qga: add vsock-listen method

Add AF_VSOCK (virtio-vsock) support as an alternative to virtio-serial.

  $ qemu-system-x86_64 -device vhost-vsock-pci,guest-cid=3 ...
  (guest)# qemu-ga -m vsock-listen -p 3:1234
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

qga/channel-posix.c

@@ -193,6 +193,31 @@ static gboolean ga_channel_open(GAChannel *c, const gchar *path, GAChannelMethod
         ga_channel_listen_add(c, fd, true);
         break;
     }
+    case GA_CHANNEL_VSOCK_LISTEN: {
+        Error *local_err = NULL;
+        SocketAddress *addr;
+        char *addr_str;
+        int fd;
+
+        addr_str = g_strdup_printf("vsock:%s", path);
+        addr = socket_parse(addr_str, &local_err);
+        g_free(addr_str);
+        if (local_err != NULL) {
+            g_critical("%s", error_get_pretty(local_err));
+            error_free(local_err);
+            return false;
+        }
+
+        fd = socket_listen(addr, &local_err);
+        qapi_free_SocketAddress(addr);
+        if (local_err != NULL) {
+            g_critical("%s", error_get_pretty(local_err));
+            error_free(local_err);
+            return false;
+        }
+        ga_channel_listen_add(c, fd, true);
+        break;
+    }
     default:
         g_critical("error binding/listening to specified socket");
         return false;

qga/channel.h

@@ -19,6 +19,7 @@ typedef enum {
     GA_CHANNEL_VIRTIO_SERIAL,
     GA_CHANNEL_ISA_SERIAL,
     GA_CHANNEL_UNIX_LISTEN,
+    GA_CHANNEL_VSOCK_LISTEN,
 } GAChannelMethod;
 
 typedef gboolean (*GAChannelCallback)(GIOCondition condition, gpointer opaque);

qga/main.c

@@ -190,8 +190,8 @@ static void usage(const char *cmd)
 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 "QEMU Guest Agent %s\n"
 "\n"
-"  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
-"                    isa-serial (virtio-serial is the default)\n"
+"  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
+"                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 "                    %s,\n"
 "                    the default for isa-serial is:\n"
@@ -659,6 +659,8 @@ static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
         channel_method = GA_CHANNEL_ISA_SERIAL;
     } else if (strcmp(method, "unix-listen") == 0) {
         channel_method = GA_CHANNEL_UNIX_LISTEN;
+    } else if (strcmp(method, "vsock-listen") == 0) {
+        channel_method = GA_CHANNEL_VSOCK_LISTEN;
     } else {
         g_critical("unsupported channel method/type: %s", method);
         return false;