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kernel-fxtec-pro1x/drivers/net/virtio_net.c
Michael S. Tsirkin 791195cc82 virtio_net: fix lockdep warning on 32 bit 
[ Upstream commit 01c3259818a11f3cc3cd767adbae6b45849c03c1 ]

When we fill up a receive VQ, try_fill_recv currently tries to count
kicks using a 64 bit stats counter. Turns out, on a 32 bit kernel that
uses a seqcount. sequence counts are "lock" constructs where you need to
make sure that writers are serialized.

In turn, this means that we mustn't run two try_fill_recv concurrently.
Which of course we don't. We do run try_fill_recv sometimes from a
softirq napi context, and sometimes from a fully preemptible context,
but the later always runs with napi disabled.

However, when it comes to the seqcount, lockdep is trying to enforce the
rule that the same lock isn't accessed from preemptible and softirq
context - it doesn't know about napi being enabled/disabled. This causes
a false-positive warning:

WARNING: inconsistent lock state
...
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.

As a work around, shut down the warning by switching
to u64_stats_update_begin_irqsave - that works by disabling
interrupts on 32 bit only, is a NOP on 64 bit.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20 08:18:37 +02:00

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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/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/scatterlist.h>
#include <linux/if_vlan.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/average.h>
#include <linux/filter.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <net/route.h>
#include <net/xdp.h>
#include <net/net_failover.h>
static int napi_weight = NAPI_POLL_WEIGHT;
module_param(napi_weight, int, 0444);
static bool csum = true, gso = true, napi_tx;
module_param(csum, bool, 0444);
module_param(gso, bool, 0444);
module_param(napi_tx, bool, 0644);
/* FIXME: MTU in config. */
#define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
#define GOOD_COPY_LEN 128
#define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
/* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
#define VIRTIO_XDP_HEADROOM 256
/* Separating two types of XDP xmit */
#define VIRTIO_XDP_TX BIT(0)
#define VIRTIO_XDP_REDIR BIT(1)
#define VIRTIO_XDP_FLAG BIT(0)
/* 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.
*/
DECLARE_EWMA(pkt_len, 0, 64)
#define VIRTNET_DRIVER_VERSION "1.0.0"
static const unsigned long guest_offloads[] = {
VIRTIO_NET_F_GUEST_TSO4,
VIRTIO_NET_F_GUEST_TSO6,
VIRTIO_NET_F_GUEST_ECN,
VIRTIO_NET_F_GUEST_UFO,
VIRTIO_NET_F_GUEST_CSUM
};
struct virtnet_stat_desc {
char desc[ETH_GSTRING_LEN];
size_t offset;
};
struct virtnet_sq_stats {
struct u64_stats_sync syncp;
u64 packets;
u64 bytes;
u64 xdp_tx;
u64 xdp_tx_drops;
u64 kicks;
};
struct virtnet_rq_stats {
struct u64_stats_sync syncp;
u64 packets;
u64 bytes;
u64 drops;
u64 xdp_packets;
u64 xdp_tx;
u64 xdp_redirects;
u64 xdp_drops;
u64 kicks;
};
#define VIRTNET_SQ_STAT(m) offsetof(struct virtnet_sq_stats, m)
#define VIRTNET_RQ_STAT(m) offsetof(struct virtnet_rq_stats, m)
static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
{ "packets", VIRTNET_SQ_STAT(packets) },
{ "bytes", VIRTNET_SQ_STAT(bytes) },
{ "xdp_tx", VIRTNET_SQ_STAT(xdp_tx) },
{ "xdp_tx_drops", VIRTNET_SQ_STAT(xdp_tx_drops) },
{ "kicks", VIRTNET_SQ_STAT(kicks) },
};
static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
{ "packets", VIRTNET_RQ_STAT(packets) },
{ "bytes", VIRTNET_RQ_STAT(bytes) },
{ "drops", VIRTNET_RQ_STAT(drops) },
{ "xdp_packets", VIRTNET_RQ_STAT(xdp_packets) },
{ "xdp_tx", VIRTNET_RQ_STAT(xdp_tx) },
{ "xdp_redirects", VIRTNET_RQ_STAT(xdp_redirects) },
{ "xdp_drops", VIRTNET_RQ_STAT(xdp_drops) },
{ "kicks", VIRTNET_RQ_STAT(kicks) },
};
#define VIRTNET_SQ_STATS_LEN ARRAY_SIZE(virtnet_sq_stats_desc)
#define VIRTNET_RQ_STATS_LEN ARRAY_SIZE(virtnet_rq_stats_desc)
/* 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.$index */
char name[40];
struct virtnet_sq_stats stats;
struct napi_struct napi;
};
/* Internal representation of a receive virtqueue */
struct receive_queue {
/* Virtqueue associated with this receive_queue */
struct virtqueue *vq;
struct napi_struct napi;
struct bpf_prog __rcu *xdp_prog;
struct virtnet_rq_stats stats;
/* Chain pages by the private ptr. */
struct page *pages;
/* Average packet length for mergeable receive buffers. */
struct ewma_pkt_len mrg_avg_pkt_len;
/* Page frag for packet buffer allocation. */
struct page_frag alloc_frag;
/* RX: fragments + linear part + virtio header */
struct scatterlist sg[MAX_SKB_FRAGS + 2];
/* Min single buffer size for mergeable buffers case. */
unsigned int min_buf_len;
/* Name of this receive queue: input.$index */
char name[40];
struct xdp_rxq_info xdp_rxq;
};
/* Control VQ buffers: protected by the rtnl lock */
struct control_buf {
struct virtio_net_ctrl_hdr hdr;
virtio_net_ctrl_ack status;
struct virtio_net_ctrl_mq mq;
u8 promisc;
u8 allmulti;
__virtio16 vid;
__virtio64 offloads;
};
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;
/* # of XDP queue pairs currently used by the driver */
u16 xdp_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;
/* 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 hotplug instances for online & dead */
struct hlist_node node;
struct hlist_node node_dead;
struct control_buf *ctrl;
/* Ethtool settings */
u8 duplex;
u32 speed;
unsigned long guest_offloads;
/* failover when STANDBY feature enabled */
struct failover *failover;
};
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];
};
static bool is_xdp_frame(void *ptr)
{
return (unsigned long)ptr & VIRTIO_XDP_FLAG;
