[dpdk-dev] [PATCH 2/3] net/virtio: add reply-ack support to Virtio-user

[Xia, Chenbo]

Hi Maxime,

> -----Original Message-----
> From: dev <dev-bounces at dpdk.org> On Behalf Of Maxime Coquelin
> Sent: Thursday, May 28, 2020 3:46 PM
> To: dev at dpdk.org; amorenoz at redhat.com; Ye, Xiaolong
> <xiaolong.ye at intel.com>; shahafs at mellanox.com; matan at mellanox.com
> Cc: Maxime Coquelin <maxime.coquelin at redhat.com>
> Subject: [dpdk-dev] [PATCH 2/3] net/virtio: add reply-ack support to Virtio-user
> 
> This patch adds support reply-ack vhost-user protocol feature, which is for now
> only used to ensure VHOST_USER_SET_MEM_TABLE requests are handled by the
> slave, but later will be used for VHOST_USER_SET_STATUS.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
> ---
>  drivers/net/virtio/virtio_user/vhost.h        |  6 ++++-
>  drivers/net/virtio/virtio_user/vhost_user.c   | 24 ++++++++++++++++---
>  .../net/virtio/virtio_user/virtio_user_dev.c  |  3 ++-
>  3 files changed, 28 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/vhost.h
> b/drivers/net/virtio/virtio_user/vhost.h
> index 9ace1a90c3..260e1c3081 100644
> --- a/drivers/net/virtio/virtio_user/vhost.h
> +++ b/drivers/net/virtio/virtio_user/vhost.h
> @@ -50,7 +50,11 @@ struct vhost_vring_addr {
> 
>  /** Protocol features. */
>  #ifndef VHOST_USER_PROTOCOL_F_MQ
> -#define VHOST_USER_PROTOCOL_F_MQ	0
> +#define VHOST_USER_PROTOCOL_F_MQ 0
> +#endif
> +
> +#ifndef VHOST_USER_PROTOCOL_F_REPLY_ACK #define
> +VHOST_USER_PROTOCOL_F_REPLY_ACK 3
>  #endif
> 
>  enum vhost_user_request {
> diff --git a/drivers/net/virtio/virtio_user/vhost_user.c
> b/drivers/net/virtio/virtio_user/vhost_user.c
> index b687665042..f8d751c98e 100644
> --- a/drivers/net/virtio/virtio_user/vhost_user.c
> +++ b/drivers/net/virtio/virtio_user/vhost_user.c
> @@ -32,6 +32,7 @@ struct vhost_user_msg {
> 
>  #define VHOST_USER_VERSION_MASK     0x3
>  #define VHOST_USER_REPLY_MASK       (0x1 << 2)
> +#define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)
>  	uint32_t flags;
>  	uint32_t size; /* the following payload size */
>  	union {
> @@ -251,6 +252,7 @@ vhost_user_sock(struct virtio_user_dev *dev,
>  	struct vhost_user_msg msg;
>  	struct vhost_vring_file *file = 0;
>  	int need_reply = 0;
> +	int has_reply_ack;
>  	int fds[VHOST_MEMORY_MAX_NREGIONS];
>  	int fd_num = 0;
>  	int len;
> @@ -263,6 +265,9 @@ vhost_user_sock(struct virtio_user_dev *dev,
>  	if (dev->is_server && vhostfd < 0)
>  		return -1;
> 
> +	if (dev->protocol_features & (1ULL <<
> VHOST_USER_PROTOCOL_F_REPLY_ACK))
> +		has_reply_ack = 1;
> +
>  	msg.request = req;
>  	msg.flags = VHOST_USER_VERSION;
>  	msg.size = 0;
> @@ -291,6 +296,9 @@ vhost_user_sock(struct virtio_user_dev *dev,
>  		msg.size = sizeof(m.payload.memory.nregions);
>  		msg.size += sizeof(m.payload.memory.padding);
>  		msg.size += fd_num * sizeof(struct vhost_memory_region);
> +
> +		if (has_reply_ack)
> +			msg.flags |= VHOST_USER_NEED_REPLY_MASK;

Do we have counterpart in vhost-user to handle such case as VHOST_USER_SET_MEM_TABLE may have
a need-reply mask? Do I miss something?

Thanks,
Chenbo

>  		break;
> 
>  	case VHOST_USER_SET_LOG_FD:
> @@ -339,7 +347,7 @@ vhost_user_sock(struct virtio_user_dev *dev,
>  		return -1;
>  	}
> 
> -	if (need_reply) {
> +	if (need_reply || msg.flags & VHOST_USER_NEED_REPLY_MASK) {
>  		if (vhost_user_read(vhostfd, &msg) < 0) {
>  			PMD_DRV_LOG(ERR, "Received msg failed: %s",
>  				    strerror(errno));
> @@ -369,8 +377,18 @@ vhost_user_sock(struct virtio_user_dev *dev,
>  			       sizeof(struct vhost_vring_state));
>  			break;
>  		default:
> -			PMD_DRV_LOG(ERR, "Received unexpected msg type");
> -			return -1;
> +			/* Reply-ack handling */
> +			if (msg.size != sizeof(m.payload.u64)) {
> +				PMD_DRV_LOG(ERR, "Received bad msg size");
> +				return -1;
> +			}
> +
> +			if (msg.payload.u64 != 0) {
> +				PMD_DRV_LOG(ERR, "Slave replied NACK");
> +				return -1;
> +			}
> +
> +			break;
>  		}
>  	}
> 
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index 3afb09df2d..ea22af5dc4 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -423,7 +423,8 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
>  	 1ULL << VHOST_USER_F_PROTOCOL_FEATURES)
> 
>  #define VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES		\
> -	(1ULL << VHOST_USER_PROTOCOL_F_MQ)
> +	(1ULL << VHOST_USER_PROTOCOL_F_MQ |		\
> +	 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK)
> 
>  int
>  virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
> --
> 2.26.2