Open-IOV vGPU-IO: host-side GSP emulation for unmodified NVIDIA guest drivers https://git.vgpu.io/open-iov.git/atom?h=master 2026-10-24T00:01:53+00:00 2026-10-24T00:01:53+00:00 Arthur Hanson Rasmusson arthur@vgpu.io 2026-10-24T00:01:53+00:00 urn:sha1:ccdc1240d5df9777503a05b247109b6136d03313 r575 starved-release wedge (live): an unreadable UVM CE entry's rescued stale page decoded a release to a foreign VA (0x12006c004, pay=60); the rescue paths adopted it as the channel's tracking slot (last_rel_va) and every later recovery release targeted it, while the client's real pool (0x121000000) stopped at 25 - the client spun in uvm_tracker_wait for 34 (exact-slot poke delivered it and the client completed green). For CE channels only a pool-shaped release target (0x121000000..0x122000000) may become last_rel_va; a foreign rescued release is refused (witnessed, bounded) and the pool step is delivered through the exact-slot fallback / deferred-release machinery instead. The fake's read-before-write keeps the delivery monotonic even when a legit push carries multiple releases. Also: gsp_rm_ev_{seq,nlist,cl} runtime knobs for the guest-RM event drop A/B (the r576 experiment: guest consumes every POST_EVENT record and never enters nv_post_event), and the GR-DEC launch dump now covers 256 data pages (the mail VADD fill carries n_data=969). New: tools/cuda-ab/evhold.cu - deterministic CUDA event holder/wait probe (context + cudaEventSynchronize + a hold window) for the event experiments.