Re: [dpdk-dev] [PATCH v3 1/2] net/virtio: add vhost-user protocol features support

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

Hi Adrian,

> -----Original Message-----
> From: Adrian Moreno <amorenoz@redhat.com>
> Sent: Thursday, July 2, 2020 3:44 PM
> To: dev@dpdk.org
> Cc: Xia, Chenbo <chenbo.xia@intel.com>; Wang, Zhihong
> <zhihong.wang@intel.com>; Wang, Xiao W <xiao.w.wang@intel.com>; Yigit,
> Ferruh <ferruh.yigit@intel.com>; maxime.coquelin@redhat.com
> Subject: [PATCH v3 1/2] net/virtio: add vhost-user protocol features support
> 
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> 
> This patch adds support for Vhost-user protocol features.
> It is required to support protocol features that were not in
> initial Vhost-user specification, such as reply-ack, MTU...
> 
> Also, this patch prevents Virtio multiqueue feature negotiation
> if the slave does not support MQ protocol feature as stated
> in Vhost-user specification:
> "The multiple queues feature is supported only when the protocol
> feature ``VHOST_USER_PROTOCOL_F_MQ`` (bit 0) is set."
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_user/vhost.h        |  9 +++++
>  drivers/net/virtio/virtio_user/vhost_user.c   |  5 +++
>  .../net/virtio/virtio_user/virtio_user_dev.c  | 39 ++++++++++++++++++-
>  .../net/virtio/virtio_user/virtio_user_dev.h  |  3 ++
>  drivers/net/virtio/virtio_user_ethdev.c       | 19 +++++++++
>  5 files changed, 73 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/vhost.h
> b/drivers/net/virtio/virtio_user/vhost.h
> index 1e784e58e..9ace1a90c 100644
> --- a/drivers/net/virtio/virtio_user/vhost.h
> +++ b/drivers/net/virtio/virtio_user/vhost.h
> @@ -44,6 +44,15 @@ struct vhost_vring_addr {
>  	uint64_t log_guest_addr;
>  };

[snip]

> @@ -446,6 +455,10 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char
> *path, int queues,
>  		return -1;
>  	}
> 
> +	if (!is_vhost_user_by_type(dev->path))
> +		dev->unsupported_features |=
> +			(1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
> +
>  	if (!dev->is_server) {
>  		if (dev->ops->send_request(dev, VHOST_USER_SET_OWNER,
>  					   NULL) < 0) {
> @@ -460,6 +473,26 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char
> *path, int queues,
>  				     strerror(errno));
>  			return -1;
>  		}
> +
> +
> +		if (dev->device_features &
> +				(1ULL <<
> VHOST_USER_F_PROTOCOL_FEATURES)) {
> +			if (dev->ops->send_request(dev,
> +
> 	VHOST_USER_GET_PROTOCOL_FEATURES,
> +					&protocol_features))
> +				return -1;
> +
> +			dev->protocol_features &= protocol_features;
> +
> +			if (dev->ops->send_request(dev,
> +
> 	VHOST_USER_SET_PROTOCOL_FEATURES,
> +						&dev->protocol_features))
> +				return -1;
> +
> +			if (!(dev->protocol_features &
> +						(1ULL <<
> VHOST_USER_PROTOCOL_F_MQ)))
> +				dev->unsupported_features |= (1ull <<
> VIRTIO_NET_F_MQ);
> +		}
>  	} else {
>  		/* We just pretend vhost-user can support all these features.
>  		 * Note that this could be problematic that if some feature is
> @@ -469,6 +502,8 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char
> *path, int queues,
>  		dev->device_features = VIRTIO_USER_SUPPORTED_FEATURES;
>  	}
> 
> +
> +
>  	if (!mrg_rxbuf)
>  		dev->unsupported_features |= (1ull <<
> VIRTIO_NET_F_MRG_RXBUF);
> 
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> index 3b6b6065a..56e638f8a 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> @@ -40,6 +40,9 @@ struct virtio_user_dev {
>  	uint64_t	device_features; /* supported features by device */
>  	uint64_t	frontend_features; /* enabled frontend features */
>  	uint64_t	unsupported_features; /* unsupported features mask
> */
> +	uint64_t	protocol_features; /* negotiated protocol features
> +					    * (Vhost-user only)
> +					    */
>  	uint8_t		status;
>  	uint16_t	port_id;
>  	uint8_t		mac_addr[RTE_ETHER_ADDR_LEN];
> diff --git a/drivers/net/virtio/virtio_user_ethdev.c
> b/drivers/net/virtio/virtio_user_ethdev.c
> index 798f191c3..ccb5a18e2 100644
> --- a/drivers/net/virtio/virtio_user_ethdev.c
> +++ b/drivers/net/virtio/virtio_user_ethdev.c
> @@ -68,6 +68,7 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
>  	int connectfd;
>  	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
>  	struct virtio_hw *hw = eth_dev->data->dev_private;
> +	uint64_t protocol_features;
> 
>  	connectfd = accept(dev->listenfd, NULL, NULL);
>  	if (connectfd < 0)
> @@ -81,6 +82,24 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
>  		return -1;
>  	}
> 
> +	if (dev->device_features &
> +			(1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) {
> +		if (dev->ops->send_request(dev,
> +
> 	VHOST_USER_GET_PROTOCOL_FEATURES,
> +					&protocol_features))
> +			return -1;
> +
> +		dev->protocol_features &= protocol_features;
> +
> +		if (dev->ops->send_request(dev,
> +
> 	VHOST_USER_SET_PROTOCOL_FEATURES,
> +					&dev->protocol_features))
> +			return -1;
> +	}
> +
> +	if (!(dev->protocol_features & (1ULL <<
> VHOST_USER_PROTOCOL_F_MQ)))
> +		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MQ);
> +

Should this 'if' be put into above '{}' ? This should be under the condition that
VHOST_USER_F_PROTOCOL_FEATURES is supported, right?  Like the code
change in 'virtio_user_dev_init'.

Thanks,
Chenbo

>  	dev->device_features |= dev->frontend_features;
> 
>  	/* umask vhost-user unsupported features */
> --
> 2.26.2