[PATCH v2 4/4] virtio-net: block migration if RSS feature negotiated

[Yuri Benditovich]

Block migration for reference implementation of
RSS feature in QEMU. When we add support for RSS
on backend side, we'll implement migration of
current RSS settings.

Signed-off-by: Yuri Benditovich <address@hidden>
---
 hw/net/virtio-net.c            | 18 ++++++++++++++++++
 include/hw/virtio/virtio-net.h |  1 +
 2 files changed, 19 insertions(+)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index abc41fdb16..943d1931a2 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -37,6 +37,7 @@
 #include "qapi/qapi-events-migration.h"
 #include "hw/virtio/virtio-access.h"
 #include "migration/misc.h"
+#include "migration/blocker.h"
 #include "standard-headers/linux/ethtool.h"
 #include "sysemu/sysemu.h"
 #include "trace.h"
@@ -627,6 +628,12 @@ static void virtio_net_reset(VirtIODevice *vdev)
     n->announce_timer.round = 0;
     n->status &= ~VIRTIO_NET_S_ANNOUNCE;
 
+    if (n->migration_blocker) {
+        migrate_del_blocker(n->migration_blocker);
+        error_free(n->migration_blocker);
+        n->migration_blocker = NULL;
+    }
+
     /* Flush any MAC and VLAN filter table state */
     n->mac_table.in_use = 0;
     n->mac_table.first_multi = 0;
@@ -1003,6 +1010,17 @@ static void virtio_net_set_features(VirtIODevice *vdev, 
uint64_t features)
         vhost_net_ack_features(get_vhost_net(nc->peer), features);
     }
 
+    if (virtio_has_feature(features, VIRTIO_NET_F_RSS)) {
+        if (!n->migration_blocker) {
+            error_setg(&n->migration_blocker, "virtio-net: RSS negotiated");
+            migrate_add_blocker(n->migration_blocker, &err);
+            if (err) {
+                error_report_err(err);
+                err = NULL;
+            }
+        }
+    }
+
     if (virtio_has_feature(features, VIRTIO_NET_F_CTRL_VLAN)) {
         memset(n->vlans, 0, MAX_VLAN >> 3);
     } else {
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index 45670dd054..fba768ba9b 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -180,6 +180,7 @@ struct VirtIONet {
     virtio_net_conf net_conf;
     NICConf nic_conf;
     DeviceState *qdev;
+    Error *migration_blocker;
     int multiqueue;
     uint16_t max_queues;
     uint16_t curr_queues;
-- 
2.17.1