diff options
Diffstat (limited to 'drivers/net/virtio_net.c')
| -rw-r--r-- | drivers/net/virtio_net.c | 2041 |
1 files changed, 2041 insertions, 0 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c new file mode 100644 index 000000000..63c7810e1 --- /dev/null +++ b/drivers/net/virtio_net.c @@ -0,0 +1,2041 @@ +/* A network driver using virtio. + * + * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ +//#define DEBUG +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/ethtool.h> +#include <linux/module.h> +#include <linux/virtio.h> +#include <linux/virtio_net.h> +#include <linux/scatterlist.h> +#include <linux/if_vlan.h> +#include <linux/slab.h> +#include <linux/cpu.h> +#include <linux/average.h> +#include <net/busy_poll.h> + +static int napi_weight = NAPI_POLL_WEIGHT; +module_param(napi_weight, int, 0444); + +static bool csum = true, gso = true; +module_param(csum, bool, 0444); +module_param(gso, bool, 0444); + +/* FIXME: MTU in config. */ +#define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) +#define GOOD_COPY_LEN 128 + +/* Weight used for the RX packet size EWMA. The average packet size is used to + * determine the packet buffer size when refilling RX rings. As the entire RX + * ring may be refilled at once, the weight is chosen so that the EWMA will be + * insensitive to short-term, transient changes in packet size. + */ +#define RECEIVE_AVG_WEIGHT 64 + +/* Minimum alignment for mergeable packet buffers. */ +#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256) + +#define VIRTNET_DRIVER_VERSION "1.0.0" + +struct virtnet_stats { + struct u64_stats_sync tx_syncp; + struct u64_stats_sync rx_syncp; + u64 tx_bytes; + u64 tx_packets; + + u64 rx_bytes; + u64 rx_packets; +}; + +/* 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]; + + /* Name of the send queue: output.$index */ + char name[40]; +}; + +/* Internal representation of a receive virtqueue */ +struct receive_queue { + /* Virtqueue associated with this receive_queue */ + struct virtqueue *vq; + + struct napi_struct napi; + + /* Chain pages by the private ptr. */ + struct page *pages; + + /* Average packet length for mergeable receive buffers. */ + struct ewma mrg_avg_pkt_len; + + /* Page frag for packet buffer allocation. */ + struct page_frag alloc_frag; + + /* RX: fragments + linear part + virtio header */ + struct scatterlist sg[MAX_SKB_FRAGS + 2]; + + /* Name of this receive queue: input.$index */ + char name[40]; +}; + +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; + + /* 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; + + /* Host can handle any s/g split between our header and packet data */ + bool any_header_sg; + + /* Packet virtio header size */ + u8 hdr_len; + + /* 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; + + /* Does the affinity hint is set for virtqueues? */ + bool affinity_hint_set; + + /* CPU hot plug notifier */ + struct notifier_block nb; +}; + +struct padded_vnet_hdr { + struct virtio_net_hdr_mrg_rxbuf hdr; + /* + * hdr is in a separate sg buffer, and data sg buffer shares same page + * with this header sg. This padding makes next sg 16 byte aligned + * after the header. + */ + char padding[4]; +}; + +/* 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 (vq->index - 1) / 2; +} + +static int txq2vq(int txq) +{ + return txq * 2 + 1; +} + +static int vq2rxq(struct virtqueue *vq) +{ + return vq->index / 2; +} + +static int rxq2vq(int rxq) +{ + return rxq * 2; +} + +static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb) +{ + return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb; +} + +/* + * 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 receive_queue *rq, struct page *page) +{ + struct page *end; + + /* 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)rq->pages; + rq->pages = page; +} + +static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) +{ + struct page *p = rq->pages; + + if (p) { + rq->pages = (struct page *)p->private; + /* clear private here, it is used to chain pages */ + p->private = 0; + } else + p = alloc_page(gfp_mask); + return p; +} + +static void skb_xmit_done(struct virtqueue *vq) +{ + struct virtnet_info *vi = vq->vdev->priv; + + /* Suppress further interrupts. */ + virtqueue_disable_cb(vq); + + /* We were probably waiting for more output buffers. */ + netif_wake_subqueue(vi->dev, vq2txq(vq)); +} + +static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx) +{ + unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1); + return (truesize + 1) * MERGEABLE_BUFFER_ALIGN; +} + +static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx) +{ + return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN); + +} + +static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize) +{ + unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN; + return (unsigned long)buf | (size - 1); +} + +/* Called from bottom half context */ +static struct sk_buff *page_to_skb(struct virtnet_info *vi, + struct receive_queue *rq, + struct page *page, unsigned int offset, + unsigned int len, unsigned int truesize) +{ + struct sk_buff *skb; + struct virtio_net_hdr_mrg_rxbuf *hdr; + unsigned int copy, hdr_len, hdr_padded_len; + char *p; + + p = page_address(page) + offset; + + /* copy small packet so we can reuse these pages for small data */ + skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); + if (unlikely(!skb)) + return NULL; + + hdr = skb_vnet_hdr(skb); + + hdr_len = vi->hdr_len; + if (vi->mergeable_rx_bufs) + hdr_padded_len = sizeof *hdr; + else + hdr_padded_len = sizeof(struct padded_vnet_hdr); + + memcpy(hdr, p, hdr_len); + + len -= hdr_len; + offset += hdr_padded_len; + p += hdr_padded_len; + + copy = len; + if (copy > skb_tailroom(skb)) + copy = skb_tailroom(skb); + memcpy(skb_put(skb, copy), p, copy); + + len -= copy; + offset += copy; + + if (vi->mergeable_rx_bufs) { + if (len) + skb_add_rx_frag(skb, 0, page, offset, len, truesize); + else + put_page(page); + return skb; + } + + /* + * Verify that we can indeed put this data