Re: [PATCH v5 resend 05/12] vhost: add VHOST_USER_SET_VRING_ENABLE message

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Sep 18, 2015 at 11:10:54PM +0800, Yuanhan Liu wrote:
> From: Changchun Ouyang <changchun.ouyang@intel.com>
> 
> This message is used to enable/disable a specific vring queue pair.
> The first queue pair is enabled by default.
> 
> Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> ---
>  lib/librte_vhost/rte_virtio_net.h             |  1 +
>  lib/librte_vhost/vhost_rxtx.c                 | 10 ++++++++++
>  lib/librte_vhost/vhost_user/vhost-net-user.c  |  5 +++++
>  lib/librte_vhost/vhost_user/vhost-net-user.h  |  1 +
>  lib/librte_vhost/vhost_user/virtio-net-user.c | 22 ++++++++++++++++++++++
>  lib/librte_vhost/vhost_user/virtio-net-user.h |  3 +++
>  lib/librte_vhost/virtio-net.c                 | 12 +++++++++---
>  7 files changed, 51 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
> index 5dd6493..08b69df 100644
> --- a/lib/librte_vhost/rte_virtio_net.h
> +++ b/lib/librte_vhost/rte_virtio_net.h
> @@ -89,6 +89,7 @@ struct vhost_virtqueue {
>  	volatile uint16_t	last_used_idx_res;	/**< Used for multiple devices reserving buffers. */
>  	int			callfd;			/**< Used to notify the guest (trigger interrupt). */
>  	int			kickfd;			/**< Currently unused as polling mode is enabled. */
> +	int			enabled;
>  	struct buf_vector	buf_vec[BUF_VECTOR_MAX];	/**< for scatter RX. */
>  } __rte_cache_aligned;
>  
> diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
> index a4ab6ca..aa9ccda 100644
> --- a/lib/librte_vhost/vhost_rxtx.c
> +++ b/lib/librte_vhost/vhost_rxtx.c
> @@ -86,6 +86,9 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
>  	}
>  
>  	vq = dev->virtqueue[queue_id];
> +	if (unlikely(vq->enabled == 0))
> +		return 0;
> +
>  	count = (count > MAX_PKT_BURST) ? MAX_PKT_BURST : count;
>  
>  	/*
> @@ -278,6 +281,7 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint32_t queue_id,
>  	 * (guest physical addr -> vhost virtual addr)
>  	 */
>  	vq = dev->virtqueue[queue_id];
> +
>  	vb_addr = gpa_to_vva(dev, vq->buf_vec[vec_idx].buf_addr);
>  	vb_hdr_addr = vb_addr;
>  
> @@ -485,6 +489,9 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
>  	}
>  
>  	vq = dev->virtqueue[queue_id];
> +	if (unlikely(vq->enabled == 0))
> +		return 0;
> +
>  	count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
>  
>  	if (count == 0)
> @@ -583,6 +590,9 @@ rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
>  	}
>  
>  	vq = dev->virtqueue[queue_id];
> +	if (unlikely(vq->enabled == 0))
> +		return 0;
> +
>  	avail_idx =  *((volatile uint16_t *)&vq->avail->idx);
>  
>  	/* If there are no available buffers then return. */
> diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.c b/lib/librte_vhost/vhost_user/vhost-net-user.c
> index 8675cd4..f681676 100644
> --- a/lib/librte_vhost/vhost_user/vhost-net-user.c
> +++ b/lib/librte_vhost/vhost_user/vhost-net-user.c
> @@ -99,6 +99,7 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
>  	[VHOST_USER_GET_PROTOCOL_FEATURES]  = "VHOST_USER_GET_PROTOCOL_FEATURES",
>  	[VHOST_USER_SET_PROTOCOL_FEATURES]  = "VHOST_USER_SET_PROTOCOL_FEATURES",
>  	[VHOST_USER_GET_QUEUE_NUM]  = "VHOST_USER_GET_QUEUE_NUM",
> +	[VHOST_USER_SET_VRING_ENABLE]  = "VHOST_USER_SET_VRING_ENABLE",
>  };
>  
>  /**
> @@ -428,6 +429,10 @@ vserver_message_handler(int connfd, void *dat, int *remove)
>  		send_vhost_message(connfd, &msg);
>  		break;
>  
> +	case VHOST_USER_SET_VRING_ENABLE:
> +		user_set_vring_enable(ctx, &msg.payload.state);
> +		break;
> +
>  	default:
>  		break;
>  
> diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.h b/lib/librte_vhost/vhost_user/vhost-net-user.h
> index 389d21d..38637cc 100644
> --- a/lib/librte_vhost/vhost_user/vhost-net-user.h
> +++ b/lib/librte_vhost/vhost_user/vhost-net-user.h
> @@ -66,6 +66,7 @@ typedef enum VhostUserRequest {
>  	VHOST_USER_GET_PROTOCOL_FEATURES = 15,
>  	VHOST_USER_SET_PROTOCOL_FEATURES = 16,
>  	VHOST_USER_GET_QUEUE_NUM = 17,
> +	VHOST_USER_SET_VRING_ENABLE = 18,
>  	VHOST_USER_MAX
>  } VhostUserRequest;
>  
> diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c b/lib/librte_vhost/vhost_user/virtio-net-user.c
> index e83d279..9871f20 100644
> --- a/lib/librte_vhost/vhost_user/virtio-net-user.c
> +++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
> @@ -306,6 +306,28 @@ user_get_vring_base(struct vhost_device_ctx ctx,
>  	return 0;
>  }
>  
> +/*
> + * when virtio queues are ready to work, qemu will send us to
> + * enable the virtio queue pair.
> + */
> +int
> +user_set_vring_enable(struct vhost_device_ctx ctx,
> +		      struct vhost_vring_state *state)
> +{
> +	struct virtio_net *dev = get_device(ctx);
> +	uint32_t base_idx = state->index;
> +	int enabled = (int)state->num;
> +
> +	RTE_LOG(INFO, VHOST_CONFIG,
> +		"set queue enable: %d to qp idx: %d\n",
> +		enabled, state->index);
> +
> +	dev->virtqueue[base_idx + VIRTIO_RXQ]->enabled = enabled;
> +	dev->virtqueue[base_idx + VIRTIO_TXQ]->enabled = enabled;
> +
> +	return 0;
> +}
> +
>  void
>  user_destroy_device(struct vhost_device_ctx ctx)
>  {

