[libvirt] Libvirt Support Virtio-serail

[Daniel P. Berrange]

On Mon, May 14, 2012 at 10:03:11AM +0000, Pankaj Rawat wrote:
> Actually I wanted to have private communication channel b/w host and guest
> By default I cannot have multiple console on guest through virsh console guestname
> ( they all are dependent on each other , if I execute a command on one shell its
> output is reflected on all of them ).
> I wanted to login into guest from multiple shells(and the console should be independent of each other)

If you want multiple interactive consoles, you need to configure
multiple <console> devices.


> Virtio-serial have this feature ,I have gone through various install option on web , but they don't seem to work.

virtio-serial is not intended for consoles - it is for application
communication channels.


> Our kernel version for host and guest is 2.6.32-220.4.1.el6.x86_64
> 
> We goes through the mentioned link
> And edit our xml file by adding
> 
> <channel type='pty'>
>    <target type='virtio' name='arbitrary.virtio.serial.port.name'/>
>    <address type='virtio-serial' controller='0' bus='0' port='1'/>
> </channel>
> Then we tried to access the channel device through virsh console guest_name dev_name
> 
> It gives error :-
> 
> # virsh console serial vport0p1
> Connected to domain serial
> Escape character is ^]
> error: internal error cannot find character device vport0p1

The 'virsh consolve' command is only intended for use with interactive
consoles for administrators. As such it completely ignores any <channel>
devices which are for non-interactive use. So what you see here is
normal. The vkirtio serial port is definitely available for use by
your application

What you actually want is to configure multiple <consolke> devices

    <console type='pty'>
      <target type='virtio'/>
    </console>
    <console type='pty'>
      <target type='virtio'/>
    </console>
    <console type='pty'>
      <target type='virtio'/>
    </console>
    <console type='pty'>
      <target type='virtio'/>
    </console>

They will be given names console0, console1, etc so with virsh console

    # virsh console --device console1  serial

Daniel
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