Re: [Qemu-devel] Monitor

[NyOS <lista@nyos.homelinux.net>]

On Sat, 15 Jul 2006 23:51:39 +0200, Michael Fisher <desnotes@gmail.com>  
wrote:

> 1. Can the commands (i.e. sendkeys, savevm, loadvm) be initiated from
> within the guest OS? If so, can you give me an example?
Of course, by its nature, not. A good emulator cannot allow that.
However, - if you configure your system well - it is possibile with  
external programs:
Launch qemu with network support, use a named pipe as monitor, and do  
something on the host to grant guest some access (launch sshd for instance  
and install ssh client on guest)
mknod monitor.pipe p <-- this line creates a new named pipe, called  
"monitor.pipe"
qemu -hda disc.img -monitor pipe:monitor.pipe -net nic -net user <-- use  
monitor.pipe as monitor.. note that you cannot reach original monitor  
(alt-ctr-2) this way

connect to host from inside, and use "echo 'command' > monitor.pipe"

It sounds quite useless.. but it isn't if you use a GNU netcat (nc) server  
on host, which listens on a tcp/ip port.. That way, a simple telnet  
program could be used as a terminal from inside (I mean from guest)

nc -T -l -t -p 8898 >monitor.pipe

(There might be some patches around that make possibile to use a tcp/ip  
server as a monitor/serial/parallel device..)

>
> 2. When executing 'savevm' can it be saved to a virtual disk?
By default, not.
With the same trick, you can ask the host to make some VM saves, and then  
fetch it through scp/ftp/samba/whatever you want

>
> Thanks,
>
> desNotes
>

Best regards,

Nyos