[RFC v2 3/9] virtio_net: introduce vhost_set_state

[Cindy Lu <lulu@redhat.com>]

Introduce a function to set the state to the vhost driver.
vDPA need to sync the driver's state to NIC

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 hw/net/vhost_net.c                | 9 +++++++++
 hw/net/virtio-net.c               | 9 +++++++++
 include/hw/virtio/vhost-backend.h | 2 ++
 include/net/vhost_net.h           | 2 +-
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index d1d421e3d9..63b2a85d6e 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -465,3 +465,12 @@ int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
 
     return vhost_ops->vhost_net_set_mtu(&net->dev, mtu);
 }
+int vhost_set_state(NetClientState *nc, uint8_t state)
+{
+    struct vhost_net *net = get_vhost_net(nc);
+    struct vhost_dev *hdev = &net->dev;
+        if (hdev->vhost_ops->vhost_set_state) {
+                return hdev->vhost_ops->vhost_set_state(hdev, state);
+        }
+    return 0;
+}
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index db3d7c38e6..1bddb4b4af 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -206,6 +206,9 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
     NetClientState *nc = qemu_get_queue(n->nic);
     int queues = n->multiqueue ? n->max_queues : 1;
+    NetClientState *peer = qemu_get_peer(nc, 0);
+    uint8_t status_set  = vdev->status ;
+    uint8_t vhost_started_pre = n->vhost_started;
 
     if (!get_vhost_net(nc->peer)) {
         return;
@@ -245,6 +248,7 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
                 return;
             }
         }
+        status_set = status_set | VIRTIO_CONFIG_S_DRIVER_OK;
 
         n->vhost_started = 1;
         r = vhost_net_start(vdev, n->nic->ncs, queues);
@@ -252,11 +256,16 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
             error_report("unable to start vhost net: %d: "
                          "falling back on userspace virtio", -r);
             n->vhost_started = 0;
+            status_set = status_set & ~VIRTIO_CONFIG_S_DRIVER_OK;
         }
     } else {
         vhost_net_stop(vdev, n->nic->ncs, queues);
+        status_set = status_set & ~VIRTIO_CONFIG_S_DRIVER_OK;
         n->vhost_started = 0;
     }
+    if (vhost_started_pre != n->vhost_started) {
+            vhost_set_state(peer, status_set);
+    }
 }
 
 static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index 6f6670783f..f823055167 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -112,6 +112,7 @@ typedef int (*vhost_get_inflight_fd_op)(struct vhost_dev *dev,
 typedef int (*vhost_set_inflight_fd_op)(struct vhost_dev *dev,
                                         struct vhost_inflight *inflight);
 
+typedef int (*vhost_set_state_op)(struct vhost_dev *dev, uint8_t state);
 typedef struct VhostOps {
     VhostBackendType backend_type;
     vhost_backend_init vhost_backend_init;
@@ -152,6 +153,7 @@ typedef struct VhostOps {
     vhost_backend_mem_section_filter_op vhost_backend_mem_section_filter;
     vhost_get_inflight_fd_op vhost_get_inflight_fd;
     vhost_set_inflight_fd_op vhost_set_inflight_fd;
+    vhost_set_state_op vhost_set_state;
 } VhostOps;
 
 extern const VhostOps user_ops;
diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index 77e47398c4..6548a5a105 100644
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -39,5 +39,5 @@ int vhost_set_vring_enable(NetClientState * nc, int enable);
 uint64_t vhost_net_get_acked_features(VHostNetState *net);
 
 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu);
-
+int vhost_set_state(NetClientState *nc, uint8_t state);
 #endif
-- 
2.21.1