[ovs-dev] [RFC] dpdk: support multiple queues in vhost
Traynor, Kevin
kevin.traynor at intel.com
Tue Aug 11 16:24:01 UTC 2015
> -----Original Message-----
> From: dev [mailto:dev-bounces at openvswitch.org] On Behalf Of Flavio Leitner
> Sent: Friday, July 31, 2015 11:30 PM
> To: dev at openvswitch.org
> Cc: Flavio Leitner
> Subject: [ovs-dev] [RFC] dpdk: support multiple queues in vhost
>
> This RFC is based on the vhost multiple queues work on
> dpdk-dev: http://dpdk.org/ml/archives/dev/2015-June/019345.html
Hi Flavio - the patch looks good, one minor comment below.
>
> Signed-off-by: Flavio Leitner <fbl at redhat.com>
> ---
> lib/netdev-dpdk.c | 61 ++++++++++++++++++++++++++++++++++++-----------------
> --
> 1 file changed, 40 insertions(+), 21 deletions(-)
>
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> index 5ae805e..493172c 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -215,12 +215,9 @@ struct netdev_dpdk {
> * If the numbers match, 'txq_needs_locking' is false, otherwise it is
> * true and we will take a spinlock on transmission */
> int real_n_txq;
> + int real_n_rxq;
> bool txq_needs_locking;
>
> - /* Spinlock for vhost transmission. Other DPDK devices use spinlocks in
> - * dpdk_tx_queue */
> - rte_spinlock_t vhost_tx_lock;
> -
> /* virtio-net structure for vhost device */
> OVSRCU_TYPE(struct virtio_net *) virtio_dev;
>
> @@ -602,13 +599,10 @@ dpdk_dev_parse_name(const char dev_name[], const char
> prefix[],
> static int
> vhost_construct_helper(struct netdev *netdev_) OVS_REQUIRES(dpdk_mutex)
> {
> - struct netdev_dpdk *netdev = netdev_dpdk_cast(netdev_);
> -
> if (rte_eal_init_ret) {
> return rte_eal_init_ret;
> }
>
> - rte_spinlock_init(&netdev->vhost_tx_lock);
> return netdev_dpdk_init(netdev_, -1, DPDK_DEV_VHOST);
> }
>
> @@ -791,9 +785,16 @@ netdev_dpdk_vhost_set_multiq(struct netdev *netdev_,
> unsigned int n_txq,
> ovs_mutex_lock(&dpdk_mutex);
> ovs_mutex_lock(&netdev->mutex);
>
> + rte_free(netdev->tx_q);
> + /* FIXME: the number of vqueues needs to match */
> netdev->up.n_txq = n_txq;
> - netdev->real_n_txq = 1;
> - netdev->up.n_rxq = 1;
> + netdev->up.n_rxq = n_rxq;
> +
> + /* vring has txq = rxq */
> + netdev->real_n_txq = n_rxq;
> + netdev->real_n_rxq = n_rxq;
> + netdev->txq_needs_locking = netdev->real_n_txq != netdev->up.n_txq;
> + netdev_dpdk_alloc_txq(netdev, netdev->up.n_txq);
>
> ovs_mutex_unlock(&netdev->mutex);
> ovs_mutex_unlock(&dpdk_mutex);
> @@ -904,14 +905,14 @@ netdev_dpdk_vhost_rxq_recv(struct netdev_rxq *rxq_,
> struct netdev *netdev = rx->up.netdev;
> struct netdev_dpdk *vhost_dev = netdev_dpdk_cast(netdev);
> struct virtio_net *virtio_dev = netdev_dpdk_get_virtio(vhost_dev);
> - int qid = 1;
> + int qid = rxq_->queue_id;
> uint16_t nb_rx = 0;
>
> if (OVS_UNLIKELY(!is_vhost_running(virtio_dev))) {
> return EAGAIN;
> }
>
> - nb_rx = rte_vhost_dequeue_burst(virtio_dev, qid,
> + nb_rx = rte_vhost_dequeue_burst(virtio_dev, VIRTIO_TXQ + qid * 2,
> vhost_dev->dpdk_mp->mp,
> (struct rte_mbuf **)packets,
> NETDEV_MAX_BURST);
> @@ -958,8 +959,9 @@ netdev_dpdk_rxq_recv(struct netdev_rxq *rxq_, struct
> dp_packet **packets,
> }
>
> static void
> -__netdev_dpdk_vhost_send(struct netdev *netdev, struct dp_packet **pkts,
> - int cnt, bool may_steal)
> +__netdev_dpdk_vhost_send(struct netdev *netdev, int qid,
> + struct dp_packet **pkts, int cnt,
> + bool may_steal)
> {
> struct netdev_dpdk *vhost_dev = netdev_dpdk_cast(netdev);
> struct virtio_net *virtio_dev = netdev_dpdk_get_virtio(vhost_dev);
> @@ -974,13 +976,16 @@ __netdev_dpdk_vhost_send(struct netdev *netdev, struct
> dp_packet **pkts,
> goto out;
> }
>
> - /* There is vHost TX single queue, So we need to lock it for TX. */
> - rte_spinlock_lock(&vhost_dev->vhost_tx_lock);
> + if (vhost_dev->txq_needs_locking) {
> + qid = qid % vhost_dev->real_n_txq;
> + rte_spinlock_lock(&vhost_dev->tx_q[qid].tx_lock);
> + }
>
> do {
> + int vhost_qid = VIRTIO_RXQ + qid * VIRTIO_QNUM;
> unsigned int tx_pkts;
>
> - tx_pkts = rte_vhost_enqueue_burst(virtio_dev, VIRTIO_RXQ,
> + tx_pkts = rte_vhost_enqueue_burst(virtio_dev, vhost_qid,
> cur_pkts, cnt);
> if (OVS_LIKELY(tx_pkts)) {
> /* Packets have been sent.*/
> @@ -999,7 +1004,7 @@ __netdev_dpdk_vhost_send(struct netdev *netdev, struct
> dp_packet **pkts,
> * Unable to enqueue packets to vhost interface.
