From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756223Ab2GEKiM (ORCPT ); Thu, 5 Jul 2012 06:38:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10558 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932257Ab2GEKiH (ORCPT ); Thu, 5 Jul 2012 06:38:07 -0400 From: Jason Wang To: mst@redhat.com, mashirle@us.ibm.com, krkumar2@in.ibm.com, habanero@linux.vnet.ibm.com, rusty@rustcorp.com.au, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, edumazet@google.com, tahm@linux.vnet.ibm.com, jwhan@filewood.snu.ac.kr, davem@davemloft.net Cc: akong@redhat.com, kvm@vger.kernel.org, sri@us.ibm.com, Jason Wang Subject: [net-next RFC V5 4/5] virtio_net: multiqueue support Date: Thu, 5 Jul 2012 18:29:53 +0800 Message-Id: <1341484194-8108-5-git-send-email-jasowang@redhat.com> In-Reply-To: <1341484194-8108-1-git-send-email-jasowang@redhat.com> References: <1341484194-8108-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch converts virtio_net to a multi queue device. After negotiated VIRTIO_NET_F_MULTIQUEUE feature, the virtio device has many tx/rx queue pairs, and driver could read the number from config space. The driver expects the number of rx/tx queue paris is equal to the number of vcpus. To maximize the performance under this per-cpu rx/tx queue pairs, some optimization were introduced: - Txq selection is based on the processor id in order to avoid contending a lock whose owner may exits to host. - Since the txq/txq were per-cpu, affinity hint were set to the cpu that owns the queue pairs. Signed-off-by: Krishna Kumar Signed-off-by: Jason Wang --- drivers/net/virtio_net.c | 645 ++++++++++++++++++++++++++++++------------- include/linux/virtio_net.h | 2 + 2 files changed, 452 insertions(+), 195 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 1db445b..7410187 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -26,6 +26,7 @@ #include #include #include +#include static int napi_weight = 128; module_param(napi_weight, int, 0444); @@ -41,6 +42,8 @@ module_param(gso, bool, 0444); #define VIRTNET_SEND_COMMAND_SG_MAX 2 #define VIRTNET_DRIVER_VERSION "1.0.0" +#define MAX_QUEUES 256 + struct virtnet_stats { struct u64_stats_sync tx_syncp; struct u64_stats_sync rx_syncp; @@ -51,43 +54,69 @@ 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; + + /* Back pointer to the virtnet_info */ + struct virtnet_info *vi; + struct napi_struct napi; - unsigned int status; /* Number of input buffers, and max we've ever had. */ unsigned int num, max; + /* Work struct for refilling if we run low on memory. */ + struct delayed_work refill; + + /* 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 { + u16 num_queue_pairs; /* # of RX/TX vq pairs */ + + struct send_queue *sq[MAX_QUEUES] ____cacheline_aligned_in_smp; + struct receive_queue *rq[MAX_QUEUES] ____cacheline_aligned_in_smp; + struct virtqueue *cvq; + + struct virtio_device *vdev; + struct net_device *dev; + unsigned int status; + /* 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; /* Active statistics */ struct virtnet_stats __percpu *stats; - /* Work struct for refilling if we run low on memory. */ - struct delayed_work refill; - /* Work struct for config space updates */ struct work_struct config_work; /* 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 { @@ -108,6 +137,22 @@ struct padded_vnet_hdr { char padding[6]; }; +static inline int txq_get_qnum(struct virtnet_info *vi, struct virtqueue *vq) +{ + int ret = virtqueue_get_queue_index(vq); + + /* skip ctrl vq */ + if (vi->has_cvq) + return (ret - 1) / 2; + else + return ret / 2; +} + +static inline int rxq_get_qnum(struct virtnet_info *vi, struct virtqueue *vq) +{ + return virtqueue_get_queue_index(vq) / 2; +} + static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) { return (struct skb_vnet_hdr *)skb->cb; @@ -117,22 +162,22 @@ 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. */ 