net: virtio-net and vmxnet3 use offloading API

With this patch, virtio-net and vmxnet3 frontends make
use of the qemu_peer_* API for backend offloadings manipulations,
instead of calling TAP-specific functions directly.
We also remove the existing checks which prevent those frontends
from using offloadings with backends different from TAP (e.g. netmap).
Signed-off-by: NVincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

hw/net/vhost_net.c

@@ -106,7 +106,7 @@ struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
         goto fail;
     }
     net->nc = backend;
-    net->dev.backend_features = tap_has_vnet_hdr(backend) ? 0 :
+    net->dev.backend_features = backend->info->has_vnet_hdr(backend) ? 0 :
         (1 << VHOST_NET_F_VIRTIO_NET_HDR);
     net->backend = r;
 
@@ -117,7 +117,7 @@ struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
     if (r < 0) {
         goto fail;
     }
-    if (!tap_has_vnet_hdr_len(backend,
+    if (!backend->info->has_vnet_hdr_len(backend,
                               sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
         net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
     }

hw/net/virtio-net.c

@@ -325,11 +325,7 @@ static void peer_test_vnet_hdr(VirtIONet *n)
         return;
     }
 
-    if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
-        return;
-    }
-
-    n->has_vnet_hdr = tap_has_vnet_hdr(nc->peer);
+    n->has_vnet_hdr = qemu_peer_has_vnet_hdr(nc);
 }
 
 static int peer_has_vnet_hdr(VirtIONet *n)
@@ -342,7 +338,7 @@ static int peer_has_ufo(VirtIONet *n)
     if (!peer_has_vnet_hdr(n))
         return 0;
 
-    n->has_ufo = tap_has_ufo(qemu_get_queue(n->nic)->peer);
+    n->has_ufo = qemu_peer_has_ufo(qemu_get_queue(n->nic));
 
     return n->has_ufo;
 }
@@ -361,8 +357,8 @@ static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs)
         nc = qemu_get_subqueue(n->nic, i);
 
         if (peer_has_vnet_hdr(n) &&
-            tap_has_vnet_hdr_len(nc->peer, n->guest_hdr_len)) {
-            tap_set_vnet_hdr_len(nc->peer, n->guest_hdr_len);
+            qemu_peer_has_vnet_hdr_len(nc, n->guest_hdr_len)) {
+            qemu_peer_set_vnet_hdr_len(nc, n->guest_hdr_len);
             n->host_hdr_len = n->guest_hdr_len;
         }
     }
@@ -463,7 +459,7 @@ static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
 
 static void virtio_net_apply_guest_offloads(VirtIONet *n)
 {
-    tap_set_offload(qemu_get_subqueue(n->nic, 0)->peer,
+    qemu_peer_set_offload(qemu_get_subqueue(n->nic, 0),
             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),
             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),
             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),
@@ -1544,7 +1540,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
     peer_test_vnet_hdr(n);
     if (peer_has_vnet_hdr(n)) {
         for (i = 0; i < n->max_queues; i++) {
-            tap_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
+            qemu_peer_using_vnet_hdr(qemu_get_subqueue(n->nic, i), true);
         }
         n->host_hdr_len = sizeof(struct virtio_net_hdr);
     } else {

hw/net/vmxnet3.c

@@ -1290,7 +1290,7 @@ static void vmxnet3_update_features(VMXNET3State *s)
               s->lro_supported, rxcso_supported,
               s->rx_vlan_stripping);
     if (s->peer_has_vhdr) {
-        tap_set_offload(qemu_get_queue(s->nic)->peer,
+        qemu_peer_set_offload(qemu_get_queue(s->nic),
                         rxcso_supported,
                         s->lro_supported,
                         s->lro_supported,
@@ -1883,11 +1883,9 @@ static NetClientInfo net_vmxnet3_info = {
 
 static bool vmxnet3_peer_has_vnet_hdr(VMXNET3State *s)
 {
-    NetClientState *peer = qemu_get_queue(s->nic)->peer;
+    NetClientState *nc = qemu_get_queue(s->nic);
 
-    if ((NULL != peer)                              &&
-        (peer->info->type == NET_CLIENT_OPTIONS_KIND_TAP)   &&
-        tap_has_vnet_hdr(peer)) {
+    if (qemu_peer_has_vnet_hdr(nc)) {
         return true;
     }
 
@@ -1935,10 +1933,10 @@ static void vmxnet3_net_init(VMXNET3State *s)
     s->lro_supported = false;
 
     if (s->peer_has_vhdr) {
-        tap_set_vnet_hdr_len(qemu_get_queue(s->nic)->peer,
+        qemu_peer_set_vnet_hdr_len(qemu_get_queue(s->nic),
             sizeof(struct virtio_net_hdr));
 
-        tap_using_vnet_hdr(qemu_get_queue(s->nic)->peer, 1);
+        qemu_peer_using_vnet_hdr(qemu_get_queue(s->nic), 1);
     }
 
     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);