kvm tools: More error handling in the ipc code

Add perror() calls to a couple of exit paths, to ease debugging.

There are also two places where we print "Failed starting IPC thread",
but one is really an epoll failure, so make that obvious.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

1 files changed, 13 insertions, 4 deletions

diff --git a/kvm-ipc.c b/kvm-ipc.c
index bdcc0d1f..78975192 100644
--- a/kvm-ipc.c
+++ b/kvm-ipc.c
@@ -49,18 +49,25 @@ static int kvm__create_socket(struct kvm *kvm)
 	}
 
 	s = socket(AF_UNIX, SOCK_STREAM, 0);
-	if (s < 0)
+	if (s < 0) {
+		perror("socket");
 		return s;
+	}
+
 	local.sun_family = AF_UNIX;
 	strlcpy(local.sun_path, full_name, sizeof(local.sun_path));
 	len = strlen(local.sun_path) + sizeof(local.sun_family);
 	r = bind(s, (struct sockaddr *)&local, len);
-	if (r < 0)
+	if (r < 0) {
+		perror("bind");
 		goto fail;
+	}
 
 	r = listen(s, 5);
-	if (r < 0)
+	if (r < 0) {
+		perror("listen");
 		goto fail;
+	}
 
 	return s;
 
@@ -430,6 +437,7 @@ int kvm_ipc__init(struct kvm *kvm)
 
 	epoll_fd = epoll_create(KVM_IPC_MAX_MSGS);
 	if (epoll_fd < 0) {
+		perror("epoll_create");
 		ret = epoll_fd;
 		goto err;
 	}
@@ -437,13 +445,14 @@ int kvm_ipc__init(struct kvm *kvm)
 	ev.events = EPOLLIN | EPOLLET;
 	ev.data.fd = sock;
 	if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) < 0) {
-		pr_err("Failed starting IPC thread");
+		pr_err("Failed adding socket to epoll");
 		ret = -EFAULT;
 		goto err_epoll;
 	}
 
 	stop_fd = eventfd(0, 0);
 	if (stop_fd < 0) {
+		perror("eventfd");
 		ret = stop_fd;
 		goto err_epoll;
 	}