From 393f1c676d0fc9c7b37ab6a52efe7e2d288d7e90 Mon Sep 17 00:00:00 2001 From: Arthur Hanson Rasmusson Date: Wed, 21 Oct 2026 14:02:15 -0400 Subject: gr: r420b author the guest QMD release on every outcome when release0 is redirected With gsp_phys_rmcall_gr_rel_mod=1 (release0 -> module semaphore, the ordering fix for the engine-release-before-copy-out race) the engine never writes the guest's own QMD release word, so the host must author it on EVERY backend outcome. The hold's success/fail edges do; a launch with no deferred release records (no hold engaged) fell through and its client hung on a word nothing would ever write - the r414 saxpy f0 cur=5 stall. The backend now reports qmd_rel_redirected in the copy result whenever it points release0 at the module semaphore (rel_mod, or no targetable guest release page). svc_fwd_gr_work folds that into the existing gr_rel_unobserved latch, which makes the bounded outcome check author the word on done (success or failure) - the same forward-only write the hold edges perform. rel_mod=0 paths are unchanged (the engine still authors the word and the latch is only set on an unresolved release page). --- kernel/gsp_sema_service.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/gsp_sema_service.c') diff --git a/kernel/gsp_sema_service.c b/kernel/gsp_sema_service.c index 6585aaf..a465469 100644 --- a/kernel/gsp_sema_service.c +++ b/kernel/gsp_sema_service.c @@ -17173,6 +17173,17 @@ static void svc_fwd_gr_work(void) ga_va, ga_used, ga_led); hw_rc = gsp_phys_backend_guest_gr_submit(&gs, &cp); + /* + * r420b: the backend redirected the launch's QMD release0 to the + * module semaphore (rel_mod=1 or no targetable guest release page), so + * the ENGINE never writes the guest's own QMD release word. Treat the + * word as unobserved so the bounded outcome check (and the hold's + * edges) author it in software on every outcome; without this a + * rel_mod=1 launch with no deferred release records is never completed + * on the guest word and the client hangs (the r414 saxpy stall). + */ + if (cp.qmd_rel_redirected) + svc_fwd_req.gr_rel_unobserved = true; if (!hw_rc) { svc.fwd_gr_ok++; } else { -- cgit v1.2.3