Re: [PATCH drm-next 00/14] [RFC] DRM GPUVA Manager & Nouveau VM_BIND UAPI

["Christian König" <christian.koenig@amd.com>]

Am 18.01.23 um 07:12 schrieb Danilo Krummrich:
> This patch series provides a new UAPI for the Nouveau driver in order to
> support Vulkan features, such as sparse bindings and sparse residency.
>
> Furthermore, with the DRM GPUVA manager it provides a new DRM core feature to
> keep track of GPU virtual address (VA) mappings in a more generic way.
>
> The DRM GPUVA manager is indented to help drivers implement userspace-manageable
> GPU VA spaces in reference to the Vulkan API. In order to achieve this goal it
> serves the following purposes in this context.
>
>      1) Provide a dedicated range allocator to track GPU VA allocations and
>         mappings, making use of the drm_mm range allocator.

This means that the ranges are allocated by the kernel? If yes that's a 
really really bad idea.

Regards,
Christian.

>
>      2) Generically connect GPU VA mappings to their backing buffers, in
>         particular DRM GEM objects.
>
>      3) Provide a common implementation to perform more complex mapping
>         operations on the GPU VA space. In particular splitting and merging
>         of GPU VA mappings, e.g. for intersecting mapping requests or partial
>         unmap requests.
>
> The new VM_BIND Nouveau UAPI build on top of the DRM GPUVA manager, itself
> providing the following new interfaces.
>
>      1) Initialize a GPU VA space via the new DRM_IOCTL_NOUVEAU_VM_INIT ioctl
>         for UMDs to specify the portion of VA space managed by the kernel and
>         userspace, respectively.
>
>      2) Allocate and free a VA space region as well as bind and unbind memory
>         to the GPUs VA space via the new DRM_IOCTL_NOUVEAU_VM_BIND ioctl.
>
>      3) Execute push buffers with the new DRM_IOCTL_NOUVEAU_EXEC ioctl.
>
> Both, DRM_IOCTL_NOUVEAU_VM_BIND and DRM_IOCTL_NOUVEAU_EXEC, make use of the DRM
> scheduler to queue jobs and support asynchronous processing with DRM syncobjs
> as synchronization mechanism.
>
> By default DRM_IOCTL_NOUVEAU_VM_BIND does synchronous processing,
> DRM_IOCTL_NOUVEAU_EXEC supports asynchronous processing only.
>
> The new VM_BIND UAPI for Nouveau makes also use of drm_exec (execution context
> for GEM buffers) by Christian König. Since the patch implementing drm_exec was
> not yet merged into drm-next it is part of this series, as well as a small fix
> for this patch, which was found while testing this series.
>
> This patch series is also available at [1].
>
> There is a Mesa NVK merge request by Dave Airlie [2] implementing the
> corresponding userspace parts for this series.
>
> The Vulkan CTS test suite passes the sparse binding and sparse residency test
> cases for the new UAPI together with Dave's Mesa work.
>
> There are also some test cases in the igt-gpu-tools project [3] for the new UAPI
> and hence the DRM GPU VA manager. However, most of them are testing the DRM GPU
> VA manager's logic through Nouveau's new UAPI and should be considered just as
> helper for implementation.
>
> However, I absolutely intend to change those test cases to proper kunit test
> cases for the DRM GPUVA manager, once and if we agree on it's usefulness and
> design.
>
> [1] https://gitlab.freedesktop.org/nouvelles/kernel/-/tree/new-uapi-drm-next /
>      https://gitlab.freedesktop.org/nouvelles/kernel/-/merge_requests/1
> [2] https://gitlab.freedesktop.org/nouveau/mesa/-/merge_requests/150/
> [3] https://gitlab.freedesktop.org/dakr/igt-gpu-tools/-/tree/wip_nouveau_vm_bind
>
> I also want to give credit to Dave Airlie, who contributed a lot of ideas to
> this patch series.
>
> Christian König (1):
>    drm: execution context for GEM buffers
>
> Danilo Krummrich (13):
>    drm/exec: fix memory leak in drm_exec_prepare_obj()
>    drm: manager to keep track of GPUs VA mappings
>    drm: debugfs: provide infrastructure to dump a DRM GPU VA space
>    drm/nouveau: new VM_BIND uapi interfaces
>    drm/nouveau: get vmm via nouveau_cli_vmm()