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 @@ -140,15 +185,15 @@ 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); + netif_wake_subqueue(vi->dev, txq_get_qnum(vi, vq)); } static void set_skb_frag(struct sk_buff *skb, struct page *page, @@ -167,9 +212,10 @@ 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->vi; struct sk_buff *skb; struct skb_vnet_hdr *hdr; unsigned int copy, hdr_len, offset; @@ -225,12 +271,12 @@ 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; @@ -244,7 +290,7 @@ 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); @@ -257,13 +303,14 @@ 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 net_device *dev = rq->vi->dev; struct virtnet_info *vi = netdev_priv(dev); struct virtnet_stats *stats = this_cpu_ptr(vi->stats); struct sk_buff *skb; @@ -274,7 +321,7 @@ 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; @@ -286,14 +333,14 @@ 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; } @@ -363,90 +410,91 @@ 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 sk_buff *skb; struct skb_vnet_hdr *hdr; int err; - skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); + skb = __netdev_alloc_skb_ip_align(rq->vi->dev, MAX_PACKET_LEN, gfp); if (unlikely(!skb)) return -ENOMEM; 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, rq->sg + 1, 0, skb->len); - skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); + err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp); - err = virtqueue_add_buf(vi->rvq, vi->rx_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; } @@ -458,97 +506,104 @@ 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->vi; 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) +static void skb_recv_done(struct virtqueue *vq) { - struct virtnet_info *vi = rvq->vdev->priv; + struct virtnet_info *vi = vq->vdev->priv; + struct napi_struct *napi = &vi->rq[rxq_get_qnum(vi, vq)]->napi; + /* Schedule NAPI, Suppress further interrupts if successful. */ - if (napi_schedule_prep(&vi->napi)) { - virtqueue_disable_cb(rvq); - __napi_schedule(&vi->napi); + if (napi_schedule_prep(napi)) { + virtqueue_disable_cb(vq); + __napi_schedule(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 napi_struct *napi; + struct receive_queue *rq; 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); + rq = container_of(work, struct receive_queue, refill.work); + napi = &rq->napi; + + napi_disable(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) - queue_delayed_work(system_nrt_wq, &vi->refill, HZ/2); + queue_delayed_work(system_nrt_wq, &rq->refill, HZ/2); } 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); 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)) - queue_delayed_work(system_nrt_wq, &vi->refill, 0); + if (rq->num < rq->max / 2) { + if (!try_fill_recv(rq, GFP_ATOMIC)) + queue_delayed_work(system_nrt_wq, &rq->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; } @@ -557,13 +612,14 @@ again: return received; } -static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) +static unsigned int free_old_xmit_skbs(struct virtnet_info *vi, + struct virtqueue *vq) { struct sk_buff *skb; unsigned int len, tot_sgs = 0; struct virtnet_stats *stats = this_cpu_ptr(vi->stats); - while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) { + while ((skb = virtqueue_get_buf(vq, &len)) != NULL) { pr_debug("Sent skb %p\n", skb); u64_stats_update_begin(&stats->tx_syncp); @@ -577,7 +633,8 @@ 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 virtnet_info *vi, struct sk_buff *skb, + struct virtqueue *vq, struct scatterlist *sg) { struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; @@ -615,44 +672,47 @@ 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(sg, &hdr->mhdr, sizeof hdr->mhdr); else - sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); + sg_set_buf(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, sg + 1, 0, skb->len) + 1; + return