open-iov.git/tools/guest-diag/semfix_watch.py, branch reg-probe

kernel: GR context-promote bisection modes 4-17 and server-managed-ctxbuf registry variant; complete vgsp rename; docs/tooling refresh

2026-10-02T19:13:06+00:00

- gsp_phys_booter: GR promote bisection modes 4-17 (two-phase zero-field VA, batched entries, hVirtMemory, bare VA, KMD SKIP_CTXBUFFER_ALLOC channel, old-interface GPU_INITIALIZE_CTX, FBMEM context buffer, UVM-faithful PA-only, PATCH/PM auxiliary promotes, server-managed no-promote path); PATCH/PM geometry queries and buffers; pre-boot SET_REGISTRY profile selection - gsp_phys_gpu: gsp_phys_rmcall_gr_promote clamp 0..17 and gsp_phys_srv_ctxbuf parameter; registry image variant with RMSetClientRMAllocatedCtxBuffer=0 - vgsp rename across kernel, scripts, tools and docs (module vgsp.ko, /sys/kernel/debug/vgsp/, vgsp-: log prefixes) - risc-v-gsp-rm-debugger user-facing rename and docs/CI refresh; guest-diag tool updates; README/SBOM/install/Makefile sync Live status: CE ladder and P6 guest-copy forwarding green; GR engine context commit still open (all promote shapes accepted or cleanly refused; the channel stays CTXNOTVALID) - see Handoff-vGPU-IO.md Addendum 21 (local).

guest-diag: cycle monitor CPUs on kernel-VA translation failure

2026-09-30T13:32:48+00:00

HMP x/gva2gpa translate with the selected vCPU's CR3; while that CPU runs user code under PTI the kernel half is hidden, so kernel-VA reads (the tracking-sem chain and the CE pushbuffer CPU alias) fail and the pin pass aborts. Try the other vCPUs before giving up: during an active CUDA client at least one CPU is in kernel mode, so the chain/pin work no longer require the client to be parked in sleep().

guest-diag: pushbuffer pin survives PTI holes (full-range scan + bounded retries until complete)

2026-09-30T09:28:13+00:00

sema-svc: apply releases before push memsets; poller: bypass read cache

2026-09-29T19:34:18+00:00

guest-diag: print tracking-sem state (index, queued, payload) on change

2026-09-29T19:08:39+00:00

The final cuCtxCreate stall is a UVM tracking semaphore whose completed value stays 0; the pool payload is the ground truth. semfix now prints idx/+0x10/+0x28/payload for every tracking sem it sees, whenever a field changes, so the last stall before a failure is visible in its log.

guest-diag: cheaper trace read, optional push sampler, bigger pagemap batches

2026-09-29T18:47:17+00:00

Under load the semfix poll grepped the whole (growing) trace file and the track_waits push block spawned three guest processes per sample, both of which slowed the pin path into the client's failure window. The trace read now tails 128 KB; track_waits.sh gates the push dump behind PUSH=0; the pagemap helper reads 32 KB chunks.

kernel: batch the map-add channel rewind; trust injected streams for ops

2026-09-29T18:25:05+00:00

Two fixes for the CE data path. (1) svc_handle_map_add rewound every channel by 8 ring entries on every injected mapping; a 16 MB push-buffer pin is thousands of page injections, so the pump's last_get was pinned in place and it re-read the same entries for the whole batch (3645 submissions, zero ops). The rewind now runs once per drained batch. (2) The push-start heuristic (op=INC_METHOD at address 0) rejects UVM's real CE memop pushes, which start with an IMM method at address 8 (observed 0x60020002, PTE data words) or a release method at 0x700 (0x200381c0); a buffer read through a host-injected (ipin) translation is now decoded fully trusted, ops included. Result on the next boot: memset=2718/0/0 ringops=1794 (first sustained CE work), false 12k->1.9k. semfix_watch: bulk-pin contiguous runs via sema_map_add len, read rm_mem size, 16 MB (4096 page) cap, non-blocking QMP read (the fixed 30 ms sleep made 4096 gva2gpa calls take two minutes), and KEEP_TRACE=1 to preserve the guest trace for post-mortems.

guest-diag: deterministic channel->pool->manager->pushbuffer chain + chunk-read diagnostics

2026-09-29T17:32:46+00:00

semfix_watch.py now resolves the CE pushbuffer from guest truth instead of scanning a wide raw window: it walks uvm_channel_t +0=pool, pool+0=manager, manager+8=pushbuffer, pushbuffer+8=rm_mem, rm_mem+0x10=vas[] and prefers the rm_mem whose GPU VA is in the 0x120000000 CE pushbuffer range. Three entry points: uvch probe on __uvm_push_begin_acquire_on_channel_with_info, uvbp probe on uvm_pushbuffer_begin_push, and the uvmt tracking-sem kptr (channel scan back from sem). Misses now print structured hop counters so a failed chunk read is distinguishable from a failed chain. guest_kprobes.sh (re)installs uvmt/uvch/uvbp/uvpbf after every guest boot (plain, module: and bare spellings).

guest-diag: identify pushbuffer rm_mem by vmalloc CPU VA (any GPU VA)

2026-09-29T17:27:22+00:00

guest-diag: widen pushbuffer chain scan (256KB, slab-prefix filter)

2026-09-29T17:24:27+00:00