| Message ID | 20230803165238.8798-1-dakr@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Nouveau VM_BIND UAPI & DRM GPUVA Manager (merged) | expand |
On Fri, 4 Aug 2023 at 02:52, Danilo Krummrich <dakr@redhat.com> wrote: > > This patch series provides a new UAPI for the Nouveau driver in order to > support Vulkan features, such as sparse bindings and sparse residency. > Now that Faith has reviewed the uAPI and userspace work, I think we should try and steer this in. I think the only thing I see is the SPDX + MIT header in some places, I think we can drop the MIT bits where SPDX is there, and leave copyright and authorship (if you like), personally I've been leaving authorship up to git, as it saves trouble with people randomly emailing you about things you wrote 10 years ago. Otherwise for the series: Reviewed-by: Dave Airlie <airlied@redhat.com> Dave.
On Thu, Aug 3, 2023 at 4:45 PM Dave Airlie <airlied@gmail.com> wrote: > On Fri, 4 Aug 2023 at 02:52, Danilo Krummrich <dakr@redhat.com> wrote: > > > > This patch series provides a new UAPI for the Nouveau driver in order to > > support Vulkan features, such as sparse bindings and sparse residency. > > > > Now that Faith has reviewed the uAPI and userspace work, I think we > should try and steer this in. > > I think the only thing I see is the SPDX + MIT header in some places, > I think we can drop the MIT bits where SPDX is there, and leave > copyright and authorship (if you like), personally I've been leaving > authorship up to git, as it saves trouble with people randomly > emailing you about things you wrote 10 years ago. > > Otherwise for the series: > Reviewed-by: Dave Airlie <airlied@redhat.com> > FYI: There's a small, easily resolved conflict with the uapi fixup patch. I don't care too much which goes in first but I'd like both to land before I merge NVK so I don't have to deal with a nouveau_deprecated.h. ~Faith > Dave. >
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 (merged into drm-misc/drm-misc-next since V8). 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 infrastructure to track GPU VA allocations and mappings, using an interval tree (RB-tree). 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 Changes in V2: ============== Nouveau: - Reworked the Nouveau VM_BIND UAPI to avoid memory allocations in fence signalling critical sections. Updates to the VA space are split up in three separate stages, where only the 2. stage executes in a fence signalling critical section: 1. update the VA space, allocate new structures and page tables 2. (un-)map the requested memory bindings 3. free structures and page tables - Separated generic job scheduler code from specific job implementations. - Separated the EXEC and VM_BIND implementation of the UAPI. - Reworked the locking parts of the nvkm/vmm RAW interface, such that (un-)map operations can be executed in fence signalling critical sections. GPUVA Manager: - made drm_gpuva_regions optional for users of the GPUVA manager - allow NULL GEMs for drm_gpuva entries - swichted from drm_mm to maple_tree for track drm_gpuva / drm_gpuva_region entries - provide callbacks for users to allocate custom drm_gpuva_op structures to allow inheritance - added user bits to drm_gpuva_flags - added a prefetch operation type in order to support generating prefetch operations in the same way other operations generated - hand the responsibility for mutual exclusion for a GEM's drm_gpuva list to the user; simplified corresponding (un-)link functions Maple Tree: - I added two maple tree patches to the series, one to support custom tree walk macros and one to hand the locking responsibility to the user of the GPUVA manager without pre-defined lockdep checks. Changes in V3: ============== Nouveau: - Reworked the Nouveau VM_BIND UAPI to do the job cleanup (including page table cleanup) within a workqueue rather than the job_free() callback of the scheduler itself. A job_free() callback can stall the execution (run() callback) of the next job in the queue. Since the page table cleanup requires to take the same locks as need to be taken for page table allocation, doing it directly in the job_free() callback would still violate the fence signalling critical path. - Separated Nouveau fence allocation and emit, such that we do not violate the fence signalling critical path in EXEC jobs. - Implement "regions" (for handling sparse mappings