Re: [Qemu-devel] [RFC] libvhost-user: implement VHOST_USER_PROTOCOL_F_KICK_CALL_MSGS

[Johannes Berg]

On Mon, 2019-09-09 at 09:48 -0400, Michael S. Tsirkin wrote:

> > I suppose we could fail a later command that already needs a reply
> > without REPLY_ACK, but that seems difficult to debug?
> 
> Next command is GET_FEATURES. Return an error response from that
> and device init will fail.

Hmm, what's an error here though? You can only return a value, no?

> > Anyway, if you feel that we should have this as some sort of safeguard I
> > can try to do that; to me it feels rather pointless as libvhost-user is
> > more of a sample implementation than anything else.
> 
> Exactly for this reason :)

:)

> > Unless you also wanted to write into the spec that F_KICK_CALL_MSGS
> > absolutely *requires* F_REPLY_ACK,
> 
> yep

Sure, I'm fine with that.

> We can document how to behave in case of inconsistent protocol features,
> yes.

OK.

johannes