net/virtio-user: fix status management

[ upstream commit d0131e4 ]

Apart from the virtio status, there should be also a network related
status for link status management, current implementation mixes up these
two statuses.

One issue caused by this mixup is when virtio-user running in server mode
and vhost as a client connects to it, a RARP packet will be generated by
virtio-user due to VIRTIO_NET_S_ANNOUNCE bit is detected in the "status"
in interrupt handler.

VIRTIO_NET_S_LINK_UP and VIRTIO_NET_S_ANNOUNCE should be managed by a
separated field. This patch adds a "net_status" field for this purpose.

Fixes: e9efa4d ("net/virtio-user: add new virtual PCI driver")

Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

drivers/net/virtio/virtio_user/virtio_user_dev.h

@@ -36,6 +36,7 @@ struct virtio_user_dev {
 	uint64_t	frontend_features; /* enabled frontend features */
 	uint64_t	unsupported_features; /* unsupported features mask */
 	uint8_t		status;
+	uint16_t	net_status;
 	uint16_t	port_id;
 	uint8_t		mac_addr[ETHER_ADDR_LEN];
 	char		path[PATH_MAX];

drivers/net/virtio/virtio_user_ethdev.c

@@ -139,7 +139,7 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t offset,
 			}
 			r = recv(dev->vhostfd, buf, 128, MSG_PEEK);
 			if (r == 0 || (r < 0 && errno != EAGAIN)) {
-				dev->status &= (~VIRTIO_NET_S_LINK_UP);
+				dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
 				PMD_DRV_LOG(ERR, "virtio-user port %u is down",
 					    hw->port_id);
 
@@ -151,20 +151,20 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t offset,
 						  virtio_user_delayed_handler,
 						  (void *)hw);
 			} else {
-				dev->status |= VIRTIO_NET_S_LINK_UP;
+				dev->net_status |= VIRTIO_NET_S_LINK_UP;
 			}
 			if (fcntl(dev->vhostfd, F_SETFL,
 					flags & ~O_NONBLOCK) == -1) {
 				PMD_DRV_LOG(ERR, "error clearing O_NONBLOCK flag");
 				return;
 			}
 		} else if (dev->is_server) {
-			dev->status &= (~VIRTIO_NET_S_LINK_UP);
+			dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
 			if (virtio_user_server_reconnect(dev) >= 0)
-				dev->status |= VIRTIO_NET_S_LINK_UP;
+				dev->net_status |= VIRTIO_NET_S_LINK_UP;
 		}
 
-		*(uint16_t *)dst = dev->status;
+		*(uint16_t *)dst = dev->net_status;
 	}
 
 	if (offset == offsetof(struct virtio_net_config, max_virtqueue_pairs))