Open-IOV vGPU-IO: host-side GSP emulation for unmodified NVIDIA guest drivers https://git.vgpu.io/open-iov.git/atom?h=cs-share 2026-10-05T16:47:47+00:00 2026-10-05T16:47:47+00:00 Arthur Hanson Rasmusson arthur@vgpu.io 2026-10-05T16:47:47+00:00 urn:sha1:0f227d063e281c4b8ec21e61132ae1ddf0920053 The 708a3802 per-type VRAM change stripped an nvidia- prefix from mdev->type->sysfs_name, but sysfs_name is the registered type name verbatim; the mdev core only prefixes the type DIRECTORY with the parent driver string. Every lookup failed, so all mdevs silently fell back to 512 MiB, nvidia-vgpu-turing-1g was unreachable and available_instances capped at 1. Match sysfs_name directly in get_available, show_description and mdev_create. Also canonicalise the NV_PFB_PRI_MMU_LOCAL_MEMORY_RANGE encoder (BAR0+0x100ce0) by stripping factors of two from MAG so 512 MiB encodes 0x19 again (1 GiB 0x1a, 2 GiB 0x1b) instead of the non-canonical 0x204. Default-512M behaviour is now byte-equivalent to the known-good pre-VRAM module except max_instances=2. Module sha256 cb1724d3. 2026-10-05T16:25:05+00:00 Arthur Hanson Rasmusson arthur@vgpu.io 2026-10-05T16:25:05+00:00 urn:sha1:708a3802824358c1770d5ad0b3c2e24fae114eb8 - nv_vgpu_type_info/ioctl gain vram_mb; nv_vgpu_device gains fb_emul_size bound from the mdev type at create (default 512 MiB). - New nvidia-vgpu-turing-1g type (1024 MiB); turing max_instances 1 -> 2; show_description reports the per-type framebuffer and max_instance. - Thread fb_emul_size through GSCI fb_length/region/frtsOffset, WPR2, NV_PFB_PRI_MMU_LOCAL_MEMORY_RANGE, the vidmem allocator bound and the BAR1 shadow; bar_info callback uses the per-device size. - UNTESTED at commit time: builds clean; validation blocked by the Xid 140 incident (reboot pending). See Handoff-vGPU-IO.md ADDENDUM 48. 2026-10-04T20:19:31+00:00 Arthur Hanson Rasmusson arthur@vgpu.io 2026-10-04T20:19:31+00:00 urn:sha1:aa3520f252182aaf64ea0b8856a3ac5e4466ce0e The no-claim emulation path now runs a stock CUDA program end to end: device properties, cudaMalloc, a GPU-authored string kernel read back byte-for-byte, two 4 MB host-to-device copies, a 1 M-element vectorAdd executed on the physical GPU through the host bridge, and the device-to-host copy-back verified element by element. Three consecutive supervised cycles report MAIL + VADD bad=0 checksum=392344090.500000 + STATUS OK with identical input/output hashes. Two data-path correctness fixes make the transfers sound: - Once-only op execution per GPFIFO entry. The pump replays recently consumed ring entries when translation batches are injected so missed releases can land; re-executing a CE copy is not idempotent because its source is a client staging buffer that may have been refilled. Slots now record their raw entry words and a replayed entry matching that identity suppresses operations while still processing releases. - Per-page translation of virtual operands. svc_copy resolved only the first page of a VA range and walked the PA linearly; client staging ranges are frequently split (observed 195 + 61 pages), so the tail of alternating chunks was read from unrelated memory. Multi-page copies now re-resolve each 4 KB page through the trusted resolver. Also carries the earlier uncommitted emulation fixes that got the client to the launch (QMD address-window gate, counter registration persistence, 512 MiB emulated FB, bridge slot hygiene) and bounded diagnostics (sema-bigop, sema-bigcopy, bridge-in/out hashes, daemon INCHECK/OUTCHECK/dumps). 2026-09-23T09:46:43+00:00 Open-IOV dev@open-iov.org 2026-09-23T09:44:08+00:00 urn:sha1:68cdd7728a7cc6715bbbff7decfe2b11c3bdf558 Open-IOV virtualizes NVIDIA GPUs so that unmodified guest drivers run with real GPU functionality - CUDA first, 3D and video to follow - on unmodified hosts, without a proprietary vGPU license and without patching any driver, firmware or hypervisor. Core principle: emulate the interface, pass through the work. kernel/ open-iov-vfio.ko - host VFIO mdev driver: virtual GPU device (PCI config space, BAR shadows, MSI-X), GSP boot emulation, GSP-RM message-queue/RPC emulation, memory model (GPU-VA to guest-PA discovery) and the semaphore-completion service that advances guest UVM progress. userspace/ libiov.so management API and examples. tools/ guest diagnostics, firmware analysis wrappers, RM probes. scripts/ stack manager, VM harness, build/load/test automation. config/ hardware/version profiles (the portability surface). docs/ documentation tree - start at docs/README.md. wiki/ long-form firmware and protocol deep dives. Status: initialization works end to end for a stock 570.144 Linux guest on Turing (TU104): driver probe, nvidia-smi, the full GSP-RM control battery, object creation and the early CUDA/UVM start-up path. GPU work forwarding - the step that makes CUDA kernels execute on real hardware - is the active work item; see docs/04-implementation/01-known-knowns-and-unknowns.md. License: BSD-3-Clause for the project; GPL-2.0 for kernel modules that link GPL-only kernel interfaces. See LICENSE and docs/09-reference/legal-and-licensing.md.