through PDEs and dual page tables) within Nouveau. - Drop the requirement for every mapping to be contained within a region. - Add necassary synchronization of VM_BIND job operation sequences in order to work around limitations in page table handling. This will be addressed in a future re-work of Nouveau's page table handling. - Fixed a couple of race conditions found through more testing. Thanks to Dave for consitently trying to break it. :-) GPUVA Manager: - Implement pre-allocation capabilities for tree modifications within fence signalling critical sections. - Implement accessors to to apply tree modification while walking the GPUVA tree in order to actually support processing of drm_gpuva_ops through callbacks in fence signalling critical sections rather than through pre-allocated operation lists. - Remove merging of GPUVAs; the kernel has limited to none knowlege about the semantics of mapping sequences. Hence, merging is purely speculative. It seems that gaining a significant (or at least a measurable) performance increase through merging is way more likely to happen when userspace is responsible for merging mappings up to the next larger page size if possible. - Since merging was removed, regions pretty much loose their right to exist. They might still be useful for handling dual page tables or similar mechanisms, but since Nouveau seems to be the only driver having a need for this for now, regions were removed from the GPUVA manager. - Fixed a couple of maple_tree related issues; thanks to Liam for helping me out. Changes in V4: ============== Nouveau: - Refactored how specific VM_BIND and EXEC jobs are created and how their arguments are passed to the generic job implementation. - Fixed a UAF race condition where bind job ops could have been freed already while still waiting for a job cleanup to finish. This is due to in certain cases we need to wait for mappings actually being unmapped before creating sparse regions in the same area. - Re-based the code onto drm_exec v4 patch. GPUVA Manager: - Fixed a maple tree related bug when pre-allocating MA states. (Boris Brezillion) - Made struct drm_gpuva_fn_ops a const object in all occurrences. (Boris Brezillion) Changes in V5: ============== Nouveau: - Link and unlink GPUVAs outside the fence signalling critical path in nouveau_uvmm_bind_job_submit() holding the dma-resv lock. Mutual exclusion of BO evicts causing mapping invalidation and regular mapping operations is ensured with dma-fences. GPUVA Manager: - Removed the separate GEMs GPUVA list lock. Link and unlink as well as iterating the GEM's GPUVA list should be protected with the GEM's dma-resv lock instead. - Renamed DRM_GPUVA_EVICTED flag to DRM_GPUVA_INVALIDATED. Mappings do not get eviced, they might get invalidated due to eviction. - Maple tree uses the 'unsinged long' type for node entries. While this works for GPU VA spaces larger than 32-bit on 64-bit kernel, the GPU VA space is limited to 32-bit on 32-bit kernels as well. As long as we do not have a 64-bit capable maple tree for 32-bit kernels, the GPU VA manager contains checks to throw warnings when GPU VA entries exceed the maple tree's storage capabilities. - Extended the Documentation and added example code as requested by Donald Robson. Changes in V6 ============= Nouveau: - Re-based the code onto drm_exec v5 patch. GPUVA Manager: - Switch from maple tree to RB-tree. It turned out that mas_preallocate() requires the maple tree not to change in between pre-allocating nodes with mas_preallocate() and inserting an entry with the help of the pre-allocated memory (mas_insert_prealloc()). However, considering that drivers typically implement interfaces where jobs to create GPU mappings can be submitted by userspace, are queued up by the kernel and are processed asynchronously in dma-fence signalling critical paths, this is a major issue. In the ioctl() used to submit a job we'd need to pre-allocated memory with mas_preallocate(), however, previously queued up jobs could concurrently alter the maple tree resulting in potentially insufficient pre-allocated memory for the currently submitted job on execution time. There is a detailed and still ongoing discussion about this topic one the -mm list [1]. So far the only solution seems to be to use GFP_ATOMIC and allocate memory directly in the fence signalling critical path, where we need it. However, I think that is not