[RFC PATCH v2 1/3] net: add ability to hide (disable) vhost_net

[Yuri Benditovich <yuri.benditovich@daynix.com>]

If 'vhost_net_disabled' in the NetClientState of the
net device, get_vhost_net for TAP returns NULL. Network adapters
can use this ability to hide the vhost_net temporary between
resets in case some active features contradict with vhost.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
---
 hw/net/vhost_net.c | 4 +++-
 include/net/net.h  | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 24d555e764..6660efd9ea 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -436,7 +436,9 @@ VHostNetState *get_vhost_net(NetClientState *nc)
 
     switch (nc->info->type) {
     case NET_CLIENT_DRIVER_TAP:
-        vhost_net = tap_get_vhost_net(nc);
+        if (!nc->vhost_net_disabled) {
+            vhost_net = tap_get_vhost_net(nc);
+        }
         break;
 #ifdef CONFIG_VHOST_NET_USER
     case NET_CLIENT_DRIVER_VHOST_USER:
diff --git a/include/net/net.h b/include/net/net.h
index a02949f6db..a938211524 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -103,6 +103,7 @@ struct NetClientState {
     int vring_enable;
     int vnet_hdr_len;
     bool is_netdev;
+    bool vhost_net_disabled;
     QTAILQ_HEAD(, NetFilterState) filters;
 };
 
-- 
2.26.2