Re: [RFC qemu 0/4] A PV solution for live migration optimization

From: Amit Shah
Date: Thu Mar 10 2016 - 02:58:01 EST

On (Thu) 10 Mar 2016 [07:44:19], Li, Liang Z wrote:
> Hi Amit,
> Could provide more information on how to use virtio-serial to exchange data? Thread , Wiki or code are all OK.
> I have not find some useful information yet.

See this commit in the Linux sources:


that adds a way to send guest trace data over to the host. I think
that's the most relevant to your use-case. However, you'll have to
add an in-kernel user of virtio-serial (like the virtio-console code
-- the code that deals with tty and hvc currently). There's no other
non-tty user right now, and this is the right kind of use-case to add
one for!

For many other (userspace) use-cases, see the qemu-guest-agent in the
qemu sources.

The API is documented in the wiki:

and the feature pages have some information that may help as well:

There are some links in here too:

Hope this helps.