Hi all: This series is an update version of multiqueue virtio-net driver based on Krishna Kumar's work to let virtio-net use multiple rx/tx queues to do the packets reception and transmission. Please review and comments. A protype implementation of qemu-kvm support could by found in git://github.com/jasowang/qemu-kvm-mq.git. To start a guest with two queues, you could specify the queues parameters to both tap and virtio-net like: ./qemu-kvm -netdev tap,queues=2,... -device virtio-net-pci,queues=2,... then enable the multiqueue through ethtool by: ethtool -L eth0 combined 2 Changes from RFC v7: Addressing Rusty's comments: - align the implementation (location of cvq) to v5. - fix the style issue. - use a global refill instead of per-vq one. - check the VIRTIO_NET_F_RFS before calling virtnet_set_queues() Addresing Michael's comments - rename the curr_queue_pairs in virtnet_probe() to max_queue_pairs - validate the number of queue pairs supported by the device against VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MIN and VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MAX. - don't crash when failing to change the number of virtqueues - don't set the affinity hint when onle single queue is used or there's too much virtqueues - add a TODO of handling cpu hotplug - allow user to set the nubmer of queue pairs between 1 and max_queue_pairs Changes from RFC v6: - Align the implementation with the RFC spec update v5 - Addressing Rusty's comments: * split the patches * rename to max_queue_pairs and curr_queue_pairs * remove the useless status * fix the hibernation bug - Addressing Ben's comments: * check other parameters in ethtool_set_queues Changes from RFC v5: - Align the implementation with the RFC spec update v4 - Switch the mode between single mode and multiqueue mode without reset - Remove the 256 limitation of queues - Use helpers to do the mapping between virtqueues and tx/rx queues - Use commbined channels instead of separated rx/tx queus when do the queue number configuartion - Other coding style comments from Michael Changes from RFC v4: - Add ability to negotiate the number of queues through control virtqueue - Ethtool -{L|l} support and default the tx/rx queue number to 1 - Expose the API to set irq affinity instead of irq itself Changes from RFC v3: - Rebase to the net-next - Let queue 2 to be the control virtqueue to obey the spec - Prodives irq affinity - Choose txq based on processor id Reference: - Virtio spec RFC: patchwork.ozlabs.org/patch/201303 - RFC V7:lkml.org/lkml/2012/11/27/177 - RFC V6: lkml.org/lkml/2012/10/30/127 - RFC V5: lwn.net/Articles/505388 - RFC V4: lkml.org/lkml/2012/6/25/120 - RFC V2: lwn.net/Articles/467283 Perf Numbers: Will do some basic test and post as a reply to this mail. Jason Wang (3): virtio-net: separate fields of sending/receiving queue from virtnet_info virtio_net: multiqueue support virtio-net: change the number of queues through ethtool drivers/net/virtio_net.c | 723 ++++++++++++++++++++++++++++----------- include/uapi/linux/virtio_net.h | 16 + 2 files changed, 546 insertions(+), 193 deletions(-)
Jason Wang
2012-Dec-04 11:07 UTC
[PATCH net-next 1/3] virtio-net: separate fields of sending/receiving queue from virtnet_info
To support multiqueue transmitq/receiveq, the first step is to separate queue related structure from virtnet_info. This patch introduce send_queue and receive_queue structure and use the pointer to them as the parameter in functions handling sending/receiving. Signed-off-by: Krishna Kumar <krkumar2 at in.ibm.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/net/virtio_net.c | 271 +++++++++++++++++++++++++--------------------- 1 files changed, 149 insertions(+), 122 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 8262232..266f712 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -51,16 +51,40 @@ struct virtnet_stats { u64 rx_packets; }; -struct virtnet_info { - struct virtio_device *vdev; - struct virtqueue *rvq, *svq, *cvq; - struct net_device *dev; +/* Internal representation of a send virtqueue */ +struct send_queue { + /* Virtqueue associated with this send _queue */ + struct virtqueue *vq; + + /* TX: fragments + linear part + virtio header */ + struct scatterlist sg[MAX_SKB_FRAGS + 2]; +}; + +/* Internal representation of a receive virtqueue */ +struct receive_queue { + /* Virtqueue associated with this receive_queue */ + struct virtqueue *vq; + struct napi_struct napi; - unsigned int status; /* Number of input buffers, and max we've ever had. */ unsigned int num, max; + /* Chain pages by the private ptr. */ + struct page *pages; + + /* RX: fragments + linear part + virtio header */ + struct scatterlist sg[MAX_SKB_FRAGS + 2]; +}; + +struct virtnet_info { + struct virtio_device *vdev; + struct virtqueue *cvq; + struct net_device *dev; + struct send_queue sq; + struct receive_queue rq; + unsigned int status; + /* I like... big packets and I cannot lie! */ bool big_packets; @@ -81,13 +105,6 @@ struct virtnet_info { /* Lock for config space updates */ struct mutex config_lock; - - /* Chain pages by the private ptr. */ - struct page *pages; - - /* fragments + linear part + virtio header */ - struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; - struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; }; struct skb_vnet_hdr { @@ -117,22 +134,22 @@ static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) * private is used to chain pages for big packets, put the whole * most recent used list in the beginning for reuse */ -static void give_pages(struct virtnet_info *vi, struct page *page) +static void give_pages(struct receive_queue *rq, struct page *page) { struct page *end; - /* Find end of list, sew whole thing into vi->pages. */ + /* Find end of list, sew whole thing into vi->rq.pages. */ for (end = page; end->private; end = (struct page *)end->private); - end->private = (unsigned long)vi->pages; - vi->pages = page; + end->private = (unsigned long)rq->pages; + rq->pages = page; } -static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) +static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) { - struct page *p = vi->pages; + struct page *p = rq->pages; if (p) { - vi->pages = (struct page *)p->private; + rq->pages = (struct page *)p->private; /* clear private here, it is used to chain pages */ p->private = 0; } else @@ -140,12 +157,12 @@ static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) return p; } -static void skb_xmit_done(struct virtqueue *svq) +static void skb_xmit_done(struct virtqueue *vq) { - struct virtnet_info *vi = svq->vdev->priv; + struct virtnet_info *vi = vq->vdev->priv; /* Suppress further interrupts. */ - virtqueue_disable_cb(svq); + virtqueue_disable_cb(vq); /* We were probably waiting for more output buffers. */ netif_wake_queue(vi->dev); @@ -167,9 +184,10 @@ static void set_skb_frag(struct sk_buff *skb, struct page *page, } /* Called from bottom half context */ -static struct sk_buff *page_to_skb(struct virtnet_info *vi, +static struct sk_buff *page_to_skb(struct receive_queue *rq, struct page *page, unsigned int len) { + struct virtnet_info *vi = rq->vq->vdev->priv; struct sk_buff *skb; struct skb_vnet_hdr *hdr; unsigned int copy, hdr_len, offset; @@ -224,12 +242,12 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, } if (page) - give_pages(vi, page); + give_pages(rq, page); return skb; } -static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) +static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb) { struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); struct page *page; @@ -243,7 +261,7 @@ static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) skb->dev->stats.rx_length_errors++; return -EINVAL; } - page = virtqueue_get_buf(vi->rvq, &len); + page = virtqueue_get_buf(rq->vq, &len); if (!page) { pr_debug("%s: rx error: %d buffers missing\n", skb->dev->name, hdr->mhdr.num_buffers); @@ -256,14 +274,15 @@ static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) set_skb_frag(skb, page, 0, &len); - --vi->num; + --rq->num; } return 0; } -static void receive_buf(struct net_device *dev, void *buf, unsigned int len) +static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) { - struct virtnet_info *vi = netdev_priv(dev); + struct virtnet_info *vi = rq->vq->vdev->priv; + struct net_device *dev = vi->dev; struct virtnet_stats *stats = this_cpu_ptr(vi->stats); struct sk_buff *skb; struct page *page; @@ -273,7 +292,7 @@ static void receive_buf(struct net_device *dev, void *buf, unsigned int len) pr_debug("%s: short packet %i\n", dev->name, len); dev->stats.rx_length_errors++; if (vi->mergeable_rx_bufs || vi->big_packets) - give_pages(vi, buf); + give_pages(rq, buf); else dev_kfree_skb(buf); return; @@ -285,14 +304,14 @@ static void receive_buf(struct net_device *dev, void *buf, unsigned int len) skb_trim(skb, len); } else { page = buf; - skb = page_to_skb(vi, page, len); + skb = page_to_skb(rq, page, len); if (unlikely(!skb)) { dev->stats.rx_dropped++; - give_pages(vi, page); + give_pages(rq, page); return; } if (vi->mergeable_rx_bufs) - if (receive_mergeable(vi, skb)) { + if (receive_mergeable(rq, skb)) { dev_kfree_skb(skb); return; } @@ -359,8 +378,9 @@ frame_err: dev_kfree_skb(skb); } -static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) +static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) { + struct virtnet_info *vi = rq->vq->vdev->priv; struct sk_buff *skb; struct skb_vnet_hdr *hdr; int err; @@ -372,77 +392,77 @@ static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) skb_put(skb, MAX_PACKET_LEN); hdr = skb_vnet_hdr(skb); - sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr); + sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); - skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); + skb_to_sgvec(skb, rq->sg + 1, 0, skb->len); - err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 2, skb, gfp); + err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp); if (err < 0) dev_kfree_skb(skb); return err; } -static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) +static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp) { struct page *first, *list = NULL; char *p; int i, err, offset; - /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */ + /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */ for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { - first = get_a_page(vi, gfp); + first = get_a_page(rq, gfp); if (!first) { if (list) - give_pages(vi, list); + give_pages(rq, list); return -ENOMEM; } - sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE); + sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE); /* chain new page in list head to match sg */ first->private = (unsigned long)list; list = first; } - first = get_a_page(vi, gfp); + first = get_a_page(rq, gfp); if (!first) { - give_pages(vi, list); + give_pages(rq, list); return -ENOMEM; } p = page_address(first); - /* vi->rx_sg[0], vi->rx_sg[1] share the same page */ - /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */ - sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr)); + /* rq->sg[0], rq->sg[1] share the same page */ + /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */ + sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr)); - /* vi->rx_sg[1] for data packet, from offset */ + /* rq->sg[1] for data packet, from offset */ offset = sizeof(struct padded_vnet_hdr); - sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset); + sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset); /* chain first in list head */ first->private = (unsigned long)list; - err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2, + err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2, first, gfp); if (err < 0) - give_pages(vi, first); + give_pages(rq, first); return err; } -static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) +static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) { struct page *page; int err; - page = get_a_page(vi, gfp); + page = get_a_page(rq, gfp); if (!page) return -ENOMEM; - sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE); + sg_init_one(rq->sg, page_address(page), PAGE_SIZE); - err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 1, page, gfp); + err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp); if (err < 0) - give_pages(vi, page); + give_pages(rq, page); return err; } @@ -454,65 +474,68 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) * before we're receiving packets, or from refill_work which is * careful to disable receiving (using napi_disable). */ -static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) +static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp) { + struct virtnet_info *vi = rq->vq->vdev->priv; int err; bool oom; do { if (vi->mergeable_rx_bufs) - err = add_recvbuf_mergeable(vi, gfp); + err = add_recvbuf_mergeable(rq, gfp); else if (vi->big_packets) - err = add_recvbuf_big(vi, gfp); + err = add_recvbuf_big(rq, gfp); else - err = add_recvbuf_small(vi, gfp); + err = add_recvbuf_small(rq, gfp); oom = err == -ENOMEM; if (err < 0) break; - ++vi->num; + ++rq->num; } while (err > 0); - if (unlikely(vi->num > vi->max)) - vi->max = vi->num; - virtqueue_kick(vi->rvq); + if (unlikely(rq->num > rq->max)) + rq->max = rq->num; + virtqueue_kick(rq->vq); return !oom; } static void skb_recv_done(struct virtqueue *rvq) { struct virtnet_info *vi = rvq->vdev->priv; + struct receive_queue *rq = &vi->rq; + /* Schedule NAPI, Suppress further interrupts if successful. */ - if (napi_schedule_prep(&vi->napi)) { + if (napi_schedule_prep(&rq->napi)) { virtqueue_disable_cb(rvq); - __napi_schedule(&vi->napi); + __napi_schedule(&rq->napi); } } -static void virtnet_napi_enable(struct virtnet_info *vi) +static void virtnet_napi_enable(struct receive_queue *rq) { - napi_enable(&vi->napi); + napi_enable(&rq->napi); /* If all buffers were filled by other side before we napi_enabled, we * won't get another interrupt, so process any outstanding packets * now. virtnet_poll wants re-enable the queue, so we disable here. * We synchronize against interrupts via NAPI_STATE_SCHED */ - if (napi_schedule_prep(&vi->napi)) { - virtqueue_disable_cb(vi->rvq); + if (napi_schedule_prep(&rq->napi)) { + virtqueue_disable_cb(rq->vq); local_bh_disable(); - __napi_schedule(&vi->napi); + __napi_schedule(&rq->napi); local_bh_enable(); } } static void refill_work(struct work_struct *work) { - struct virtnet_info *vi; + struct virtnet_info *vi + container_of(work, struct virtnet_info, refill.work); bool still_empty; - vi = container_of(work, struct virtnet_info, refill.work); - napi_disable(&vi->napi); - still_empty = !try_fill_recv(vi, GFP_KERNEL); - virtnet_napi_enable(vi); + napi_disable(&vi->rq.napi); + still_empty = !try_fill_recv(&vi->rq, GFP_KERNEL); + virtnet_napi_enable(&vi->rq); /* In theory, this can happen: if we don't get any buffers in * we will *never* try to fill again. */ @@ -522,29 +545,31 @@ static void refill_work(struct work_struct *work) static int virtnet_poll(struct napi_struct *napi, int budget) { - struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); + struct receive_queue *rq + container_of(napi, struct receive_queue, napi); + struct virtnet_info *vi = rq->vq->vdev->priv; void *buf; unsigned int len, received = 0; again: while (received < budget && - (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) { - receive_buf(vi->dev, buf, len); - --vi->num; + (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { + receive_buf(rq, buf, len); + --rq->num; received++; } - if (vi->num < vi->max / 2) { - if (!try_fill_recv(vi, GFP_ATOMIC)) + if (rq->num < rq->max / 2) { + if (!try_fill_recv(rq, GFP_ATOMIC)) schedule_delayed_work(&vi->refill, 0); } /* Out of packets? */ if (received < budget) { napi_complete(napi); - if (unlikely(!virtqueue_enable_cb(vi->rvq)) && + if (unlikely(!virtqueue_enable_cb(rq->vq)) && napi_schedule_prep(napi)) { - virtqueue_disable_cb(vi->rvq); + virtqueue_disable_cb(rq->vq); __napi_schedule(napi); goto again; } @@ -553,13 +578,14 @@ again: return received; } -static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) +static unsigned int free_old_xmit_skbs(struct send_queue *sq) { struct sk_buff *skb; unsigned int len, tot_sgs = 0; + struct virtnet_info *vi = sq->vq->vdev->priv; struct virtnet_stats *stats = this_cpu_ptr(vi->stats); - while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) { + while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { pr_debug("Sent skb %p\n", skb); u64_stats_update_begin(&stats->tx_syncp); @@ -573,10 +599,11 @@ static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) return tot_sgs; } -static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) +static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) { struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; + struct virtnet_info *vi = sq->vq->vdev->priv; pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); @@ -611,25 +638,26 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) /* Encode metadata header at front. */ if (vi->mergeable_rx_bufs) - sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); + sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr); else - sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); + sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr); - hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; - return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, + hdr->num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1; + return virtqueue_add_buf(sq->vq, sq->sg, hdr->num_sg, 