vhost: multiqueue support

This patch lets vhost support multiqueue. The idea is simple, just launching
multiple threads of vhost and let each of vhost thread processing a subset of
the virtqueues of the device. After this change each emulated device can have
multiple vhost threads as its backend.

To do this, a virtqueue index were introduced to record to first virtqueue that
will be handled by this vhost_net device. Based on this and nvqs, vhost could
calculate its relative index to setup vhost_net device.

Since we may have many vhost/net devices for a virtio-net device. The setting of
guest notifiers were moved out of the starting/stopping of a specific vhost
thread. The vhost_net_{start|stop}() were renamed to
vhost_net_{start|stop}_one(), and a new vhost_net_{start|stop}() were introduced
to configure the guest notifiers and start/stop all vhost/vhost_net devices.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/hw/vhost_net.h b/hw/vhost_net.h
index 88912b85fd..2d936bb5f5 100644
--- a/hw/vhost_net.h
+++ b/hw/vhost_net.h
@@ -9,8 +9,8 @@ typedef struct vhost_net VHostNetState;
 VHostNetState *vhost_net_init(NetClientState *backend, int devfd, bool force);
 
 bool vhost_net_query(VHostNetState *net, VirtIODevice *dev);
-int vhost_net_start(VHostNetState *net, VirtIODevice *dev);
-void vhost_net_stop(VHostNetState *net, VirtIODevice *dev);
+int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, int total_queues);
+void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs, int total_queues);
 
 void vhost_net_cleanup(VHostNetState *net);