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

[Amit Shah]

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:

108fc82596e3b66b819df9d28c1ebbc9ab5de14c

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:

http://www.linux-kvm.org/page/Virtio-serial_API

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

https://fedoraproject.org/wiki/Features/VirtioSerial

There are some links in here too:

http://log.amitshah.net/2010/09/communication-between-guests-and-hosts/

Hope this helps.


                Amit