> -----Original Message-----
> From: Paolo Bonzini [mailto:pbonz...@redhat.com]
> Sent: Tuesday, November 21, 2017 8:16 AM
> To: Michael S. Tsirkin <m...@redhat.com>; Stefan Hajnoczi <stefa...@gmail.com>
> Cc: Liu, Changpeng <changpeng....@intel.com>; qemu-devel@nongnu.org;
> marcandre.lur...@redhat.com; fel...@nutanix.com; Harris, James R
> <james.r.har...@intel.com>
> Subject: Re: [PATCH v5 1/4] vhost-user: add new vhost user messages to support
> virtio config space
>
> On 20/11/2017 21:44, Michael S. Tsirkin wrote:
> > Live migrations is supposed to be migrating guest writeable state too.
> > If you mean migrating RO fields like size, then
> > I don't think it's a good idea to reuse SET_CONFIG for that.
> > SET_CONFIG should obey exactly the virtio semantics.
> >
> > And I agree, it should say that slave must treat it as a write,
> > and get config as a read according to virtio semantics.
> >
> > If someone needs to pass configuration from qemu to
> > slave, let's add specific messages with precisely defined semantics.
>
> Fair enough, but I'd add nevertheless a 32-bit flags field to both
> GET_CONFIG and SET_CONFIG, and document that the slave MUST check that
> it is zero and otherwise fail.
Ok.
>
> Paolo
