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<title>open-iov.git/tools/guest-diag/semfix_watch.py, branch master</title>
<subtitle>Open-IOV vGPU-IO: host-side GSP emulation for unmodified NVIDIA guest drivers
</subtitle>
<id>https://git.vgpu.io/open-iov.git/atom?h=master</id>
<link rel='self' href='https://git.vgpu.io/open-iov.git/atom?h=master'/>
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<updated>2026-10-12T01:53:46+00:00</updated>
<entry>
<title>guest-diag: semfix_watch read64 uncached by default (stale-cache pool-pin failure)</title>
<updated>2026-10-12T01:53:46+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-10-12T01:53:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.vgpu.io/open-iov.git/commit/?id=7de0cfd365e9c8b9fa8385c5cde60bbbbb7a3ddb'/>
<id>urn:sha1:7de0cfd365e9c8b9fa8385c5cde60bbbbb7a3ddb</id>
<content type='text'>
The watcher's resolve_sem_pool read sem-&gt;page-&gt;mem-&gt;vas through a
process-lifetime cache: a transient zero captured while UVM was still
initialising the structures was served forever, the pool pin never
landed, and the second-session client hung in cudaMallocManaged
(r88 evidence: 'pool unresolved (retry)' from the watcher while the
same walk succeeded from a fresh QMP client). Cache is now opt-in.
</content>
</entry>
<entry>
<title>spdx: add BSD-3-Clause identifiers to userspace/tools/scripts sources</title>
<updated>2026-10-08T15:53:20+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-10-08T15:53:20+00:00</published>
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<id>urn:sha1:2ee4fe8f43b0dc3e080c91931eadade1fd636c27</id>
<content type='text'>
Sweep of the 155 tracked C/Python/shell files under userspace/ (excluding
the MIT-licensed vendored userspace/extern/), tools/ and scripts/ that had
no per-file license identifier. Each gains the minimal two-line header in
the area's existing form: 'SPDX-License-Identifier: BSD-3-Clause' plus
'Copyright (c) 2026 Open-IOV contributors'; shebang and coding lines stay
first. No other content touched. kernel/** is deliberately out of scope
(recorded as a follow-up in CODESTD-REPORT-2026-10-08.md): its SPDX
coverage and MODULE_LICENSE normalization need their own GPL-2.0 pass.
</content>
</entry>
<entry>
<title>tools: arm UVM kprobes deterministically (modprobe+wait+verify) and retry pushbuffer pins</title>
<updated>2026-10-08T04:01:54+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-10-08T04:01:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.vgpu.io/open-iov.git/commit/?id=bf8915caeb4c983dbfb3b9bbd1bb3836bdc4761f'/>
<id>urn:sha1:bf8915caeb4c983dbfb3b9bbd1bb3836bdc4761f</id>
<content type='text'>
Root cause of the cudaMalloc/UVM-init stall on our bring-up path:
guest_kprobes.sh ran while nvidia_uvm was not yet loaded (it loads lazily
with the first CUDA client), so every probe add failed silently (symbols
not in kallsyms) and the host never got the #sem -&gt; pushbuffer-pin
pipeline. The CE push page (0x120021db8) then never translated and the
guest spun forever at DEVICE.

- guest_kprobes.sh: modprobe nvidia_uvm, wait (bounded 30 s) for the
  uvmt symbol, install, and print KP_ARMED/KP_FAIL for bring-up checks.
- semfix_watch.pin_pushbuffer: retry transient/partial gva2gpa misses
  in-call (bounded passes with a short sleep) instead of aborting on the
  first all-miss block; report unresolved page counts.

Validated: 2/2 cold boots (vmkeep6/7) arm the probes and run
victory_mail green in 15-20 s (MAIL + VADD bad=0 checksum=12204516 +
STATUS OK, oracle-matched); pre-fix boots with unarmed probes stalled
4/4.
</content>
</entry>
<entry>
<title>kernel: GR context-promote bisection modes 4-17 and server-managed-ctxbuf registry variant; complete vgsp rename; docs/tooling refresh</title>
<updated>2026-10-02T19:13:06+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-10-02T19:13:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.vgpu.io/open-iov.git/commit/?id=c9bf1cf098c8ea4daeb3e6c9b274a9025c03045d'/>
<id>urn:sha1:c9bf1cf098c8ea4daeb3e6c9b274a9025c03045d</id>
<content type='text'>
- 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-&lt;subsystem&gt;: 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).
</content>
</entry>
<entry>
<title>guest-diag: cycle monitor CPUs on kernel-VA translation failure</title>
<updated>2026-09-30T13:32:48+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-09-30T13:32:48+00:00</published>
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<id>urn:sha1:2ae04a244ee80f4c3bc8a9e15d2271e7fee554de</id>
<content type='text'>
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().
</content>
</entry>
<entry>
<title>guest-diag: pushbuffer pin survives PTI holes (full-range scan + bounded retries until complete)</title>
<updated>2026-09-30T09:28:13+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-09-30T09:28:13+00:00</published>
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<id>urn:sha1:14f195400a14034612fd9b1f69fb6296419eae6d</id>
<content type='text'>
</content>
</entry>
<entry>
<title>sema-svc: apply releases before push memsets; poller: bypass read cache</title>
<updated>2026-09-29T19:34:18+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-09-29T19:34:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.vgpu.io/open-iov.git/commit/?id=b7636afd9715748396325ec4dd0899c7f42ece17'/>
<id>urn:sha1:b7636afd9715748396325ec4dd0899c7f42ece17</id>
<content type='text'>
</content>
</entry>
<entry>
<title>guest-diag: print tracking-sem state (index, queued, payload) on change</title>
<updated>2026-09-29T19:08:39+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-09-29T19:08:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.vgpu.io/open-iov.git/commit/?id=e4e41324e83a250989f04fd612981a6076e8a526'/>
<id>urn:sha1:e4e41324e83a250989f04fd612981a6076e8a526</id>
<content type='text'>
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.
</content>
</entry>
<entry>
<title>guest-diag: cheaper trace read, optional push sampler, bigger pagemap batches</title>
<updated>2026-09-29T18:47:17+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-09-29T18:47:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.vgpu.io/open-iov.git/commit/?id=0cbe5604adff2bc386960edbc58f45e35e61bae8'/>
<id>urn:sha1:0cbe5604adff2bc386960edbc58f45e35e61bae8</id>
<content type='text'>
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.
</content>
</entry>
<entry>
<title>kernel: batch the map-add channel rewind; trust injected streams for ops</title>
<updated>2026-09-29T18:25:05+00:00</updated>
<author>
<name>Arthur Hanson Rasmusson</name>
<email>arthur@vgpu.io</email>
</author>
<published>2026-09-29T18:25:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.vgpu.io/open-iov.git/commit/?id=be46061c66690752bf03aaaf4d72e4fa2b5f418d'/>
<id>urn:sha1:be46061c66690752bf03aaaf4d72e4fa2b5f418d</id>
<content type='text'>
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-&gt;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.
</content>
</entry>
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