into a skb. + * This is here to handle cases when the device erroneously + * tries to receive more than is possible. This is usually + * the case of a broken device. + */ + if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { + net_dbg_ratelimited("%s: too much data\n", skb->dev->name); + dev_kfree_skb(skb); + return NULL; + } + BUG_ON(offset >= PAGE_SIZE); + while (len) { + unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len); + skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset, + frag_size, truesize); + len -= frag_size; + page = (struct page *)page->private; + offset = 0; + } + + if (page) + give_pages(rq, page); + + return skb; +} + +static struct sk_buff *receive_small(struct virtnet_info *vi, void *buf, unsigned int len) +{ + struct sk_buff * skb = buf; + + len -= vi->hdr_len; + skb_trim(skb, len); + + return skb; +} + +static struct sk_buff *receive_big(struct net_device *dev, + struct virtnet_info *vi, + struct receive_queue *rq, + void *buf, + unsigned int len) +{ + struct page *page = buf; + struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE); + + if (unlikely(!skb)) + goto err; + + return skb; + +err: + dev->stats.rx_dropped++; + give_pages(rq, page); + return NULL; +} + +static struct sk_buff *receive_mergeable(struct net_device *dev, + struct virtnet_info *vi, + struct receive_queue *rq, + unsigned long ctx, + unsigned int len) +{ + void *buf = mergeable_ctx_to_buf_address(ctx); + struct virtio_net_hdr_mrg_rxbuf *hdr = buf; + u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers); + struct page *page = virt_to_head_page(buf); + int offset = buf - page_address(page); + unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx)); + + struct sk_buff *head_skb = page_to_skb(vi, rq, page, offset, len, + truesize); + struct sk_buff *curr_skb = head_skb; + + if (unlikely(!curr_skb)) + goto err_skb; + while (--num_buf) { + int num_skb_frags; + + ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len); + if (unlikely(!ctx)) { + pr_debug("%s: rx error: %d buffers out of %d missing\n", + dev->name, num_buf, + virtio16_to_cpu(vi->vdev, + hdr->num_buffers)); + dev->stats.rx_length_errors++; + goto err_buf; + } + + buf = mergeable_ctx_to_buf_address(ctx); + page = virt_to_head_page(buf); + + num_skb_frags = skb_shinfo(curr_skb)->nr_frags; + if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) { + struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC); + + if (unlikely(!nskb)) + goto err_skb; + if (curr_skb == head_skb) + skb_shinfo(curr_skb)->frag_list = nskb; + else + curr_skb->next = nskb; + curr_skb = nskb; + head_skb->truesize += nskb->truesize; + num_skb_frags = 0; + } + truesize = max(len, mergeable_ctx_to_buf_truesize(ctx)); + if (curr_skb != head_skb) { + head_skb->data_len += len; + head_skb->len += len; + head_skb->truesize += truesize; + } + offset = buf - page_address(page); + if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) { + put_page(page); + skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1, + len, truesize); + } else { + skb_add_rx_frag(curr_skb, num_skb_frags, page, + offset, len, truesize); + } + } + + ewma_add(&rq->mrg_avg_pkt_len, head_skb->len); + return head_skb; + +err_skb: + put_page(page); + while (--num_buf) { + ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len); + if (unlikely(!ctx)) { + pr_debug("%s: rx error: %d buffers missing\n", + dev->name, num_buf); + dev->stats.rx_length_errors++; + break; + } + page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx)); + put_page(page); + } +err_buf: + dev->stats.rx_dropped++; + dev_kfree_skb(head_skb); + return NULL; +} + +static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, + void *buf, unsigned int len) +{ + struct net_device *dev = vi->dev; + struct virtnet_stats *stats = this_cpu_ptr(vi->stats); + struct sk_buff *skb; + struct virtio_net_hdr_mrg_rxbuf *hdr; + + if (unlikely(len < vi->hdr_len + ETH_HLEN)) { + pr_debug("%s: short packet %i\n", dev->name, len); + dev->stats.rx_length_errors++; + if (vi->mergeable_rx_bufs) { + unsigned long ctx = (unsigned long)buf; + void *base = mergeable_ctx_to_buf_address(ctx); + put_page(virt_to_head_page(base)); + } else if (vi->big_packets) { + give_pages(rq, buf); + } else { + dev_kfree_skb(buf); + } + return; + } + + if (vi->mergeable_rx_bufs) + skb = receive_mergeable(dev, vi, rq, (unsigned long)buf, len); + else if (vi->big_packets) + skb = receive_big(dev, vi, rq, buf, len); + else + skb = receive_small(vi, buf, len); + + if (unlikely(!skb)) + return; + + hdr = skb_vnet_hdr(skb); + + u64_stats_update_begin(&stats->rx_syncp); + stats->rx_bytes += skb->len; + stats->rx_packets++; + u64_stats_update_end(&stats->rx_syncp); + + if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + pr_debug("Needs csum!\n"); + if (!skb_partial_csum_set(skb, + virtio16_to_cpu(vi->vdev, hdr->hdr.csum_start), + virtio16_to_cpu(vi->vdev, hdr->hdr.csum_offset))) + goto frame_err; + } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + + skb->protocol = eth_type_trans(skb, dev); + pr_debug("Receiving skb proto 0x%04x len %i type %i\n", + ntohs(skb->protocol), skb->len, skb->pkt_type); + + if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { + pr_debug("GSO!\n"); + switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { + case VIRTIO_NET_HDR_GSO_TCPV4: + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; + break; + case VIRTIO_NET_HDR_GSO_UDP: + skb_shinfo(skb)->gso_type = SKB_GSO_UDP; + break; + case VIRTIO_NET_HDR_GSO_TCPV6: + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; + break; + default: + net_warn_ratelimited("%s: bad gso type %u.\n", + dev->name, hdr->hdr.gso_type); + goto frame_err; + } + + if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; + + skb_shinfo(skb)->gso_size = virtio16_to_cpu(vi->vdev, + hdr->hdr.gso_size); + if (skb_shinfo(skb)->gso_size == 0) { + net_warn_ratelimited("%s: zero gso size.