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From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Matan Azrad <matan@mellanox.com>, Xiao Wang <xiao.w.wang@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v1 3/4] vhost: improve device ready definition
Date: Fri, 19 Jun 2020 09:41:38 +0200
Message-ID: <631a3cf3-f21a-b292-b475-93552d8f73e8@redhat.com> (raw)
In-Reply-To: <1592497686-433697-4-git-send-email-matan@mellanox.com>



On 6/18/20 6:28 PM, Matan Azrad wrote:
> Some guest drivers may not configure disabled virtio queues.
> 
> In this case, the vhost management never triggers the vDPA device
> configuration because it waits to the device to be ready.

This is not vDPA-only, even with SW datapath the application's
new_device callback never gets called.

> The current ready state means that all the virtio queues should be
> configured regardless the enablement status.
> 
> In order to support this case, this patch changes the ready state:
> The device is ready when at least 1 queue pair is configured and
> enabled.
> 
> So, now, the vDPA driver will be configured when the first queue pair is
> configured and enabled.
> 
> Also the queue state operation is change to the next rules:
> 	1. queue becomes ready (enabled and fully configured) -
> 		set_vring_state(enabled).
> 	2. queue becomes not ready - set_vring_state(disabled).
> 	3. queue stay ready and VHOST_USER_SET_VRING_ENABLE massage was
> 		handled - set_vring_state(enabled).
> 
> The parallel operations for the application are adjusted too.
> 
> Signed-off-by: Matan Azrad <matan@mellanox.com>
> ---
>  lib/librte_vhost/vhost_user.c | 51 ++++++++++++++++++++++++++++---------------
>  1 file changed, 33 insertions(+), 18 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index b0849b9..cfd5f27 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1295,7 +1295,7 @@
>  {
>  	bool rings_ok;
>  
> -	if (!vq)
> +	if (!vq || !vq->enabled)
>  		return false;
>  
>  	if (vq_is_packed(dev))
> @@ -1309,24 +1309,27 @@
>  	       vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD;
>  }
>  
> +#define VIRTIO_DEV_NUM_VQS_TO_BE_READY 2u
> +
>  static int
>  virtio_is_ready(struct virtio_net *dev)
>  {
>  	struct vhost_virtqueue *vq;
>  	uint32_t i;
>  
> -	if (dev->nr_vring == 0)
> +	if (dev->nr_vring < VIRTIO_DEV_NUM_VQS_TO_BE_READY)
>  		return 0;
>  
> -	for (i = 0; i < dev->nr_vring; i++) {
> +	for (i = 0; i < VIRTIO_DEV_NUM_VQS_TO_BE_READY; i++) {
>  		vq = dev->virtqueue[i];
>  
>  		if (!vq_is_ready(dev, vq))
>  			return 0;
>  	}
>  
> -	VHOST_LOG_CONFIG(INFO,
> -		"virtio is now ready for processing.\n");
> +	if (!(dev->flags & VIRTIO_DEV_READY))
> +		VHOST_LOG_CONFIG(INFO,
> +			"virtio is now ready for processing.\n");
>  	return 1;
>  }
>  
> @@ -1970,8 +1973,6 @@ static int vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
>  	struct virtio_net *dev = *pdev;
>  	int enable = (int)msg->payload.state.num;
>  	int index = (int)msg->payload.state.index;
> -	struct rte_vdpa_device *vdpa_dev;
> -	int did = -1;
>  
>  	if (validate_msg_fds(msg, 0) != 0)
>  		return RTE_VHOST_MSG_RESULT_ERR;
> @@ -1980,15 +1981,6 @@ static int vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
>  		"set queue enable: %d to qp idx: %d\n",
>  		enable, index);
>  
> -	did = dev->vdpa_dev_id;
> -	vdpa_dev = rte_vdpa_get_device(did);
> -	if (vdpa_dev && vdpa_dev->ops->set_vring_state)
> -		vdpa_dev->ops->set_vring_state(dev->vid, index, enable);
> -
> -	if (dev->notify_ops->vring_state_changed)
> -		dev->notify_ops->vring_state_changed(dev->vid,
> -				index, enable);
> -
>  	/* On disable, rings have to be stopped being processed. */
>  	if (!enable && dev->dequeue_zero_copy)
>  		drain_zmbuf_list(dev->virtqueue[index]);
> @@ -2622,11 +2614,13 @@ typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
>  	struct virtio_net *dev;
>  	struct VhostUserMsg msg;
>  	struct rte_vdpa_device *vdpa_dev;
> +	bool ready[VHOST_MAX_VRING];
>  	int did = -1;
>  	int ret;
>  	int unlock_required = 0;
>  	bool handled;
>  	int request;
> +	uint32_t i;
>  
>  	dev = get_device(vid);
>  	if (dev == NULL)
> @@ -2668,6 +2662,10 @@ typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
>  		VHOST_LOG_CONFIG(DEBUG, "External request %d\n", request);
>  	}
>  
> +	/* Save ready status for all the VQs before message handle. */
> +	for (i = 0; i < VHOST_MAX_VRING; i++)
> +		ready[i] = vq_is_ready(dev, dev->virtqueue[i]);
> +