0, skb, GFP_ATOMIC); } static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); + struct send_queue *sq = &vi->sq; int capacity; /* Free up any pending old buffers before queueing new ones. */ - free_old_xmit_skbs(vi); + free_old_xmit_skbs(sq); /* Try to transmit */ - capacity = xmit_skb(vi, skb); + capacity = xmit_skb(sq, skb); /* This can happen with OOM and indirect buffers. */ if (unlikely(capacity < 0)) { @@ -648,7 +676,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) kfree_skb(skb); return NETDEV_TX_OK; } - virtqueue_kick(vi->svq); + virtqueue_kick(sq->vq); /* Don't wait up for transmitted skbs to be freed. */ skb_orphan(skb); @@ -658,12 +686,12 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) * before it gets out of hand. Naturally, this wastes entries. */ if (capacity < 2+MAX_SKB_FRAGS) { netif_stop_queue(dev); - if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { + if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { /* More just got used, free them then recheck. */ - capacity += free_old_xmit_skbs(vi); + capacity += free_old_xmit_skbs(sq); if (capacity >= 2+MAX_SKB_FRAGS) { netif_start_queue(dev); - virtqueue_disable_cb(vi->svq); + virtqueue_disable_cb(sq->vq); } } } @@ -731,7 +759,7 @@ static void virtnet_netpoll(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); - napi_schedule(&vi->napi); + napi_schedule(&vi->rq.napi); } #endif @@ -740,10 +768,10 @@ static int virtnet_open(struct net_device *dev) struct virtnet_info *vi = netdev_priv(dev); /* Make sure we have some buffers: if oom use wq. */ - if (!try_fill_recv(vi, GFP_KERNEL)) + if (!try_fill_recv(&vi->rq, GFP_KERNEL)) schedule_delayed_work(&vi->refill, 0); - virtnet_napi_enable(vi); + virtnet_napi_enable(&vi->rq); return 0; } @@ -808,7 +836,7 @@ static int virtnet_close(struct net_device *dev) /* Make sure refill_work doesn't re-enable napi! */ cancel_delayed_work_sync(&vi->refill); - napi_disable(&vi->napi); + napi_disable(&vi->rq.napi); return 0; } @@ -920,11 +948,10 @@ static void virtnet_get_ringparam(struct net_device *dev, { struct virtnet_info *vi = netdev_priv(dev); - ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq); - ring->tx_max_pending = virtqueue_get_vring_size(vi->svq); + ring->rx_max_pending = virtqueue_get_vring_size(vi->rq.vq); + ring->tx_max_pending = virtqueue_get_vring_size(vi->sq.vq); ring->rx_pending = ring->rx_max_pending; ring->tx_pending = ring->tx_max_pending; - } @@ -1034,8 +1061,8 @@ static int init_vqs(struct virtnet_info *vi) if (err) return err; - vi->rvq = vqs[0]; - vi->svq = vqs[1]; + vi->rq.vq = vqs[0]; + vi->sq.vq = vqs[1]; if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { vi->cvq = vqs[2]; @@ -1100,11 +1127,11 @@ static int virtnet_probe(struct virtio_device *vdev) /* Set up our device-specific information */ vi = netdev_priv(dev); - netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); + netif_napi_add(dev, &vi->rq.napi, virtnet_poll, napi_weight); vi->dev = dev; vi->vdev = vdev; vdev->priv = vi; - vi->pages = NULL; + vi->rq.pages = NULL; vi->stats = alloc_percpu(struct virtnet_stats); err = -ENOMEM; if (vi->stats == NULL) @@ -1114,8 +1141,8 @@ static int virtnet_probe(struct virtio_device *vdev) mutex_init(&vi->config_lock); vi->config_enable = true; INIT_WORK(&vi->config_work, virtnet_config_changed_work); - sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); - sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); + sg_init_table(vi->rq.sg, ARRAY_SIZE(vi->rq.sg)); + sg_init_table(vi->sq.sg, ARRAY_SIZE(vi->sq.sg)); /* If we can receive ANY GSO packets, we must allocate large ones. */ if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || @@ -1137,10 +1164,10 @@ static int virtnet_probe(struct virtio_device *vdev) } /* Last of all, set up some receive buffers. */ - try_fill_recv(vi, GFP_KERNEL); + try_fill_recv(&vi->rq, GFP_KERNEL); /* If we didn't even get one input buffer, we're useless. */ - if (vi->num == 0) { + if (vi->rq.num == 0) { err = -ENOMEM; goto unregister; } @@ -1173,22 +1200,22 @@ static void free_unused_bufs(struct virtnet_info *vi) { void *buf; while (1) { - buf = virtqueue_detach_unused_buf(vi->svq); + buf = virtqueue_detach_unused_buf(vi->sq.vq); if (!buf) break; dev_kfree_skb(buf); } while (1) { - buf = virtqueue_detach_unused_buf(vi->rvq); + buf = virtqueue_detach_unused_buf(vi->rq.vq); if (!buf) break; if (vi->mergeable_rx_bufs || vi->big_packets) - give_pages(vi, buf); + give_pages(&vi->rq, buf); else dev_kfree_skb(buf); - --vi->num; + --vi->rq.num; } - BUG_ON(vi->num != 0); + BUG_ON(vi->rq.num != 0); } static void remove_vq_common(struct virtnet_info *vi) @@ -1200,8 +1227,8 @@ static void remove_vq_common(struct virtnet_info *vi) vi->vdev->config->del_vqs(vi->vdev); - while (vi->pages) - __free_pages(get_a_page(vi, GFP_KERNEL), 0); + while (vi->rq.pages) + __free_pages(get_a_page(&vi->rq, GFP_KERNEL), 0); } static void __devexit virtnet_remove(struct virtio_device *vdev) @@ -1237,7 +1264,7 @@ static int virtnet_freeze(struct virtio_device *vdev) cancel_delayed_work_sync(&vi->refill); if (netif_running(vi->dev)) - napi_disable(&vi->napi); + napi_disable(&vi->rq.napi); remove_vq_common(vi); @@ -1256,11 +1283,11 @@ static int virtnet_restore(struct virtio_device *vdev) return err; if (netif_running(vi->dev)) - virtnet_napi_enable(vi); + virtnet_napi_enable(&vi->rq); netif_device_attach(vi->dev); - if (!try_fill_recv(vi, GFP_KERNEL)) + if (!try_fill_recv(&vi->rq, GFP_KERNEL)) schedule_delayed_work(&vi->refill, 0); mutex_lock(&vi->config_lock); -- 1.7.1
