Re: [Qemu-ppc] [PATCH 1/2] ppc/kvm: Handle the "family" CPU via alias instead of registering new types

[David Gibson]

On Wed, Feb 01, 2017 at 08:39:47AM +0100, Thomas Huth wrote:
> On 01.02.2017 01:10, David Gibson wrote:
> > On Tue, Jan 31, 2017 at 02:11:58PM +0100, Thomas Huth wrote:
> >> When running with KVM on POWER, we are registering a "family" CPU
> >> type for the host CPU that we are running on. For example, on all
> >> POWER8-compatible hosts, we register a "POWER8" CPU type, so that
> >> you can always start QEMU with "-cpu POWER8" there, without the
> >> need to know whether you are running on a POWER8, POWER8E or POWER8NVL
> >> host machine.
> >> However, we also have a "POWER8" CPU alias in the ppc_cpu_aliases list
> >> (that is mainly useful for TCG). This leads to two cosmetical drawbacks:
> >> If the user runs QEMU with "-cpu ?", we always claim that POWER8 is an
> >> "alias for POWER8_v2.0" - which is simply not true when running with
> >> KVM on POWER. And when using the 'query-cpu-definitions' QMP call,
> >> there are currently two entries for "POWER8", one for the alias, and
> >> one for the additional registered type.
> >> To solve the two problems, we should rather update the "family" alias
> >> instead of registering a new types. We then only have one "POWER8"
> >> CPU definition around, an alias, which also points to the right
> >> destination.
> >>
> >> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1396536
> >> Signed-off-by: Thomas Huth <address@hidden>
> > 
> > Reviewed-by: David Gibson <address@hidden>
> > 
> > Updating the otherwise static table of aliases is kind of ugly, but
> > then so is registering an extra full type as we do now.
> > 
> > Is this safe to apply without the follow up patch to vl.c.
> 
> Yes. It fixes the problem with "query-cpu-definitions" already. You just
> need the other patch to get the output of "-cpu ?" right, too.

Great.  Applied to ppc-for-2.9.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

signature.asc
Description: PGP signature