From fb361a520a5861368c6c36717ff1900a35dde093 Mon Sep 17 00:00:00 2001 From: Donet Tom Date: Mon, 12 Jan 2026 19:36:55 +0530 Subject: [PATCH] drm/amdkfd: Fix SVM map/unmap address conversion for non-4k page sizes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit SVM range size is tracked using the system page size. The range start and end are aligned to system page-sized PFNs, so the total SVM range size equals the total number of pages in the SVM range multiplied by the system page size. The SVM range map/unmap functions pass these system page-sized PFN numbers to amdgpu_vm_update_range(), which expects PFNs based on the GPU page size (4K). On non-4K page systems, this mismatch causes only part of the SVM range to be mapped in the GPU page table, while the rest remains unmapped. If the GPU accesses an unmapped address within the same range, it results in a GPU page fault. To fix this, the required conversion has been added in both svm_range_map_to_gpu() and svm_range_unmap_from_gpu(), ensuring that all pages in the SVM range are correctly mapped on non-4K systems. Acked-by: Christian König Reviewed-by: Philip Yang Signed-off-by: Ritesh Harjani (IBM) Signed-off-by: Donet Tom Signed-off-by: Felix Kuehling Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 29 ++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 1ed08388d364..35036d47657b 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -1355,11 +1355,16 @@ svm_range_unmap_from_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm, struct dma_fence **fence) { uint64_t init_pte_value = adev->gmc.init_pte_flags; + uint64_t gpu_start, gpu_end; - pr_debug("[0x%llx 0x%llx]\n", start, last); + /* Convert CPU page range to GPU page range */ + gpu_start = start * AMDGPU_GPU_PAGES_IN_CPU_PAGE; + gpu_end = (last + 1) * AMDGPU_GPU_PAGES_IN_CPU_PAGE - 1; - return amdgpu_vm_update_range(adev, vm, false, true, true, false, NULL, start, - last, init_pte_value, 0, 0, NULL, NULL, + pr_debug("CPU[0x%llx 0x%llx] -> GPU[0x%llx 0x%llx]\n", start, last, + gpu_start, gpu_end); + return amdgpu_vm_update_range(adev, vm, false, true, true, false, NULL, gpu_start, + gpu_end, init_pte_value, 0, 0, NULL, NULL, fence); } @@ -1439,6 +1444,9 @@ svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange, last_start, last_start + npages - 1, readonly); for (i = offset; i < offset + npages; i++) { + uint64_t gpu_start; + uint64_t gpu_end; + last_domain = dma_addr[i] & SVM_RANGE_VRAM_DOMAIN; dma_addr[i] &= ~SVM_RANGE_VRAM_DOMAIN; @@ -1456,17 +1464,22 @@ svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange, if (readonly) pte_flags &= ~AMDGPU_PTE_WRITEABLE; - pr_debug("svms 0x%p map [0x%lx 0x%llx] vram %d PTE 0x%llx\n", - prange->svms, last_start, prange->start + i, - (last_domain == SVM_RANGE_VRAM_DOMAIN) ? 1 : 0, - pte_flags); /* For dGPU mode, we use same vm_manager to allocate VRAM for * different memory partition based on fpfn/lpfn, we should use * same vm_manager.vram_base_offset regardless memory partition. */ + gpu_start = last_start * AMDGPU_GPU_PAGES_IN_CPU_PAGE; + gpu_end = (prange->start + i + 1) * AMDGPU_GPU_PAGES_IN_CPU_PAGE - 1; + + pr_debug("svms 0x%p map CPU[0x%lx 0x%llx] GPU[0x%llx 0x%llx] vram %d PTE 0x%llx\n", + prange->svms, last_start, prange->start + i, + gpu_start, gpu_end, + (last_domain == SVM_RANGE_VRAM_DOMAIN) ? 1 : 0, + pte_flags); + r = amdgpu_vm_update_range(adev, vm, false, false, flush_tlb, true, - NULL, last_start, prange->start + i, + NULL, gpu_start, gpu_end, pte_flags, (last_start - prange->start) << PAGE_SHIFT, bo_adev ? bo_adev->vm_manager.vram_base_offset : 0, -- 2.47.3