From fdbc86cf79784f56fab8115f2d565962e1111b2e Mon Sep 17 00:00:00 2001
From: Robert Wing <rew@FreeBSD.org>
Date: Sat, 15 May 2021 11:58:21 -0800
Subject: [PATCH] bhyve/snapshot: split up mutex/cond initialization from
 socket creation

Move initialization of the mutex/condition variables required by the
save/restore feature to their own function.

The unix domain socket that facilitates communication between bhyvectl
and bhyve doesn't rely on these variables in order to be functional.

Reviewed by:    markj
Differential Revision:  https://reviews.freebsd.org/D30281
---
 usr.sbin/bhyve/bhyverun.c |  3 +++
 usr.sbin/bhyve/snapshot.c | 25 ++++++++++++++++---------
 usr.sbin/bhyve/snapshot.h |  1 +
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/usr.sbin/bhyve/bhyverun.c b/usr.sbin/bhyve/bhyverun.c
index d14219bbef65..acf0df6cc9bf 100644
--- a/usr.sbin/bhyve/bhyverun.c
+++ b/usr.sbin/bhyve/bhyverun.c
@@ -1540,6 +1540,9 @@ main(int argc, char *argv[])
 	if (restore_file != NULL)
 		destroy_restore_state(&rstate);
 
+	/* initialize mutex/cond variables */
+	init_snapshot();
+
 	/*
 	 * checkpointing thread for communication with bhyvectl
 	 */
diff --git a/usr.sbin/bhyve/snapshot.c b/usr.sbin/bhyve/snapshot.c
index 019f4fdd6cb0..1a06c3e8d065 100644
--- a/usr.sbin/bhyve/snapshot.c
+++ b/usr.sbin/bhyve/snapshot.c
@@ -1493,6 +1493,22 @@ checkpoint_thread(void *param)
 	return (NULL);
 }
 
+void
+init_snapshot(void)
+{
+	int err;
+
+	err = pthread_mutex_init(&vcpu_lock, NULL);
+	if (err != 0)
+		errc(1, err, "checkpoint mutex init");
+	err = pthread_cond_init(&vcpus_idle, NULL);
+	if (err != 0)
+		errc(1, err, "checkpoint cv init (vcpus_idle)");
+	err = pthread_cond_init(&vcpus_can_run, NULL);
+	if (err != 0)
+		errc(1, err, "checkpoint cv init (vcpus_can_run)");
+}
+
 /*
  * Create the listening socket for IPC with bhyvectl
  */
@@ -1508,15 +1524,6 @@ init_checkpoint_thread(struct vmctx *ctx)
 
 	memset(&addr, 0, sizeof(addr));
 
-	err = pthread_mutex_init(&vcpu_lock, NULL);
-	if (err != 0)
-		errc(1, err, "checkpoint mutex init");
-	err = pthread_cond_init(&vcpus_idle, NULL);
-	if (err == 0)
-		err = pthread_cond_init(&vcpus_can_run, NULL);
-	if (err != 0)
-		errc(1, err, "checkpoint cv init");
-
 	socket_fd = socket(PF_UNIX, SOCK_DGRAM, 0);
 	if (socket_fd < 0) {
 		EPRINTLN("Socket creation failed: %s", strerror(errno));
diff --git a/usr.sbin/bhyve/snapshot.h b/usr.sbin/bhyve/snapshot.h
index f28b56cf0a7f..3ffd42fbeabc 100644
--- a/usr.sbin/bhyve/snapshot.h
+++ b/usr.sbin/bhyve/snapshot.h
@@ -127,6 +127,7 @@ int vm_resume_user_devs(struct vmctx *ctx);
 int get_checkpoint_msg(int conn_fd, struct vmctx *ctx);
 void *checkpoint_thread(void *param);
 int init_checkpoint_thread(struct vmctx *ctx);
+void init_snapshot(void);
 
 int load_restore_file(const char *filename, struct restore_state *rstate);