Re: [dpdk-dev] [PATCH v3 43/44] net/virtio: improve Vhost-user error logging

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

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Tuesday, January 26, 2021 1:15 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; olivier.matz@6wind.com;
> amorenoz@redhat.com; david.marchand@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v3 43/44] net/virtio: improve Vhost-user error logging
> 
> This patch improves error logging in vhost_user_read,
> especially printing errno when recv() fails.
> 
> Suggested-by: Adrian Moreno <amorenoz@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_user/vhost_user.c | 31 ++++++++++++---------
>  1 file changed, 18 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/vhost_user.c
> b/drivers/net/virtio/virtio_user/vhost_user.c
> index 088aae3aa3..ec2c53c8fb 100644
> --- a/drivers/net/virtio/virtio_user/vhost_user.c
> +++ b/drivers/net/virtio/virtio_user/vhost_user.c
> @@ -148,38 +148,43 @@ vhost_user_read(int fd, struct vhost_user_msg *msg)
>  	int ret, sz_hdr = VHOST_USER_HDR_SIZE, sz_payload;
> 
>  	ret = recv(fd, (void *)msg, sz_hdr, 0);
> -	if (ret < sz_hdr) {
> +	if (ret < 0) {
> +		PMD_DRV_LOG(ERR, "Failed to recv msg header: %s", strerror(errno));
> +		return -1;
> +	} else if (ret < sz_hdr) {
>  		PMD_DRV_LOG(ERR, "Failed to recv msg hdr: %d instead of %d.",
>  			    ret, sz_hdr);
> -		goto fail;
> +		return -1;
>  	}
> 
>  	/* validate msg flags */
>  	if (msg->flags != (valid_flags)) {
> -		PMD_DRV_LOG(ERR, "Failed to recv msg: flags %x instead of %x.",
> +		PMD_DRV_LOG(ERR, "Failed to recv msg: flags 0x%x instead of 0x%x.",
>  			    msg->flags, valid_flags);
> -		goto fail;
> +		return -1;
>  	}
> 
>  	sz_payload = msg->size;
> 
> -	if ((size_t)sz_payload > sizeof(msg->payload))
> -		goto fail;
> +	if ((size_t)sz_payload > sizeof(msg->payload)) {
> +		PMD_DRV_LOG(ERR, "Payload size overflow, header says %d but
> max %zu\n",
> +				sz_payload, sizeof(msg->payload));
> +		return -1;
> +	}
> 
>  	if (sz_payload) {
>  		ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
> -		if (ret < sz_payload) {
> -			PMD_DRV_LOG(ERR,
> -				"Failed to recv msg payload: %d instead of %d.",
> +		if (ret < 0) {
> +			PMD_DRV_LOG(ERR, "Failed to recv msg payload: %s",
> strerror(errno));
> +			return -1;
> +		} else if (ret < sz_payload) {
> +			PMD_DRV_LOG(ERR, "Failed to recv msg payload: %d instead
> of %u.",
>  				ret, msg->size);
> -			goto fail;
> +			return -1;
>  		}
>  	}
> 
>  	return 0;
> -
> -fail:
> -	return -1;
>  }
> 
>  static int
> --
> 2.29.2

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