}
static void *xdp_to_ptr(struct xdp_frame *ptr)
{
return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
}
static struct xdp_frame *ptr_to_xdp(void *ptr)
{
return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
}
/* 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 virtqueue_napi_schedule(struct napi_struct *napi,
struct virtqueue *vq)
{
if (napi_schedule_prep(napi)) {
virtqueue_disable_cb(vq);
__napi_schedule(napi);
}
}
static void virtqueue_napi_complete(struct napi_struct *napi,
struct virtqueue *vq, int processed)
{
int opaque;
opaque = virtqueue_enable_cb_prepare(vq);
if (napi_complete_done(napi, processed)) {
if (unlikely(virtqueue_poll(vq, opaque)))
virtqueue_napi_schedule(napi, vq);
} else {
virtqueue_disable_cb(vq);
}
}
static void skb_xmit_done(struct virtqueue *vq)
{
struct virtnet_info *vi = vq->vdev->priv;
struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
/* Suppress further interrupts. */
virtqueue_disable_cb(vq);
if (napi->weight)
virtqueue_napi_schedule(napi, vq);
else
/* We were probably waiting for more output buffers. */
netif_wake_subqueue(vi->dev, vq2txq(vq));
}
#define MRG_CTX_HEADER_SHIFT 22
static void *mergeable_len_to_ctx(unsigned int truesize,
unsigned int headroom)
{
return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
}
static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
{
return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
}
static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
{
return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 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,
bool hdr_valid)
{
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 = napi_alloc_skb(&rq->napi, 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);
if (hdr_valid)
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);
skb_put_data(skb, 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 int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
struct send_queue *sq,
struct xdp_frame *xdpf)
{
struct virtio_net_hdr_mrg_rxbuf *hdr;
int err;
/* virtqueue want to use data area in-front of packet */
if (unlikely(xdpf->metasize > 0))
return -EOPNOTSUPP;
if (unlikely(xdpf->headroom < vi->hdr_len))
return -EOVERFLOW;
/* Make room for virtqueue hdr (also change xdpf->headroom?) */
xdpf->data -= vi->hdr_len;
/* Zero header and leave csum up to XDP layers */
hdr = xdpf->data;
memset(hdr, 0, vi->hdr_len);
xdpf->len += vi->hdr_len;
sg_init_one(sq->sg, xdpf->data, xdpf->len);
err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
GFP_ATOMIC);
if (unlikely(err))
return -ENOSPC; /* Caller handle free/refcnt */
return 0;
}
static struct send_queue *virtnet_xdp_sq(struct virtnet_info *vi)
{
unsigned int qp;
qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
return &vi->sq[qp];
}
static int virtnet_xdp_xmit(struct net_device *dev,
int n, struct xdp_frame **frames, u32 flags)
{
struct virtnet_info *vi = netdev_priv(dev);
struct receive_queue *rq = vi->rq;
struct bpf_prog *xdp_prog;
struct send_queue *sq;
unsigned int len;
int packets = 0;
int bytes = 0;
int drops = 0;
int kicks = 0;
int ret, err;
void *ptr;
int i;
/* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
* indicate XDP resources have been successfully allocated.
*/
xdp_prog = rcu_dereference(rq->xdp_prog);
if (!xdp_prog)
return -ENXIO;
sq = virtnet_xdp_sq(vi);
if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
ret = -EINVAL;
drops = n;
goto out;
}
/* Free up any pending old buffers before queueing new ones. */
while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
if (likely(is_xdp_frame(ptr))) {
struct xdp_frame *frame = ptr_to_xdp(ptr);
bytes += frame->len;
xdp_return_frame(frame);
} else {
struct sk_buff *skb = ptr;
bytes += skb->len;
napi_consume_skb(skb, false);
}
packets++;
}
for (i = 0; i < n; i++) {
struct xdp_frame *xdpf = frames[i];
err = __virtnet_xdp_xmit_one(vi, sq, xdpf);
if (err) {
xdp_return_frame_rx_napi(xdpf);
drops++;
}
}
ret = n - drops;
if (flags & XDP_XMIT_FLUSH) {
if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
kicks = 1;
}
out:
u64_stats_update_begin(&sq->stats.syncp);
sq->stats.bytes += bytes;
sq->stats.packets += packets;
sq->stats.xdp_tx += n;
sq->stats.xdp_tx_drops += drops;
sq->stats.kicks += kicks;
u64_stats_update_end(&sq->stats.syncp);
return ret;
}
static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
{
return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
}
/* We copy the packet for XDP in the following cases:
*
* 1) Packet is scattered across multiple rx buffers.
* 2) Headroom space is insufficient.
*
* This is inefficient but it's a temporary condition that
* we hit right after XDP is enabled and until queue is refilled
* with large buffers with sufficient headroom - so it should affect
* at most queue size packets.
* Afterwards, the conditions to enable
* XDP should preclude the underlying device from sending packets
* across multiple buffers (num_buf > 1), and we make sure buffers
* have enough headroom.
*/
static struct page *xdp_linearize_page(struct receive_queue *rq,
u16 *num_buf,
struct page *p,
int offset,
int page_off,
unsigned int *len)
{
struct page *page = alloc_page(GFP_ATOMIC);
if (!page)
return NULL;
memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
page_off += *len;
while (--*num_buf) {
int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
unsigned int buflen;
void *buf;
int off;
buf = virtqueue_get_buf(rq->vq, &buflen);
if (unlikely(!buf))
goto err_buf;
p = virt_to_head_page(buf);
off = buf - page_address(p);
/* guard against a misconfigured or uncooperative backend that
* is sending packet larger than the MTU.