This addes multiqueue support to virtio_net driver. In multiple queue modes, the driver expects the number of queue paris is equal to the number of vcpus. To eliminate the contention bettwen vcpus and virtqueues, per-cpu virtqueue pairs were implemented through: - select the txq based on the smp processor id. - smp affinity hint were set to the vcpu that owns the queue pairs. Signed-off-by: Krishna Kumar <krkumar2 at in.ibm.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/net/virtio_net.c | 472 ++++++++++++++++++++++++++++++--------- include/uapi/linux/virtio_net.h | 16 ++ 2 files changed, 385 insertions(+), 103 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 266f712..912f5b2 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -81,16 +81,25 @@ struct virtnet_info { struct virtio_device *vdev; struct virtqueue *cvq; struct net_device *dev; - struct send_queue sq; - struct receive_queue rq; + struct send_queue *sq; + struct receive_queue *rq; unsigned int status; + /* Max # of queue pairs supported by the device */ + u16 max_queue_pairs; + + /* # of queue pairs currently used by the driver */ + u16 curr_queue_pairs; + /* I like... big packets and I cannot lie! */ bool big_packets; /* Host will merge rx buffers for big packets (shake it! shake it!) */ bool mergeable_rx_bufs; + /* Has control virtqueue */ + bool has_cvq; + /* enable config space updates */ bool config_enable; @@ -125,6 +134,32 @@ struct padded_vnet_hdr { char padding[6]; }; +static const struct ethtool_ops virtnet_ethtool_ops; + + +/* Converting between virtqueue no. and kernel tx/rx queue no. + * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq + */ +static int vq2txq(struct virtqueue *vq) +{ + return (virtqueue_get_queue_index(vq) - 1) / 2; +} + +static int txq2vq(int txq) +{ + return txq * 2 + 1; +} + +static int vq2rxq(struct virtqueue *vq) +{ + return virtqueue_get_queue_index(vq) / 2; +} + +static int rxq2vq(int rxq) +{ + return rxq * 2; +} + static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) { return (struct skb_vnet_hdr *)skb->cb; @@ -165,7 +200,7 @@ static void skb_xmit_done(struct virtqueue *vq) virtqueue_disable_cb(vq); /* We were probably waiting for more output buffers. */ - netif_wake_queue(vi->dev); + netif_wake_subqueue(vi->dev, vq2txq(vq)); } static void set_skb_frag(struct sk_buff *skb, struct page *page, @@ -502,7 +537,7 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp) static void skb_recv_done(struct virtqueue *rvq) { struct virtnet_info *vi = rvq->vdev->priv; - struct receive_queue *rq = &vi->rq; + struct receive_queue *rq = &vi->rq[vq2rxq(rvq)]; /* Schedule NAPI, Suppress further interrupts if successful. */ if (napi_schedule_prep(&rq->napi)) { @@ -532,15 +567,21 @@ static void refill_work(struct work_struct *work) struct virtnet_info *vi container_of(work, struct virtnet_info, refill.work); bool still_empty; + int i; + + for (i = 0; i < vi->max_queue_pairs; i++) { + struct receive_queue *rq = &vi->rq[i]; - napi_disable(&vi->rq.napi); - still_empty = !try_fill_recv(&vi->rq, GFP_KERNEL); - virtnet_napi_enable(&vi->rq); + napi_disable(&rq->napi); + still_empty = !try_fill_recv(rq, GFP_KERNEL); + virtnet_napi_enable(rq); - /* In theory, this can happen: if we don't get any buffers in - * we will *never* try to fill again. */ - if (still_empty) - schedule_delayed_work(&vi->refill, HZ/2); + /* In theory, this can happen: if we don't get any buffers in + * we will *never* try to fill again. + */ + if (still_empty) + schedule_delayed_work(&vi->refill, HZ/2); + } } static int virtnet_poll(struct napi_struct *napi, int budget) @@ -650,7 +691,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); - struct send_queue *sq = &vi->sq; + int qnum = skb_get_queue_mapping(skb); + struct send_queue *sq = &vi->sq[qnum]; int capacity; /* Free up any pending old buffers before queueing new ones. */ @@ -664,13 +706,14 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) if (likely(capacity == -ENOMEM)) { if (net_ratelimit()) dev_warn(&dev->dev, - "TX queue failure: out of memory\n"); + "TXQ (%d) failure: out of memory\n", + qnum); } else { dev->stats.tx_fifo_errors++; if (net_ratelimit()) dev_warn(&dev->dev, - "Unexpected TX queue failure: %d\n", - capacity); + "Unexpected TXQ (%d) failure: %d\n", + qnum, capacity); } dev->stats.tx_dropped++; kfree_skb(skb); @@ -685,12 +728,12 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) /* Apparently nice girls don't return TX_BUSY; stop the queue * before it gets out of hand. Naturally, this wastes entries. */ if (capacity < 2+MAX_SKB_FRAGS) { - netif_stop_queue(dev); + netif_stop_subqueue(dev, qnum); if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { /* More just got used, free them then recheck. */ capacity += free_old_xmit_skbs(sq); if (capacity >= 2+MAX_SKB_FRAGS) { - netif_start_queue(dev); + netif_start_subqueue(dev, qnum); virtqueue_disable_cb(sq->vq); } } @@ -758,23 +801,13 @@ static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, static void virtnet_netpoll(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); + int i; - napi_schedule(&vi->rq.napi); + for (i = 0; i < vi->curr_queue_pairs; i++) + napi_schedule(&vi->rq[i].napi); } #endif -static int virtnet_open(struct net_device *dev) -{ - struct virtnet_info *vi = netdev_priv(dev); - - /* Make sure we have some buffers: if oom use wq. */ - if (!try_fill_recv(&vi->rq, GFP_KERNEL)) - schedule_delayed_work(&vi->refill, 0); - - virtnet_napi_enable(&vi->rq); - return 0; -} - /* * Send command via the control virtqueue and check status. Commands * supported by the hypervisor, as indicated by feature bits, should @@ -830,13 +863,51 @@ static void virtnet_ack_link_announce(struct virtnet_info *vi) rtnl_unlock(); } +/* Caller check the support of cvq and multiqueue. */ +static int virtnet_set_queues(struct virtnet_info *vi) +{ + struct scatterlist sg; + struct virtio_net_ctrl_rfs s; + struct net_device *dev = vi->dev; + + s.virtqueue_pairs = vi->curr_queue_pairs; + sg_init_one(&sg, &s, sizeof(s)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RFS, + VIRTIO_NET_CTRL_RFS_VQ_PAIRS_SET, &sg, 1, 0)){ + dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n", + vi->curr_queue_pairs); + return -EINVAL; + } + + return 0; +} + +static int virtnet_open(struct net_device *dev) +{ + struct virtnet_info *vi = netdev_priv(dev); + int i; + + for (i = 0; i < vi->max_queue_pairs; i++) { + /* Make sure we have some buffers: if oom use wq. */ + if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) + schedule_delayed_work(&vi->refill, 0); + virtnet_napi_enable(&vi->rq[i]); + } + + return 0; +} + static int virtnet_close(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); + int i; /* Make sure refill_work doesn't re-enable napi! */ cancel_delayed_work_sync(&vi->refill); - napi_disable(&vi->rq.napi); + + for (i = 0; i < vi->max_queue_pairs; i++) + napi_disable(&vi->rq[i].napi); return 0; } @@ -948,8 +1019,8 @@ static void virtnet_get_ringparam(struct net_device *dev, { struct virtnet_info *vi = netdev_priv(dev); - ring->rx_max_pending = virtqueue_get_vring_size(vi->rq.vq); - ring->tx_max_pending = virtqueue_get_vring_size(vi->sq.vq); + ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq); + ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq); ring->rx_pending = ring->rx_max_pending; ring->tx_pending = ring->tx_max_pending; } @@ -967,12 +1038,6 @@ static void virtnet_get_drvinfo(struct net_device *dev, } -static const struct ethtool_ops virtnet_ethtool_ops = { - .get_drvinfo = virtnet_get_drvinfo, - .get_link = ethtool_op_get_link, - .get_ringparam = virtnet_get_ringparam, -}; - #define MIN_MTU 68 #define MAX_MTU 65535 @@ -984,6 +1049,21 @@ static int virtnet_change_mtu(struct net_device *dev, int new_mtu) return 0; } +/* To avoid contending a lock hold by a vcpu who would exit to host, select the + * txq based on the processor id. + * TODO: handle cpu hotplug. + */ +static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb) +{ + int txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : + smp_processor_id(); + + while (unlikely(txq >= dev->real_num_tx_queues)) + txq -= dev->real_num_tx_queues; + + return txq; +} + static const struct net_device_ops virtnet_netdev = { .ndo_open = virtnet_open, .ndo_stop = virtnet_close, @@ -995,6 +1075,7 @@ static const struct net_device_ops virtnet_netdev = { .ndo_get_stats64 = virtnet_stats, .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, + .ndo_select_queue = virtnet_select_queue, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = virtnet_netpoll, #endif @@ -1030,10 +1111,10 @@ static void virtnet_config_changed_work(struct work_struct *work) if (vi->status & VIRTIO_NET_S_LINK_UP) { netif_carrier_on(vi->dev); - netif_wake_queue(vi->dev); + netif_tx_wake_all_queues(vi->dev); } else { netif_carrier_off(vi->dev); - netif_stop_queue(vi->dev); + netif_tx_stop_all_queues(vi->dev); } done: mutex_unlock(&vi->config_lock); @@ -1046,41 +1127,219 @@ static void virtnet_config_changed(struct virtio_device *vdev) schedule_work(&vi->config_work); } -static int init_vqs(struct virtnet_info *vi) +static void free_receive_bufs(struct virtnet_info *vi) { - struct virtqueue *vqs[3]; - vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; - const char *names[] = { "input", "output", "control" }; - int nvqs, err; + int i; - /* We expect two virtqueues, receive then send, - * and optionally control. */ - nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; + for (i = 0; i < vi->max_queue_pairs; i++) { + while (vi->rq[i].pages) + __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0); + } +} - err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names); - if (err) - return err; +/* Free memory allocated for send and receive queues */ +static void virtnet_free_queues(struct virtnet_info *vi) +{ + kfree(vi->rq); + vi->rq = NULL; + kfree(vi->sq); + vi->sq = NULL; +} + +static void free_unused_bufs(struct virtnet_info *vi) +{ + void *buf; + int i; + + for (i = 0; i < vi->max_queue_pairs; i++) { + struct virtqueue *vq = vi->sq[i].vq; + while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) + dev_kfree_skb(buf); + } + + for (i = 0; i < vi->max_queue_pairs; i++) { + struct virtqueue *vq = vi->rq[i].vq; + + while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { + if (vi->mergeable_rx_bufs || vi->big_packets) + give_pages(&vi->rq[i], buf); + else + dev_kfree_skb(buf); + --vi->rq[i].num; + } + BUG_ON(vi->rq[i].num != 0); + } +} + +static void virtnet_set_affinity(struct virtnet_info *vi, bool set) +{ + int i; + + /* Don't set the affinity hint when in single queue mode or we have too + * much online cpus. + */ + if (vi->curr_queue_pairs == 1 || + vi->max_queue_pairs > num_online_cpus()) + set = false; + + for (i = 0; i < vi->max_queue_pairs; i++) { + int cpu = set ? i : -1; + virtqueue_set_affinity(vi->rq[i].vq, cpu); + virtqueue_set_affinity(vi->sq[i].vq, cpu); + } +} + +static void virtnet_del_vqs(struct virtnet_info *vi) +{ + struct virtio_device *vdev = vi->vdev; + + virtnet_set_affinity(vi, false); + + vdev->config->del_vqs(vdev); - vi->rq.vq = vqs[0]; - vi->sq.vq = vqs[1]; + virtnet_free_queues(vi); +} - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { - vi->cvq = vqs[2]; +static int virtnet_find_vqs(struct virtnet_info *vi) +{ + vq_callback_t **callbacks; + struct virtqueue **vqs; + int ret = -ENOMEM; + int i, total_vqs; + char **names; + + /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followd by + * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by + * possible control vq. + */ + total_vqs = vi->max_queue_pairs * 2 + + virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); + + /* Allocate space for find_vqs parameters */ + vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); + callbacks = kzalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); + if (!vqs || !callbacks) + goto err_mem; + names = kzalloc(total_vqs * sizeof(*names), GFP_KERNEL); + if (!names) + goto err_mem; + + /* Parameters for control virtqueue, if any */ + if (vi->has_cvq) { + callbacks[total_vqs - 1] = NULL; + names[total_vqs - 1] = kasprintf(GFP_KERNEL, "control"); + } + /* Allocate/initialize parameters for send/receive virtqueues */ + for (i = 0; i < vi->max_queue_pairs; i++) { + callbacks[rxq2vq(i)] = skb_recv_done; + callbacks[txq2vq(i)] = skb_xmit_done; + names[rxq2vq(i)] = kasprintf(GFP_KERNEL, "input.