Re: [Qemu-devel] [Qemu-ppc] [PATCHv5 0/4] Clean up compatibility mode handling

[Andrea Bolognani]

On Fri, 2017-06-02 at 13:15 +1000, David Gibson wrote:
> This is a rebased and revised version of my patches revising CPU
> compatiblity mode handling on ppc, last posted in November.  Since
> then, many of the patches have already been merged (some for 2.9, some
> since).  This is what's left.

As discussed yesterday on libvir-list, the current
implementation will abort() when the user attempts to use
a compat mode that's not valid for the host CPU, eg. on
a POWER8 host:

  $ qemu-system-ppc64 \
    -nodefaults \
    -M pseries,accel=kvm \
    -cpu host,compat=power9
  Unexpected error in ppc_set_compat() at target/ppc/compat.c:135:
  qemu-system-ppc64: Compatibility PVR 0x0f000005 not valid for CPU
  Aborted

We should probably report the error to the user in a slightly
less destructive fashion :)


[1] https://www.redhat.com/archives/libvir-list/2017-June/msg00476.html
-- 
Andrea Bolognani / Red Hat / Virtualization