On Tue, Jun 18, 2024 at 04:23:17AM +1000, Ben Skeggs wrote: > On 17/6/24 23:55, Daniel Vetter wrote: > > > On Fri, Jun 14, 2024 at 03:02:09AM +1000, Ben Skeggs wrote: > > > NVIDIA has been exploring ways to better support the effort for an > > > upstream kernel mode driver for GPUs that are capable of running GSP-RM > > > firmware, since the introduction[1] to Nova. > > > > > > Use cases have been identified for which separating the core GPU > > > programming out of the full DRM driver stack is a strong requirement > > > from our key customers. > > > > > > An upstreamed NVIDIA GPU driver should be able to support current and > > > emerging customer use cases for vGPU hosts. NVIDIA's vGPU deployments > > > to date do not support compute or graphics functionality within the > > > hypervisor host, and have no dependency on the Linux graphics subsystem, > > > instead implementing the minimal functionality required to run vGPU > > > guest VMs. > > > > > > For security-sensitive environments such as cloud infrastructure, it's > > > important to continue support for running a minimal footprint vGPU host > > > driver in a stripped-down / barebones kernel environment. > > > > > > This can be achieved by supporting both VFIO and DRM drivers as clients > > > of a core driver, without requiring a full-fledged DRM driver (or the > > > DRM subsystem itself) to be built into the host kernel. > > > > > > A core driver would be responsible for booting and communicating with > > > GSP-RM, enumeration of HW configuration, shared/partitioned resource > > > management, exception handling, and event dispatch. > > > > > > The DRM driver would do all the standard things a DRM driver does, and > > > implement GPU memory management (TTM/HMM), KMS, command submission etc, > > > as well as providing UAPI for userspace clients. These features would > > > be implemented using HW resources allocated from a core driver, rather > > > than the DRM driver being directly responsible for HW programming. > > > > > > As Nouveau's KMD is already split (in the logical sense) along similar > > > lines, we're using it here for the purposes of this RFC to demonstrate > > > the feasibility of such an architecture, and open it up for discussion. > > Sounds reasonable. > > > > Only bikeshed I have to add is that the blessed way (according to the cool > > kernel maintainers at least or something) to structure this is using > > auxbus. Definitely when you end up with more than one driver binding to > > the core (like maybe some system management interface thing, or perhaps a > > special compute-only kernel driver). > > > > https://dri.freedesktop.org/docs/drm/driver-api/auxiliary_bus.html > > Hey! > > Yes indeed. I sent this[1] series at the same time, which was initially > written to so that nouveau.ko would still get auto-loaded alongside nvkm.ko. > > Ben. > > > [1] https://lists.freedesktop.org/archives/nouveau/2024-June/044861.html Oh I missed that you've already typed up the aux bus conversion somewhere. I guess just land it all :-) -Sima > > > > > > Cheers, Sima > > > > > A link[2] to a tree containing the patches is below. > > > > > > [1] https://lore.kernel.org/all/3ed356488c9b0ca93845501425d427309f4cf616.camel@xxxxxxxxxx/ > > > [2] https://gitlab.freedesktop.org/bskeggs/nouveau/-/tree/00.03-module > > > > > > *** BLURB HERE *** > > > > > > Ben Skeggs (2): > > > drm/nouveau/nvkm: export symbols needed by the drm driver > > > drm/nouveau/nvkm: separate out into nvkm.ko > > > > > > drivers/gpu/drm/nouveau/Kbuild | 4 ++-- > > > drivers/gpu/drm/nouveau/include/nvkm/core/module.h | 3 --- > > > drivers/gpu/drm/nouveau/nouveau_drm.c | 10 +--------- > > > drivers/gpu/drm/nouveau/nvkm/core/driver.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/core/gpuobj.c | 2 ++ > > > drivers/gpu/drm/nouveau/nvkm/core/mm.c | 4 ++++ > > > drivers/gpu/drm/nouveau/nvkm/device/acpi.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/engine/gr/base.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/module.c | 8 ++++++-- > > > drivers/gpu/drm/nouveau/nvkm/subdev/bios/init.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/subdev/bios/pll.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/subdev/fb/base.c | 3 +++ > > > drivers/gpu/drm/nouveau/nvkm/subdev/gpio/base.c | 3 +++ > > > drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c | 2 ++ > > > drivers/gpu/drm/nouveau/nvkm/subdev/i2c/bus.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/subdev/therm/fan.c | 1 + > > > drivers/gpu/drm/nouveau/nvkm/subdev/volt/base.c | 1 + > > > 19 files changed, 33 insertions(+), 16 deletions(-) > > > > > > -- > > > 2.44.0 > > > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