\n", dev->name); + goto frame_err; + } + + /* Header must be checked, and gso_segs computed. */ + skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; + skb_shinfo(skb)->gso_segs = 0; + } + + skb_mark_napi_id(skb, &rq->napi); + + netif_receive_skb(skb); + return; + +frame_err: + dev->stats.rx_frame_errors++; + dev_kfree_skb(skb); +} + +static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, + gfp_t gfp) +{ + struct sk_buff *skb; + struct virtio_net_hdr_mrg_rxbuf *hdr; + int err; + + skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp); + if (unlikely(!skb)) + return -ENOMEM; + + skb_put(skb, GOOD_PACKET_LEN); + + hdr = skb_vnet_hdr(skb); + sg_init_table(rq->sg, MAX_SKB_FRAGS + 2); + sg_set_buf(rq->sg, hdr, vi->hdr_len); + skb_to_sgvec(skb, rq->sg + 1, 0, skb->len); + + err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp); + if (err < 0) + dev_kfree_skb(skb); + + return err; +} + +static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq, + gfp_t gfp) +{ + struct page *first, *list = NULL; + char *p; + int i, err, offset; + + sg_init_table(rq->sg, MAX_SKB_FRAGS + 2); + + /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */ + for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { + first = get_a_page(rq, gfp); + if (!first) { + if (list) + give_pages(rq, list); + return -ENOMEM; + } + 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(rq, gfp); + if (!first) { + give_pages(rq, list); + return -ENOMEM; + } + p = page_address(first); + + /* rq->sg[0], rq->sg[1] share the same page */ + /* a separated rq->sg[0] for header - required in case !any_header_sg */ + sg_set_buf(&rq->sg[0], p, vi->hdr_len); + + /* rq->sg[1] for data packet, from offset */ + offset = sizeof(struct padded_vnet_hdr); + sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset); + + /* chain first in list head */ + first->private = (unsigned long)list; + err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2, + first, gfp); + if (err < 0) + give_pages(rq, first); + + return err; +} + +static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len) +{ + const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); + unsigned int len; + + len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len), + GOOD_PACKET_LEN, PAGE_SIZE - hdr_len); + return ALIGN(len, MERGEABLE_BUFFER_ALIGN); +} + +static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) +{ + struct page_frag *alloc_frag = &rq->alloc_frag; + char *buf; + unsigned long ctx; + int err; + unsigned int len, hole; + + len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len); + if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp))) + return -ENOMEM; + + buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset; + ctx = mergeable_buf_to_ctx(buf, len); + get_page(alloc_frag->page); + alloc_frag->offset += len; + hole = alloc_frag->size - alloc_frag->offset; + if (hole < len) { + /* To avoid internal fragmentation, if there is very likely not + * enough space for another buffer, add the remaining space to + * the current buffer. This extra space is not included in + * the truesize stored in ctx. + */ + len += hole; + alloc_frag->offset += hole; + } + + sg_init_one(rq->sg, buf, len); + err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp); + if (err < 0) + put_page(virt_to_head_page(buf)); + + return err; +} + +/* + * Returns false if we couldn't fill entirely (OOM). + * + * Normally run in the receive path, but can also be run from ndo_open + * 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, struct receive_queue *rq, + gfp_t gfp) +{ + int err; + bool oom; + + gfp |= __GFP_COLD; + do { + if (vi->mergeable_rx_bufs) + err = add_recvbuf_mergeable(rq, gfp); + else if (vi->big_packets) + err = add_recvbuf_big(vi, rq, gfp); + else + err = add_recvbuf_small(vi, rq, gfp); + + oom = err == -ENOMEM; + if (err) + break; + } while (rq->vq->num_free); + 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[vq2rxq(rvq)]; + + /* Schedule NAPI, Suppress further interrupts if successful. */ + if (napi_schedule_prep(&rq->napi)) { + virtqueue_disable_cb(rvq); + __napi_schedule(&rq->napi); + } +} + +static void virtnet_napi_enable(struct receive_queue *rq) +{ + 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(&rq->napi)) { + virtqueue_disable_cb(rq->vq); + local_bh_disable(); + __napi_schedule(&rq->napi); + local_bh_enable(); + } +} + +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->curr_queue_pairs; i++) { + struct receive_queue *rq = &vi->rq[i]; + + napi_disable(&rq->napi); + still_empty = !try_fill_recv(vi, 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); + } +} + +static int virtnet_receive(struct receive_queue *rq, int budget) +{ + struct virtnet_info *vi = rq->vq->vdev->priv; + unsigned int len, received = 0; + void *buf; + + while (received < budget && + (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { + receive_buf(vi, rq, buf, len); + received++; + } + + if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) { + if (!try_fill_recv(vi, rq, GFP_ATOMIC)) + schedule_delayed_work(&vi->refill, 0); + } + + return received; +} + +static int virtnet_poll(struct napi_struct *napi, int budget) +{ + struct receive_queue *rq = + container_of(napi, struct receive_queue, napi); + unsigned int r, received; + + received = virtnet_receive(rq, budget); + + /* Out of packets? */ + if (received < budget) { + r = virtqueue_enable_cb_prepare(rq->vq); + napi_complete(napi); + if (unlikely(virtqueue_poll(rq->vq, r)) && + napi_schedule_prep(napi)) { + virtqueue_disable_cb(rq->vq); + __napi_schedule(napi); + } + } + + return received; +} + +#ifdef CONFIG_NET_RX_BUSY_POLL +/* must be called with local_bh_disable()d */ +static int virtnet_busy_poll(struct napi_struct *napi) +{ + struct receive_queue *rq = + container_of(napi, struct receive_queue, napi); + struct virtnet_info *vi = rq->vq->vdev->priv; + int r, received = 0, budget = 4; + + if (!