virtio/ringtest: fix up need_event math

last kicked event index must be updated unconditionally:
even if we don't need to kick, we do not want to re-check
the same entry for events.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2017-10-26 04:48:01 +03:00
parent 31919140ff
commit f229a55c31

View file

@ -188,16 +188,18 @@ bool enable_call()
void kick_available(void)
{
bool need;
/* Flush in previous flags write */
/* Barrier C (for pairing) */
smp_mb();
if (!need_event(event->kick_index,
guest.avail_idx,
guest.kicked_avail_idx))
return;
need = need_event(event->kick_index,
guest.avail_idx,
guest.kicked_avail_idx);
guest.kicked_avail_idx = guest.avail_idx;
kick();
if (need)
kick();
}
/* host side */
@ -253,14 +255,18 @@ bool use_buf(unsigned *lenp, void **bufp)
void call_used(void)
{
bool need;
/* Flush in previous flags write */
/* Barrier D (for pairing) */
smp_mb();
if (!need_event(event->call_index,
need = need_event(event->call_index,
host.used_idx,
host.called_used_idx))
return;
host.called_used_idx);
host.called_used_idx = host.used_idx;
call();
if (need)
call();
}