Subject: Re: bug#34276: ‘guix system disk-im age’ successfully builds a bad image

From: Brice Waegeneire <[email-masked]>
Date: Sat, 21 Mar 2020 16:44:02 +0000

Hello Ludo,

On 2020-03-21 15:58, Ludovic Courtès wrote:
> Any idea how to implement it?  Is QMP a request/reply kind of interface
> like the monitor?

Not really or I would have sent a patch instead.

QMP is similar to the the monitor in the sense that you can send a 
command and
receive a reply but it give us access to more features; in our case
asynchronous events. To get notified by the pvpanic device that a panic 
occured
on the guest it is needed to do the following:
1. Connect to the socket
2. Receive the server greetings
3. Respond with the capabilites request
4. Receive the capabilites respond
5. Listen on GUEST_PANICKED events

The QMP specifications are available here[0].

[0]: 
https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/interop/qmp-spec.txt;hb=HEAD

Brice.