Re: [Qemu-devel] [PATCHv2 3/5] target-ppc: Allow eventual removal of old migration mistakes

[Thomas Huth]

On 21.11.2016 06:31, David Gibson wrote:
> Until very recently, the vmstate for ppc cpus included some poorly
> thought out VMSTATE_EQUAL() components, that can easily break
> migration compatibility, and did so between qemu-2.6 and later
> versions.  A hack was recently added which fixes this migration
> breakage, but it leaves the unhelpful cruft of these fields in the
> migration stream.
> 
> dThis patch adds a new cpu property allowing these fields to be
> removed from the stream entirely.  This property is enabled by default
> for the pseries-2.8 machine type - which comes after the fix - and for
> all non-pseries machine types - which aren't mature enough to care
> about cross-version migration.
> 
> The migration hack remains in place for pseries-2.7 and earlier
> machine types, allowing backwards and forwards migration with the
> older machine types.
> 
> This restricts the migration compatibility cruft to older machine
> types, and at least opens the possibility of eventually deprecating
> and removing it entirely.

I like that idea! Patch looks fine, too, so:

Reviewed-by: Thomas Huth <address@hidden>