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

[Amit Shah <amit.shah@redhat.com>]

On (Thu) 10 Mar 2011 [11:39:16], Amit Shah wrote:
> 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 <amit.shah@redhat.com>

Updated patch below, fixes a build break after rebase.  The git tree
in the pull request has been updated with this fix.

>From 78f1d849a8d739fa7377b8a790a60ffc293aa786 Mon Sep 17 00:00:00 2001
Message-Id: <78f1d849a8d739fa7377b8a790a60ffc293aa786.1299745288.git.amit.shah@redhat.com>
In-Reply-To: <cover.1299745288.git.amit.shah@redhat.com>
References: <cover.1299745288.git.amit.shah@redhat.com>
From: Amit Shah <amit.shah@redhat.com>
Date: Thu, 3 Feb 2011 13:05:07 +0530
Subject: [PULL (resend, rebase) 2/5] virtio-serial: Disallow generic ports at id 0

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 <amit.shah@redhat.com>
---
 hw/virtio-console.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/hw/virtio-console.c b/hw/virtio-console.c
index c235b27..4440784 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 {
@@ -113,6 +114,14 @@ static int virtserialport_initfn(VirtIOSerialPort *port)
 {
     VirtConsole *vcon = DO_UPCAST(VirtConsole, port, 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, port);
 }
 
-- 
1.7.4




		Amit