Merge remote-tracking branch 'remotes/jasowang/tags/net-pull-request' into staging

Want to send earlier but most patches just come.

- fix vhost-vdpa issues when no peer
- fix virtio-pci queue enabling index value
- forbid reentrant RX

Changes from V1:

- drop the patch that has been merged

# gpg: Signature made Tue 28 Jul 2020 09:59:41 BST
# gpg:                using RSA key EF04965B398D6211
# gpg: Good signature from "Jason Wang (Jason Wang on RedHat) <jasowang@redhat.com>" [marginal]
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 215D 46F4 8246 689E C77F  3562 EF04 965B 398D 6211

* remotes/jasowang/tags/net-pull-request:
  net: forbid the reentrant RX
  virtio-net: check the existence of peer before accessing vDPA config
  virtio-pci: fix wrong index in virtio_pci_queue_enabled
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/net/virtio-net.c

@@ -125,6 +125,7 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
 {
     VirtIONet *n = VIRTIO_NET(vdev);
     struct virtio_net_config netcfg;
+    NetClientState *nc = qemu_get_queue(n->nic);
 
     int ret = 0;
     memset(&netcfg, 0 , sizeof(struct virtio_net_config));
@@ -142,13 +143,16 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
                  VIRTIO_NET_RSS_SUPPORTED_HASHES);
     memcpy(config, &netcfg, n->config_size);
 
-    NetClientState *nc = qemu_get_queue(n->nic);
-    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+    /*
+     * Is this VDPA? No peer means not VDPA: there's no way to
+     * disconnect/reconnect a VDPA peer.
+     */
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
         ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
-                             n->config_size);
-    if (ret != -1) {
-        memcpy(config, &netcfg, n->config_size);
-    }
+                                   n->config_size);
+        if (ret != -1) {
+            memcpy(config, &netcfg, n->config_size);
+        }
     }
 }
 
@@ -156,6 +160,7 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
 {
     VirtIONet *n = VIRTIO_NET(vdev);
     struct virtio_net_config netcfg = {};
+    NetClientState *nc = qemu_get_queue(n->nic);
 
     memcpy(&netcfg, config, n->config_size);
 
@@ -166,11 +171,14 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
     }
 
-    NetClientState *nc = qemu_get_queue(n->nic);
-    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
-        vhost_net_set_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
-                               0, n->config_size,
-                        VHOST_SET_CONFIG_TYPE_MASTER);
+    /*
+     * Is this VDPA? No peer means not VDPA: there's no way to
+     * disconnect/reconnect a VDPA peer.
+     */
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        vhost_net_set_config(get_vhost_net(nc->peer),
+                             (uint8_t *)&netcfg, 0, n->config_size,
+                             VHOST_SET_CONFIG_TYPE_MASTER);
       }
 }
 

hw/virtio/virtio-pci.c

@@ -1113,7 +1113,7 @@ static bool virtio_pci_queue_enabled(DeviceState *d, int n)
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
     if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
-        return proxy->vqs[vdev->queue_sel].enabled;
+        return proxy->vqs[n].enabled;
     }
 
     return virtio_queue_enabled_legacy(vdev, n);

net/queue.c

@@ -250,6 +250,9 @@ void qemu_net_queue_purge(NetQueue *queue, NetClientState *from)
 
 bool qemu_net_queue_flush(NetQueue *queue)
 {
+    if (queue->delivering)
+        return false;
+
     while (!QTAILQ_EMPTY(&queue->packets)) {
         NetPacket *packet;
         int ret;