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_phys_booter.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/gsp_phys_booter.c') diff --git a/kernel/gsp_phys_booter.c b/kernel/gsp_phys_booter.c index f7ad153..cf5061d 100644 --- a/kernel/gsp_phys_booter.c +++ b/kernel/gsp_phys_booter.c @@ -18602,6 +18602,7 @@ int gsp_phys_backend_guest_gr_submit(const struct gsp_phys_gr_submit *req, const u8 *guest_param_pg; u32 want_qmd = 0, want_ch = 0; bool qmd_rel = false, ch_rel = false; + bool qmd_rel_redirected = false; /* r420b: release0 -> module sem */ u64 qmd_rel_hpa = 0, ch_rel_hpa = 0; u64 ch_sem_va = GSP_PHYS_RMCALL_VA_SEM + 4; u64 qmd_dst = GSP_PHYS_RMCALL_VA_SRC; @@ -18859,6 +18860,15 @@ int gsp_phys_backend_guest_gr_submit(const struct gsp_phys_gr_submit *req, */ qmd_rel_hpa = 0; qmd_rel_off = 0; + /* + * r420b: the ENGINE will not write the guest's QMD + * release word this launch (rel_mod, or no targetable + * guest release page). Tell the caller so it authors + * the word in software on every outcome - otherwise a + * launch without deferred release records is never + * completed on the guest word (the r414 saxpy hang). + */ + qmd_rel_redirected = true; } } @@ -21432,6 +21442,7 @@ out: out->elapsed_ms = jiffies_to_msecs(jiffies - start); out->rc = ret; out->fault = fault; + out->qmd_rel_redirected = qmd_rel_redirected; } return ret; } -- cgit v1.2.3