[RFC PATCH v1 02/26] char-socket: allow vsock parameters (cid, port)

[Adalbert Lazăr]

The introspection tool can run in a separate VM and the introspected
VM will establish a connection using a virtual socket.

CC: "Marc-André Lureau" <address@hidden>
CC: Paolo Bonzini <address@hidden>
Signed-off-by: Adalbert Lazăr <address@hidden>
---
 chardev/char-socket.c | 27 ++++++++++++++++++++++++---
 chardev/char.c        |  3 +++
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index bd966aace1..9b2deb0125 100644
--- a/chardev/char-socket.c
+++ b/chardev/char-socket.c
@@ -23,6 +23,11 @@
  */
 
 #include "qemu/osdep.h"
+
+#ifdef CONFIG_AF_VSOCK
+#include <linux/vm_sockets.h>
+#endif /* CONFIG_AF_VSOCK */
+
 #include "chardev/char.h"
 #include "io/channel-socket.h"
 #include "io/channel-tls.h"
@@ -590,6 +595,14 @@ static char *qemu_chr_compute_filename(SocketChardev *s)
                                s->is_listen ? ",server" : "",
                                left, phost, right, pserv);
 
+#ifdef CONFIG_AF_VSOCK
+    case AF_VSOCK:
+        return g_strdup_printf("vsock:%d:%d%s",
+                               ((struct sockaddr_vm *)(ss))->svm_cid,
+                               ((struct sockaddr_vm *)(ss))->svm_port,
+                               s->is_listen ? ",server" : "");
+#endif
+
     default:
         return g_strdup_printf("unknown");
     }
@@ -1378,18 +1391,19 @@ static void qemu_chr_parse_socket(QemuOpts *opts, 
ChardevBackend *backend,
 {
     const char *path = qemu_opt_get(opts, "path");
     const char *host = qemu_opt_get(opts, "host");
+    const char *cid  = qemu_opt_get(opts, "cid");
     const char *port = qemu_opt_get(opts, "port");
     const char *fd = qemu_opt_get(opts, "fd");
     SocketAddressLegacy *addr;
     ChardevSocket *sock;
 
-    if ((!!path + !!fd + !!host) != 1) {
+    if ((!!path + !!fd + !!host + !!cid) != 1) {
         error_setg(errp,
-                   "Exactly one of 'path', 'fd' or 'host' required");
+                   "Exactly one of 'path', 'fd', 'cid' or 'host' required");
         return;
     }
 
-    if (host && !port) {
+    if ((host || cid) && !port) {
         error_setg(errp, "chardev: socket: no port given");
         return;
     }
@@ -1444,6 +1458,13 @@ static void qemu_chr_parse_socket(QemuOpts *opts, 
ChardevBackend *backend,
             .has_ipv6 = qemu_opt_get(opts, "ipv6"),
             .ipv6 = qemu_opt_get_bool(opts, "ipv6", 0),
         };
+    } else if (cid) {
+        addr->type = SOCKET_ADDRESS_LEGACY_KIND_VSOCK;
+        addr->u.vsock.data = g_new0(VsockSocketAddress, 1);
+        *addr->u.vsock.data = (VsockSocketAddress) {
+            .cid  = g_strdup(cid),
+            .port = g_strdup(port),
+        };
     } else if (fd) {
         addr->type = SOCKET_ADDRESS_LEGACY_KIND_FD;
         addr->u.fd.data = g_new(String, 1);
diff --git a/chardev/char.c b/chardev/char.c
index e77564060d..39e36ceb97 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -852,6 +852,9 @@ QemuOptsList qemu_chardev_opts = {
         },{
             .name = "host",
             .type = QEMU_OPT_STRING,
+        },{
+            .name = "cid",
+            .type = QEMU_OPT_STRING,
         },{
             .name = "port",
             .type = QEMU_OPT_STRING,