On 06/11/2015 08:13 PM, Michael S. Tsirkin wrote: > On Thu, Jun 11, 2015 at 02:10:48PM +0200, Thibaut Collet wrote: >> I am not sure to understand your remark: >> >>> It needs to be sent when backend is activated by guest kick >>> (in case of virtio 1, it's possible to use DRIVER_OK for this). >>> This does not happen when VM still runs on source. >> Could you confirm rarp can be sent by backend when the >> VHOST_USER_SET_VRING_KICK message is received by the backend ? > No - the time to send pakets is when you start processing > the rings. > > And the time to do that is when you detect a kick on > an eventfd, not when said fd is set. >
Probably not. What if guest is only doing receiving? In this case, you won't detect any kick if you don't send the rarp first.
