Re: [Qemu-devel] [PATCH for-2.7 0/5] spapr: Fix regression in CPU alias handling

[Andrea Bolognani <abologna@redhat.com>]

On Tue, 2016-08-09 at 11:17 +0200, Thomas Huth wrote:
> There is a regression with the "-cpu" parameter which has been
> introduced by the spapr CPU hotplug code: We used to allow to specify
> a "CPU family" name with the "-cpu" parameter when running on KVM so
> that the user does not need to know the gory details of the exact
> CPU version of the host CPU. For example, it was possible to
> use "-cpu POWER8" on a POWER8E host CPU. This behavior does not
> work anymore with the new hot-pluggable spapr-cpu-core types.
> Since libvirt already heavily depends on the old behavior, this
> is quite a severe regression in the QEMU parameter interface, thus
> I think these patches should still go into 2.7 if possible, to avoid
> that we break the "upper layers" with the final 2.7 release.
> 
> This patch series fixes the regression (and two more minor bugs)
> by registering a family type for the spapr-cpu-core type, too
> (see the last patch). However, since that name clashes with the
> alias types that have been defined in spapr_cpu_core.c, we first
> have to introduce there a better way to handle CPU aliases (see
> the first two patches).
> The third patch fixes a small memory leak along the way, and
> the fourth patch makes sure that we do not mess up the generic
> CPU family type registration anymore (which was another regression
> introduced with the spapr CPU hotplug code).
> 
> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1363812
> 
> Thomas Huth (5):
>   ppc: Introduce a function to look up CPU alias strings
>   hw/ppc/spapr: Look up CPU alias names instead of hard-coding the
>     aliases
>   hw/ppc/spapr: Do not leak the memory of the type string
>   ppc/kvm: Do not mess up the generic CPU family registration
>   ppc/kvm: Register also a generic spapr CPU core family type
> 
>  hw/ppc/spapr.c              |  3 ++-
>  hw/ppc/spapr_cpu_core.c     | 38 +++++++++++++++++++++-----------------
>  target-ppc/cpu.h            |  1 +
>  target-ppc/kvm.c            | 19 +++++++++++--------
>  target-ppc/translate_init.c | 13 +++++++++++++
>  5 files changed, 48 insertions(+), 26 deletions(-)

Tested-By: Andrea Bolognani <abologna@redhat.com>

-- 
Andrea Bolognani / Red Hat / Virtualization