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OpenCloudOS-Kernel/drivers/net/virtio_net.c

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/* 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");
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