This big array can be avoided if you save the ready status in the
virtqueue once message have been handled.

>  	ret = vhost_user_check_and_alloc_queue_pair(dev, &msg);
>  	if (ret < 0) {
>  		VHOST_LOG_CONFIG(ERR,
> @@ -2802,6 +2800,25 @@ typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
>  		return -1;
>  	}
>  
> +	did = dev->vdpa_dev_id;
> +	vdpa_dev = rte_vdpa_get_device(did);
> +	/* Update ready status. */
> +	for (i = 0; i < VHOST_MAX_VRING; i++) {
> +		bool cur_ready = vq_is_ready(dev, dev->virtqueue[i]);
> +
> +		if ((cur_ready && request == VHOST_USER_SET_VRING_ENABLE &&
> +				i == msg.payload.state.index) ||

Couldn't we remove above condition? Aren't the callbacks already called
in the set_vring_enable handler?

> +				cur_ready != ready[i]) {
> +			if (vdpa_dev && vdpa_dev->ops->set_vring_state)
> +				vdpa_dev->ops->set_vring_state(dev->vid, i,
> +								(int)cur_ready);
> +
> +			if (dev->notify_ops->vring_state_changed)
> +				dev->notify_ops->vring_state_changed(dev->vid,
> +							i, (int)cur_ready);
> +		}
> +	}

I think we should move this into a dedicated function, which we would
call in every message handler that can modify the ready state.

Doing so, we would not have to assume the master sent us disable request
for the queue before, ans also would have proper synchronization if the
request uses reply-ack feature as it could assume the backend is no more
processing the ring once reply-ack is received.

>  	if (!(dev->flags & VIRTIO_DEV_RUNNING) && virtio_is_ready(dev)) {
>  		dev->flags |= VIRTIO_DEV_READY;
>  
> @@ -2816,8 +2833,6 @@ typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
>  		}
>  	}
>  
> -	did = dev->vdpa_dev_id;
> -	vdpa_dev = rte_vdpa_get_device(did);
>  	if (vdpa_dev && virtio_is_ready(dev) &&
>  			!(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED) &&
>  			msg.request.master == VHOST_USER_SET_VRING_CALL) {

Shouldn't check on SET_VRING_CALL above be removed?


