each_entry_safe(prange, next, &remove_list, update_list) {
> @@ -3335,8 +3346,15 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
> continue;
> }
>
> + if (!migrated && !update_mapping) {
> + mutex_unlock(&prange->migrate_mutex);
> + continue;
> + }
> +
> + flush_tlb = !migrated && update_mapping && prange->mapped_to_gpu;
> +
Please check that this doesn't break the XNACK off case. If a new range
is created, and that does not trigger a migration or any of the
conditions that set update_mapping, we still need to make sure the GPU
mapping is created so that a GPU access to the new range won't fault.
Regards,
Felix
> r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
> - true, true);
> + true, true, flush_tlb);
> if (r)
> pr_debug("failed %d to map svm range\n", r);
>
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