Re: [dpdk-dev] [PATCH 6/9] vhost: add support for virtio status

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

Hi Maxime,

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Maxime Coquelin
> Sent: Thursday, May 14, 2020 4:02 PM
> To: Ye, Xiaolong <xiaolong.ye@intel.com>; shahafs@mellanox.com;
> matan@mellanox.com; amorenoz@redhat.com; Wang, Xiao W
> <xiao.w.wang@intel.com>; viacheslavo@mellanox.com; dev@dpdk.org
> Cc: jasowang@redhat.com; lulu@redhat.com; Maxime Coquelin
> <maxime.coquelin@redhat.com>
> Subject: [dpdk-dev] [PATCH 6/9] vhost: add support for virtio status
> 
> This patch adds support to the new Virtio device status Vhost-user protocol
> feature.
> 
> Getting such information in the backend helps to know when the driver is done
> with the device configuration and so makes the initialization phase more robust.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/librte_vhost/rte_vhost.h  |  4 ++++
>  lib/librte_vhost/vhost.h      |  9 ++++++++
>  lib/librte_vhost/vhost_user.c | 40 +++++++++++++++++++++++++++++++++++
>  lib/librte_vhost/vhost_user.h |  6 ++++--
>  4 files changed, 57 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h index
> 5c72fba797..b4b7aa1928 100644
> --- a/lib/librte_vhost/rte_vhost.h
> +++ b/lib/librte_vhost/rte_vhost.h
> @@ -85,6 +85,10 @@ extern "C" {
>  #define VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD 12  #endif
> 
> +#ifndef VHOST_USER_PROTOCOL_F_STATUS
> +#define VHOST_USER_PROTOCOL_F_STATUS 15 #endif
> +
>  /** Indicate whether protocol features negotiation is supported. */  #ifndef
> VHOST_USER_F_PROTOCOL_FEATURES
>  #define VHOST_USER_F_PROTOCOL_FEATURES	30
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> df98d15de6..9a9c0a98f5 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -202,6 +202,14 @@ struct vhost_virtqueue {
>  	TAILQ_HEAD(, vhost_iotlb_entry) iotlb_pending_list;  }
> __rte_cache_aligned;
> 
> +/* Virtio device status as per Virtio specification */
> +#define VIRTIO_DEVICE_STATUS_ACK		0x01
> +#define VIRTIO_DEVICE_STATUS_DRIVER		0x02
> +#define VIRTIO_DEVICE_STATUS_DRIVER_OK		0x04
> +#define VIRTIO_DEVICE_STATUS_FEATURES_OK	0x08
> +#define VIRTIO_DEVICE_STATUS_DEV_NEED_RESET	0x40
> +#define VIRTIO_DEVICE_STATUS_FAILED		0x80
> +
>  /* Old kernels have no such macros defined */  #ifndef
> VIRTIO_NET_F_GUEST_ANNOUNCE
>   #define VIRTIO_NET_F_GUEST_ANNOUNCE 21 @@ -364,6 +372,7 @@ struct
> virtio_net {
>  	uint64_t		log_addr;
>  	struct rte_ether_addr	mac;
>  	uint16_t		mtu;
> +	uint8_t			status;
> 
>  	struct vhost_device_ops const *notify_ops;
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c index
> 4a847f368c..e5a44be58d 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -87,6 +87,7 @@ static const char *vhost_message_str[VHOST_USER_MAX]
> = {
>  	[VHOST_USER_POSTCOPY_END]  = "VHOST_USER_POSTCOPY_END",
>  	[VHOST_USER_GET_INFLIGHT_FD] = "VHOST_USER_GET_INFLIGHT_FD",
>  	[VHOST_USER_SET_INFLIGHT_FD] = "VHOST_USER_SET_INFLIGHT_FD",
> +	[VHOST_USER_SET_STATUS] = "VHOST_USER_SET_STATUS",
>  };
> 
>  static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg); @@ -1328,6
> +1329,11 @@ virtio_is_ready(struct virtio_net *dev)
>  			return 0;
>  	}
> 
> +	/* If supported, ensure the frontend is really done with config */
> +	if (dev->protocol_features & (1ULL <<
> VHOST_USER_PROTOCOL_F_STATUS))
> +		if (!(dev->status & VIRTIO_DEVICE_STATUS_DRIVER_OK))
> +			return 0;
> +
>  	dev->flags |= VIRTIO_DEV_READY;
> 
>  	VHOST_LOG_CONFIG(INFO,
> @@ -2425,6 +2431,39 @@ vhost_user_postcopy_end(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
>  	return RTE_VHOST_MSG_RESULT_REPLY;
>  }
> 
> +static int
> +vhost_user_set_status(struct virtio_net **pdev, struct VhostUserMsg *msg,
> +			int main_fd __rte_unused)
> +{
> +	struct virtio_net *dev = *pdev;
> +
> +	/* As per Virtio specification, the device status is 8bits long */
> +	if (msg->payload.u64 > UINT8_MAX) {
> +		VHOST_LOG_CONFIG(ERR, "Invalid VHOST_USER_SET_STATUS
> payload 0x%" PRIx64 "\n",
> +				msg->payload.u64);
> +		return RTE_VHOST_MSG_RESULT_ERR;
> +	}
> +
> +	dev->status = msg->payload.u64;
> +
> +	VHOST_LOG_CONFIG(INFO, "New device status(0x%08x):\n"
> +			"\t-ACKNOWLEDGE: %u\n"
> +			"\t-DRIVER: %u\n"
> +			"\t-FEATURES_OK: %u\n"
> +			"\t-DRIVER_OK: %u\n"
> +			"\t-DEVICE_NEED_RESET: %u\n"
> +			"\t-FAILED: %u\n",
> +			dev->status,
> +			!!(dev->status & VIRTIO_DEVICE_STATUS_ACK),
> +			!!(dev->status & VIRTIO_DEVICE_STATUS_DRIVER),
> +			!!(dev->status &
> VIRTIO_DEVICE_STATUS_FEATURES_OK),
> +			!!(dev->status & VIRTIO_DEVICE_STATUS_DRIVER_OK),
> +			!!(dev->status &
> VIRTIO_DEVICE_STATUS_DEV_NEED_RESET),
> +			!!(dev->status & VIRTIO_DEVICE_STATUS_FAILED));
> +
> +	return RTE_VHOST_MSG_RESULT_OK;

