Re: [Qemu-devel] [PATCH for-2.0] target-i386: reorder fields in cpu/msr_hyperv_hypercall subsection

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Apr 02, 2014 at 04:42:08PM +0100, Peter Maydell wrote:
> On 2 April 2014 16:33, Paolo Bonzini <pbonzini@redhat.com> wrote:
> > The subsection already exists in one well-known enterprise Linux
> > distribution, but for some strange reason the fields were swapped
> > when forward-porting the patch to upstream.
> >
> > Limit headaches for said enterprise Linux distributor when the
> > time will come to rebase their version of QEMU.
> >
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > ---
> >  target-i386/machine.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/target-i386/machine.c b/target-i386/machine.c
> > index 24bc373..168cab6 100644
> > --- a/target-i386/machine.c
> > +++ b/target-i386/machine.c
> > @@ -569,8 +569,8 @@ static const VMStateDescription vmstate_msr_hypercall_hypercall = {
> >      .minimum_version_id = 1,
> >      .minimum_version_id_old = 1,
> >      .fields      = (VMStateField []) {
> > -        VMSTATE_UINT64(env.msr_hv_hypercall, X86CPU),
> >          VMSTATE_UINT64(env.msr_hv_guest_os_id, X86CPU),
> > +        VMSTATE_UINT64(env.msr_hv_hypercall, X86CPU),
> >          VMSTATE_END_OF_LIST()
> >      }
> 
> Surely this is a migration compatibility break and you need to bump
> the version fields here?
> 
> thanks
> -- PMM

Not if we fix it before we put out 2.0.