(vi->status & VIRTIO_NET_S_LINK_UP)) + return LL_FLUSH_FAILED; + + if (!napi_schedule_prep(napi)) + return LL_FLUSH_BUSY; + + virtqueue_disable_cb(rq->vq); + +again: + received += virtnet_receive(rq, budget); + + r = virtqueue_enable_cb_prepare(rq->vq); + clear_bit(NAPI_STATE_SCHED, &napi->state); + if (unlikely(virtqueue_poll(rq->vq, r)) && + napi_schedule_prep(napi)) { + virtqueue_disable_cb(rq->vq); + if (received < budget) { + budget -= received; + goto again; + } else { + __napi_schedule(napi); + } + } + + return received; +} +#endif /* CONFIG_NET_RX_BUSY_POLL */ + +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++) { + if (i < vi->curr_queue_pairs) + /* Make sure we have some buffers: if oom use wq. */ + if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL)) + schedule_delayed_work(&vi->refill, 0); + virtnet_napi_enable(&vi->rq[i]); + } + + return 0; +} + +static void free_old_xmit_skbs(struct send_queue *sq) +{ + struct sk_buff *skb; + unsigned int len; + struct virtnet_info *vi = sq->vq->vdev->priv; + struct virtnet_stats *stats = this_cpu_ptr(vi->stats); + + while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { + pr_debug("Sent skb %p\n", skb); + + u64_stats_update_begin(&stats->tx_syncp); + stats->tx_bytes += skb->len; + stats->tx_packets++; + u64_stats_update_end(&stats->tx_syncp); + + dev_kfree_skb_any(skb); + } +} + +static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) +{ + struct virtio_net_hdr_mrg_rxbuf *hdr; + const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; + struct virtnet_info *vi = sq->vq->vdev->priv; + unsigned num_sg; + unsigned hdr_len = vi->hdr_len; + bool can_push; + + pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); + + can_push = vi->any_header_sg && + !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) && + !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len; + /* Even if we can, don't push here yet as this would skew + * csum_start offset below. */ + if (can_push) + hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len); + else + hdr = skb_vnet_hdr(skb); + + if (skb->ip_summed == CHECKSUM_PARTIAL) { + hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; + hdr->hdr.csum_start = cpu_to_virtio16(vi->vdev, + skb_checksum_start_offset(skb)); + hdr->hdr.csum_offset = cpu_to_virtio16(vi->vdev, + skb->csum_offset); + } else { + hdr->hdr.flags = 0; + hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; + } + + if (skb_is_gso(skb)) { + hdr->hdr.hdr_len = cpu_to_virtio16(vi->vdev, skb_headlen(skb)); + hdr->hdr.gso_size = cpu_to_virtio16(vi->vdev, + skb_shinfo(skb)->gso_size); + if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) + hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; + else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) + hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; + else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) + hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; + else + BUG(); + if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) + hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; + } else { + hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; + hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; + } + + if (vi->mergeable_rx_bufs) + hdr->num_buffers = 0; + + sg_init_table(sq->sg, MAX_SKB_FRAGS + 2); + if (can_push) { + __skb_push(skb, hdr_len); + num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len); + /* Pull header back to avoid skew in tx bytes calculations. */ + __skb_pull(skb, hdr_len); + } else { + sg_set_buf(sq->sg, hdr, hdr_len); + num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1; + } + return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, 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 send_queue *sq = &vi->sq[qnum]; + int err; + struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum); + bool kick = !skb->xmit_more; + + /* Free up any pending old buffers before queueing new ones. */ + free_old_xmit_skbs(sq); + + /* timestamp packet in software */ + skb_tx_timestamp(skb); + + /* Try to transmit */ + err = xmit_skb(sq, skb); + + /* This should not happen! */ + if (unlikely(err)) { + dev->stats.tx_fifo_errors++; + if (net_ratelimit()) + dev_warn(&dev->dev, + "Unexpected TXQ (%d) queue failure: %d\n", qnum, err); + dev->stats.tx_dropped++; + dev_kfree_skb_any(skb); + return NETDEV_TX_OK; + } + + /* Don't wait up for transmitted skbs to be freed. */ + skb_orphan(skb); + nf_reset(skb); + + /* If running out of space, stop queue to avoid getting packets that we + * are then unable to transmit. + * An alternative would be to force queuing layer to requeue the skb by + * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be + * returned in a normal path of operation: it means that driver is not + * maintaining the TX queue stop/start state properly, and causes + * the stack to do a non-trivial amount of useless work. + * Since most packets only take 1 or 2 ring slots, stopping the queue + * early means 16 slots are typically wasted. + */ + if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { + netif_stop_subqueue(dev, qnum); + if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { + /* More just got used, free them then recheck. */ + free_old_xmit_skbs(sq); + if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { + netif_start_subqueue(dev, qnum); + virtqueue_disable_cb(sq->vq); + } + } + } + + if (kick || netif_xmit_stopped(txq)) + virtqueue_kick(sq->vq); + + return NETDEV_TX_OK; +} + +/* + * Send command via the control virtqueue and check status. Commands + * supported by the hypervisor, as indicated by feature bits, should + * never fail unless improperly formatted. + */ +static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, + struct scatterlist *out) +{ + struct scatterlist *sgs[4], hdr, stat; + struct virtio_net_ctrl_hdr ctrl; + virtio_net_ctrl_ack status = ~0; + unsigned out_num = 0, tmp; + + /* Caller should know better */ + BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)); + + ctrl.class = class; + ctrl.cmd = cmd; + /* Add header */ + sg_init_one(&hdr, &ctrl, sizeof(ctrl)); + sgs[out_num++] = &hdr; + + if (out) + sgs[out_num++] = out; + + /* Add return status. */ + sg_init_one(&stat, &status, sizeof(status)); + sgs[out_num] = &stat; + + BUG_ON(out_num + 1 > ARRAY_SIZE(sgs)); + virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC); + + if (unlikely(!virtqueue_kick(vi->cvq))) + return status == VIRTIO_NET_OK; + + /* Spin for a response, the kick causes an ioport write, trapping + * into the hypervisor, so the request should be handled immediately. + */ + while (!virtqueue_get_buf(vi->cvq, &tmp) && + !virtqueue_is_broken(vi->cvq)) + cpu_relax(); + + return status == VIRTIO_NET_OK; +} + +static int virtnet_set_mac_address(struct net_device *dev, void *p) +{ + struct virtnet_info *vi = netdev_priv(dev); + struct virtio_device *vdev = vi->vdev; + int ret; + struct sockaddr *addr = p; + struct scatterlist sg; + + ret = eth_prepare_mac_addr_change(dev, p); + if (ret) + return ret; + + if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) { + sg_init_one(&sg, addr->sa_data, dev->addr_len); + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, + VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) { + dev_warn(&vdev->dev, + "Failed to set mac address by vq command.\n"); + return -EINVAL; + } + } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) && + !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { + unsigned int i; + + /* Naturally, this has an atomicity problem. */ + for (i = 0; i < dev->addr_len; i++) + virtio_cwrite8(vdev, + offsetof(struct virtio_net_config, mac) + + i, addr->sa_data[i]); + } + + eth_commit_mac_addr_change(dev, p); + + return 0; +} + +static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, + struct rtnl_link_stats64 *tot) +{ + struct virtnet_info *vi = netdev_priv(dev); + int cpu; + unsigned int start; + + for_each_possible_cpu(cpu) { + struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); + u64 tpackets, tbytes, rpackets, rbytes; + + do { + start = u64_stats_fetch_begin_irq(&stats->tx_syncp); + tpackets = stats->tx_packets; + tbytes = stats->tx_bytes; + } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start)); + + do { + start = u64_stats_fetch_begin_irq(&stats->rx_syncp); + rpackets = stats->rx_packets; + rbytes = stats->rx_bytes; + } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start)); + + tot->rx_packets += rpackets; + tot->tx_packets += tpackets; + tot->rx_bytes += rbytes; + tot->tx_bytes += tbytes; + } + + tot->tx_dropped = dev->stats.tx_dropped; + tot->tx_fifo_errors = dev->stats.tx_fifo_errors; + tot->rx_dropped = dev->stats.rx_dropped; + tot->rx_length_errors = dev->stats.rx_length_errors; + tot->rx_frame_errors = dev->stats.rx_frame_errors; + + return tot; +} + +#ifdef CONFIG_NET_POLL_CONTROLLER +static void virtnet_netpoll(struct net_device *dev) +{ + struct virtnet_info *vi = netdev_priv(dev); + int i; + + for (i = 0; i < vi->curr_queue_pairs; i++) + napi_schedule(&vi->rq[i].napi); +} +#endif + +static void virtnet_ack_link_announce(struct virtnet_info *vi) +{ + rtnl_lock(); + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE, + VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL)) + dev_warn(&vi->dev->dev, "Failed to ack link announce.\n"); + rtnl_unlock(); +} + +static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) +{ + struct scatterlist sg; + struct virtio_net_ctrl_mq s; + struct net_device *dev = vi->dev; + + if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ)) + return 0; + + s.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs); + sg_init_one(&sg, &s, sizeof(s)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ, + VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) { + dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n", + queue_pairs); + return -EINVAL; + } else { + vi->curr_queue_pairs = queue_pairs; + /* virtnet_open() will refill when device is going to up. */ + if (dev->flags & IFF_UP) + schedule_delayed_work(&vi->refill, 0); + } + + 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); + + for (i = 0; i < vi->max_queue_pairs; i++) + napi_disable(&vi->rq[i].napi); + + return 0; +} + +static void virtnet_set_rx_mode(struct net_device *dev) +{ + struct virtnet_info *vi = netdev_priv(dev); + struct scatterlist sg[2]; + u8 promisc, allmulti; + struct virtio_net_ctrl_mac *mac_data; + struct netdev_hw_addr *ha; + int uc_count; + int mc_count; + void *buf; + int i; + + /* We can't dynamically set ndo_set_rx_mode, so return gracefully */ + if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) + return; + + promisc = ((dev->flags & IFF_PROMISC) != 0); + allmulti = ((dev->flags & IFF_ALLMULTI) != 0); + + sg_init_one(sg, &promisc, sizeof(promisc)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, + VIRTIO_NET_CTRL_RX_PROMISC, sg)) + dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", + promisc ? "en" : "dis"); + + sg_init_one(sg, &allmulti, sizeof(allmulti)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, + VIRTIO_NET_CTRL_RX_ALLMULTI, sg)) + dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", + allmulti ? "en" : "dis"); + + uc_count = netdev_uc_count(dev); + mc_count = netdev_mc_count(dev); + /* MAC filter - use one buffer for both lists */ + buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + + (2 * sizeof(mac_data->entries)), GFP_ATOMIC); + mac_data = buf; + if (!buf) + return; + + sg_init_table(sg, 2); + + /* Store the unicast list and count in the front of the buffer */ + mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count); + i = 0; + netdev_for_each_uc_addr(ha, dev) + memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); + + sg_set_buf(&sg[0], mac_data, + sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); + + /* multicast list and count fill the end */ + mac_data = (void *)&mac_data->macs[uc_count][0]; + + mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count); + i = 0; + netdev_for_each_mc_addr(ha, dev) + memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); + + sg_set_buf(&sg[1], mac_data, + sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, + VIRTIO_NET_CTRL_MAC_TABLE_SET, sg)) + dev_warn(&dev->dev, "Failed to set MAC filter table.