[PATCH v3 4/6] vdpa: add NetClientState->start() callback

["Eugenio Pérez" <eperezma@redhat.com>]

It allows per-net client operations right after device's successful
start.

Vhost-vdpa net will use it to add the CVQ buffers to restore the device
status.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 include/net/net.h  | 2 ++
 hw/net/vhost_net.c | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/include/net/net.h b/include/net/net.h
index 523136c7ac..ad9e80083a 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -44,6 +44,7 @@ typedef struct NICConf {
 
 typedef void (NetPoll)(NetClientState *, bool enable);
 typedef bool (NetCanReceive)(NetClientState *);
+typedef int (NetStart)(NetClientState *);
 typedef ssize_t (NetReceive)(NetClientState *, const uint8_t *, size_t);
 typedef ssize_t (NetReceiveIOV)(NetClientState *, const struct iovec *, int);
 typedef void (NetCleanup) (NetClientState *);
@@ -71,6 +72,7 @@ typedef struct NetClientInfo {
     NetReceive *receive_raw;
     NetReceiveIOV *receive_iov;
     NetCanReceive *can_receive;
+    NetStart *start;
     NetCleanup *cleanup;
     LinkStatusChanged *link_status_changed;
     QueryRxFilter *query_rx_filter;
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index ccac5b7a64..ddd9ee0441 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -274,6 +274,13 @@ static int vhost_net_start_one(struct vhost_net *net,
             }
         }
     }
+
+    if (net->nc->info->start) {
+        r = net->nc->info->start(net->nc);
+        if (r < 0) {
+            goto fail;
+        }
+    }
     return 0;
 fail:
     file.fd = -1;
-- 
2.31.1