*/
if ((page_off + buflen + tailroom) > PAGE_SIZE) {
put_page(p);
goto err_buf;
}
memcpy(page_address(page) + page_off,
page_address(p) + off, buflen);
page_off += buflen;
put_page(p);
}
/* Headroom does not contribute to packet length */
*len = page_off - VIRTIO_XDP_HEADROOM;
return page;
err_buf:
__free_pages(page, 0);
return NULL;
}
static struct sk_buff *receive_small(struct net_device *dev,
struct virtnet_info *vi,
struct receive_queue *rq,
void *buf, void *ctx,
unsigned int len,
unsigned int *xdp_xmit,
struct virtnet_rq_stats *stats)
{
struct sk_buff *skb;
struct bpf_prog *xdp_prog;
unsigned int xdp_headroom = (unsigned long)ctx;
unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
unsigned int headroom = vi->hdr_len + header_offset;
unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
struct page *page = virt_to_head_page(buf);
unsigned int delta = 0;
struct page *xdp_page;
int err;
len -= vi->hdr_len;
stats->bytes += len;
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
if (xdp_prog) {
struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
struct xdp_frame *xdpf;
struct xdp_buff xdp;
void *orig_data;
u32 act;
if (unlikely(hdr->hdr.gso_type))
goto err_xdp;
if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
int offset = buf - page_address(page) + header_offset;
unsigned int tlen = len + vi->hdr_len;
u16 num_buf = 1;
xdp_headroom = virtnet_get_headroom(vi);
header_offset = VIRTNET_RX_PAD + xdp_headroom;
headroom = vi->hdr_len + header_offset;
buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
xdp_page = xdp_linearize_page(rq, &num_buf, page,
offset, header_offset,
&tlen);
if (!xdp_page)
goto err_xdp;
buf = page_address(xdp_page);
put_page(page);
page = xdp_page;
}
xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
xdp.data = xdp.data_hard_start + xdp_headroom;
xdp_set_data_meta_invalid(&xdp);
xdp.data_end = xdp.data + len;
xdp.rxq = &rq->xdp_rxq;
orig_data = xdp.data;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
stats->xdp_packets++;
switch (act) {
case XDP_PASS:
/* Recalculate length in case bpf program changed it */
delta = orig_data - xdp.data;
len = xdp.data_end - xdp.data;
break;
case XDP_TX:
stats->xdp_tx++;
xdpf = convert_to_xdp_frame(&xdp);
if (unlikely(!xdpf))
goto err_xdp;
err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
if (unlikely(err < 0)) {
trace_xdp_exception(vi->dev, xdp_prog, act);
goto err_xdp;
}
*xdp_xmit |= VIRTIO_XDP_TX;
rcu_read_unlock();
goto xdp_xmit;
case XDP_REDIRECT:
stats->xdp_redirects++;
err = xdp_do_redirect(dev, &xdp, xdp_prog);
if (err)
goto err_xdp;
*xdp_xmit |= VIRTIO_XDP_REDIR;
rcu_read_unlock();
goto xdp_xmit;
default:
bpf_warn_invalid_xdp_action(act);
/* fall through */
case XDP_ABORTED:
trace_xdp_exception(vi->dev, xdp_prog, act);
case XDP_DROP:
goto err_xdp;
}
}
rcu_read_unlock();
skb = build_skb(buf, buflen);
if (!skb) {
put_page(page);
goto err;
}
skb_reserve(skb, headroom - delta);
skb_put(skb, len);
if (!delta) {
buf += header_offset;
memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
} /* keep zeroed vnet hdr since packet was changed by bpf */
err:
return skb;
err_xdp:
rcu_read_unlock();
stats->xdp_drops++;
stats->drops++;
put_page(page);
xdp_xmit:
return NULL;
}
static struct sk_buff *receive_big(struct net_device *dev,
struct virtnet_info *vi,
struct receive_queue *rq,
void *buf,
unsigned int len,
struct virtnet_rq_stats *stats)
{
struct page *page = buf;
struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len,
PAGE_SIZE, true);
stats->bytes += len - vi->hdr_len;
if (unlikely(!skb))
goto err;
return skb;
err:
stats->drops++;
give_pages(rq, page);
return NULL;
}
static struct sk_buff *receive_mergeable(struct net_device *dev,
struct virtnet_info *vi,
struct receive_queue *rq,
void *buf,
void *ctx,
unsigned int len,
unsigned int *xdp_xmit,
struct virtnet_rq_stats *stats)
{
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);
struct sk_buff *head_skb, *curr_skb;
struct bpf_prog *xdp_prog;
unsigned int truesize;
unsigned int headroom = mergeable_ctx_to_headroom(ctx);
int err;
head_skb = NULL;
stats->bytes += len - vi->hdr_len;
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
if (xdp_prog) {
struct xdp_frame *xdpf;
struct page *xdp_page;
struct xdp_buff xdp;
void *data;
u32 act;
/* Transient failure which in theory could occur if
* in-flight packets from before XDP was enabled reach
* the receive path after XDP is loaded.
*/
if (unlikely(hdr->hdr.gso_type))
goto err_xdp;
/* This happens when rx buffer size is underestimated
* or headroom is not enough because of the buffer
* was refilled before XDP is set. This should only
* happen for the first several packets, so we don't
* care much about its performance.
*/
if (unlikely(num_buf > 1 ||
headroom < virtnet_get_headroom(vi))) {
/* linearize data for XDP */
xdp_page = xdp_linearize_page(rq, &num_buf,
page, offset,
VIRTIO_XDP_HEADROOM,
&len);
if (!xdp_page)
goto err_xdp;
offset = VIRTIO_XDP_HEADROOM;
} else {
xdp_page = page;
}
/* Allow consuming headroom but reserve enough space to push
* the descriptor on if we get an XDP_TX return code.
*/
data = page_address(xdp_page) + offset;
xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
xdp.data = data + vi->hdr_len;
xdp_set_data_meta_invalid(&xdp);
xdp.data_end = xdp.data + (len - vi->hdr_len);
xdp.rxq = &rq->xdp_rxq;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
stats->xdp_packets++;
switch (act) {
case XDP_PASS:
/* recalculate offset to account for any header
* adjustments. Note other cases do not build an
* skb and avoid using offset
*/
offset = xdp.data -
page_address(xdp_page) - vi->hdr_len;
/* recalculate len if xdp.data or xdp.data_end were
* adjusted
*/
len = xdp.data_end - xdp.data + vi->hdr_len;
/* We can only create skb based on xdp_page. */
if (unlikely(xdp_page != page)) {
rcu_read_unlock();
put_page(page);
head_skb = page_to_skb(vi, rq, xdp_page,
offset, len,
PAGE_SIZE, false);
return head_skb;
}
break;
case XDP_TX:
stats->xdp_tx++;
xdpf = convert_to_xdp_frame(&xdp);
if (unlikely(!xdpf))
goto err_xdp;
err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
if (unlikely(err < 0)) {
trace_xdp_exception(vi->dev, xdp_prog, act);
if (unlikely(xdp_page != page))
put_page(xdp_page);
goto err_xdp;
}
*xdp_xmit |= VIRTIO_XDP_TX;
if (unlikely(xdp_page != page))
put_page(page);
rcu_read_unlock();
goto xdp_xmit;
case XDP_REDIRECT:
stats->xdp_redirects++;
err = xdp_do_redirect(dev, &xdp, xdp_prog);
if (err) {
if (unlikely(xdp_page != page))
put_page(xdp_page);
goto err_xdp;
}
*xdp_xmit |= VIRTIO_XDP_REDIR;
if (unlikely(xdp_page != page))
put_page(page);
rcu_read_unlock();
goto xdp_xmit;
default:
bpf_warn_invalid_xdp_action(act);
/* fall through */
case XDP_ABORTED:
trace_xdp_exception(vi->dev, xdp_prog, act);
/* fall through */
case XDP_DROP:
if (unlikely(xdp_page != page))
__free_pages(xdp_page, 0);
goto err_xdp;
}
}
rcu_read_unlock();
truesize = mergeable_ctx_to_truesize(ctx);
if (unlikely(len > truesize)) {
pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
dev->name, len, (unsigned long)ctx);
dev->stats.rx_length_errors++;
goto err_skb;
}
head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog);
curr_skb = head_skb;
if (unlikely(!curr_skb))
goto err_skb;
while (--num_buf) {
int num_skb_frags;
buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
