Re: [PATCH v3 23/23] migration: Use multifd before we check for the zero page

[Peter Xu]

On Thu, Dec 02, 2021 at 06:38:27PM +0100, Juan Quintela wrote:
> This needs to be improved to be compatible with old versions.

Any plan to let new binary work with old binary?

Maybe boost the version field for multifd packet (along with a
multifd_version=2 parameter and only set on new machine types)?

PS: We should really have some handshake mechanism between src/dst, I dreamt it
for a long time..  So that we only need to specify the capability/parameters on
src someday and we'll never see incompatible migration failing randomly because
the handshake should guarantee no stupid mistake..  Sad.

> 
> But .... if we don't care about RDMA, why do we care about
> control_save_page()?

Could anyone help to explain why we don't care?  I still see bugfixes coming..

Thanks,

-- 
Peter Xu