  reply	other threads:[~2020-06-19  7:41 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-18 16:28 [dpdk-dev] [PATCH v1 0/4] vhost: improve ready state Matan Azrad
2020-06-18 16:28 ` [dpdk-dev] [PATCH v1 1/4] vhost: support host notifier queue configuration Matan Azrad
2020-06-19  6:44   ` Maxime Coquelin
2020-06-19 13:28     ` Matan Azrad
2020-06-19 14:01       ` Maxime Coquelin
2020-06-21  6:26         ` Matan Azrad
2020-06-22  8:06           ` Maxime Coquelin
2020-06-18 16:28 ` [dpdk-dev] [PATCH v1 2/4] vhost: skip access lock when vDPA is configured Matan Azrad
2020-06-19  6:49   ` Maxime Coquelin
2020-06-18 16:28 ` [dpdk-dev] [PATCH v1 3/4] vhost: improve device ready definition Matan Azrad
2020-06-19  7:41   ` Maxime Coquelin [this message]
2020-06-19 12:04     ` Maxime Coquelin
2020-06-19 13:11     ` Matan Azrad
2020-06-19 13:54       ` Maxime Coquelin
2020-06-21  6:20         ` Matan Azrad
2020-06-22  8:04           ` Maxime Coquelin
2020-06-22  8:41             ` Matan Azrad
2020-06-22  8:56               ` Maxime Coquelin
2020-06-22 10:06                 ` Matan Azrad
2020-06-22 12:32                   ` Maxime Coquelin
2020-06-22 13:43                     ` Matan Azrad
2020-06-22 14:55                       ` Maxime Coquelin
2020-06-22 15:51                         ` Matan Azrad
2020-06-22 16:47                           ` Maxime Coquelin
2020-06-23  9:02                             ` Matan Azrad
2020-06-23  9:19                               ` Maxime Coquelin
2020-06-23 11:53                                 ` Matan Azrad
2020-06-23 13:55                                   ` Maxime Coquelin
2020-06-23 14:33                                     ` Maxime Coquelin
2020-06-23 14:52                                     ` Matan Azrad
2020-06-23 15:18                                       ` Maxime Coquelin
2020-06-24  5:54                                         ` Matan Azrad
2020-06-24  7:22                                           ` Maxime Coquelin
2020-06-24  8:38                                             ` Matan Azrad
2020-06-24  9:12                                               ` Maxime Coquelin
2020-06-18 16:28 ` [dpdk-dev] [PATCH v1 4/4] vdpa/mlx5: support queue update Matan Azrad
2020-06-25 13:38 ` [dpdk-dev] [PATCH v2 0/5] vhost: improve ready state Matan Azrad
2020-06-25 13:38   ` [dpdk-dev] [PATCH v2 1/5] vhost: skip access lock when vDPA is configured Matan Azrad
2020-06-28  3:06     ` Xia, Chenbo
2020-06-25 13:38   ` [dpdk-dev] [PATCH v2 2/5] vhost: improve device readiness notifications Matan Azrad
2020-06-26 12:10     ` Maxime Coquelin
2020-06-28  3:08     ` Xia, Chenbo
2020-06-25 13:38   ` [dpdk-dev] [PATCH v2 3/5] vhost: handle memory hotplug with vDPA devices Matan Azrad
2020-06-26 12:15     ` Maxime Coquelin
2020-06-28  3:18     ` Xia, Chenbo
2020-06-25 13:38   ` [dpdk-dev] [PATCH v2 4/5] vhost: notify virtq file descriptor update Matan Azrad
2020-06-26 12:19     ` Maxime Coquelin
2020-06-28  3:19     ` Xia, Chenbo
2020-06-25 13:38   ` [dpdk-dev] [PATCH v2 5/5] vdpa/mlx5: support queue update Matan Azrad
2020-06-26 12:29     ` Maxime Coquelin
2020-06-29 14:08   ` [dpdk-dev] [PATCH v3 0/6] vhost: improve ready state Matan Azrad
2020-06-29 14:08     ` [dpdk-dev] [PATCH v3 1/6] vhost: support host notifier queue configuration Matan Azrad
2020-06-29 14:08     ` [dpdk-dev] [PATCH v3 2/6] vhost: skip access lock when vDPA is configured Matan Azrad
2020-06-29 14:08     ` [dpdk-dev] [PATCH v3 3/6] vhost: improve device readiness notifications Matan Azrad
2020-06-29 14:08     ` [dpdk-dev] [PATCH v3 4/6] vhost: handle memory hotplug with vDPA devices Matan Azrad
2020-06-29 14:08     ` [dpdk-dev] [PATCH v3 5/6] vhost: notify virtq file descriptor update Matan Azrad
2020-06-29 14:08     ` [dpdk-dev] [PATCH v3 6/6] vdpa/mlx5: support queue update Matan Azrad
2020-06-29 17:24     ` [dpdk-dev] [PATCH v3 0/6] vhost: improve ready state Maxime Coquelin
2020-07-17  1:41       ` Wang, Yinan

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