From ae507e6f241c7e3498728f9d1ffc2d41ede5cd64 Mon Sep 17 00:00:00 2001 From: Arthur Hanson Rasmusson Date: Mon, 5 Oct 2026 13:06:39 -0400 Subject: vgsp: guest GR forwarding backend and capture (gsp_phys_gr_forward, default off) Add a default-off guest GR (compute) forwarding path so a guest CUDA launch submitted on its GR channel can be executed by the physical GR engine on the ladder channel, with fail-closed fallback to the host CUDA bridge and the unchanged software release path. - New module parameter gsp_phys_gr_forward (default 0) and accessor. - New GR execution gate: boot_stage.rmcall_gr_exec_ok, latched only after a real GR submission logs REAL GR SEM OK; the backend refuses while it is unset. - Sema capture: a completed 64-word inline QMD on a trusted, non-replay GR decode becomes an svc_gr_cand (push identity, decoded release0, parameter/program/pointer fields, up to 8 captured inline-write records); the CUDA bridge stays authoritative while the parameter is off and is reached in order forward -> bridge -> software release. - Backend: gsp_phys_backend_guest_gr_submit() maps pages at their own guest VAs through fresh Tier-1 small-PT pages/PDE installs or relocates inline-captured pages to ladder shadow pages (Tier 2), builds SET_OBJECT + the inline-QMD method run + REPORT_SEMAPHORE on the compute subchannel, reuses the shared GPFIFO/USERD/doorbell publish tail (extracted from the CE submit path, CE bytes unchanged) and polls the QMD release and/or module semaphore, draining the epoch-gated fault queue on timeout. - Sema wiring: GR requests reuse the INFLIGHT/hold/deferral machinery so the guest channel release applies only on the submit's success/failure edge; hold shims preserve the channel engine type. - Counters and a work_gr state line plus a stats accessor. - Bounds are fixed: 16 pages, 8 inline records, 64 QMD words; every pointer/size checked, pool exhaustion and stale mappings fail closed. - New ABI layouts pinned with static_asserts. Compile-only change: no device test performed. --- kernel/gsp_sema_service.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/gsp_sema_service.h') diff --git a/kernel/gsp_sema_service.h b/kernel/gsp_sema_service.h index 22e9edc..4b04892 100644 --- a/kernel/gsp_sema_service.h +++ b/kernel/gsp_sema_service.h @@ -147,6 +147,17 @@ void gsp_sema_service_fwd_fault_stats(u64 *matched, u64 *unmatched, u64 *delivered, u64 *no_event, u64 *late_release); +/* + * GR (compute) forwarding counters for the gsp-phys-state work_gr line: + * captures offered to the request path (req), launches the physical GR + * channel completed (ok), offerings that fell back to the CUDA bridge / + * software release (fallback), gate refusals (refused), backend timeouts + * (timeout) and timeouts carrying a decoded engine fault (fault). All zero + * while gsp_phys_gr_forward=0. Plain reads, safe from the debugfs show path. + */ +void gsp_sema_service_fwd_gr_stats(u64 *req, u64 *ok, u64 *fallback, + u64 *refused, u64 *timeout, u64 *fault); + /* * Discover and pin GR (compute) channel rings after the CE region of the * channel video-memory allocation. Set false to leave GR rings untranslated -- cgit v1.2.3