From 22a6840ff282727df3e3c745d92d764c7081f49b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= Date: Thu, 20 Oct 2022 17:52:50 +0200 Subject: [PATCH] vhost: use avail event idx on vhost_svq_kick MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit So SVQ code knows if an event is needed. The code is not reachable at the moment. Reviewed-by: Michael S. Tsirkin Signed-off-by: Eugenio Pérez Signed-off-by: Jason Wang --- hw/virtio/vhost-shadow-virtqueue.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index f5c0fad3fc..f306ebef72 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -218,12 +218,22 @@ static bool vhost_svq_add_split(VhostShadowVirtqueue *svq, static void vhost_svq_kick(VhostShadowVirtqueue *svq) { + bool needs_kick; + /* * We need to expose the available array entries before checking the used * flags */ smp_mb(); - if (svq->vring.used->flags & VRING_USED_F_NO_NOTIFY) { + + if (virtio_vdev_has_feature(svq->vdev, VIRTIO_RING_F_EVENT_IDX)) { + uint16_t avail_event = *(uint16_t *)(&svq->vring.used->ring[svq->vring.num]); + needs_kick = vring_need_event(avail_event, svq->shadow_avail_idx, svq->shadow_avail_idx - 1); + } else { + needs_kick = !(svq->vring.used->flags & VRING_USED_F_NO_NOTIFY); + } + + if (!needs_kick) { return; }