AMD is building a system architecture for the Frontier supercomputer with a coherent interconnect between CPUs and GPUs. This hardware architecture allows the CPUs to coherently access GPU device memory. We have hardware in our labs and we are working with our partner HPE on the BIOS, firmware and software for delivery to the DOE.
The system BIOS advertises the GPU device memory (aka VRAM) as SPM (special purpose memory) in the UEFI system address map. The amdgpu driver registers the memory with devmap as MEMORY_DEVICE_PUBLIC using devm_memremap_pages.
This patch series adds MEMORY_DEVICE_PUBLIC, which is similar to MEMORY_DEVICE_GENERIC in that it can be mapped for CPU access, but adds support for migrating this memory similar to MEMORY_DEVICE_PRIVATE. We also included and updated two patches from Ralph Campbell (Nvidia), which change ZONE_DEVICE reference counting as requested in previous reviews of this patch series (see https://patchwork.freedesktop.org/series/90706/). Finally, we extended hmm_test to cover migration of MEMORY_DEVICE_PUBLIC.
This work is based on HMM and our SVM memory manager, which has landed in Linux 5.14 recently.
Alex Sierra (12): mm: add iomem vma selection for memory migration mm: add zone device public type memory support drm/amdkfd: ref count init for device pages drm/amdkfd: add SPM support for SVM drm/amdkfd: public type as sys mem on migration to ram mm: add public type support to migrate_vma helpers mm: call pgmap->ops->page_free for DEVICE_PUBLIC pages lib: test_hmm add ioctl to get zone device type lib: test_hmm add module param for zone device type lib: add support for device public type in test_hmm tools: update hmm-test to support device public type tools: update test_hmm script to support SP config
Ralph Campbell (2): ext4/xfs: add page refcount helper mm: remove extra ZONE_DEVICE struct page refcount
arch/powerpc/kvm/book3s_hv_uvmem.c | 2 +- drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 36 ++-- drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +- fs/dax.c | 8 +- fs/ext4/inode.c | 5 +- fs/fuse/dax.c | 4 +- fs/xfs/xfs_file.c | 4 +- include/linux/dax.h | 10 + include/linux/memremap.h | 15 +- include/linux/migrate.h | 1 + include/linux/mm.h | 19 +- lib/test_hmm.c | 247 +++++++++++++++-------- lib/test_hmm_uapi.h | 16 ++ mm/internal.h | 8 + mm/memcontrol.c | 6 +- mm/memory-failure.c | 6 +- mm/memremap.c | 70 ++----- mm/migrate.c | 27 +-- mm/page_alloc.c | 3 + mm/swap.c | 45 +---- tools/testing/selftests/vm/hmm-tests.c | 142 +++++++++++-- tools/testing/selftests/vm/test_hmm.sh | 20 +- 22 files changed, 443 insertions(+), 253 deletions(-)