vhost: fix dequeue zero copy with virtio1

This fix dequeue zero copy can not work with Qemu
version >= 2.7. Since from Qemu 2.7 virtio device
use virtio-1 protocol, the zero copy code path
forget to add offset to buffer address.

Fixes: b0a985d1f340 ("vhost: add dequeue zero copy")
Cc: stable@dpdk.org
Signed-off-by: Junjie Chen <junjie.j.chen@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Yuanhan Liu <yliu@fridaylinux.org>

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 2227ced..38796b3 100644 (file)
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -948,7 +948,8 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
                                        desc->addr + desc_offset, cpy_len)))) {
                        cur->data_len = cpy_len;
                        cur->data_off = 0;
-                       cur->buf_addr = (void *)(uintptr_t)desc_addr;
+                       cur->buf_addr = (void *)(uintptr_t)(desc_addr
+                               + desc_offset);
                        cur->buf_iova = hpa;
 
                        /*