It might be a good idea to flush any packets being processed
on relevant cores at this point.


> diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.h b/lib/librte_vhost/vhost_user/virtio-net-user.h
> index e7a6ff4..d46057e 100644
> --- a/lib/librte_vhost/vhost_user/virtio-net-user.h
> +++ b/lib/librte_vhost/vhost_user/virtio-net-user.h
> @@ -50,5 +50,8 @@ void user_set_protocol_features(struct vhost_device_ctx ctx,
>  
>  int user_get_vring_base(struct vhost_device_ctx, struct vhost_vring_state *);
>  
> +int user_set_vring_enable(struct vhost_device_ctx ctx,
> +			  struct vhost_vring_state *state);
> +
>  void user_destroy_device(struct vhost_device_ctx);
>  #endif
> diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
> index 643a92e..5fe1ad6 100644
> --- a/lib/librte_vhost/virtio-net.c
> +++ b/lib/librte_vhost/virtio-net.c
> @@ -254,7 +254,7 @@ rm_config_ll_entry(struct virtio_net_config_ll *ll_dev,
>  }
>  
>  static void
> -init_vring_queue(struct vhost_virtqueue *vq)
> +init_vring_queue(struct vhost_virtqueue *vq, int qp_idx)
>  {
>  	memset(vq, 0, sizeof(struct vhost_virtqueue));
>  
> @@ -263,13 +263,19 @@ init_vring_queue(struct vhost_virtqueue *vq)
>  
>  	/* Backends are set to -1 indicating an inactive device. */
>  	vq->backend = -1;
> +
> +	/* always set the default vq pair to enabled */
> +	if (qp_idx == 0)
> +		vq->enabled = 1;
>  }
>  
>  static void
>  init_vring_queue_pair(struct virtio_net *dev, uint32_t qp_idx)
>  {
> -	init_vring_queue(dev->virtqueue[qp_idx * VIRTIO_QNUM + VIRTIO_RXQ]);
> -	init_vring_queue(dev->virtqueue[qp_idx * VIRTIO_QNUM + VIRTIO_TXQ]);
> +	uint32_t base_idx = qp_idx * VIRTIO_QNUM;
> +
> +	init_vring_queue(dev->virtqueue[base_idx + VIRTIO_RXQ], qp_idx);
> +	init_vring_queue(dev->virtqueue[base_idx + VIRTIO_TXQ], qp_idx);
>  }
>  
>  static int
> -- 
> 1.9.0