From f255addeec6dbb12bd7bbf2f0e1d1cec76ff2ecc Mon Sep 17 00:00:00 2001 From: Arthur Hanson Rasmusson Date: Tue, 6 Oct 2026 23:05:02 -0400 Subject: vgsp: mode 35 m64 - forced module-sem release discriminant + fallback poll fix + post-mortem dumps m63 (E2 lane enable) got the forwarded QMD into SKED: CWD_TABLE_0 left the cold value, CWD_TABLE_1 carried the QMD id (0x1070), SKED_ACTIVITY fired, FECS_CURRENT_CTX showed V7's instance with VALID=1 - but the release write never landed (relw=5) and no engine fault is logged. m64 discriminates 'engine completed but the shadow release was lost' from 'engine never completed': param gsp_phys_rmcall_gr_rel_mod=1 forces QMD release0 to the module window-0 semaphore with a distinct payload (0x600df00d) and polls the SEM chunk. Also fixes the latent fallback (it set no poll source, so a module-sem release could never complete) and dumps the full QMD w2..w15 + the guest release page words in the post-mortem. --- kernel/gsp_phys_gpu.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'kernel/gsp_phys_gpu.c') diff --git a/kernel/gsp_phys_gpu.c b/kernel/gsp_phys_gpu.c index 974100a..f323c6c 100644 --- a/kernel/gsp_phys_gpu.c +++ b/kernel/gsp_phys_gpu.c @@ -703,6 +703,28 @@ int gsp_phys_rmcall_gr_qmdwin_value(void) } EXPORT_SYMBOL_GPL(gsp_phys_rmcall_gr_qmdwin_value); +/* + * m64 forced module-semaphore release (gsp_phys_rmcall_gr_rel_mod; default 0). + * When set, a forwarded GR launch ignores the resolved guest release page and + * points QMD release0 at the module window-0 semaphore VA + * (GSP_PHYS_RMCALL_VA_SEM), which the host polls at the SEM chunk's host VA. + * Discriminant for "engine completed but the shadow release write was lost" + * vs "engine never completed": with the module release, a completed QMD is + * always observable. Also makes the existing module-release fallback + * observable (it previously set no poll source, so it could never complete). + */ +static int gsp_phys_rmcall_gr_rel_mod_param; +module_param_named(gsp_phys_rmcall_gr_rel_mod, + gsp_phys_rmcall_gr_rel_mod_param, int, 0644); +MODULE_PARM_DESC(gsp_phys_rmcall_gr_rel_mod, + "Force the forwarded GR QMD release0 to the module semaphore (default 0; 1 = m64 engine-completion discriminant)"); + +int gsp_phys_rmcall_gr_rel_mod_value(void) +{ + return gsp_phys_rmcall_gr_rel_mod_param; +} +EXPORT_SYMBOL_GPL(gsp_phys_rmcall_gr_rel_mod_value); + /* * Ladder VAS ownership selector (gsp_phys_rmcall_vas_shared; default 0). * The H1 GR promote wall is a direct consequence of the ladder's -- cgit v1.2.3