On Fri, Oct 10, 2014 at 03:42:41PM +0530, Prerna Saxena wrote:
>
> >From 7228aacaa4b24907b1cbf33838ada8fb81890419 Mon Sep 17 00:00:00 2001
> From: Prerna Saxena <prerna@xxxxxxxxxxxxxxxxxx>
> Date: Tue, 7 Oct 2014 10:53:08 +0530
>
> PowerISA allows processors to run VMs in binary compatibility ("compat")
> mode supporting an older version of ISA. QEMU has recently added support to
> explicitly denote a VM running in compatibility mode through commit 6d9412ea
> & 8dfa3a5e85.
> Now, a "compat" mode VM can be run by invoking this qemu commandline on a
> POWER8 host: -cpu host,compat=power7.
If this is using 'host'
>
> This patch allows libvirt to extend the "fallback" semantics of cpu model to
> describe this new mode for PowerKVM guests.
> As an example:
> When a user wants to request a power7 vm to run in compatibility mode on
> a Power8 host, this can be described in XML as follows :
> <cpu mode='custom' match='exact'>
> <model fallback='compat'>power7</model>
> </cpu>
Then I don't think this should be using mode='custom', but rather it
should be 'host-passthrough'. We would use the <model> to denote the
compatibility mode for the host passthrough. IOW, it feels like this
is better described as
<cpu mode='host-passthrough' match='exact'>
<model>power7</model>
</cpu>
Regards,
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list