if (unlikely(!buf)) {
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;
}
stats->bytes += len;
page = virt_to_head_page(buf);
truesize = mergeable_ctx_to_truesize(ctx);
if (unlikely(len > truesize)) {
pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
dev->name, len, (unsigned long)ctx);
dev->stats.rx_length_errors++;
goto err_skb;
}
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;
}
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_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
return head_skb;
err_xdp:
rcu_read_unlock();
stats->xdp_drops++;
err_skb:
put_page(page);
while (num_buf-- > 1) {
buf = virtqueue_get_buf(rq->vq, &len);
if (unlikely(!buf)) {
pr_debug("%s: rx error: %d buffers missing\n",
dev->name, num_buf);
dev->stats.rx_length_errors++;
break;
}
stats->bytes += len;
page = virt_to_head_page(buf);
put_page(page);
}
err_buf:
stats->drops++;
dev_kfree_skb(head_skb);
xdp_xmit:
return NULL;
}
static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
void *buf, unsigned int len, void **ctx,
unsigned int *xdp_xmit,
struct virtnet_rq_stats *stats)
{
struct net_device *dev = vi->dev;
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) {
put_page(virt_to_head_page(buf));
} else if (vi->big_packets) {
give_pages(rq, buf);
} else {
put_page(virt_to_head_page(buf));
}
return;
}
if (vi->mergeable_rx_bufs)
skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
stats);
else if (vi->big_packets)
skb = receive_big(dev, vi, rq, buf, len, stats);
else
skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
if (unlikely(!skb))
return;
hdr = skb_vnet_hdr(skb);
if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
skb->ip_summed = CHECKSUM_UNNECESSARY;
if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
virtio_is_little_endian(vi->vdev))) {
net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
dev->name, hdr->hdr.gso_type,
hdr->hdr.gso_size);
goto frame_err;
}
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);
napi_gro_receive(&rq->napi, skb);
return;
frame_err:
dev->stats.rx_frame_errors++;
dev_kfree_skb(skb);
}
/* Unlike mergeable buffers, all buffers are allocated to the
* same size, except for the headroom. For this reason we do
* not need to use mergeable_len_to_ctx here - it is enough
* to store the headroom as the context ignoring the truesize.
*/
static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
gfp_t gfp)
{
struct page_frag *alloc_frag = &rq->alloc_frag;
char *buf;
unsigned int xdp_headroom = virtnet_get_headroom(vi);
void *ctx = (void *)(unsigned long)xdp_headroom;
int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
int err;
len = SKB_DATA_ALIGN(len) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
return -ENOMEM;
buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
get_page(alloc_frag->page);
alloc_frag->offset += len;
sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
vi->hdr_len + GOOD_PACKET_LEN);
err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
if (err < 0)
put_page(virt_to_head_page(buf));
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 receive_queue *rq,
struct ewma_pkt_len *avg_pkt_len,
unsigned int room)
{
const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
unsigned int len;
if (room)
return PAGE_SIZE - room;
len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
rq->min_buf_len, PAGE_SIZE - hdr_len);
return ALIGN(len, L1_CACHE_BYTES);
}
static int add_recvbuf_mergeable(struct virtnet_info *vi,
struct receive_queue *rq, gfp_t gfp)
{
struct page_frag *alloc_frag = &rq->alloc_frag;
unsigned int headroom = virtnet_get_headroom(vi);
unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
char *buf;
void *ctx;
int err;
unsigned int len, hole;
/* Extra tailroom is needed to satisfy XDP's assumption. This
* means rx frags coalescing won't work, but consider we've
* disabled GSO for XDP, it won't be a big issue.
*/
len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
return -ENOMEM;
buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
buf += headroom; /* advance address leaving hole at front of pkt */
get_page(alloc_frag->page);
alloc_frag->offset += len + room;
hole = alloc_frag->size - alloc_frag->offset;
if (hole < len + room) {
/* To avoid internal fragmentation, if there is very likely not
* enough space for another buffer, add the remaining space to
* the current buffer.
*/
len += hole;
alloc_frag->offset += hole;
}
sg_init_one(rq->sg, buf, len);
ctx = mergeable_len_to_ctx(len, headroom);
err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, 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;
do {
if (vi->mergeable_rx_bufs)
err = add_recvbuf_mergeable(vi, 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);
if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
unsigned long flags;
flags = u64_stats_update_begin_irqsave(&rq->stats.syncp);
rq->stats.kicks++;
u64_stats_update_end_irqrestore(&rq->stats.syncp, flags);
}
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)];
virtqueue_napi_schedule(&rq->napi, rvq);
}
static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
{
napi_enable(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.
* Call local_bh_enable after to trigger softIRQ processing.
*/
local_bh_disable();
virtqueue_napi_schedule(napi, vq);
local_bh_enable();
}
static void virtnet_napi_tx_enable(struct virtnet_info *vi,
struct virtqueue *vq,
struct napi_struct *napi)
{
if (!napi->weight)
return;
/* Tx napi touches cachelines on the cpu handling tx interrupts. Only
* enable the feature if this is likely affine with the transmit path.
*/
if (!vi->affinity_hint_set) {
napi->weight = 0;
return;
}
return virtnet_napi_enable(vq, napi);
}
static void virtnet_napi_tx_disable(struct napi_struct *napi)
{
if (napi->weight)
napi_disable(napi);
}
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->vq, &rq->napi);
/* 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,
unsigned int *xdp_xmit)
{
struct virtnet_info *vi = rq->vq->vdev->priv;
struct virtnet_rq_stats stats = {};
unsigned int len;
void *buf;
int i;
if (!vi->big_packets || vi->mergeable_rx_bufs) {
void *ctx;
while (stats.packets < budget &&
(buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
stats.packets++;
}
} else {
while (stats.packets < budget &&
(buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
stats.packets++;
}
}
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);
}
u64_stats_update_begin(&rq->stats.syncp);
for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
size_t offset = virtnet_rq_stats_desc[i].offset;
u64 *item;
item = (u64 *)((u8 *)&rq->stats + offset);
*item += *(u64 *)((u8 *)&stats + offset);
}
u64_stats_update_end(&rq->stats.syncp);
return stats.packets;
}
static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
{
unsigned int len;
unsigned int packets = 0;
unsigned int bytes = 0;
void *ptr;
while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
if (likely(!is_xdp_frame(ptr))) {
struct sk_buff *skb = ptr;
pr_debug("Sent skb %p\n", skb);
bytes += skb->len;
napi_consume_skb(skb, in_napi);
} else {
struct xdp_frame *frame = ptr_to_xdp(ptr);
bytes += frame->len;
xdp_return_frame(frame);
}
packets++;
}
/* Avoid overhead when no packets have been processed
* happens when called speculatively from start_xmit.
