[PATCH v4 0/2] rust: drm: gpuvm: implement Send and Sync for refcounted handles

[Sami Tolvanen <samitolvanen@google.com>]

Hi folks,

GpuVaAlloc and GpuVmBo implement neither Send or Sync, so drivers
that move them between threads need their own unsafe impls. GpuVm
implements both unconditionally, which Sashiko points out is
unsound.

Path 1 requires Send + Sync on DriverGpuVm and its associated data
instead of bounding each impl separately, as discussed in the v3
thread. Patch 2 adds bounds for GpuVaAlloc and GpuVmBo.

This series is based on Deborah's DeviceContext patch as they would
otherwise conflict:

https://lore.kernel.org/rust-for-linux/20260610-gpuvm_device_context_v1-v1-1-01a890b17448@collabora.com/

Sami

---
v4:
- Moved the bounds to the DriverGpuVm trait as discussed in the
  v3 thread, and reordered the series.
- Added Send for VaData as pointed out by Sashiko again.
- Rebased on top of Deborah's DeviceContext patch.

v3:
- Added a patch for GpuVm, and changed GpuVmBo bounds based on
  another Sashiko analysis.

v2:
- Added a missing T::Object: Send + Sync bound pointed out by
  Sashiko.

---
Sami Tolvanen (2):
      rust: drm: gpuvm: require Send + Sync for the driver's associated data
      rust: drm: gpuvm: implement Send and Sync for GpuVaAlloc and GpuVmBo

 rust/kernel/drm/gpuvm/mod.rs   | 26 +++++++++++++++-----------
 rust/kernel/drm/gpuvm/va.rs    |  8 ++++++++
 rust/kernel/drm/gpuvm/vm_bo.rs |  9 +++++++++
 3 files changed, 32 insertions(+), 11 deletions(-)
---
base-commit: 550dc7536644db2d67c6f8cf525bba682fba08d9
change-id: 20260611-gpuvm-sync-send-aa47a9001ae6
prerequisite-change-id: 20260610-gpuvm_device_context_v1-367c21f94e1e:v1
prerequisite-patch-id: eb2074676db5d923c8505208388fd1c0dba58b6a