\n"); + + kfree(buf); +} + +static int virtnet_vlan_rx_add_vid(struct net_device *dev, + __be16 proto, u16 vid) +{ + struct virtnet_info *vi = netdev_priv(dev); + struct scatterlist sg; + + sg_init_one(&sg, &vid, sizeof(vid)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, + VIRTIO_NET_CTRL_VLAN_ADD, &sg)) + dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); + return 0; +} + +static int virtnet_vlan_rx_kill_vid(struct net_device *dev, + __be16 proto, u16 vid) +{ + struct virtnet_info *vi = netdev_priv(dev); + struct scatterlist sg; + + sg_init_one(&sg, &vid, sizeof(vid)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, + VIRTIO_NET_CTRL_VLAN_DEL, &sg)) + dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); + return 0; +} + +static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu) +{ + int i; + + if (vi->affinity_hint_set) { + for (i = 0; i < vi->max_queue_pairs; i++) { + virtqueue_set_affinity(vi->rq[i].vq, -1); + virtqueue_set_affinity(vi->sq[i].vq, -1); + } + + vi->affinity_hint_set = false; + } +} + +static void virtnet_set_affinity(struct virtnet_info *vi) +{ + int i; + int cpu; + + /* In multiqueue mode, when the number of cpu is equal to the number of + * queue pairs, we let the queue pairs to be private to one cpu by + * setting the affinity hint to eliminate the contention. + */ + if (vi->curr_queue_pairs == 1 || + vi->max_queue_pairs != num_online_cpus()) { + virtnet_clean_affinity(vi, -1); + return; + } + + i = 0; + for_each_online_cpu(cpu) { + virtqueue_set_affinity(vi->rq[i].vq, cpu); + virtqueue_set_affinity(vi->sq[i].vq, cpu); + netif_set_xps_queue(vi->dev, cpumask_of(cpu), i); + i++; + } + + vi->affinity_hint_set = true; +} + +static int virtnet_cpu_callback(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb); + + switch(action & ~CPU_TASKS_FROZEN) { + case CPU_ONLINE: + case CPU_DOWN_FAILED: + case CPU_DEAD: + virtnet_set_affinity(vi); + break; + case CPU_DOWN_PREPARE: + virtnet_clean_affinity(vi, (long)hcpu); + break; + default: + break; + } + + return NOTIFY_OK; +} + +static void virtnet_get_ringparam(struct net_device *dev, + struct ethtool_ringparam *ring) +{ + struct virtnet_info *vi = netdev_priv(dev); + + 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; +} + + +static void virtnet_get_drvinfo(struct net_device *dev, + struct ethtool_drvinfo *info) +{ + struct virtnet_info *vi = netdev_priv(dev); + struct virtio_device *vdev = vi->vdev; + + strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); + strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); + strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); + +} + +/* 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; + int err; + + /* 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 || queue_pairs == 0) + return -EINVAL; + + get_online_cpus(); + err = virtnet_set_queues(vi, queue_pairs); + if (!err) { + netif_set_real_num_tx_queues(dev, queue_pairs); + netif_set_real_num_rx_queues(dev, queue_pairs); + + virtnet_set_affinity(vi); + } + put_online_cpus(); + + return err; +} + +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, + .get_ts_info = ethtool_op_get_ts_info, +}; + +#define MIN_MTU 68 +#define MAX_MTU 65535 + +static int virtnet_change_mtu(struct net_device *dev, int new_mtu) +{ + if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) + return -EINVAL; + dev->mtu = new_mtu; + return 0; +} + +static const struct net_device_ops virtnet_netdev = { + .ndo_open = virtnet_open, + .ndo_stop = virtnet_close, + .ndo_start_xmit = start_xmit, + .ndo_validate_addr = eth_validate_addr, + .ndo_set_mac_address = virtnet_set_mac_address, + .ndo_set_rx_mode = virtnet_set_rx_mode, + .ndo_change_mtu = virtnet_change_mtu, + .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, +#ifdef CONFIG_NET_POLL_CONTROLLER + .ndo_poll_controller = virtnet_netpoll, +#endif +#ifdef CONFIG_NET_RX_BUSY_POLL + .ndo_busy_poll = virtnet_busy_poll, +#endif +}; + +static void virtnet_config_changed_work(struct work_struct *work) +{ + struct virtnet_info *vi = + container_of(work, struct virtnet_info, config_work); + u16 v; + + if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS, + struct virtio_net_config, status, &v) < 0) + return; + + if (v & VIRTIO_NET_S_ANNOUNCE) { + netdev_notify_peers(vi->dev); + virtnet_ack_link_announce(vi); + } + + /* Ignore unknown (future) status bits */ + v &= VIRTIO_NET_S_LINK_UP; + + if (vi->status == v) + return; + + vi->status = v; + + if (vi->status & VIRTIO_NET_S_LINK_UP) { + netif_carrier_on(vi->dev); + netif_tx_wake_all_queues(vi->dev); + } else { + netif_carrier_off(vi->dev); + netif_tx_stop_all_queues(vi->dev); + } +} + +static void virtnet_config_changed(struct virtio_device *vdev) +{ + struct virtnet_info *vi = vdev->priv; + + schedule_work(&vi->config_work); +} + +static void virtnet_free_queues(struct virtnet_info *vi) +{ + int i; + + for (i = 0; i < vi->max_queue_pairs; i++) { + napi_hash_del(&vi->rq[i].napi); + netif_napi_del(&vi->rq[i].napi); + } + + kfree(vi->rq); + kfree(vi->sq); +} + +static void free_receive_bufs(struct virtnet_info *vi) +{ + int i; + + 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); + } +} + +static void free_receive_page_frags(struct virtnet_info *vi) +{ + int i; + for (i = 0; i < vi->max_queue_pairs; i++) + if (vi->rq[i].alloc_frag.page) + put_page(vi->rq[i].alloc_frag.page); +} + +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) { + unsigned long ctx = (unsigned long)buf; + void *base = mergeable_ctx_to_buf_address(ctx); + put_page(virt_to_head_page(base)); + } else if (vi->big_packets) { + give_pages(&vi->rq[i], buf); + } else { + dev_kfree_skb(buf); + } + } + } +} + +static void virtnet_del_vqs(struct virtnet_info *vi) +{ + struct virtio_device *vdev = vi->vdev; + + virtnet_clean_affinity(vi, -1); + + 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; + const char **names; + + /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed 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); + if (!vqs) + goto err_vq; + callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); + if (!callbacks) + goto err_callback; + names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); + if (!names) + goto err_names; + + /* Parameters for control virtqueue, if any */ + if (vi->has_cvq) { + callbacks[total_vqs - 1] = NULL; + names[total_vqs - 1] = "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; + sprintf(vi->rq[i].name, "input.