*/
if (!packets)
return;
u64_stats_update_begin(&sq->stats.syncp);
sq->stats.bytes += bytes;
sq->stats.packets += packets;
u64_stats_update_end(&sq->stats.syncp);
}
static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
{
if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
return false;
else if (q < vi->curr_queue_pairs)
return true;
else
return false;
}
static void virtnet_poll_cleantx(struct receive_queue *rq)
{
struct virtnet_info *vi = rq->vq->vdev->priv;
unsigned int index = vq2rxq(rq->vq);
struct send_queue *sq = &vi->sq[index];
struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
return;
if (__netif_tx_trylock(txq)) {
free_old_xmit_skbs(sq, true);
__netif_tx_unlock(txq);
}
if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
netif_tx_wake_queue(txq);
}
static int virtnet_poll(struct napi_struct *napi, int budget)
{
struct receive_queue *rq =
container_of(napi, struct receive_queue, napi);
struct virtnet_info *vi = rq->vq->vdev->priv;
struct send_queue *sq;
unsigned int received;
unsigned int xdp_xmit = 0;
virtnet_poll_cleantx(rq);
received = virtnet_receive(rq, budget, &xdp_xmit);
/* Out of packets? */
if (received < budget)
virtqueue_napi_complete(napi, rq->vq, received);
if (xdp_xmit & VIRTIO_XDP_REDIR)
xdp_do_flush_map();
if (xdp_xmit & VIRTIO_XDP_TX) {
sq = virtnet_xdp_sq(vi);
if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
u64_stats_update_begin(&sq->stats.syncp);
sq->stats.kicks++;
u64_stats_update_end(&sq->stats.syncp);
}
}
return received;
}
static int virtnet_open(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
int i, err;
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);
err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i);
if (err < 0)
return err;
err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
MEM_TYPE_PAGE_SHARED, NULL);
if (err < 0) {
xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
return err;
}
virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
}
return 0;
}
static int virtnet_poll_tx(struct napi_struct *napi, int budget)
{
struct send_queue *sq = container_of(napi, struct send_queue, napi);
struct virtnet_info *vi = sq->vq->vdev->priv;
unsigned int index = vq2txq(sq->vq);
struct netdev_queue *txq;
if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
/* We don't need to enable cb for XDP */
napi_complete_done(napi, 0);
return 0;
}
txq = netdev_get_tx_queue(vi->dev, index);
__netif_tx_lock(txq, raw_smp_processor_id());
free_old_xmit_skbs(sq, true);
__netif_tx_unlock(txq);
virtqueue_napi_complete(napi, sq->vq, 0);
if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
netif_tx_wake_queue(txq);
return 0;
}
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;
int 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 (virtio_net_hdr_from_skb(skb, &hdr->hdr,
virtio_is_little_endian(vi->vdev), false,
0))
BUG();
if (vi->mergeable_rx_bufs)
hdr->num_buffers = 0;
sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
if (can_push) {
__skb_push(skb, hdr_len);
num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
if (unlikely(num_sg < 0))
return num_sg;
/* 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);
if (unlikely(num_sg < 0))
return num_sg;
num_sg++;
}
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;
bool use_napi = sq->napi.weight;
/* Free up any pending old buffers before queueing new ones. */
free_old_xmit_skbs(sq, false);
if (use_napi && kick)
virtqueue_enable_cb_delayed(sq->vq);
/* 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. */
if (!use_napi) {
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 (!use_napi &&
unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
/* More just got used, free them then recheck. */
free_old_xmit_skbs(sq, false);
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)) {
if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
u64_stats_update_begin(&sq->stats.syncp);
sq->stats.kicks++;
u64_stats_update_end(&sq->stats.syncp);
}
}
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;
unsigned out_num = 0, tmp;
/* Caller should know better */
BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
vi->ctrl->status = ~0;
vi->ctrl->hdr.class = class;
vi->ctrl->hdr.cmd = cmd;
/* Add header */
sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
sgs[out_num++] = &hdr;
if (out)
sgs[out_num++] = out;
/* Add return status. */
sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->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 vi->ctrl->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 vi->ctrl->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;
struct scatterlist sg;
if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
return -EOPNOTSUPP;
addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
if (!addr)
return -ENOMEM;
ret = eth_prepare_mac_addr_change(dev, addr);
if (ret)
goto out;
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");
ret = -EINVAL;
goto out;
}
} 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);
ret = 0;
out:
kfree(addr);
return ret;
}
static void virtnet_stats(struct net_device *dev,
struct rtnl_link_stats64 *tot)
{
struct virtnet_info *vi = netdev_priv(dev);
unsigned int start;
int i;
for (i = 0; i < vi->max_queue_pairs; i++) {
u64 tpackets, tbytes, rpackets, rbytes, rdrops;
struct receive_queue *rq = &vi->rq[i];
struct send_queue *sq = &vi->sq[i];
do {
start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
tpackets = sq->stats.packets;
tbytes = sq->stats.bytes;
} while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
do {
start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
rpackets = rq->stats.packets;
rbytes = rq->stats.bytes;
rdrops = rq->stats.drops;
} while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
tot->rx_packets += rpackets;
tot->tx_packets += tpackets;
tot->rx_bytes += rbytes;
tot->tx_bytes += tbytes;
tot->rx_dropped += rdrops;
}
tot->tx_dropped = dev->stats.tx_dropped;
tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
tot->rx_length_errors = dev->stats.rx_length_errors;
tot->rx_frame_errors = dev->stats.rx_frame_errors;
}
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 net_device *dev = vi->dev;
if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
return 0;
vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
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_set_queues(struct virtnet_info *vi, u16 queue_pairs)
{
int err;
rtnl_lock();
err = _virtnet_set_queues(vi, queue_pairs);
rtnl_unlock();
return err;
}
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++) {
xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
napi_disable(&vi->rq[i].napi);
virtnet_napi_tx_disable(&vi->sq[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];
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;
vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->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",
vi->ctrl->promisc ? "en" : "dis");
sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->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",
vi->ctrl->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;
vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->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;
vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->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, NULL);
virtqueue_set_affinity(vi->sq[i].vq, NULL);
}
vi->affinity_hint_set = false;
}
}
static void virtnet_set_affinity(struct virtnet_info *vi)
{
cpumask_var_t mask;
int stragglers;
int group_size;
int i, j, cpu;
int num_cpu;
int stride;
if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
virtnet_clean_affinity(vi, -1);
return;
}
num_cpu = num_online_cpus();
stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
stragglers = num_cpu >= vi->curr_queue_pairs ?