what we want to rely on. I think we should definitely continue in trying to find a solution on how to fit in the maple tree (or how to make the maple tree fit in). However, for now it seems to be more expedient to move on using a RB-tree. [1] https://lore.kernel.org/lkml/20230612203953.2093911-15-Liam.Howlett@oracle.com/ - Provide a flag to let driver optionally provide their own lock to lock linking and unlinking of GPUVAs to GEM objects. The DRM GPUVA manager still does not take the locks itself, but rather contains lockdep checks on either the GEMs dma-resv lock (default) or, if DRM_GPUVA_MANAGER_LOCK_EXTERN is set, the driver provided lock. (Boris Brezillon) Changes in V7 ============= Nouveau: - Rebase to drm_exec v7. - Move drm_gem_gpuva_init() before ttm_bo_init_validate(), but after initialization of the corresponding dma-resv. GPUVA Manager: - Fix drm_gpuva_find_first() range parameter in drm_gpuva_for_each_va* macros. (Boris) - Simplify drm_gpuva_for_each_va* macros using a __drm_gpuva_next() helper. (Boris) - Move lockdep checks for an optional external GEM gpuva list lock out of the GPUVA Manager to drm_gem.h. (Boris) - Fix code style issues pointed out by Thomas. - Switch to EXPORT_SYMBOL_GPL(). (Christoph) Changes in V8 ============= Nouveau: - n/a GPUVA Manager: - Fix documentation about locking the GEMs GPUVA list. (Donald) - Fix a few minor checkpatch warnings. Changes in V9 ============= Nouveau: - uAPI header (Faith, Dave): - documented preconditions to successfully initialize the VM_BIND uAPI - renamed drm_nouveau_vm_init unmanaged_{addr,size} to kernel_managed_{addr,size} - add NOUVEAU_GEM_DOMAIN_NO_SHARE flag - allow VM_BIND and EXEC jobs with op_count == 0 (Faith) - add a common dma-resv object for the VM and handle NOUVEAU_GEM_DOMAIN_NO_SHARE accordingly - add armed_submit() callback to nouveau_job - make use of drm_gpuva_map() rather than open code the GPUVA initialization GPUVA Manager : - n/a (merged into drm-misc/drm-misc-next since V8) DRM GEM: - added a patch to fix lockdep checks of GEM GPUVA locks Danilo Krummrich (11): drm/gem: fix lockdep check for dma-resv lock 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: separate fence alloc and emit 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 new VM_BIND uAPI drm/nouveau: debugfs: implement DRM GPU VA debugfs Documentation/gpu/driver-uapi.rst | 11 + drivers/gpu/drm/nouveau/Kbuild | 3 + drivers/gpu/drm/nouveau/Kconfig | 2 + drivers/gpu/drm/nouveau/dispnv04/crtc.c | 9 +- drivers/gpu/drm/nouveau/include/nvif/if000c.h | 26 +- drivers/gpu/drm/nouveau/include/nvif/vmm.h | 19 +- .../gpu/drm/nouveau/include/nvkm/subdev/mmu.h | 20 +- drivers/gpu/drm/nouveau/nouveau_abi16.c | 24 + drivers/gpu/drm/nouveau/nouveau_abi16.h | 1 + drivers/gpu/drm/nouveau/nouveau_bo.c | 221 +- drivers/gpu/drm/nouveau/nouveau_bo.h | 3 +- drivers/gpu/drm/nouveau/nouveau_chan.c | 22 +- drivers/gpu/drm/nouveau/nouveau_chan.h | 1 + drivers/gpu/drm/nouveau/nouveau_debugfs.c | 39 + drivers/gpu/drm/nouveau/nouveau_dmem.c | 9 +- drivers/gpu/drm/nouveau/nouveau_drm.c | 27 +- drivers/gpu/drm/nouveau/nouveau_drv.h | 93 +- drivers/gpu/drm/nouveau/nouveau_exec.c | 436 ++++ drivers/gpu/drm/nouveau/nouveau_exec.h | 54 + drivers/gpu/drm/nouveau/nouveau_fence.c | 23 +- drivers/gpu/drm/nouveau/nouveau_fence.h | 5 +- drivers/gpu/drm/nouveau/nouveau_gem.c | 86 +- drivers/gpu/drm/nouveau/nouveau_gem.h | 3 +- drivers/gpu/drm/nouveau/nouveau_mem.h | 5 + drivers/gpu/drm/nouveau/nouveau_prime.c | 13 +- drivers/gpu/drm/nouveau/nouveau_sched.c | 444 ++++ drivers/gpu/drm/nouveau/nouveau_sched.h | 127 ++ drivers/gpu/drm/nouveau/nouveau_svm.c | 2 +- drivers/gpu/drm/nouveau/nouveau_uvmm.c | 1946 +++++++++++++++++ drivers/gpu/drm/nouveau/nouveau_uvmm.h | 108 + drivers/gpu/drm/nouveau/nouveau_vmm.c | 4 +- drivers/gpu/drm/nouveau/nvif/vmm.c | 100 +- .../gpu/drm/nouveau/nvkm/subdev/mmu/uvmm.c | 213 +- drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 197 +- drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h | 25 + .../drm/nouveau/nvkm/subdev/mmu/vmmgf100.c | 16 +- .../drm/nouveau/nvkm/subdev/mmu/vmmgp100.c | 16 +- .../gpu/drm/nouveau/nvkm/subdev/mmu/vmmnv50.c | 27 +- include/drm/drm_gem.h | 15 +- include/uapi/drm/nouveau_drm.h | 217 ++ 40 files changed, 4362 insertions(+), 250 deletions(-) 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 base-commit: e4774e9968b26dc5d225ce629af8081ddab0029a