Re: [qemu-s390x] [PATCH v2] s390x/cpumodel: fix segmentation fault when baselining models

[Cornelia Huck]

On Wed, 18 Jul 2018 11:23:30 +0200
David Hildenbrand <address@hidden> wrote:

> Usually, when baselining two CPU models, whereby one of them has base
> CPU features disabled (e.g. z14-base,msa=off), we fallback to an older
> model that did not have these features in the base model. We always try to
> create a "sane" CPU model (as far as possible), and one part of it is that
> removing base features is no good and to be avoided.
> 
> Now, if we disable base features that were part of a z900, we're out of
> luck. We won't find a CPU model and QEMU will segfault. This is a
> scenario that should never happen in real life, but it can be used to
> crash QEMU.
> 
> So let's properly report an error if we baseline e.g.:
> 
> { "execute": "query-cpu-model-baseline",
>   "arguments" : { "modela": { "name": "z14-base", "props": {"esan3" : false}},
>                   "modelb": { "name": "z14"}} }
> 
> Instead of segfaulting.
> 
> Signed-off-by: David Hildenbrand <address@hidden>
> ---
>  target/s390x/cpu_models.c | 8 ++++++++
>  1 file changed, 8 insertions(+)

Thanks, queued to s390-fixes.