Open-IOV vGPU-IO: host-side GSP emulation for unmodified NVIDIA guest drivers https://git.vgpu.io/open-iov.git/atom?h=m32reorder 2026-10-02T07:31:06+00:00 2026-10-02T07:31:06+00:00 Arthur Hanson Rasmusson arthur@vgpu.io 2026-10-02T07:24:35+00:00 urn:sha1:d2de7bf1d6bb7d0931085f87da6c3013cd7f1aca - file-backed guest RAM (launcher memory-backend-file share=on) and in-kernel GPA->HPA translation through the shared file page cache (read_cache_page + page_to_phys + pfn_valid), opened O_LARGEFILE; new default-off gsp_phys_guest_mem parameter - debugfs gsp-phys-guest-ram (path + gpa/off/size ranges) and gsp-phys-guest-gpa (one pinned GPA per boot); rm-call triggers 6/7 run host->guest and guest->host 4 KiB CE copies; trigger 8 is a PTE self-test through a fresh slot - guest page-table slots are pre-built during ladder stage 3: runtime PTE writes into an already-walked page-table line are not observed without a TLB invalidate - guest RAM layout (q35 4.2, 4 GiB): below-4G GPA == file offset, above-4G offset = GPA - 0x80000000 (2 GiB PCI hole) - tests: tools/test/gpage_test.c guest probe; docs + STATE-CURRENT record the live green (G2H/W2G with semaphore release, guest observed the write, smoke ALL OK 64/64, clean latched release)