>    drm/nouveau: bo: initialize GEM GPU VA interface
>    drm/nouveau: move usercopy helpers to nouveau_drv.h
>    drm/nouveau: fence: fail to emit when fence context is killed
>    drm/nouveau: chan: provide nouveau_channel_kill()
>    drm/nouveau: nvkm/vmm: implement raw ops to manage uvmm
>    drm/nouveau: implement uvmm for user mode bindings
>    drm/nouveau: implement new VM_BIND UAPI
>    drm/nouveau: debugfs: implement DRM GPU VA debugfs
>
>   Documentation/gpu/driver-uapi.rst             |   11 +
>   Documentation/gpu/drm-mm.rst                  |   43 +
>   drivers/gpu/drm/Kconfig                       |    6 +
>   drivers/gpu/drm/Makefile                      |    3 +
>   drivers/gpu/drm/amd/amdgpu/Kconfig            |    1 +
>   drivers/gpu/drm/drm_debugfs.c                 |   56 +
>   drivers/gpu/drm/drm_exec.c                    |  294 ++++
>   drivers/gpu/drm/drm_gem.c                     |    3 +
>   drivers/gpu/drm/drm_gpuva_mgr.c               | 1323 +++++++++++++++++
>   drivers/gpu/drm/nouveau/Kbuild                |    3 +
>   drivers/gpu/drm/nouveau/Kconfig               |    2 +
>   drivers/gpu/drm/nouveau/include/nvif/if000c.h |   23 +-
>   drivers/gpu/drm/nouveau/include/nvif/vmm.h    |   17 +-
>   .../gpu/drm/nouveau/include/nvkm/subdev/mmu.h |   10 +
>   drivers/gpu/drm/nouveau/nouveau_abi16.c       |   23 +
>   drivers/gpu/drm/nouveau/nouveau_abi16.h       |    1 +
>   drivers/gpu/drm/nouveau/nouveau_bo.c          |  152 +-
>   drivers/gpu/drm/nouveau/nouveau_bo.h          |    2 +-
>   drivers/gpu/drm/nouveau/nouveau_chan.c        |   16 +-
>   drivers/gpu/drm/nouveau/nouveau_chan.h        |    1 +
>   drivers/gpu/drm/nouveau/nouveau_debugfs.c     |   24 +
>   drivers/gpu/drm/nouveau/nouveau_drm.c         |   25 +-
>   drivers/gpu/drm/nouveau/nouveau_drv.h         |   92 +-
>   drivers/gpu/drm/nouveau/nouveau_exec.c        |  310 ++++
>   drivers/gpu/drm/nouveau/nouveau_exec.h        |   55 +
>   drivers/gpu/drm/nouveau/nouveau_fence.c       |    7 +
>   drivers/gpu/drm/nouveau/nouveau_fence.h       |    2 +-
>   drivers/gpu/drm/nouveau/nouveau_gem.c         |   83 +-
>   drivers/gpu/drm/nouveau/nouveau_mem.h         |    5 +
>   drivers/gpu/drm/nouveau/nouveau_prime.c       |    2 +-
>   drivers/gpu/drm/nouveau/nouveau_sched.c       |  780 ++++++++++
>   drivers/gpu/drm/nouveau/nouveau_sched.h       |   98 ++
>   drivers/gpu/drm/nouveau/nouveau_svm.c         |    2 +-
>   drivers/gpu/drm/nouveau/nouveau_uvmm.c        |  575 +++++++
>   drivers/gpu/drm/nouveau/nouveau_uvmm.h        |   68 +
>   drivers/gpu/drm/nouveau/nouveau_vmm.c         |    4 +-
>   drivers/gpu/drm/nouveau/nvif/vmm.c            |   73 +-
>   .../gpu/drm/nouveau/nvkm/subdev/mmu/uvmm.c    |  168 ++-
>   .../gpu/drm/nouveau/nvkm/subdev/mmu/uvmm.h    |    1 +
>   drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c |   32 +-
>   drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h |    3 +
>   include/drm/drm_debugfs.h                     |   25 +
>   include/drm/drm_drv.h                         |    6 +
>   include/drm/drm_exec.h                        |  144 ++
>   include/drm/drm_gem.h                         |   75 +
>   include/drm/drm_gpuva_mgr.h                   |  527 +++++++
>   include/uapi/drm/nouveau_drm.h                |  216 +++
>   47 files changed, 5266 insertions(+), 126 deletions(-)
>   create mode 100644 drivers/gpu/drm/drm_exec.c
>   create mode 100644 drivers/gpu/drm/drm_gpuva_mgr.c
>   create mode 100644 drivers/gpu/drm/nouveau/nouveau_exec.c
>   create mode 100644 drivers/gpu/drm/nouveau/nouveau_exec.h
>   create mode 100644 drivers/gpu/drm/nouveau/nouveau_sched.c
>   create mode 100644 drivers/gpu/drm/nouveau/nouveau_sched.h
>   create mode 100644 drivers/gpu/drm/nouveau/nouveau_uvmm.c
>   create mode 100644 drivers/gpu/drm/nouveau/nouveau_uvmm.h
>   create mode 100644 include/drm/drm_exec.h
>   create mode 100644 include/drm/drm_gpuva_mgr.h
>
>
> base-commit: 0b45ac1170ea6416bc1d36798414c04870cd356d