lkml.org 
[lkml]   [2023]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH drm-next 00/14] [RFC] DRM GPUVA Manager & Nouveau VM_BIND UAPI
From
On 1/18/23 16:37, Christian König wrote:
> Am 18.01.23 um 16:34 schrieb Danilo Krummrich:
>> Hi Christian,
>>
>> On 1/18/23 09:53, Christian König wrote:
>>> 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.
>>
>> No, it's just for keeping track of the ranges userspace has allocated.
>
> Ok, that makes more sense.
>
> So basically you have an IOCTL which asks kernel for a free range? Or
> what exactly is the drm_mm used for here?

Not even that, userspace provides both the base address and the range,
the kernel really just keeps track of things. Though, writing a UAPI on
top of the GPUVA manager asking for a free range instead would be
possible by just adding the corresponding wrapper functions to get a
free hole.

Currently, and that's what I think I read out of your question, the main
benefit of using drm_mm over simply stuffing the entries into a list or
something boils down to easier collision detection and iterating
sub-ranges of the whole VA space.

>
> Regards,
> Christian.
>
>>
>> - Danilo
>>
>>>
>>> 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
>>>
>>
>

\
 
 \ /
  Last update: 2023-03-26 23:46    [W:0.710 / U:1.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site