virtqueue_add_buf(vq, 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); + int qnum = skb_get_queue_mapping(skb); + struct virtqueue *vq = vi->sq[qnum]->vq; int capacity; /* Free up any pending old buffers before queueing new ones. */ - free_old_xmit_skbs(vi); + free_old_xmit_skbs(vi, vq); /* Try to transmit */ - capacity = xmit_skb(vi, skb); + capacity = xmit_skb(vi, skb, vq, vi->sq[qnum]->sg); /* This can happen with OOM and indirect buffers. */ if (unlikely(capacity < 0)) { 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); return NETDEV_TX_OK; } - virtqueue_kick(vi->svq); + virtqueue_kick(vq); /* Don't wait up for transmitted skbs to be freed. */ skb_orphan(skb); @@ -661,13 +721,13 @@ 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); - if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { + netif_stop_subqueue(dev, qnum); + if (unlikely(!virtqueue_enable_cb_delayed(vq))) { /* More just got used, free them then recheck. */ - capacity += free_old_xmit_skbs(vi); + capacity += free_old_xmit_skbs(vi, vq); if (capacity >= 2+MAX_SKB_FRAGS) { - netif_start_queue(dev); - virtqueue_disable_cb(vi->svq); + netif_start_subqueue(dev, qnum); + virtqueue_disable_cb(vq); } } } @@ -700,7 +760,8 @@ static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, unsigned int start; for_each_possible_cpu(cpu) { - struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); + struct virtnet_stats __percpu *stats + = per_cpu_ptr(vi->stats, cpu); u64 tpackets, tbytes, rpackets, rbytes; do { @@ -734,20 +795,26 @@ 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->napi); + for (i = 0; i < vi->num_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); + int i; - /* Make sure we have some buffers: if oom use wq. */ - if (!try_fill_recv(vi, GFP_KERNEL)) - queue_delayed_work(system_nrt_wq, &vi->refill, 0); + for (i = 0; i < vi->num_queue_pairs; i++) { + /* Make sure we have some buffers: if oom use wq. */ + if (!try_fill_recv(vi->rq[i], GFP_KERNEL)) + queue_delayed_work(system_nrt_wq, + &vi->rq[i]->refill, 0); + virtnet_napi_enable(vi->rq[i]); + } - virtnet_napi_enable(vi); return 0; } @@ -809,10 +876,13 @@ static void virtnet_ack_link_announce(struct virtnet_info *vi) 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->napi); + for (i = 0; i < vi->num_queue_pairs; i++) { + cancel_delayed_work_sync(&vi->rq[i]->refill); + napi_disable(&vi->rq[i]->napi); + } return 0; } @@ -924,11 +994,10 @@ 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[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; - } @@ -961,6 +1030,19 @@ 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. + */ +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, @@ -972,6 +1054,7 @@ 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 @@ -1007,10 +1090,10 @@ 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); @@ -1023,41 +1106,217 @@ static void virtnet_config_changed(struct virtio_device *vdev) queue_work(system_nrt_wq, &vi->config_work); } -static int init_vqs(struct virtnet_info *vi) +static void free_receive_bufs(struct virtnet_info *vi) +{ + int i; + + for (i = 0; i < vi->num_queue_pairs; i++) { + while (vi->rq[i]->pages) + __free_pages(get_a_page(vi->rq[i], GFP_KERNEL), 0); + } +} + +/* Free memory allocated for send and receive queues */ +static void virtnet_free_queues(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->num_queue_pairs; i++) { + kfree(vi->rq[i]); + vi->rq[i] = NULL; + kfree(vi->sq[i]); + vi->sq[i] = NULL; + } +} - err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names); - if (err) - return err; +static void free_unused_bufs(struct virtnet_info *vi) +{ + void *buf; + int i; + + for (i = 0; i < vi->num_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->num_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; + + if (vi->num_queue_pairs == 1) + return; + + for (i = 0; i < vi->num_queue_pairs; i++) { + int