On Mon, 7 Oct 2024 16:37:12 +0000 Ankit Agrawal <ankita@xxxxxxxxxx> wrote: > >> > >> NVIDIA's recently introduced Grace Blackwell (GB) Superchip in > >> continuation with the Grace Hopper (GH) superchip that provides a > >> cache coherent access to CPU and GPU to each other's memory with > >> an internal proprietary chip-to-chip (C2C) cache coherent interconnect. > >> The in-tree nvgrace-gpu driver manages the GH devices. The intention > >> is to extend the support to the new Grace Blackwell boards. > > > > Where do we stand on QEMU enablement of GH, or the GB support here? > > IIRC, the nvgrace-gpu variant driver was initially proposed with QEMU > > being the means through which the community could make use of this > > driver, but there seem to be a number of pieces missing for that > > support. Thanks, > > > > Alex > > Hi Alex, the Qemu enablement changes for GH is already in Qemu 9.0. > This is the Generic initiator change that got merged: > https://lore.kernel.org/all/20240308145525.10886-1-ankita@xxxxxxxxxx/ > > The missing pieces are actually in the kvm/kernel viz: > 1. KVM need to map the device memory as Normal. The KVM patch was > proposed here. This patch need refresh to address the suggestions: > https://lore.kernel.org/all/20230907181459.18145-2-ankita@xxxxxxxxxx/ > 2. ECC handling series for the GPU device memory that is remap_pfn_range() > mapped: https://lore.kernel.org/all/20231123003513.24292-1-ankita@xxxxxxxxxx/ > > With those changes, the GH would be functional with the Qemu 9.0. Sure, unless we note that those series were posted a year ago, which makes it much harder to claim that we're actively enabling upstream testing for this driver that we're now trying to extend to new hardware. Thanks, Alex > We discovered a separate Qemu issue while doing verification of Grace Blackwell, > where the 512G of highmem proved short here: > https://github.com/qemu/qemu/blob/v9.0.0/hw/arm/virt.c#L211 > We are planning to have a proposal for the fix floated for that. > > Thanks > Ankit Agrawal >
