Why Xen 3.1.0 disable the qemu control monitor

Why Xen 3.1.0 disable the qemu control monitor

[Steven Hu]

Hello, all
I found that in Xen 3.1.0 I can't press Ctrl+ALT+2 to open the console
of qemu to do some administration. The root cause is that the value of
"monitor_device " is "null" now. In Xen 3.0.4, the value is "vc". If
there is no control console, how can I add a usb device to the guest
OS. Could you guys tell me why we disable the console in Xen 3.1.0.
thank.

RE: Why Xen 3.1.0 disable the qemu control monitor

[James Harper]

I asked this very same question just recently.

The answer is put 'monitor=yes" in the config, because the default is
now off for security reasons.

James

> -----Original Message-----
> From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-
> bounces@lists.xensource.com] On Behalf Of Steven Hu
> Sent: Tuesday, 12 June 2007 15:19
> To: xen-devel@lists.xensource.com
> Subject: [Xen-devel] Why Xen 3.1.0 disable the qemu control monitor
> 
> Hello, all
> I found that in Xen 3.1.0 I can't press Ctrl+ALT+2 to open the console
> of qemu to do some administration. The root cause is that the value of
> "monitor_device " is "null" now. In Xen 3.0.4, the value is "vc". If
> there is no control console, how can I add a usb device to the guest
> OS. Could you guys tell me why we disable the console in Xen 3.1.0.
> thank.
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

Re: Why Xen 3.1.0 disable the qemu control monitor

[Daniel P. Berrange]

On Tue, Jun 12, 2007 at 01:19:04PM +0800, Steven Hu wrote:
> Hello, all
> I found that in Xen 3.1.0 I can't press Ctrl+ALT+2 to open the console
> of qemu to do some administration. The root cause is that the value of
> "monitor_device " is "null" now. In Xen 3.0.4, the value is "vc". If
> there is no control console, how can I add a usb device to the guest
> OS. Could you guys tell me why we disable the console in Xen 3.1.0.
> thank.

It is a huge security hole if using the VNC server to access the guest
console. Anyone who can access the VNC server would be able to trivially
root the entire Dom0 host if the monitor is enabled. See CVE 2007 0998


http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-0998

Dan.
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