num_cpu % vi->curr_queue_pairs :
0;
cpu = cpumask_next(-1, cpu_online_mask);
for (i = 0; i < vi->curr_queue_pairs; i++) {
group_size = stride + (i < stragglers ? 1 : 0);
for (j = 0; j < group_size; j++) {
cpumask_set_cpu(cpu, mask);
cpu = cpumask_next_wrap(cpu, cpu_online_mask,
nr_cpu_ids, false);
}
virtqueue_set_affinity(vi->rq[i].vq, mask);
virtqueue_set_affinity(vi->sq[i].vq, mask);
__netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, false);
cpumask_clear(mask);
}
vi->affinity_hint_set = true;
free_cpumask_var(mask);
}
static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
{
struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
node);
virtnet_set_affinity(vi);
return 0;
}
static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
{
struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
node_dead);
virtnet_set_affinity(vi);
return 0;
}
static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
{
struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
node);
virtnet_clean_affinity(vi, cpu);
return 0;
}
static enum cpuhp_state virtionet_online;
static int virtnet_cpu_notif_add(struct virtnet_info *vi)
{
int ret;
ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
if (ret)
return ret;
ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
&vi->node_dead);
if (!ret)
return ret;
cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
return ret;
}
static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
{
cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
&vi->node_dead);
}
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;
/* For now we don't support modifying channels while XDP is loaded
* also when XDP is loaded all RX queues have XDP programs so we only
* need to check a single RX queue.
*/
if (vi->rq[0].xdp_prog)
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_strings(struct net_device *dev, u32 stringset, u8 *data)
{
struct virtnet_info *vi = netdev_priv(dev);
char *p = (char *)data;
unsigned int i, j;
switch (stringset) {
case ETH_SS_STATS:
for (i = 0; i < vi->curr_queue_pairs; i++) {
for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
i, virtnet_rq_stats_desc[j].desc);
p += ETH_GSTRING_LEN;
}
}
for (i = 0; i < vi->curr_queue_pairs; i++) {
for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s",
i, virtnet_sq_stats_desc[j].desc);
p += ETH_GSTRING_LEN;
}
}
break;
}
}
static int virtnet_get_sset_count(struct net_device *dev, int sset)
{
struct virtnet_info *vi = netdev_priv(dev);
switch (sset) {
case ETH_SS_STATS:
return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
VIRTNET_SQ_STATS_LEN);
default:
return -EOPNOTSUPP;
}
}
static void virtnet_get_ethtool_stats(struct net_device *dev,
struct ethtool_stats *stats, u64 *data)
{
struct virtnet_info *vi = netdev_priv(dev);
unsigned int idx = 0, start, i, j;
const u8 *stats_base;
size_t offset;
for (i = 0; i < vi->curr_queue_pairs; i++) {
struct receive_queue *rq = &vi->rq[i];
stats_base = (u8 *)&rq->stats;
do {
start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
offset = virtnet_rq_stats_desc[j].offset;
data[idx + j] = *(u64 *)(stats_base + offset);
}
} while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
idx += VIRTNET_RQ_STATS_LEN;
}
for (i = 0; i < vi->curr_queue_pairs; i++) {
struct send_queue *sq = &vi->sq[i];
stats_base = (u8 *)&sq->stats;
do {
start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
offset = virtnet_sq_stats_desc[j].offset;
data[idx + j] = *(u64 *)(stats_base + offset);
}
} while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
idx += VIRTNET_SQ_STATS_LEN;
}
}
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;
}
/* Check if the user is trying to change anything besides speed/duplex */
static bool
virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd)
{
struct ethtool_link_ksettings diff1 = *cmd;
struct ethtool_link_ksettings diff2 = {};
/* cmd is always set so we need to clear it, validate the port type
* and also without autonegotiation we can ignore advertising
*/
diff1.base.speed = 0;
diff2.base.port = PORT_OTHER;
ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
diff1.base.duplex = 0;
diff1.base.cmd = 0;
diff1.base.link_mode_masks_nwords = 0;
return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
bitmap_empty(diff1.link_modes.supported,
__ETHTOOL_LINK_MODE_MASK_NBITS) &&
bitmap_empty(diff1.link_modes.advertising,
__ETHTOOL_LINK_MODE_MASK_NBITS) &&
bitmap_empty(diff1.link_modes.lp_advertising,
__ETHTOOL_LINK_MODE_MASK_NBITS);
}
static int virtnet_set_link_ksettings(struct net_device *dev,
const struct ethtool_link_ksettings *cmd)
{
struct virtnet_info *vi = netdev_priv(dev);
u32 speed;
speed = cmd->base.speed;
/* don't allow custom speed and duplex */
if (!ethtool_validate_speed(speed) ||
!ethtool_validate_duplex(cmd->base.duplex) ||
!virtnet_validate_ethtool_cmd(cmd))
return -EINVAL;
vi->speed = speed;
vi->duplex = cmd->base.duplex;
return 0;
}
static int virtnet_get_link_ksettings(struct net_device *dev,
struct ethtool_link_ksettings *cmd)
{
struct virtnet_info *vi = netdev_priv(dev);
cmd->base.speed = vi->speed;
cmd->base.duplex = vi->duplex;
cmd->base.port = PORT_OTHER;
return 0;
}
static void virtnet_init_settings(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
vi->speed = SPEED_UNKNOWN;
vi->duplex = DUPLEX_UNKNOWN;
}
static void virtnet_update_settings(struct virtnet_info *vi)
{
u32 speed;
u8 duplex;
if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
return;
speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config,
speed));
if (ethtool_validate_speed(speed))
vi->speed = speed;
duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config,
duplex));
if (ethtool_validate_duplex(duplex))
vi->duplex = duplex;
}
static const struct ethtool_ops virtnet_ethtool_ops = {
.get_drvinfo = virtnet_get_drvinfo,
.get_link = ethtool_op_get_link,
.get_ringparam = virtnet_get_ringparam,
.get_strings = virtnet_get_strings,
.get_sset_count = virtnet_get_sset_count,
.get_ethtool_stats = virtnet_get_ethtool_stats,
.set_channels = virtnet_set_channels,
.get_channels = virtnet_get_channels,
.get_ts_info = ethtool_op_get_ts_info,
