Alex Deucher
2023-Jan-18 16:54 UTC
[Nouveau] [PATCH drm-next 00/14] [RFC] DRM GPUVA Manager & Nouveau VM_BIND UAPI
On Wed, Jan 18, 2023 at 11:50 AM Danilo Krummrich <dakr at redhat.com> wrote:> > > > On 1/18/23 17:30, Alex Deucher wrote: > > On Wed, Jan 18, 2023 at 11:19 AM Danilo Krummrich <dakr at redhat.com> wrote: > >> > >> On 1/18/23 16:37, Christian K?nig wrote: > >>> Am 18.01.23 um 16:34 schrieb Danilo Krummrich: > >>>> Hi Christian, > >>>> > >>>> On 1/18/23 09:53, Christian K?nig 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. > > > > Why not just do this in userspace? We have a range manager in > > libdrm_amdgpu that you could lift out into libdrm or some other > > helper. > > The kernel still needs to keep track of the mappings within the various > VA spaces, e.g. it silently needs to unmap mappings that are backed by > BOs that get evicted and remap them once they're validated (or swapped > back in).Ok, you are just using this for maintaining the GPU VM space in the kernel. Alex> > > > > Alex > > > > > >> > >>> > >>> 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 K?nig. 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 K?nig (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 > >>>>> > >>>> > >>> > >> > > >
Dave Airlie
2023-Jan-18 19:17 UTC
[Nouveau] [PATCH drm-next 00/14] [RFC] DRM GPUVA Manager & Nouveau VM_BIND UAPI
On Thu, 19 Jan 2023 at 02:54, Alex Deucher <alexdeucher at gmail.com> wrote:> > On Wed, Jan 18, 2023 at 11:50 AM Danilo Krummrich <dakr at redhat.com> wrote: > > > > > > > > On 1/18/23 17:30, Alex Deucher wrote: > > > On Wed, Jan 18, 2023 at 11:19 AM Danilo Krummrich <dakr at redhat.com> wrote: > > >> > > >> On 1/18/23 16:37, Christian K?nig wrote: > > >>> Am 18.01.23 um 16:34 schrieb Danilo Krummrich: > > >>>> Hi Christian, > > >>>> > > >>>> On 1/18/23 09:53, Christian K?nig 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. > > > > > > Why not just do this in userspace? We have a range manager in > > > libdrm_amdgpu that you could lift out into libdrm or some other > > > helper. > > > > The kernel still needs to keep track of the mappings within the various > > VA spaces, e.g. it silently needs to unmap mappings that are backed by > > BOs that get evicted and remap them once they're validated (or swapped > > back in). > > Ok, you are just using this for maintaining the GPU VM space in the kernel. >Yes the idea behind having common code wrapping drm_mm for this is to allow us to make the rules consistent across drivers. Userspace (generally Vulkan, some compute) has interfaces that pretty much dictate a lot of how VMA tracking works, esp around lifetimes, sparse mappings and splitting/merging underlying page tables, I'd really like this to be more consistent across drivers, because already I think we've seen with freedreno some divergence from amdgpu and we also have i915/xe to deal with. I'd like to at least have one place that we can say this is how it should work, since this is something that *should* be consistent across drivers mostly, as it is more about how the uapi is exposed. Dave.