> * Check available entries before retrying.
> */
> - while (!rte_vring_available_entries(virtio_dev, VIRTIO_RXQ)) {
> + while (!rte_vring_available_entries(virtio_dev, vhost_qid)) {
> if (OVS_UNLIKELY((rte_get_timer_cycles() - start) >
> timeout)) {
> expired = 1;
> break;
> @@ -1011,7 +1016,10 @@ __netdev_dpdk_vhost_send(struct netdev *netdev, struct
> dp_packet **pkts,
> }
> }
> } while (cnt);
> - rte_spinlock_unlock(&vhost_dev->vhost_tx_lock);
> +
> + if (vhost_dev->txq_needs_locking) {
> + rte_spinlock_unlock(&vhost_dev->tx_q[qid].tx_lock);
> + }
>
> rte_spinlock_lock(&vhost_dev->stats_lock);
> vhost_dev->stats.tx_packets += (total_pkts - cnt);
> @@ -1116,7 +1124,7 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct
> dp_packet **pkts,
> }
>
> if (dev->type == DPDK_DEV_VHOST) {
> - __netdev_dpdk_vhost_send(netdev, (struct dp_packet **) mbufs,
> newcnt, true);
> + __netdev_dpdk_vhost_send(netdev, qid, (struct dp_packet **) mbufs,
> newcnt, true);
> } else {
> dpdk_queue_pkts(dev, qid, mbufs, newcnt);
> dpdk_queue_flush(dev, qid);
> @@ -1128,7 +1136,7 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct
> dp_packet **pkts,
> }
>
> static int
> -netdev_dpdk_vhost_send(struct netdev *netdev, int qid OVS_UNUSED, struct
> dp_packet **pkts,
> +netdev_dpdk_vhost_send(struct netdev *netdev, int qid, struct dp_packet
> **pkts,
> int cnt, bool may_steal)
> {
> if (OVS_UNLIKELY(pkts[0]->source != DPBUF_DPDK)) {
> @@ -1141,7 +1149,7 @@ netdev_dpdk_vhost_send(struct netdev *netdev, int qid
> OVS_UNUSED, struct dp_pack
> }
> }
> } else {
> - __netdev_dpdk_vhost_send(netdev, pkts, cnt, may_steal);
> + __netdev_dpdk_vhost_send(netdev, qid, pkts, cnt, may_steal);
> }
> return 0;
> }
> @@ -1656,7 +1664,18 @@ new_device(struct virtio_net *dev)
> /* Add device to the vhost port with the same name as that passed down.
> */
> LIST_FOR_EACH(netdev, list_node, &dpdk_list) {
> if (strncmp(dev->ifname, netdev->vhost_id, IF_NAME_SZ) == 0) {
> + int qp_num = rte_vhost_qp_num_get(dev);
> ovs_mutex_lock(&netdev->mutex);
> + if (qp_num != netdev->real_n_rxq) {
> + VLOG_INFO("vHost Device '%s' (%ld) can't be added - "
> + "unmatched number of queues %d and %d",
> + dev->ifname, dev->device_fh, qp_num,
> + netdev->real_n_rxq);
In this case, could we adjust our real_n_tx/rxq to the num supported by the
device and set txq_needs_locking, rather than return error?
> + ovs_mutex_unlock(&netdev->mutex);
> + ovs_mutex_unlock(&dpdk_mutex);
> + return -1;
> + }
> +
> ovsrcu_set(&netdev->virtio_dev, dev);
> ovs_mutex_unlock(&netdev->mutex);
> exists = true;
> --
> 2.1.0
>
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