[Qemu-devel] [PATCH v7 06/13] Refactor virtio-net to use a generic get_vhost_net

[Antonios Motakis <a.motakis@virtualopensystems.com>]

This decouples virtio-net from the TAP netdev backend and allows support
for other backends to be implemented.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
---
 hw/net/vhost_net.c      | 30 +++++++++++++++++++++++++++---
 hw/net/virtio-net.c     | 39 ++++++++++++++-------------------------
 include/net/vhost_net.h |  1 +
 3 files changed, 42 insertions(+), 28 deletions(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 6aa6e87..7ee904e 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -231,7 +231,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     }
 
     for (i = 0; i < total_queues; i++) {
-        r = vhost_net_start_one(tap_get_vhost_net(ncs[i].peer), dev, i * 2);
+        r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev, i * 2);
 
         if (r < 0) {
             goto err;
@@ -248,7 +248,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
 
 err:
     while (--i >= 0) {
-        vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
+        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
     }
     return r;
 }
@@ -269,7 +269,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
     assert(r >= 0);
 
     for (i = 0; i < total_queues; i++) {
-        vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
+        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
     }
 }
 
@@ -289,6 +289,25 @@ void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 {
     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 }
+
+VHostNetState *get_vhost_net(NetClientState *nc)
+{
+    VHostNetState *vhost_net = 0;
+
+    if (!nc) {
+        return 0;
+    }
+
+    switch (nc->info->type) {
+    case NET_CLIENT_OPTIONS_KIND_TAP:
+        vhost_net = tap_get_vhost_net(nc);
+        break;
+    default:
+        break;
+    }
+
+    return vhost_net;
+}
 #else
 struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
                                  bool force)
@@ -335,4 +354,9 @@ void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
                               int idx, bool mask)
 {
 }
+
+VHostNetState *get_vhost_net(NetClientState *nc)
+{
+    return 0;
+}
 #endif
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 3626608..72acd15 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -105,14 +105,7 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
     NetClientState *nc = qemu_get_queue(n->nic);
     int queues = n->multiqueue ? n->max_queues : 1;
 
-    if (!nc->peer) {
-        return;
-    }
-    if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
-        return;
-    }
-
-    if (!tap_get_vhost_net(nc->peer)) {
+    if (!get_vhost_net(nc->peer)) {
         return;
     }
 
@@ -122,7 +115,7 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
     }
     if (!n->vhost_started) {
         int r;
-        if (!vhost_net_query(tap_get_vhost_net(nc->peer), vdev)) {
+        if (!vhost_net_query(get_vhost_net(nc->peer), vdev)) {
             return;
         }
         n->vhost_started = 1;
@@ -325,11 +318,13 @@ static void peer_test_vnet_hdr(VirtIONet *n)
         return;
     }
 
-    if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
-        return;
+    switch (nc->peer->info->type) {
+    case NET_CLIENT_OPTIONS_KIND_TAP:
+        n->has_vnet_hdr = tap_has_vnet_hdr(nc->peer);
+        break;
+    default:
+        break;
     }
-
-    n->has_vnet_hdr = tap_has_vnet_hdr(nc->peer);
 }
 
 static int peer_has_vnet_hdr(VirtIONet *n)
@@ -437,13 +432,10 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
         features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
     }
 
-    if (!nc->peer || nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
+    if (!get_vhost_net(nc->peer)) {
         return features;
     }
-    if (!tap_get_vhost_net(nc->peer)) {
-        return features;
-    }
-    return vhost_net_get_features(tap_get_vhost_net(nc->peer), features);
+    return vhost_net_get_features(get_vhost_net(nc->peer), features);
 }
 
 static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
@@ -507,13 +499,10 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
     for (i = 0;  i < n->max_queues; i++) {
         NetClientState *nc = qemu_get_subqueue(n->nic, i);
 
-        if (!nc->peer || nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
-            continue;
-        }
-        if (!tap_get_vhost_net(nc->peer)) {
+        if (!get_vhost_net(nc->peer)) {
             continue;
         }
-        vhost_net_ack_features(tap_get_vhost_net(nc->peer), features);
+        vhost_net_ack_features(get_vhost_net(nc->peer), features);
     }
 }
 
@@ -1443,7 +1432,7 @@ static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
     assert(n->vhost_started);
-    return vhost_net_virtqueue_pending(tap_get_vhost_net(nc->peer), idx);
+    return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
 }
 
 static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
@@ -1452,7 +1441,7 @@ static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
     assert(n->vhost_started);
-    vhost_net_virtqueue_mask(tap_get_vhost_net(nc->peer),
+    vhost_net_virtqueue_mask(get_vhost_net(nc->peer),
                              vdev, idx, mask);
 }
 
diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index 2d936bb..e2bd61c 100644
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -20,4 +20,5 @@ void vhost_net_ack_features(VHostNetState *net, unsigned features);
 bool vhost_net_virtqueue_pending(VHostNetState *net, int n);
 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
                               int idx, bool mask);
+VHostNetState *get_vhost_net(NetClientState *nc);
 #endif
-- 
1.8.3.2