[Qemu-devel] [PULL (resend, rebase) 2/5] virtio-serial: Disallow generic ports at id 0

[Amit Shah]

Port 0 is reserved for virtconsole devices for backward compatibility
with the old -virtioconsole (from qemu 0.12) device type.

libvirt prior to commit 8e28c5d40200b4c5d483bd585d237b9d870372e5 used
port 0 for generic ports.  libvirt will no longer do that, but disallow
instantiating generic ports at id 0 from qemu as well.

Signed-off-by: Amit Shah <address@hidden>
---
 hw/virtio-console.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/hw/virtio-console.c b/hw/virtio-console.c
index c235b27..699f190 100644
--- a/hw/virtio-console.c
+++ b/hw/virtio-console.c
@@ -11,6 +11,7 @@
  */
 
 #include "qemu-char.h"
+#include "qemu-error.h"
 #include "virtio-serial.h"
 
 typedef struct VirtConsole {
@@ -113,7 +114,15 @@ static int virtserialport_initfn(VirtIOSerialPort *port)
 {
     VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
 
-    return generic_port_init(vcon, port);
+    if (port->id == 0) {
+        /*
+         * Disallow a generic port at id 0, that's reserved for
+         * console ports.
+         */
+        error_report("Port number 0 on virtio-serial devices reserved for 
virtconsole devices for backward compatibility.");
+        return -1;
+    }
+    return generic_port_init(vcon, dev);
 }
 
 static VirtIOSerialPortInfo virtserialport_info = {
-- 
1.7.4