Check correct thread state at finalization

Prevents external threads from being left in Running state when they
finish, causing the virtual CPU to be always occupied with at least one
thread. This situation causes the virtual CPU to never report any
subsystem.

src/emu/CMakeLists.txt

@@ -45,6 +45,7 @@ add_library(emu STATIC
   ovni/probe.c
   ovni/create.c
   ovni/event.c
+  ovni/finish.c
   nanos6/setup.c
   nanos6/event.c
   nosv/setup.c

src/emu/ovni/finish.c

@@ -0,0 +1,21 @@
+/* Copyright (c) 2021-2023 Barcelona Supercomputing Center (BSC)
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#include "ovni_priv.h"
+
+int
+ovni_finish(struct emu *emu)
+{
+	struct system *sys = &emu->system;
+	int ret = 0;
+
+	/* Ensure that all threads are in the Dead state */
+	for (struct thread *t = sys->threads; t; t = t->gnext) {
+		if (t->state != TH_ST_DEAD) {
+			err("thread %d is not dead (%s)", t->tid, t->id);
+			ret = -1;
+		}
+	}
+
+	return ret;
+}

src/emu/ovni/ovni_priv.h

@@ -38,5 +38,6 @@ struct ovni_cpu {
 int ovni_probe(struct emu *emu);
 int ovni_create(struct emu *emu);
 int ovni_event(struct emu *emu);
+int ovni_finish(struct emu *emu);
 
 #endif /* OVNI_PRIV_H */

src/emu/ovni/probe.c

@@ -10,6 +10,7 @@ struct model_spec model_ovni = {
 	.connect = NULL,
 	.event   = ovni_event,
 	.probe   = ovni_probe,
+	.finish  = ovni_finish,
 };
 
 int