%d", i); + names[txq2vq(i)] = kasprintf(GFP_KERNEL, "output.%d", i); + } + + ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, + (const char **)names); + if (ret) + goto err_names; + + if (vi->has_cvq) { + vi->cvq = vqs[total_vqs - 1]; if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) vi->dev->features |= NETIF_F_HW_VLAN_FILTER; } + + for (i = 0; i < vi->max_queue_pairs; i++) { + vi->rq[i].vq = vqs[rxq2vq(i)]; + vi->sq[i].vq = vqs[txq2vq(i)]; + } + + kfree(callbacks); + kfree(vqs); + + return 0; + +err_names: + for (i = 0; i < total_vqs * 2; i++) + kfree(names[i]); + kfree(names); + +err_mem: + kfree(callbacks); + kfree(vqs); + + return ret; +} + +static int virtnet_alloc_queues(struct virtnet_info *vi) +{ + int i; + + vi->sq = kzalloc(sizeof(vi->sq[0]) * vi->max_queue_pairs, GFP_KERNEL); + vi->rq = kzalloc(sizeof(vi->rq[0]) * vi->max_queue_pairs, GFP_KERNEL); + if (!vi->rq || !vi->sq) + goto err; + + INIT_DELAYED_WORK(&vi->refill, refill_work); + /* setup initial receive and send queue parameters */ + for (i = 0; i < vi->max_queue_pairs; i++) { + vi->rq[i].pages = NULL; + netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll, + napi_weight); + + sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); + sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); + } + + + return 0; + +err: + virtnet_free_queues(vi); + return -ENOMEM; +} + +static int init_vqs(struct virtnet_info *vi) +{ + int ret; + + /* Allocate send & receive queues */ + ret = virtnet_alloc_queues(vi); + if (ret) + goto err; + + ret = virtnet_find_vqs(vi); + if (ret) + goto err_free; + + virtnet_set_affinity(vi, true); return 0; + +err_free: + virtnet_free_queues(vi); +err: + return ret; } static int virtnet_probe(struct virtio_device *vdev) { - int err; + int i, err; struct net_device *dev; struct virtnet_info *vi; + u16 max_queue_pairs; + + /* Find if host supports multiqueue virtio_net device */ + err = virtio_config_val(vdev, VIRTIO_NET_F_RFS, + offsetof(struct virtio_net_config, + max_virtqueue_pairs), &max_queue_pairs); + + /* We need at least 2 queue's */ + if (err || max_queue_pairs < VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MIN || + max_queue_pairs > VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MAX) + max_queue_pairs = 1; /* Allocate ourselves a network device with room for our info */ - dev = alloc_etherdev(sizeof(struct virtnet_info)); + dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs); if (!dev) return -ENOMEM; @@ -1127,22 +1386,17 @@ static int virtnet_probe(struct virtio_device *vdev) /* Set up our device-specific information */ vi = netdev_priv(dev); - netif_napi_add(dev, &vi->rq.napi, virtnet_poll, napi_weight); vi->dev = dev; vi->vdev = vdev; vdev->priv = vi; - vi->rq.pages = NULL; vi->stats = alloc_percpu(struct virtnet_stats); err = -ENOMEM; if (vi->stats == NULL) goto free; - INIT_DELAYED_WORK(&vi->refill, refill_work); mutex_init(&vi->config_lock); vi->config_enable = true; INIT_WORK(&vi->config_work, virtnet_config_changed_work); - sg_init_table(vi->rq.sg, ARRAY_SIZE(vi->rq.sg)); - sg_init_table(vi->sq.sg, ARRAY_SIZE(vi->sq.sg)); /* If we can receive ANY GSO packets, we must allocate large ones. */ if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || @@ -1153,10 +1407,21 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) vi->mergeable_rx_bufs = true; + if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) + vi->has_cvq = true; + + /* Use single tx/rx queue pair as default */ + vi->curr_queue_pairs = 1; + vi->max_queue_pairs = max_queue_pairs; + + /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ err = init_vqs(vi); if (err) goto free_stats; + netif_set_real_num_tx_queues(dev, 1); + netif_set_real_num_rx_queues(dev, 1); + err = register_netdev(dev); if (err) { pr_debug("virtio_net: registering device failed\n"); @@ -1164,12 +1429,15 @@ static int virtnet_probe(struct virtio_device *vdev) } /* Last of all, set up some receive buffers. */ - try_fill_recv(&vi->rq, GFP_KERNEL); - - /* If we didn't even get one input buffer, we're useless. */ - if (vi->rq.num == 0) { - err = -ENOMEM; - goto unregister; + for (i = 0; i < vi->max_queue_pairs; i++) { + try_fill_recv(&vi->rq[i], GFP_KERNEL); + + /* If we didn't even get one input buffer, we're useless. */ + if (vi->rq[i].num == 0) { + free_unused_bufs(vi); + err = -ENOMEM; + goto free_recv_bufs; + } } /* Assume link up if device can't report link status, @@ -1182,13 +1450,19 @@ static int virtnet_probe(struct virtio_device *vdev) netif_carrier_on(dev); } - pr_debug("virtnet: registered device %s\n", dev->name); + pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", + dev->name, max_queue_pairs); + return 0; -unregister: +free_recv_bufs: + free_receive_bufs(vi); unregister_netdev(dev); + free_vqs: - vdev->config->del_vqs(vdev); + cancel_delayed_work_sync(&vi->refill); + virtnet_del_vqs(vi); + free_stats: free_percpu(vi->stats); free: @@ -1196,28 +1470,6 @@ free: return err; } -static void free_unused_bufs(struct virtnet_info *vi) -{ - void *buf; - while (1) { - buf = virtqueue_detach_unused_buf(vi->sq.vq); - if (!buf) - break; - dev_kfree_skb(buf); - } - while (1) { - buf = virtqueue_detach_unused_buf(vi->rq.vq); - if (!buf) - break; - if (vi->mergeable_rx_bufs || vi->big_packets) - give_pages(&vi->rq, buf); - else - dev_kfree_skb(buf); - --vi->rq.num; - } - BUG_ON(vi->rq.num != 0); -} - static void remove_vq_common(struct virtnet_info *vi) { vi->vdev->config->reset(vi->vdev); @@ -1225,10 +1477,9 @@ static void remove_vq_common(struct virtnet_info *vi) /* Free unused buffers in both send and recv, if any. */ free_unused_bufs(vi); - vi->vdev->config->del_vqs(vi->vdev); + free_receive_bufs(vi); - while (vi->rq.pages) - __free_pages(get_a_page(&vi->rq, GFP_KERNEL), 0); + virtnet_del_vqs(vi); } static void __devexit virtnet_remove(struct virtio_device *vdev) @@ -1254,6 +1505,7 @@ static void __devexit virtnet_remove(struct virtio_device *vdev) static int virtnet_freeze(struct virtio_device *vdev) { struct virtnet_info *vi = vdev->priv; + int i; /* Prevent config work handler from accessing the device */ mutex_lock(&vi->config_lock); @@ -1264,7 +1516,10 @@ static int virtnet_freeze(struct virtio_device *vdev) cancel_delayed_work_sync(&vi->refill); if (netif_running(vi->dev)) - napi_disable(&vi->rq.napi); + for (i = 0; i < vi->max_queue_pairs; i++) { + napi_disable(&vi->rq[i].napi); + netif_napi_del(&vi->rq[i].napi); + } remove_vq_common(vi); @@ -1276,24 +1531,29 @@ static int virtnet_freeze(struct virtio_device *vdev) static int virtnet_restore(struct virtio_device *vdev) { struct virtnet_info *vi = vdev->priv; - int err; + int err, i; err = init_vqs(vi); if (err) return err; if (netif_running(vi->dev)) - virtnet_napi_enable(&vi->rq); + for (i = 0; i < vi->max_queue_pairs; i++) + virtnet_napi_enable(&vi->rq[i]); netif_device_attach(vi->dev); - if (!try_fill_recv(&vi->rq, GFP_KERNEL)) - schedule_delayed_work(&vi->refill, 0); + for (i = 0; i < vi->max_queue_pairs; i++) + if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) + schedule_delayed_work(&vi->refill, 0); mutex_lock(&vi->config_lock); vi->config_enable = true; mutex_unlock(&vi->config_lock); + if (vi->has_cvq && virtio_has_feature(vi->vdev, VIRTIO_NET_F_RFS)) + virtnet_set_queues(vi); + return 0; } #endif @@ -1311,7 +1571,7 @@ static unsigned int features[] = { VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, - VIRTIO_NET_F_GUEST_ANNOUNCE, + VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_RFS, }; static struct virtio_driver virtio_net_driver = { @@ -1329,6 +1589,12 @@ static struct virtio_driver virtio_net_driver = { #endif }; +static const struct ethtool_ops virtnet_ethtool_ops = { + .get_drvinfo = virtnet_get_drvinfo, + .get_link = ethtool_op_get_link, + .get_ringparam = virtnet_get_ringparam, +}; + static int __init init(void) { return register_virtio_driver(&virtio_net_driver); diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h index 2470f54..6056cec 100644 --- a/include/uapi/linux/virtio_net.h +++ b/include/uapi/linux/virtio_net.h @@ -51,6 +51,7 @@ #define VIRTIO_NET_F_CTRL_RX_EXTRA 20 /* Extra RX mode control support */ #define VIRTIO_NET_F_GUEST_ANNOUNCE 21 /* Guest can announce device on the * network */ +#define VIRTIO_NET_F_RFS 22 /* Device supports multiple TXQ/RXQ */ #define VIRTIO_NET_S_LINK_UP 1 /* Link is up */ #define VIRTIO_NET_S_ANNOUNCE 2 /* Announcement is needed */ @@ -60,6 +61,8 @@ struct virtio_net_config { __u8 mac[6]; /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */ __u16 status; + /* Total number of RX/TX queues */ + __u16 max_virtqueue_pairs; } __attribute__((packed)); /* This is the first element of the scatter-gather list. If you don't @@ -166,4 +169,17 @@ struct virtio_net_ctrl_mac { #define VIRTIO_NET_CTRL_ANNOUNCE 3 #define VIRTIO_NET_CTRL_ANNOUNCE_ACK 0 +/* + * Control multiqueue + * + */ +struct virtio_net_ctrl_rfs { + u16 virtqueue_pairs; +}; + +#define VIRTIO_NET_CTRL_RFS 4 + #define VIRTIO_NET_CTRL_RFS_VQ_PAIRS_SET 0 + #define VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MIN 1 + #define VIRTIO_NET_CTRL_RFS_VQ_PAIRS_MAX 0x8000 + #endif /* _LINUX_VIRTIO_NET_H */ -- 1.7.1
Jason Wang
2012-Dec-04 11:07 UTC
[PATCH net-next 3/3] virtio-net: change the number of queues through ethtool
This patch implement the ethtool_{set|get}_channels method of ethool to allow user to change the number of queues dymaically when the device is running. This would let the user to configure it on demand. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/net/virtio_net.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 44 insertions(+), 0 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 912f5b2..b9f9887 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1589,10 +1589,54 @@ static struct virtio_driver virtio_net_driver = { #endif }; +/* TODO: Eliminate OOO packets during switching */ +static int virtnet_set_channels(struct net_device *dev, + struct ethtool_channels *channels) +{ + struct virtnet_info *vi = netdev_priv(dev); + u16 queue_pairs = channels->combined_count; + u16 old_queue_pairs = vi->curr_queue_pairs; + + /* We don't support separate rx/tx channels. + * We don't allow setting 'other' channels. + */ + if (channels->rx_count || channels->tx_count || channels->other_count) + return -EINVAL; + + if (queue_pairs > vi->max_queue_pairs) + return -EINVAL; + + vi->curr_queue_pairs = queue_pairs; + if (virtnet_set_queues(vi) == 0) { + netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs); + netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs); + + virtnet_set_affinity(vi, true); + } else + vi->curr_queue_pairs = old_queue_pairs; + + return 0; +} + +static void virtnet_get_channels(struct net_device *dev, + struct ethtool_channels *channels) +{ + struct virtnet_info *vi = netdev_priv(dev); + + channels->combined_count = vi->curr_queue_pairs; + channels->max_combined = vi->max_queue_pairs; + channels->max_other = 0; + channels->rx_count = 0; + channels->tx_count = 0; + channels->other_count = 0; +} + static const struct ethtool_ops virtnet_ethtool_ops = { .get_drvinfo = virtnet_get_drvinfo, .get_link = ethtool_op_get_link, .get_ringparam = virtnet_get_ringparam, + .set_channels = virtnet_set_channels, + .get_channels = virtnet_get_channels, }; static int __init init(void) -- 1.7.1