Improve bhyve exit(3) error code.

The bhyve(8) exit status indicates how the VM was terminated:

0	rebooted
1	powered off
2	halted
3	triple fault

The problem is when we have wrappers around bhyve that parses the exit
error code and gets an exit(1) for an error but interprets it as "powered off".
So to mitigate this issue and makes it less error prone for third part
applications, I have added a new exit code 4 that is "exited due to an error".

For now the bhyve(8) exit status are:
0	rebooted
1	powered off
2	halted
3	triple fault
4	exited due to an error

Reviewed by:	@jhb
MFC after:	2 weeks.
Sponsored by:	iXsystems Inc.
Differential Revision:	https://reviews.freebsd.org/D16161

1 files changed, 7 insertions, 7 deletions

diff --git a/usr.sbin/bhyve/mevent_test.c b/usr.sbin/bhyve/mevent_test.c
index 2cae7783f541..1a9c168da6de 100644
--- a/usr.sbin/bhyve/mevent_test.c
+++ b/usr.sbin/bhyve/mevent_test.c
@@ -143,7 +143,7 @@ echoer(void *param)
 	mev = mevent_add(fd, EVF_READ, echoer_callback, &sync);
 	if (mev == NULL) {
 		printf("Could not allocate echoer event\n");
-		exit(1);
+		exit(4);
 	}
 
 	while (!pthread_cond_wait(&sync.e_cond, &sync.e_mt)) {
@@ -200,8 +200,8 @@ acceptor(void *param)
 	static int first;
 
 	if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
-		perror("socket");
-		exit(1);
+		perror("cannot create socket");
+		exit(4);
 	}
 
 	sin.sin_len = sizeof(sin);
@@ -210,13 +210,13 @@ acceptor(void *param)
 	sin.sin_port = htons(TEST_PORT);
 
 	if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
-		perror("bind");
-		exit(1);
+		perror("cannot bind socket");
+		exit(4);
 	}
 
 	if (listen(s, 1) < 0) {
-		perror("listen");
-		exit(1);
+		perror("cannot listen socket");
+		exit(4);
 	}
 
 	(void) mevent_add(s, EVF_READ, acceptor_callback, NULL);