vgsp-sema: host-triggered VAS pdb discovery (sema_pdb_discover va,pa -> verify the parked COPY_SERVER_PDES candidates against a content-verified ring pair, then fall back to the vidmem walk-root sweep) + runtime-tunable candidate age-out (sema_vas_cand_ms; the default 15 s ages the client's VAS candidate out exactly when its channels first register, so the verified walk can never anchor it by itself)

1 files changed, 31 insertions, 0 deletions

diff --git a/kernel/main.c b/kernel/main.c
index dd11d12..5ff5047 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -2960,6 +2960,37 @@ module_param_cb(sema_map_add, &nv_vgpu_sema_map_add_ops, NULL, 0200);
 MODULE_PARM_DESC(sema_map_add, "Inject a GPU VA -> guest PA mapping (hex va,hex pa)");
 
 /*
+ * Debug: retrigger the client-VAS page-directory discovery with a host
+ * content-verified {ring VA -> ring PA} pair (the ring page's GPFIFO
+ * entries are the fingerprint):
+ *   echo 0x<va>,0x<pa> > .../parameters/sema_pdb_discover
+ */
+static int nv_vgpu_sema_pdb_discover_set(const char *val,
+					 const struct kernel_param *kp)
+{
+	char buf[64];
+	char *comma;
+	u64 va = 0, pa = 0;
+
+	strscpy(buf, val, sizeof(buf));
+	comma = strchr(buf, ',');
+	if (!comma)
+		return -EINVAL;
+	*comma = '\0';
+	if (kstrtoull(buf, 0, &va) || kstrtoull(comma + 1, 0, &pa))
+		return -EINVAL;
+
+	return gsp_sema_service_pdb_discover(va, pa);
+}
+
+static const struct kernel_param_ops nv_vgpu_sema_pdb_discover_ops = {
+	.set = nv_vgpu_sema_pdb_discover_set,
+};
+
+module_param_cb(sema_pdb_discover, &nv_vgpu_sema_pdb_discover_ops, NULL, 0200);
+MODULE_PARM_DESC(sema_pdb_discover, "Retrigger the VAS pdb discovery with a verified ring pair (hex va,hex pa)");
+
+/*
  * Debug: register a channel's GPU completion counter (guest PA of the u32
  * tracking counter the GPU would write when a push completes):
  *   echo <h_object>,<pa> > .../parameters/sema_counter