open-iov.git/tools/guest-diag/guest_kprobes.sh, branch gr-forwarding

guest-diag: mount tracefs before installing kprobes

2026-09-30T14:14:09+00:00

A fresh boot can leave /sys/kernel/tracing as an unmounted mount point; the probe adds then fail silently (probe count 0) and the whole sem/kptr pipeline goes blind.

guest-diag: enlarge and clear the trace ring at probe install

2026-09-29T21:31:55+00:00

The client's spin floods the default ring with uvmt/uvsv events; a one-shot uvbp event was overwritten before the pin scanner read it (push-buffer pin landed ~50 s after the client began pushing). 64 MB ring + clear.

guest-diag: probe the tracker completion check and its result

2026-09-29T21:17:42+00:00

uvsv/uvsvr capture (sem, value) and the boolean return of uvm_gpu_tracking_semaphore_is_value_completed, so a wait that fails despite an advanced payload is visible as a false return.

guest-diag: probe uvm_tracker_wait_for_entry for the exact (channel, value) wait

2026-09-29T21:02:05+00:00

The failing wait is uvm_tracker_wait_for_entry inside channel_pool_add (UVM_GPU_REGISTER): capture the tracker entry's channel pointer and value so the host can tell which release value is still missing.

kernel: authoritative host-injected VA->PA pins (ipin table) + wider pin table

2026-09-29T17:52:49+00:00

The CE push-buffer page 0x120000000 resolved to a zero-filled page even after sema_map_add injected the correct translation: the shared pin table silently dropped inserts once a hash cluster exceeded the 32-probe window (the page hashes to slot 0, a hot cluster), and lookups fell through to the content-scanned map and answered with a stale page - so every CE push read as implausible and memset stayed 0. Injected translations now live in a separate authoritative table checked before every other source and are never written by self-discovery; the general pin table is 4x larger with a 4x probe window and counts drops (pin_drop/ipin_drop) in the stats line. guest_kprobes.sh disables the kprobe group before removal (EBUSY) and matches p:kprobes/; the guest wait sampler can run counters-only with GDB=0.

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).