I see in your patch for virtio-user SET_STATUS support (http://patchwork.dpdk.org/patch/70677/), the 
VHOST_USER_SET_STATUS msg may request a reply, but this func does not handle this case. If we don't
handle here,  vhost_user_msg_handler will return RTE_VHOST_MSG_RESULT_ERR later. So should we
handle the case here?

Thanks,
Chenbo

> +}
> +
>  typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
>  					struct VhostUserMsg *msg,
>  					int main_fd);
> @@ -2457,6 +2496,7 @@ static vhost_message_handler_t
> vhost_message_handlers[VHOST_USER_MAX] = {
>  	[VHOST_USER_POSTCOPY_END] = vhost_user_postcopy_end,
>  	[VHOST_USER_GET_INFLIGHT_FD] = vhost_user_get_inflight_fd,
>  	[VHOST_USER_SET_INFLIGHT_FD] = vhost_user_set_inflight_fd,
> +	[VHOST_USER_SET_STATUS] = vhost_user_set_status,
>  };
> 
>  /* return bytes# of read on success or negative val on failure. */ diff --git
> a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h index
> 1f65efa4a9..74fd361e3a 100644
> --- a/lib/librte_vhost/vhost_user.h
> +++ b/lib/librte_vhost/vhost_user.h
> @@ -23,7 +23,8 @@
>  					 (1ULL <<
> VHOST_USER_PROTOCOL_F_CRYPTO_SESSION) | \
>  					 (1ULL <<
> VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) | \
>  					 (1ULL <<
> VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) | \
> -					 (1ULL <<
> VHOST_USER_PROTOCOL_F_PAGEFAULT))
> +					 (1ULL <<
> VHOST_USER_PROTOCOL_F_PAGEFAULT) | \
> +					 (1ULL <<
> VHOST_USER_PROTOCOL_F_STATUS))
> 
>  typedef enum VhostUserRequest {
>  	VHOST_USER_NONE = 0,
> @@ -56,7 +57,8 @@ typedef enum VhostUserRequest {
>  	VHOST_USER_POSTCOPY_END = 30,
>  	VHOST_USER_GET_INFLIGHT_FD = 31,
>  	VHOST_USER_SET_INFLIGHT_FD = 32,
> -	VHOST_USER_MAX = 33
> +	VHOST_USER_SET_STATUS = 36,
> +	VHOST_USER_MAX = 37
>  } VhostUserRequest;
> 
>  typedef enum VhostUserSlaveRequest {
> --
> 2.25.4