Re: [Qemu-devel] [PATCH] Migration compatibility for serial

[Paolo Bonzini <pbonzini@redhat.com>]

On 17/06/2015 13:45, Michael S. Tsirkin wrote:
>> > Where, in the specific case of migration?
> Just look at hour compat flags.
> 
> For example (intentionally using serial here):
>         {\
>             .driver   = "pci-serial",\
>             .property = "prog_if",\
>             .value    = stringify(0),\
>         },\
>         {\
>             .driver   = "pci-serial-2x",\
>             .property = "prog_if",\
>             .value    = stringify(0),\
>         },\
>         {\
>             .driver   = "pci-serial-4x",\
>             .property = "prog_if",\
>             .value    = stringify(0),\
>         },\
> 
> apparently some clients check the specific prog if
> value, completely breaking if the value was incorrect.
> So we fixed it for new machine types but not old ones.

That has nothing to do with migration.

Paolo