.get_link_ksettings = virtnet_get_link_ksettings,
.set_link_ksettings = virtnet_set_link_ksettings,
};
static void virtnet_freeze_down(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
int i;
/* Make sure no work handler is accessing the device */
flush_work(&vi->config_work);
netif_tx_lock_bh(vi->dev);
netif_device_detach(vi->dev);
netif_tx_unlock_bh(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);
virtnet_napi_tx_disable(&vi->sq[i].napi);
}
}
}
static int init_vqs(struct virtnet_info *vi);
static int virtnet_restore_up(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].vq, &vi->rq[i].napi);
virtnet_napi_tx_enable(vi, vi->sq[i].vq,
&vi->sq[i].napi);
}
}
netif_tx_lock_bh(vi->dev);
netif_device_attach(vi->dev);
netif_tx_unlock_bh(vi->dev);
return err;
}
static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
{
struct scatterlist sg;
vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
dev_warn(&vi->dev->dev, "Fail to set guest offload. \n");
return -EINVAL;
}
return 0;
}
static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
{
u64 offloads = 0;
if (!vi->guest_offloads)
return 0;
return virtnet_set_guest_offloads(vi, offloads);
}
static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
{
u64 offloads = vi->guest_offloads;
if (!vi->guest_offloads)
return 0;
return virtnet_set_guest_offloads(vi, offloads);
}
static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
struct netlink_ext_ack *extack)
{
unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
struct virtnet_info *vi = netdev_priv(dev);
struct bpf_prog *old_prog;
u16 xdp_qp = 0, curr_qp;
int i, err;
if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
&& (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO/CSUM, disable LRO/CSUM first");
return -EOPNOTSUPP;
}
if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
return -EINVAL;
}
if (dev->mtu > max_sz) {
NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
return -EINVAL;
}
curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
if (prog)
xdp_qp = nr_cpu_ids;
/* XDP requires extra queues for XDP_TX */
if (curr_qp + xdp_qp > vi->max_queue_pairs) {
NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available");
netdev_warn(dev, "request %i queues but max is %i\n",
curr_qp + xdp_qp, vi->max_queue_pairs);
return -ENOMEM;
}
old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
if (!prog && !old_prog)
return 0;
if (prog) {
prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
if (IS_ERR(prog))
return PTR_ERR(prog);
}
/* Make sure NAPI is not using any XDP TX queues for RX. */
if (netif_running(dev)) {
for (i = 0; i < vi->max_queue_pairs; i++) {
napi_disable(&vi->rq[i].napi);
virtnet_napi_tx_disable(&vi->sq[i].napi);
}
}
if (!prog) {
for (i = 0; i < vi->max_queue_pairs; i++) {
rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
if (i == 0)
virtnet_restore_guest_offloads(vi);
}
synchronize_net();
}
err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
if (err)
goto err;
netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
vi->xdp_queue_pairs = xdp_qp;
if (prog) {
for (i = 0; i < vi->max_queue_pairs; i++) {
rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
if (i == 0 && !old_prog)
virtnet_clear_guest_offloads(vi);
}
}
for (i = 0; i < vi->max_queue_pairs; i++) {
if (old_prog)
bpf_prog_put(old_prog);
if (netif_running(dev)) {
virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
virtnet_napi_tx_enable(vi, vi->sq[i].vq,
&vi->sq[i].napi);
}
}
return 0;
err:
if (!prog) {
virtnet_clear_guest_offloads(vi);
for (i = 0; i < vi->max_queue_pairs; i++)
rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
}
if (netif_running(dev)) {
for (i = 0; i < vi->max_queue_pairs; i++) {
virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
virtnet_napi_tx_enable(vi, vi->sq[i].vq,
&vi->sq[i].napi);
}
}
if (prog)
bpf_prog_sub(prog, vi->max_queue_pairs - 1);
return err;
}
static u32 virtnet_xdp_query(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
const struct bpf_prog *xdp_prog;
int i;
for (i = 0; i < vi->max_queue_pairs; i++) {
xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
if (xdp_prog)
return xdp_prog->aux->id;
}
return 0;
}
static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = virtnet_xdp_query(dev);
return 0;
default:
return -EINVAL;
}
}
static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
size_t len)
{
struct virtnet_info *vi = netdev_priv(dev);
int ret;
if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
return -EOPNOTSUPP;
ret = snprintf(buf, len, "sby");
if (ret >= len)
return -EOPNOTSUPP;
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_get_stats64 = virtnet_stats,
.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
.ndo_bpf = virtnet_xdp,
.ndo_xdp_xmit = virtnet_xdp_xmit,
.ndo_features_check = passthru_features_check,
.ndo_get_phys_port_name = virtnet_get_phys_port_name,
};
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) {
virtnet_update_settings(vi);
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);
netif_napi_del(&vi->sq[i].napi);
}
/* We called napi_hash_del() before netif_napi_del(),
* we need to respect an RCU grace period before freeing vi->rq
*/
synchronize_net();
kfree(vi->rq);
kfree(vi->sq);
kfree(vi->ctrl);
}
static void _free_receive_bufs(struct virtnet_info *vi)
{
struct bpf_prog *old_prog;
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);
old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
if (old_prog)
bpf_prog_put(old_prog);
}
}
static void free_receive_bufs(struct virtnet_info *vi)
{
rtnl_lock();
_free_receive_bufs(vi);
rtnl_unlock();
}
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) {
if (!is_xdp_frame(buf))
dev_kfree_skb(buf);
else
xdp_return_frame(ptr_to_xdp(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) {
put_page(virt_to_head_page(buf));
} else if (vi->big_packets) {
give_pages(&vi->rq[i], buf);
} else {
put_page(virt_to_head_page(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);
}
/* How large should a single buffer be so a queue full of these can fit at
* least one full packet?
* Logic below assumes the mergeable buffer header is used.
