From: Balazs Nemeth Date: Fri, 14 May 2021 16:02:07 +0000 (+0200) Subject: vhost: fix stored last used index X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=3ad55b8e94caa33c55895600865fe7edf7cc8d53;p=dpdk.git vhost: fix stored last used index The optimization introduced by commit d18db8049c7c ("vhost: read last used index once") didn't account for the fact that vhost_flush_enqueue_shadow_packed increments the last_used_idx. For this reason, store last_used_idx after the potential call to vhost_flush_enqueue_shadow_packed. Bugzilla ID: 699 Fixes: d18db8049c7c ("vhost: read last used index once") Signed-off-by: Balazs Nemeth Reviewed-by: David Marchand Reviewed-by: Maxime Coquelin Tested-by: Wei Ling --- diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index abfd67d38c..8da8a86a10 100644 --- a/lib/vhost/virtio_net.c +++ b/lib/vhost/virtio_net.c @@ -218,14 +218,17 @@ vhost_flush_enqueue_batch_packed(struct virtio_net *dev, { uint16_t i; uint16_t flags; - uint16_t last_used_idx = vq->last_used_idx; - struct vring_packed_desc *desc_base = &vq->desc_packed[last_used_idx]; + uint16_t last_used_idx; + struct vring_packed_desc *desc_base; if (vq->shadow_used_idx) { do_data_copy_enqueue(dev, vq); vhost_flush_enqueue_shadow_packed(dev, vq); } + last_used_idx = vq->last_used_idx; + desc_base = &vq->desc_packed[last_used_idx]; + flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq->used_wrap_counter); vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {