Messages in this thread | | | Date | Wed, 18 Jan 2023 17:19:44 +0100 | Subject | Re: [PATCH drm-next 00/14] [RFC] DRM GPUVA Manager & Nouveau VM_BIND UAPI | From | Danilo Krummrich <> |
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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 >>> >> >
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