From 04aad03adc45683d03fe1451b8f234061e6b88ff Mon Sep 17 00:00:00 2001 From: Arthur Hanson Rasmusson Date: Sun, 18 Oct 2026 12:00:52 -0400 Subject: vgsp: fail4 discrimination tooling - copy-out page witnesses + full-boot bigcopy resolution budget Four guest CUDA clients fail all-bad while four pass; the aggregate counters cannot separate 'engine result never produced' from 'produced but written to a different guest page than the client's read resolves'. Add the two per-page witnesses that correlate the write side with the read side: - gsp_phys_gr_copyout_dump (booter, default 1): per-changed-page OUT-PAGE-WIT va= hpa= first8/last8=, bounded 12 pages per launch, plus one RELOC-CENSUS line per launch (gaps vs late-resolved words vs late pages). - sema_bigcopy_log (sema service, default 24, was a hardcoded per-boot budget): the svc_copy large-copy proof already logs both operands' resolved VA -> pa/aperture/provenance and the first 16 bytes each side; raising the budget past the boot's head makes the failing clients' H2D/D2H resolutions visible. Discrimination test for the next cycle: same device VA on OUT-PAGE-WIT (copy-out HPA) and sema-bigcopy (D2H source pa) with different PAs proves the produced-but-misplaced class; equal PAs redirects to the readback content/engine-input path. (cherry picked from commit 78ea8b7807231ac418a17b85c29ed1845e1b0062) --- kernel/gsp_sema_service.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel/gsp_sema_service.h') diff --git a/kernel/gsp_sema_service.h b/kernel/gsp_sema_service.h index 95f9a4e..4c9042a 100644 --- a/kernel/gsp_sema_service.h +++ b/kernel/gsp_sema_service.h @@ -303,6 +303,14 @@ extern bool gsp_sema_pool_hold_fresh; */ extern bool gsp_sema_copy_dst_pin_guard; +/* + * COPYWIT fail4: per-boot line budget for the sema-bigcopy resolution + * witnesses (svc_copy's large-copy VA -> pa proof). Raise it for a + * discrimination cycle so the failing clients' H2D/D2H resolutions are + * visible; 0 disables the lines. + */ +extern unsigned gsp_sema_bigcopy_log_max; + /* * F1-b: authorship gate for the GR completion release the forwarded launch's * poll waits on. When on (default), a RAM-sweep release whose VA equals the -- cgit v1.2.3