[PATCH v6 0/4] virtio-gpu: Add userptr support for compute workloads

[Honglei Huang <honghuan@amd.com>]

Hello,

This series adds virtio-gpu userptr support for ROCm native compute
contexts. The guest kernel pins an existing userspace mapping with
FOLL_LONGTERM and exposes it to the host as ordinary CREATE_BLOB
backing entries, avoiding a second shmem allocation and memcpy.

USE_USERPTR and USERPTR_RDONLY are guest-only DRM ioctl selectors.
They are not added to virtio_gpu.h; the device does not need a new
wire flag.

Patches overview:
1. Add VIRTIO_GPU_CAPSET_ROCM capability for compute workloads
2. Extend DRM UAPI with guest-only userptr flags and userptr field
3. Implement core userptr functionality with page management
4. Wire blob ioctl creation to userptr objects

Tests:
- Full OPENCL CTS tests passed on ROCm 5.7.0 in V2000 platform.
- Near 70% percentage of OPENCL CTS tests passed on ROCm 7.0 W7900 platform.
- most HIP catch tests passed on ROCm 7.0 W7900 platform.
- Some AI applications enabled on ROCm 7.0 W7900 platform.
- latest ROCm 7.14 and ROCm 10 testing is ongoing.

V6 changes:
- Rebase onto drm-misc-next
- Keep USE_USERPTR / USERPTR_RDONLY as guest-only DRM flags; drop the
  virtio wire-header patch (5 patches down to 4)
- Fix userptr lifetime, DMA mapping, memlock accounting, alignment
  checks, and PRIME SG export
- Updated corresponding cover letter and commit messages

V5 changes:
    - Add VIRTIO_GPU_BLOB_FLAG_USERPTR_RDONLY definition to patch 2
    - Dropped unused VIRTIO_GPU_F_RESOURCE_USERPTR feature bit in patch 2
    - Included VIRTIO_GPU_BLOB_FLAG_USERPTR_RDONLY in VIRTGPU_BLOB_FLAG_USE_MASK in patch 5
    - Add check for userptr feature in patch 5 before creating userptr blob resource
    - Updated corresponding cover letter and commit messages

V4 changes:
    - Renamed VIRTIO_GPU_CAPSET_HSAKMT to VIRTIO_GPU_CAPSET_ROCM
    - Remove userptr feature probing cause it can reuse the guest
      blob resource code path, reduce patch count from 6 to 5
    - Updated corresponding commit messages
    - Consolidated userptr feature detection in final patch
    - Update corresponding cover letter content

V3 changes:
    - Split into focused patches for easier review
    - Removed complex interval tree userptr management
    - Simplified resource creation without deduplication
    - Added VIRTGPU_PARAM_RESOURCE_USERPTR for feature detection
    - Improved UAPI documentation and error handling
    - Enhanced code quality with proper cleanup paths
    - Removed MMU notifier dependencies for simplicity
    - Fixed resource lifecycle management issues

V2: - Split add HSAKMT context and blob userptr resource to two patches.
    - Remove MMU notifier related patches, cause use not moveable user space
      memory with MMU notifier is not a good idea.
    - Remove HSAKMT context check when create context, let all the context
      support the userptr feature.
    - Remove MMU notifier related content in cover letter.
    - Add more comments  for patch 6 in cover letter.

Previous version:
https://lore.kernel.org/dri-devel/20260116083808.325180-1-honglei1.huang@amd.com/

Honglei Huang (4):
  drm/virtio-gpu: Add VIRTIO_GPU_CAPSET_ROCM capability
  drm/virtgpu api: add blob userptr resource
  drm/virtio: implement userptr support for zero-copy memory access
  drm/virtio: wire blob ioctl creation to userptr objects

 drivers/gpu/drm/virtio/Makefile          |   3 +-
 drivers/gpu/drm/virtio/virtgpu_drv.h     |  36 +++
 drivers/gpu/drm/virtio/virtgpu_ioctl.c   |  20 +-
 drivers/gpu/drm/virtio/virtgpu_object.c  |  10 +
 drivers/gpu/drm/virtio/virtgpu_userptr.c | 323 +++++++++++++++++++++++
 include/uapi/drm/virtgpu_drm.h           |  10 +
 include/uapi/linux/virtio_gpu.h          |   1 +
 7 files changed, 400 insertions(+), 3 deletions(-)
 create mode 100644 drivers/gpu/drm/virtio/virtgpu_userptr.c

base-commit: 766bfba0f3bae329f99b42dcabc3ef11fa368f0b
-- 
2.34.1