From: Honglei Huang <[email protected]>
The intent of this series is to make drm_gpusvm more flexible and give
drivers more freedom over how they assemble the MM related and device
side operations. It implements the direction Matt suggested in [1]:
Mirror MR in gitlab: [4]
- Move struct drm_gpusvm_pages out of struct drm_gpusvm_range.
- Embed a struct drm_device in struct drm_gpusvm_pages and drive all
DMA through it.
- Drop struct drm_device from struct drm_gpusvm.
- Have the driver's range structure embed one or more struct
drm_gpusvm_pages in addition to struct drm_gpusvm_range.
- Drop the range-based helpers (drm_gpusvm_range_pages_valid,
drm_gpusvm_range_get_pages, drm_gpusvm_range_unmap_pages) and update
drivers to use the drm_gpusvm_pages helpers instead.
In essence the series does only two abstractions, plus the xe
adaptation that follows from them:
- range vs pages: split drm_gpusvm_range (MM / VA range state) from
drm_gpusvm_pages (device physical related), so the two sides can
have independent lifetimes and ownership.
- drm_gpusvm vs drm_device: make drm_gpusvm pure MM level and push
the device side down onto drm_gpusvm_pages, which is where DMA
actually happens.
- xe is updated to fit the modifications, no functional change
intended.
V2:
- Followed in Matt's v0 review fixups [2]:
- keep unmapped flag in pages structures.
- add pages_count to drm_gpusvm_range_set_unmapped() set pages unmapped
flag.
let frame work can check unmapped status in drm_gpusvm_get_pages().
- Add drm_gpusvm_init_pages to init the drm_device and sequence number.
- Remove drm_device from drm_gpusvm_get_pages() parameters.
- Reworked the DOC: overview and usage examples to describe the new
model: struct drm_gpusvm_pages, the 1:1 / N:1 driver layouts, and
examples that operate on a driver embedded pages object by the
drm_gpusvm_pages helpers and etc.
- remove WARN_ON_ONCE in __drm_gpusvm_unmap_pages.
- Dropped RFC.
Follow-up (not in this series):
- modify drm_gpusvm_get_pages() to support one time hmm range fault
and multi drm device dma mapping.
- Add no dma device support for drm_gpusvm_get_pages().
tests:
AMDGPU:
based on amdgpu adaptation patch in [3], but still SVM:DRM = 1:1,
1:n is on going needs many modifications and testings.
Tested on gfx943 (MI300X) and gfx906 (MI60) with XNACK on/off:
- KFD test: 95%+ passed.
- ROCR test: all passed.
- HIP catch test: gfx943 (MI300X): 99% passed.
gfx906 (MI60): 99% passed.
INTEL XE:
Waiting for the xe driver git lab CI result: [4]
links:
[1]
https://lore.kernel.org/amd-gfx/acRgr7QwdULsn6G2@gsse-cloud1/#:~:text=I%20think%20roughly,drm_gpusvm_pages%0A%20%20helpers%20instead.
[2]
https://gitlab.freedesktop.org/mbrost/xe-kernel-driver-svn-perf-6-15-2025/-/commit/623f6a50c037d9e44f6c9fbe6859a0ba7ad50177
[3]
https://lore.kernel.org/amd-gfx/[email protected]/
[4] https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/360
Honglei Huang (5):
drm/gpusvm: split MM state flags out of drm_gpusvm_pages_flags
drm/gpusvm: embed struct drm_device into drm_gpusvm_pages
drm/xe: have xe_svm_range embed one drm_gpusvm_pages
drm/gpusvm: move struct drm_gpusvm_pages out of struct
drm_gpusvm_range
drm/gpusvm: let the drm_gpusvm core context purely MM level
drivers/gpu/drm/drm_gpusvm.c | 221 ++++++++++++++++++--------------
drivers/gpu/drm/xe/xe_pt.c | 2 +-
drivers/gpu/drm/xe/xe_svm.c | 37 ++++--
drivers/gpu/drm/xe/xe_svm.h | 8 +-
drivers/gpu/drm/xe/xe_userptr.c | 3 +-
include/drm/drm_gpusvm.h | 66 +++++++---
6 files changed, 199 insertions(+), 138 deletions(-)
--
2.34.1