*/
static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
{
const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
unsigned int rq_size = virtqueue_get_vring_size(vq);
unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
return max(max(min_buf_len, hdr_len) - hdr_len,
(unsigned int)GOOD_PACKET_LEN);
}
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;
bool *ctx;
/* 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 = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
if (!vqs)
goto err_vq;
callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
if (!callbacks)
goto err_callback;
names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
if (!names)
goto err_names;
if (!vi->big_packets || vi->mergeable_rx_bufs) {
ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
goto err_ctx;
} else {
ctx = NULL;
}
/* 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;
if (ctx)
ctx[rxq2vq(i)] = true;
}
ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
names, ctx, NULL);
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->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
vi->sq[i].vq = vqs[txq2vq(i)];
}
/* run here: ret == 0. */
err_find:
kfree(ctx);
err_ctx:
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->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
if (!vi->ctrl)
goto err_ctrl;
vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
if (!vi->sq)
goto err_sq;
vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), 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);
netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
napi_tx ? napi_weight : 0);
sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
u64_stats_init(&vi->rq[i].stats.syncp);
u64_stats_init(&vi->sq[i].stats.syncp);
}
return 0;
err_rq:
kfree(vi->sq);
err_sq:
kfree(vi->ctrl);
err_ctrl:
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,
char *buf)
{
struct virtnet_info *vi = netdev_priv(queue->dev);
unsigned int queue_index = get_netdev_rx_queue_index(queue);
unsigned int headroom = virtnet_get_headroom(vi);
unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
struct ewma_pkt_len *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(&vi->rq[queue_index], avg,
SKB_DATA_ALIGN(headroom + tailroom)));
}
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;
}
#define MIN_MTU ETH_MIN_MTU
#define MAX_MTU ETH_MAX_MTU
static int virtnet_validate(struct virtio_device *vdev)
{
if (!vdev->config->get) {
dev_err(&vdev->dev, "%s failure: config access disabled\n",
__func__);
return -EINVAL;
}
if (!virtnet_validate_features(vdev))
return -EINVAL;
if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
int mtu = virtio_cread16(vdev,
offsetof(struct virtio_net_config,
mtu));
if (mtu < MIN_MTU)
__virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
}
return 0;
}
static int virtnet_probe(struct virtio_device *vdev)
{
int i, err = -ENOMEM;
struct net_device *dev;
struct virtnet_info *vi;
u16 max_queue_pairs;
int mtu;
/* 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;
if (csum)
dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
dev->hw_features |= NETIF_F_TSO
| 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;
dev->features |= NETIF_F_GSO_ROBUST;
if (gso)
dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
/* (!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;
/* MTU range: 68 - 65535 */
dev->min_mtu = MIN_MTU;
dev->max_mtu = MAX_MTU;
/* 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;
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) ||
virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
vi->any_header_sg = true;
if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
vi->has_cvq = true;
if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
mtu = virtio_cread16(vdev,
offsetof(struct virtio_net_config,
mtu));
if (mtu < dev->min_mtu) {
/* Should never trigger: MTU was previously validated
* in virtnet_validate.
*/
dev_err(&vdev->dev, "device MTU appears to have changed "
"it is now %d < %d", mtu, dev->min_mtu);
goto free;
}
dev->mtu = mtu;
dev->max_mtu = mtu;
/* TODO: size buffers correctly in this case. */
if (dev->mtu > ETH_DATA_LEN)
vi->big_packets = true;
}
if (vi->any_header_sg)
dev->needed_headroom = vi->hdr_len;
/* Enable multiqueue by default */
if (num_online_cpus() >= max_queue_pairs)
vi->curr_queue_pairs = max_queue_pairs;
else
vi->curr_queue_pairs = num_online_cpus();
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;
#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);
virtnet_init_settings(dev);
if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
vi->failover = net_failover_create(vi->dev);
if (IS_ERR(vi->failover)) {
err = PTR_ERR(vi->failover);
goto free_vqs;
}
}
err = register_netdev(dev);
if (err) {
pr_debug("virtio_net: registering device failed\n");
goto free_failover;
}
virtio_device_ready(vdev);
err = virtnet_cpu_notif_add(vi);
if (err) {
pr_debug("virtio_net: registering cpu notifier failed\n");
goto free_unregister_netdev;
}
virtnet_set_queues(vi, vi->curr_queue_pairs);
/* Assume link up if device can't report link status,
otherwise get link status from config. */
netif_carrier_off(dev);
if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
schedule_work(&vi->config_work);
} else {
vi->status = VIRTIO_NET_S_LINK_UP;
virtnet_update_settings(vi);
netif_carrier_on(dev);
}
for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
if (virtio_has_feature(vi->vdev, guest_offloads[i]))
set_bit(guest_offloads[i], &vi->guest_offloads);
pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
dev->name, max_queue_pairs);
return 0;
free_unregister_netdev:
vi->vdev->config->reset(vdev);
unregister_netdev(dev);
free_failover:
net_failover_destroy(vi->failover);
free_vqs:
cancel_delayed_work_sync(&vi->refill);
free_receive_page_frags(vi);
virtnet_del_vqs(vi);
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;
virtnet_cpu_notif_remove(vi);
/* Make sure no work handler is accessing the device. */
flush_work(&vi->config_work);
unregister_netdev(vi->dev);
net_failover_destroy(vi->failover);
remove_vq_common(vi);
free_netdev(vi->dev);
}
static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
virtnet_cpu_notif_remove(vi);
virtnet_freeze_down(vdev);
remove_vq_common(vi);
return 0;
}
static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
int err;
err = virtnet_restore_up(vdev);
if (err)
return err;
virtnet_set_queues(vi, vi->curr_queue_pairs);
err = virtnet_cpu_notif_add(vi);
if (err)
return err;
return 0;
}
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
{ 0 },
};
#define VIRTNET_FEATURES \
VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
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_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
static unsigned int features[] = {
VIRTNET_FEATURES,
};
static unsigned int features_legacy[] = {
VIRTNET_FEATURES,
VIRTIO_NET_F_GSO,
VIRTIO_F_ANY_LAYOUT,
};
static struct virtio_driver virtio_net_driver = {
.feature_table = features,
.feature_table_size = ARRAY_SIZE(features),
.feature_table_legacy = features_legacy,
.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.validate = virtnet_validate,
.probe = virtnet_probe,
.remove = virtnet_remove,
.config_changed = virtnet_config_changed,
#ifdef CONFIG_PM_SLEEP
.freeze = virtnet_freeze,
.restore = virtnet_restore,
#endif
};
static __init int virtio_net_driver_init(void)
{
int ret;
ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
virtnet_cpu_online,
virtnet_cpu_down_prep);
if (ret < 0)
goto out;
virtionet_online = ret;
ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
NULL, virtnet_cpu_dead);
if (ret)
goto err_dead;
ret = register_virtio_driver(&virtio_net_driver);
if (ret)
goto err_virtio;
return 0;
err_virtio:
cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
err_dead:
cpuhp_remove_multi_state(virtionet_online);
out:
return ret;
}
module_init(virtio_net_driver_init);
static __exit void virtio_net_driver_exit(void)
{
unregister_virtio_driver(&virtio_net_driver);
cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
cpuhp_remove_multi_state(virtionet_online);
}
module_exit(virtio_net_driver_exit);
MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio network driver");
MODULE_LICENSE("GPL");
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