%d", i); + sprintf(vi->sq[i].name, "output.%d", i); + names[rxq2vq(i)] = vi->rq[i].name; + names[txq2vq(i)] = vi->sq[i].name; + } + + ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, + names); + if (ret) + goto err_find; + + 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_CTAG_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(names); + kfree(callbacks); + kfree(vqs); + + return 0; + +err_find: + kfree(names); +err_names: + kfree(callbacks); +err_callback: + kfree(vqs); +err_vq: + return ret; +} + +static int virtnet_alloc_queues(struct virtnet_info *vi) +{ + int i; + + vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL); + if (!vi->sq) + goto err_sq; + vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL); + if (!vi->rq) + goto err_rq; + + INIT_DELAYED_WORK(&vi->refill, refill_work); + 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); + napi_hash_add(&vi->rq[i].napi); + + sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); + ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT); + sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); + } + + return 0; + +err_rq: + kfree(vi->sq); +err_sq: + 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; + + get_online_cpus(); + virtnet_set_affinity(vi); + put_online_cpus(); + + return 0; + +err_free: + virtnet_free_queues(vi); +err: + return ret; +} + +#ifdef CONFIG_SYSFS +static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue, + struct rx_queue_attribute *attribute, char *buf) +{ + struct virtnet_info *vi = netdev_priv(queue->dev); + unsigned int queue_index = get_netdev_rx_queue_index(queue); + struct ewma *avg; + + BUG_ON(queue_index >= vi->max_queue_pairs); + avg = &vi->rq[queue_index].mrg_avg_pkt_len; + return sprintf(buf, "%u\n", get_mergeable_buf_len(avg)); +} + +static struct rx_queue_attribute mergeable_rx_buffer_size_attribute = + __ATTR_RO(mergeable_rx_buffer_size); + +static struct attribute *virtio_net_mrg_rx_attrs[] = { + &mergeable_rx_buffer_size_attribute.attr, + NULL +}; + +static const struct attribute_group virtio_net_mrg_rx_group = { + .name = "virtio_net", + .attrs = virtio_net_mrg_rx_attrs +}; +#endif + +static bool virtnet_fail_on_feature(struct virtio_device *vdev, + unsigned int fbit, + const char *fname, const char *dname) +{ + if (!virtio_has_feature(vdev, fbit)) + return false; + + dev_err(&vdev->dev, "device advertises feature %s but not %s", + fname, dname); + + return true; +} + +#define VIRTNET_FAIL_ON(vdev, fbit, dbit) \ + virtnet_fail_on_feature(vdev, fbit, #fbit, dbit) + +static bool virtnet_validate_features(struct virtio_device *vdev) +{ + if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) && + (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX, + "VIRTIO_NET_F_CTRL_VQ") || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN, + "VIRTIO_NET_F_CTRL_VQ") || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE, + "VIRTIO_NET_F_CTRL_VQ") || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR, + "VIRTIO_NET_F_CTRL_VQ"))) { + return false; + } + + return true; +} + +static int virtnet_probe(struct virtio_device *vdev) +{ + int i, err; + struct net_device *dev; + struct virtnet_info *vi; + u16 max_queue_pairs; + + if (!vdev->config->get) { + dev_err(&vdev->dev, "%s failure: config access disabled\n", + __func__); + return -EINVAL; + } + + if (!virtnet_validate_features(vdev)) + return -EINVAL; + + /* Find if host supports multiqueue virtio_net device */ + err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ, + 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_MQ_VQ_PAIRS_MIN || + max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX || + !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) + max_queue_pairs = 1; + + /* Allocate ourselves a network device with room for our info */ + dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs); + if (!dev) + return -ENOMEM; + + /* Set up network device as normal. */ + dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE; + dev->netdev_ops = &virtnet_netdev; + dev->features = NETIF_F_HIGHDMA; + + dev->ethtool_ops = &virtnet_ethtool_ops; + SET_NETDEV_DEV(dev, &vdev->dev); + + /* Do we support "hardware" checksums? */ + if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { + /* This opens up the world of extra features. */ + dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; + if (csum) + dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; + + if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { + dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO + | NETIF_F_TSO_ECN | NETIF_F_TSO6; + } + /* Individual feature bits: what can host handle? */ + if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) + dev->hw_features |= NETIF_F_TSO; + if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) + dev->hw_features |= NETIF_F_TSO6; + if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) + dev->hw_features |= NETIF_F_TSO_ECN; + if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) + dev->hw_features |= NETIF_F_UFO; + + dev->features |= NETIF_F_GSO_ROBUST; + + if (gso) + dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); + /* (!csum && gso) case will be fixed by register_netdev() */ + } + if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM)) + dev->features |= NETIF_F_RXCSUM; + + dev->vlan_features = dev->features; + + /* Configuration may specify what MAC to use. Otherwise random. */ + if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) + virtio_cread_bytes(vdev, + offsetof(struct