On Wed, Aug 10, 2016 at 08:11:16PM +0530, Bharata B Rao wrote:
> Hi,
>
> With CPU core hotplug support in pseries-2.7, we will have to specify
> the compat type using -global only as we don't yet take care of parsing
> -cpu cputype,compat=.
>
> There have been patches to support that:
>
> sPAPR specific one:
> https://lists.nongnu.org/archive/html/qemu-devel/2016-06/msg07564.html
>
> PPC generic one:
> https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg02676.html
>
> but the patch isn't upstream yet.
>
> The result is that instead of specifying
>
> -cpu host,compat=power7 for pseries-2.7, we will have to use
>
> -cpu host -global driver=host-powerpc64-cpu,property=compat,value=power7
>
> This behaviour is specific to pseries-2.7 and for earlier machine types
> the original way of specifying compat with -cpu works.
>
> Will this be a concern for libvirt ? Would it be difficult for libvirt to
> switch to -global when generating QEMU cmdline for compat mode for pseries-2.7
> machine.
>
> Or, should we just include one of the above patches so that
> -cpu cputype,compat= continues to work for peseries-2.7 ?
I believe we should include the generic PPC patch ("ppc: parse
cpu features once") in 2.7.
--
Eduardo