cpu = set ? i : -1; + virtqueue_set_affinity(vi->rq[i]->vq, cpu); + virtqueue_set_affinity(vi->sq[i]->vq, cpu); + } + return; +} + +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); + + virtnet_free_queues(vi); +} + +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; - vi->rvq = vqs[0]; - vi->svq = vqs[1]; + /* + * We expect 1 RX virtqueue followed by 1 TX virtqueue, followd by + * possible control virtqueue and followed by the same + * 'vi->num_queue_pairs-1' more times + */ + total_vqs = vi->num_queue_pairs * 2 + + virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); + + /* Allocate space for find_vqs parameters */ + vqs = kmalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); + callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); + names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); + if (!vqs || !callbacks || !names) + goto err; + + /* Parameters for control virtqueue, if any */ + if (vi->has_cvq) { + callbacks[2] = NULL; + names[2] = "control"; + } + + /* Allocate/initialize parameters for send/receive virtqueues */ + for (i = 0; i < vi->num_queue_pairs * 2; i += 2) { + int j = (i == 0 ? i : i + vi->has_cvq); + callbacks[j] = skb_recv_done; + callbacks[j + 1] = skb_xmit_done; + names[j] = kasprintf(GFP_KERNEL, "input.%d", i / 2); + names[j + 1] = kasprintf(GFP_KERNEL, "output.%d", i / 2); + } - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { + ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, + (const char **)names); + if (ret) + goto err; + + if (vi->has_cvq) vi->cvq = vqs[2]; - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) - vi->dev->features |= NETIF_F_HW_VLAN_FILTER; + for (i = 0; i < vi->num_queue_pairs * 2; i += 2) { + int j = i == 0 ? i : i + vi->has_cvq; + vi->rq[i / 2]->vq = vqs[j]; + vi->sq[i / 2]->vq = vqs[j + 1]; } - return 0; + +err: + if (ret && names) + for (i = 0; i < vi->num_queue_pairs * 2; i++) + kfree(names[i]); + + kfree(names); + kfree(callbacks); + kfree(vqs); + + return ret; +} + +static int virtnet_alloc_queues(struct virtnet_info *vi) +{ + int ret = -ENOMEM; + int i; + + for (i = 0; i < vi->num_queue_pairs; i++) { + vi->rq[i] = kzalloc(sizeof(*vi->rq[i]), GFP_KERNEL); + vi->sq[i] = kzalloc(sizeof(*vi->sq[i]), GFP_KERNEL); + if (!vi->rq[i] || !vi->sq[i]) + goto err; + } + + ret = 0; + + /* setup initial receive and send queue parameters */ + for (i = 0; i < vi->num_queue_pairs; i++) { + vi->rq[i]->vi = vi; + vi->rq[i]->pages = NULL; + INIT_DELAYED_WORK(&vi->rq[i]->refill, refill_work); + 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)); + } + +err: + if (ret) + virtnet_free_queues(vi); + + return ret; +} + +static int virtnet_setup_vqs(struct virtnet_info *vi) +{ + int ret; + + /* Allocate send & receive queues */ + ret = virtnet_alloc_queues(vi); + if (!ret) { + ret = virtnet_find_vqs(vi); + if (ret) + virtnet_free_queues(vi); + else + virtnet_set_affinity(vi, true); + } + + return ret; } static int virtnet_probe(struct virtio_device *vdev) { - int err; + int i, err; struct net_device *dev; struct virtnet_info *vi; + u16 num_queues, num_queue_pairs; + + /* Find if host supports multiqueue virtio_net device */ + err = virtio_config_val(vdev, VIRTIO_NET_F_MULTIQUEUE, + offsetof(struct virtio_net_config, + num_queues), &num_queues); + + /* We need atleast 2 queue's */ + if (err || num_queues < 2) + num_queues = 2; + if (num_queues > MAX_QUEUES * 2) + num_queues = MAX_QUEUES; + + num_queue_pairs = num_queues / 2; /* 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), num_queue_pairs); if (!dev) return -ENOMEM; @@ -1103,22 +1362,18 @@ 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); vi->dev = dev; vi->vdev = vdev; vdev->priv = vi; - vi->pages = NULL; vi->stats = alloc_percpu(struct virtnet_stats); err = -ENOMEM; if (vi->stats == NULL) - goto free; + goto free_netdev; - 