virtio_net_config, mac), + dev->dev_addr, dev->addr_len); + else + eth_hw_addr_random(dev); + + /* Set up our device-specific information */ + vi = netdev_priv(dev); + vi->dev = dev; + vi->vdev = vdev; + vdev->priv = vi; + vi->stats = alloc_percpu(struct virtnet_stats); + err = -ENOMEM; + if (vi->stats == NULL) + goto free; + + for_each_possible_cpu(i) { + struct virtnet_stats *virtnet_stats; + virtnet_stats = per_cpu_ptr(vi->stats, i); + u64_stats_init(&virtnet_stats->tx_syncp); + u64_stats_init(&virtnet_stats->rx_syncp); + } + + INIT_WORK(&vi->config_work, virtnet_config_changed_work); + + /* If we can receive ANY GSO packets, we must allocate large ones. */ + if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || + virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || + virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) || + virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO)) + vi->big_packets = true; + + if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) + vi->mergeable_rx_bufs = true; + + if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) || + virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) + vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); + else + vi->hdr_len = sizeof(struct virtio_net_hdr); + + if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) + vi->any_header_sg = true; + + if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) + vi->has_cvq = true; + + if (vi->any_header_sg) + dev->needed_headroom = vi->hdr_len; + + /* 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; + +#ifdef CONFIG_SYSFS + if (vi->mergeable_rx_bufs) + dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group; +#endif + netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs); + netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs); + + err = register_netdev(dev); + if (err) { + pr_debug("virtio_net: registering device failed\n"); + goto free_vqs; + } + + virtio_device_ready(vdev); + + /* Last of all, set up some receive buffers. */ + for (i = 0; i < vi->curr_queue_pairs; i++) { + try_fill_recv(vi, &vi->rq[i], GFP_KERNEL); + + /* If we didn't even get one input buffer, we're useless. */ + if (vi->rq[i].vq->num_free == + virtqueue_get_vring_size(vi->rq[i].vq)) { + free_unused_bufs(vi); + err = -ENOMEM; + goto free_recv_bufs; + } + } + + vi->nb.notifier_call = &virtnet_cpu_callback; + err = register_hotcpu_notifier(&vi->nb); + if (err) { + pr_debug("virtio_net: registering cpu notifier failed\n"); + goto free_recv_bufs; + } + + /* Assume link up if device can't report link status, + otherwise get link status from config. */ + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { + netif_carrier_off(dev); + schedule_work(&vi->config_work); + } else { + vi->status = VIRTIO_NET_S_LINK_UP; + netif_carrier_on(dev); + } + + pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", + dev->name, max_queue_pairs); + + return 0; + +free_recv_bufs: + vi->vdev->config->reset(vdev); + + free_receive_bufs(vi); + unregister_netdev(dev); +free_vqs: + cancel_delayed_work_sync(&vi->refill); + free_receive_page_frags(vi); + virtnet_del_vqs(vi); +free_stats: + free_percpu(vi->stats); +free: + free_netdev(dev); + return err; +} + +static void remove_vq_common(struct virtnet_info *vi) +{ + vi->vdev->config->reset(vi->vdev); + + /* Free unused buffers in both send and recv, if any. */ + free_unused_bufs(vi); + + free_receive_bufs(vi); + + free_receive_page_frags(vi); + + virtnet_del_vqs(vi); +} + +static void virtnet_remove(struct virtio_device *vdev) +{ + struct virtnet_info *vi = vdev->priv; + + unregister_hotcpu_notifier(&vi->nb); + + /* Make sure no work handler is accessing the device. */ + flush_work(&vi->config_work); + + unregister_netdev(vi->dev); + + remove_vq_common(vi); + + free_percpu(vi->stats); + free_netdev(vi->dev); +} + +#ifdef CONFIG_PM_SLEEP +static int virtnet_freeze(struct virtio_device *vdev) +{ + struct virtnet_info *vi = vdev->priv; + int i; + + unregister_hotcpu_notifier(&vi->nb); + + /* Make sure no work handler is accessing the device */ + flush_work(&vi->config_work); + + netif_device_detach(vi->dev); + cancel_delayed_work_sync(&vi->refill); + + if (netif_running(vi->dev)) { + for (i = 0; i < vi->max_queue_pairs; i++) + napi_disable(&vi->rq[i].napi); + } + + remove_vq_common(vi); + + return 0; +} + +static int virtnet_restore(struct virtio_device *vdev) +{ + struct virtnet_info *vi = vdev->priv; + int err, i; + + err = init_vqs(vi); + if (err) + return err; + + virtio_device_ready(vdev); + + if (netif_running(vi->dev)) { + for (i = 0; i < vi->curr_queue_pairs; i++) + if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL)) + schedule_delayed_work(&vi->refill, 0); + + for (i = 0; i < vi->max_queue_pairs; i++) + virtnet_napi_enable(&vi->rq[i]); + } + + netif_device_attach(vi->dev); + + rtnl_lock(); + virtnet_set_queues(vi, vi->curr_queue_pairs); + rtnl_unlock(); + + err = register_hotcpu_notifier(&vi->nb); + if (err) + return err; + + return 0; +} +#endif + +static struct virtio_device_id id_table[] = { + { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; + +static unsigned int features[] = { + VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, + VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, + VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, + VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, + 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_MQ, + VIRTIO_NET_F_CTRL_MAC_ADDR, + VIRTIO_F_ANY_LAYOUT, +}; + +static struct virtio_driver virtio_net_driver = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), + .driver.name = KBUILD_MODNAME, + .driver.owner = THIS_MODULE, + .id_table = id_table, + .probe = virtnet_probe, + .remove = virtnet_remove, + .config_changed = virtnet_config_changed, +#ifdef CONFIG_PM_SLEEP + .freeze = virtnet_freeze, + .restore = virtnet_restore, +#endif +}; + +module_virtio_driver(virtio_net_driver); + +MODULE_DEVICE_TABLE(virtio, id_table); +MODULE_DESCRIPTION("Virtio network driver"); +MODULE_LICENSE("GPL"); |