Re: [dpdk-stable] [PATCH] net/virtio-user: fix virtio net status management

["Xia, Chenbo" <chenbo.xia@intel.com>]

> -----Original Message-----
> From: Wang, Xiao W <xiao.w.wang@intel.com>
> Sent: Tuesday, July 28, 2020 2:52 PM
> To: maxime.coquelin@redhat.com
> Cc: dev@dpdk.org; Wang, Zhihong <zhihong.wang@intel.com>; Xia, Chenbo
> <chenbo.xia@intel.com>; Wang, Xiao W <xiao.w.wang@intel.com>;
> stable@dpdk.org
> Subject: [PATCH] net/virtio-user: fix virtio net status management
> 
> 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: e9efa4d93821 ("net/virtio-user: add new virtual PCI driver")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
> ---
>  drivers/net/virtio/virtio_user/virtio_user_dev.h |  1 +
>  drivers/net/virtio/virtio_user_ethdev.c          | 10 +++++-----
>  2 files changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> index 56e638f8a..554174e81 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> @@ -44,6 +44,7 @@ struct virtio_user_dev {
>  					    * (Vhost-user only)
>  					    */
>  	uint8_t		status;
> +	uint16_t	net_status;
>  	uint16_t	port_id;
>  	uint8_t		mac_addr[RTE_ETHER_ADDR_LEN];
>  	char		path[PATH_MAX];
> diff --git a/drivers/net/virtio/virtio_user_ethdev.c
> b/drivers/net/virtio/virtio_user_ethdev.c
> index e51425c4f..6003f6d50 100644
> --- a/drivers/net/virtio/virtio_user_ethdev.c
> +++ b/drivers/net/virtio/virtio_user_ethdev.c
> @@ -205,7 +205,7 @@ 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);
> 
> @@ -217,7 +217,7 @@ 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) {
> @@ -225,12 +225,12 @@ virtio_user_read_dev_config(struct virtio_hw *hw,
> size_t offset,
>  				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))
> --
> 2.15.1

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>