Re: [dpdk-dev] [PATCH v4 02/12] vhost: support multiple queues in virtio dev

["Ouyang, Changchun" <changchun.ouyang@intel.com>]

Hi Tetsuya,

> -----Original Message-----
> From: Tetsuya Mukawa [mailto:mukawa@igel.co.jp]
> Sent: Thursday, September 3, 2015 10:27 AM
> To: dev@dpdk.org; Ouyang, Changchun
> Subject: Re: [dpdk-dev] [PATCH v4 02/12] vhost: support multiple queues in
> virtio dev
> 
> On 2015/08/12 17:02, Ouyang Changchun wrote:
> > diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.h
> > b/lib/librte_vhost/vhost_user/virtio-net-user.h
> > index df24860..2429836 100644
> > --- a/lib/librte_vhost/vhost_user/virtio-net-user.h
> > +++ b/lib/librte_vhost/vhost_user/virtio-net-user.h
> > @@ -46,4 +46,6 @@ void user_set_vring_kick(struct vhost_device_ctx,
> > struct VhostUserMsg *);
> >
> >  /*
> > @@ -206,9 +213,17 @@ cleanup_device(struct virtio_net *dev)  static
> > void  free_device(struct virtio_net_config_ll *ll_dev)  {
> > -	/* Free any malloc'd memory */
> > -	rte_free(ll_dev->dev.virtqueue[VIRTIO_RXQ]);
> > -	rte_free(ll_dev->dev.virtqueue[VIRTIO_TXQ]);
> > +	uint32_t qp_idx;
> > +
> > +	/*
> > +	 * Free any malloc'd memory.
> > +	 */
> > +	/* Free every queue pair. */
> > +	for (qp_idx = 0; qp_idx < ll_dev->dev.virt_qp_nb; qp_idx++) {
> > +		uint32_t virt_rx_q_idx = qp_idx * VIRTIO_QNUM +
> VIRTIO_RXQ;
> > +		rte_free(ll_dev->dev.virtqueue[virt_rx_q_idx]);
> 
> Hi Changchun,
> 
> Should we free tx queue also here?
>

We don't need do it, as we allocate once for both rx and tx queue.
Thus, we allocate once, free once.
Pls see the following code snippet:

+ *  Alloc mem for vring queue pair.
+ */
+int
+alloc_vring_queue_pair(struct virtio_net *dev, uint16_t qp_idx) {
+	struct vhost_virtqueue *virtqueue = NULL;
+	uint32_t virt_rx_q_idx = qp_idx * VIRTIO_QNUM + VIRTIO_RXQ;
+	uint32_t virt_tx_q_idx = qp_idx * VIRTIO_QNUM + VIRTIO_TXQ;
 
-	/* Backends are set to -1 indicating an inactive device. */
-	dev->virtqueue[VIRTIO_RXQ]->backend = VIRTIO_DEV_STOPPED;
-	dev->virtqueue[VIRTIO_TXQ]->backend = VIRTIO_DEV_STOPPED;
+	virtqueue = rte_malloc(NULL, sizeof(struct vhost_virtqueue) * VIRTIO_QNUM, 0);
+	if (virtqueue == NULL) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"Failed to allocate memory for virt qp:%d.\n", qp_idx);
+		return -1;
+	}
+
+	dev->virtqueue[virt_rx_q_idx] = virtqueue;
+	dev->virtqueue[virt_tx_q_idx] = virtqueue + VIRTIO_TXQ;
+
+	init_vring_queue_pair(dev, qp_idx);
+
+	return 0;
 }

Thanks
Changchun

> 
> > +	}
> > +	rte_free(ll_dev->dev.virtqueue);
> >  	rte_free(ll_dev);
> >  }
> >
> >