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->rx_sg, ARRAY_SIZE(vi->rx_sg)); - sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); + vi->num_queue_pairs = num_queue_pairs; /* If we can receive ANY GSO packets, we must allocate large ones. */ if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || @@ -1129,9 +1384,17 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) vi->mergeable_rx_bufs = true; - err = init_vqs(vi); + if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) + vi->has_cvq = true; + + /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ + err = virtnet_setup_vqs(vi); if (err) - goto free_stats; + goto free_netdev; + + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) && + virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) + dev->features |= NETIF_F_HW_VLAN_FILTER; err = register_netdev(dev); if (err) { @@ -1140,12 +1403,15 @@ static int virtnet_probe(struct virtio_device *vdev) } /* Last of all, set up some receive buffers. */ - try_fill_recv(vi, GFP_KERNEL); - - /* If we didn't even get one input buffer, we're useless. */ - if (vi->num == 0) { - err = -ENOMEM; - goto unregister; + for (i = 0; i < num_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, @@ -1158,42 +1424,25 @@ 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, num_queue_pairs); + return 0; -unregister: +free_recv_bufs: + free_receive_bufs(vi); unregister_netdev(dev); + free_vqs: - vdev->config->del_vqs(vdev); -free_stats: - free_percpu(vi->stats); -free: + for (i = 0; i < num_queue_pairs; i++) + cancel_delayed_work_sync(&vi->rq[i]->refill); + virtnet_del_vqs(vi); + +free_netdev: free_netdev(dev); return err; } -static void free_unused_bufs(struct virtnet_info *vi) -{ - void *buf; - while (1) { - buf = virtqueue_detach_unused_buf(vi->svq); - if (!buf) - break; - dev_kfree_skb(buf); - } - while (1) { - buf = virtqueue_detach_unused_buf(vi->rvq); - if (!buf) - break; - if (vi->mergeable_rx_bufs || vi->big_packets) - give_pages(vi, buf); - else - dev_kfree_skb(buf); - --vi->num; - } - BUG_ON(vi->num != 0); -} - static void remove_vq_common(struct virtnet_info *vi) { vi->vdev->config->reset(vi->vdev); @@ -1201,10 +1450,9 @@ 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->pages) - __free_pages(get_a_page(vi, GFP_KERNEL), 0); + virtnet_del_vqs(vi); } static void __devexit virtnet_remove(struct virtio_device *vdev) @@ -1230,6 +1478,7 @@ 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); @@ -1237,10 +1486,13 @@ static int virtnet_freeze(struct virtio_device *vdev) mutex_unlock(&vi->config_lock); netif_device_detach(vi->dev); - cancel_delayed_work_sync(&vi->refill); + for (i = 0; i < vi->num_queue_pairs; i++) + cancel_delayed_work_sync(&vi->rq[i]->refill); if (netif_running(vi->dev)) - napi_disable(&vi->napi); + for (i = 0; i < vi->num_queue_pairs; i++) + napi_disable(&vi->rq[i]->napi); + remove_vq_common(vi); @@ -1252,19 +1504,22 @@ 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); + err = virtnet_setup_vqs(vi); if (err) return err; if (netif_running(vi->dev)) - virtnet_napi_enable(vi); + for (i = 0; i < vi->num_queue_pairs; i++) + virtnet_napi_enable(vi->rq[i]); netif_device_attach(vi->dev); - if (!try_fill_recv(vi, GFP_KERNEL)) - queue_delayed_work(system_nrt_wq, &vi->refill, 0); + for (i = 0; i < vi->num_queue_pairs; i++) + if (!try_fill_recv(vi->rq[i], GFP_KERNEL)) + queue_delayed_work(system_nrt_wq, + &vi->rq[i]->refill, 0); mutex_lock(&vi->config_lock); vi->config_enable = true; @@ -1287,7 +1542,7 @@ 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_MULTIQUEUE, }; static struct virtio_driver virtio_net_driver = { diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 1bc7e30..60f09ff 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -61,6 +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 num_queues; } __attribute__((packed)); /* This is the first element of the scatter-gather list. If you don't -- 1.7.1