This series aims at providing an initial implementation of multi-device SVM, where communitcation with peers (migration and direct execution out of peer memory) uses some form of fast interconnect. In this series we're using pcie p2p.
In a multi-device environment, the struct pages for device-private memory (the dev_pagemap) may take up a significant amount of system memory. We therefore want to provide a means of revoking / removing the dev_pagemaps not in use. In particular when a device is offlined, we want to block migrating *to* the device memory and migrate data already existing in the devices memory to system. The dev_pagemap then becomes unused and can be removed. Removing and setting up a large dev_pagemap is also quite time-consuming, so removal of unused dev_pagemaps only happens on system memory pressure using a shrinker. Patch 1 is a small debug printout fix. Patch 2 fixes a condition where memory was used while being cleared. Patches 3-8 deals with dynamic drm_pagemaps as described above. Patches 9-13 adds infrastructure to handle remote drm_pagemaps with fast interconnects. Patch 14 extends the xe madvise() UAPI to handle remote drm_pagemaps. Patch 15 adds a pcie-p2p dma SVM interconnect to the xe driver. Patch 16 adds some SVM-related debug printouts for xe. Patch 17 adds documentation on how the drm_pagemaps are reference counted. Patch 18 Cleans up the usage of the dev_private owner. Patch 19 Introduces a gpusvm function to scan the current CPU address space. Patch 20 Uses the above function in Xe to avoid unnecessary migrations. Patch 21 Adds drm_pagemap support for p2p destination migration. Patch 22 Adds drm_pagemap support for p2p source migration. What's still missing is implementation of migration policies. That will be implemented in follow-up series. v2: - Address review comments from Matt Brost. - Fix compilation issues reported by automated testing - Add patch 1, 17. - What's now patch 16 was extended to support p2p migration. v3: - Add patches 2, 18, 19, 10, 22. Main functionality is the address space scan to avoid unnecessary migration, and p2p source migration which is needed on Xe to decompress and to flush out the L2 cache. - Rework what's now Patch 21 slightly. - Minor fixes all over the place. Test-with: [email protected] Thomas Hellström (22): drm/xe/svm: Fix a debug printout drm/pagemap, drm/xe: Ensure that the devmem allocation is idle before use drm/pagemap, drm/xe: Add refcounting to struct drm_pagemap drm/pagemap: Add a refcounted drm_pagemap backpointer to struct drm_pagemap_zdd drm/pagemap, drm/xe: Manage drm_pagemap provider lifetimes drm/pagemap: Add a drm_pagemap cache and shrinker drm/xe: Use the drm_pagemap cache and shrinker drm/pagemap: Remove the drm_pagemap_create() interface drm/pagemap_util: Add a utility to assign an owner to a set of interconnected gpus drm/xe: Use the drm_pagemap_util helper to get a svm pagemap owner drm/xe: Pass a drm_pagemap pointer around with the memory advise attributes drm/xe: Use the vma attibute drm_pagemap to select where to migrate drm/xe: Simplify madvise_preferred_mem_loc() drm/xe/uapi: Extend the madvise functionality to support foreign pagemap placement for svm drm/xe: Support pcie p2p dma as a fast interconnect drm/xe/vm: Add a couple of VM debug printouts drm/xe/svm: Document how xe keeps drm_pagemap references drm/pagemap, drm/xe: Clean up the use of the device-private page owner drm/gpusvm: Introduce a function to scan the current migration state drm/xe: Use drm_gpusvm_scan_mm() drm/pagemap, drm/xe: Support destination migration over interconnect drm/pagemap: Support source migration over interconnect drivers/gpu/drm/Makefile | 3 +- drivers/gpu/drm/drm_gpusvm.c | 124 +++++ drivers/gpu/drm/drm_pagemap.c | 552 ++++++++++++++++---- drivers/gpu/drm/drm_pagemap_util.c | 568 +++++++++++++++++++++ drivers/gpu/drm/xe/xe_device.c | 20 + drivers/gpu/drm/xe/xe_device.h | 2 + drivers/gpu/drm/xe/xe_device_types.h | 5 + drivers/gpu/drm/xe/xe_migrate.c | 3 +- drivers/gpu/drm/xe/xe_svm.c | 719 ++++++++++++++++++++++----- drivers/gpu/drm/xe/xe_svm.h | 84 +++- drivers/gpu/drm/xe/xe_tile.c | 34 +- drivers/gpu/drm/xe/xe_tile.h | 21 + drivers/gpu/drm/xe/xe_userptr.c | 2 +- drivers/gpu/drm/xe/xe_vm.c | 65 ++- drivers/gpu/drm/xe/xe_vm.h | 1 + drivers/gpu/drm/xe/xe_vm_madvise.c | 106 +++- drivers/gpu/drm/xe/xe_vm_types.h | 21 +- drivers/gpu/drm/xe/xe_vram_types.h | 15 +- include/drm/drm_gpusvm.h | 29 ++ include/drm/drm_pagemap.h | 128 ++++- include/drm/drm_pagemap_util.h | 92 ++++ include/uapi/drm/xe_drm.h | 18 +- 22 files changed, 2322 insertions(+), 290 deletions(-) create mode 100644 drivers/gpu/drm/drm_pagemap_util.c create mode 100644 include/drm/drm_pagemap_util.h -- 2.51.1
