Re: [Qemu-devel] [PATCH 05/11] qemu: MSI-X support functions

[Paul Brook]

> > If you can't create an identical machine from scratch then I don't
> > consider snapshot/migration to be a useful feature. i.e. as soon as you
> > shutdown and restart the guest it is liable to break anyway.
>
> Why is liable to break?

A VM booted on an old version of qemu and migrated to a new version will 
behave differently to a the same VM booted on a new version of qemu.
I hope I don't need to explain why this is bad.

As previously discussed, any guest visible changes are liable to break a guest 
OS, particularly guests like Windows which deliberately break when run on 
"different" hardware. Personally I don't particularly care, but if we support 
live migration we also need to support "cold" migration - i.e. shutdown and 
restart.

>So once you load and image with MSIX capability off,
>it will stay off across guest restarts.

I'm assuming guest restart includes restarting qemu.

Paul