Re: [Qemu-devel] virtio-serial: A guest <-> host interface for simple communication

Jamie Lokier
2009-06-24T17:50:07Z

Amit Shah wrote:
> On (Wed) Jun 24 2009 [17:40:49], Jamie Lokier wrote:
> > Amit Shah wrote:
> > > A few sample uses for a vmchannel are to share the host and guest
> > > clipboards (to allow copy/paste between a host and a guest), to
> > > lock the screen of the guest session when the vnc viewer is closed,
> > > to find out which applications are installed on a guest OS even when
> > > the guest is powered down (using virt-inspector) and so on.
> >
> > Those all look like useful features.
> >
> > Can you run an application to provide those features on a guest which
> > _doesn't_ have a vmchannel/virtio-serial support in the kernel?
> >
> > Or will it be restricted only to guests which have QEMU-specific
> > support in their kernel?
>
> libguestfs currently uses the -net user based vmchannel interface that
> exists in current qemu. That doesn't need a kernel that doesn't have
> support for virtio-serial.

That's great!

If that works fine, and guest apps/libraries are using that as a
fallback anyway, what benefit do they get from switching to
virtio-serial when they detect that instead, given they still have
code for the -net method?

Is the plan to remove -net user based support from libguestfs?

Is virtio-serial significantly simpler to use?

-- Jamie