[Qemu-devel] [PATCH-RFC 13/13] virtio-net: connect to vhost net backend

[Michael S. Tsirkin]

start/stop backend on driver start/stop

Signed-off-by: Michael S. Tsirkin <address@hidden>
---
 hw/virtio-net.c |   40 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 40 insertions(+), 0 deletions(-)

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index c2a389f..99169e1 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -17,6 +17,7 @@
 #include "net/tap.h"
 #include "qemu-timer.h"
 #include "virtio-net.h"
+#include "vhost_net.h"
 
 #define VIRTIO_NET_VM_VERSION    11
 
@@ -47,6 +48,7 @@ typedef struct VirtIONet
     uint8_t nomulti;
     uint8_t nouni;
     uint8_t nobcast;
+    uint8_t vhost_started;
     struct {
         int in_use;
         int first_multi;
@@ -114,6 +116,10 @@ static void virtio_net_reset(VirtIODevice *vdev)
     n->nomulti = 0;
     n->nouni = 0;
     n->nobcast = 0;
+    if (n->vhost_started) {
+        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
+        n->vhost_started = 0;
+    }
 
     /* Flush any MAC and VLAN filter table state */
     n->mac_table.in_use = 0;
@@ -820,6 +826,36 @@ static NetClientInfo net_virtio_info = {
     .link_status_changed = virtio_net_set_link_status,
 };
 
+static void virtio_net_set_status(struct VirtIODevice *vdev)
+{
+    VirtIONet *n = to_virtio_net(vdev);
+    if (!n->nic->nc.peer) {
+        return;
+    }
+    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
+        return;
+    }
+
+    if (!tap_get_vhost_net(n->nic->nc.peer)) {
+        return;
+    }
+    if (!!n->vhost_started == !!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+        return;
+    }
+    if (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) {
+        int r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), vdev);
+        if (r < 0) {
+            fprintf(stderr, "unable to start vhost net: "
+                    "falling back on userspace virtio\n");
+        } else {
+            n->vhost_started = 1;
+        }
+    } else {
+        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
+        n->vhost_started = 0;
+    }
+}
+
 VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)
 {
     VirtIONet *n;
@@ -835,6 +871,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf 
*conf)
     n->vdev.set_features = virtio_net_set_features;
     n->vdev.bad_features = virtio_net_bad_features;
     n->vdev.reset = virtio_net_reset;
+    n->vdev.set_status = virtio_net_set_status;
     n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
     n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
     n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
@@ -864,6 +901,9 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf 
*conf)
 void virtio_net_exit(VirtIODevice *vdev)
 {
     VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
+    if (n->vhost_started) {
+        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
+    }
 
     qemu_purge_queued_packets(&n->nic->nc);
 
-- 
1.6.6.rc1.43.gf55cc