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linux-sg2042/drivers/net/virtio_net.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/* A network driver using virtio.
*
* Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
*/
//#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 <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 = true;
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;
unsigned long guest_offloads_capable;
/* 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, unsigned int metasize)
{
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);
/* hdr_valid means no XDP, so we can copy the vnet header */
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);
if (metasize) {
__skb_pull(skb, metasize);
skb_metadata_set(skb, metasize);
}
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;
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_access_pointer(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;
unsigned int metasize = 0;
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.data_end = xdp.data + len;
xdp.data_meta = xdp.data;
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;
metasize = xdp.data - xdp.data_meta;
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 (!xdp_prog) {
buf += header_offset;
memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
} /* keep zeroed vnet hdr since XDP is loaded */
if (metasize)
skb_metadata_set(skb, metasize);
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, 0);
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;
unsigned int metasize = 0;
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.data_end = xdp.data + (len - vi->hdr_len);
xdp.data_meta = xdp.data;
xdp.rxq = &rq->xdp_rxq;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
stats->xdp_packets++;
switch (act) {
case XDP_PASS:
metasize = xdp.data - xdp.data_meta;
/* recalculate offset to account for any header
* adjustments and minus the metasize to copy the
* metadata in page_to_skb(). Note other cases do not
* build an skb and avoid using offset
*/
offset = xdp.data - page_address(xdp_page) -
vi->hdr_len - metasize;
/* recalculate len if xdp.data, xdp.data_end or
* xdp.data_meta were adjusted
*/
len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
/* 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,
metasize);
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,
metasize);
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_record_rx_queue(skb, vq2rxq(rq->vq));
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)) {
u64_stats_update_begin(&rq->stats.syncp);
rq->stats.kicks++;
u64_stats_update_end(&rq->stats.syncp);
}
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 > min((unsigned int)budget, 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();
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 = !netdev_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_ct(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)
{
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);
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);
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;
}
static int virtnet_set_link_ksettings(struct net_device *dev,
const struct ethtool_link_ksettings *cmd)
{
struct virtnet_info *vi = netdev_priv(dev);
return ethtool_virtdev_set_link_ksettings(dev, cmd,
&vi->speed, &vi->duplex);
}
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 int virtnet_set_coalesce(struct net_device *dev,
struct ethtool_coalesce *ec)
{
struct virtnet_info *vi = netdev_priv(dev);
int i, napi_weight;
if (ec->tx_max_coalesced_frames > 1 ||
ec->rx_max_coalesced_frames != 1)
return -EINVAL;
napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
if (napi_weight ^ vi->sq[0].napi.weight) {
if (dev->flags & IFF_UP)
return -EBUSY;
for (i = 0; i < vi->max_queue_pairs; i++)
vi->sq[i].napi.weight = napi_weight;
}
return 0;
}
static int virtnet_get_coalesce(struct net_device *dev,
struct ethtool_coalesce *ec)
{
struct ethtool_coalesce ec_default = {
.cmd = ETHTOOL_GCOALESCE,
.rx_max_coalesced_frames = 1,
};
struct virtnet_info *vi = netdev_priv(dev);
memcpy(ec, &ec_default, sizeof(ec_default));
if (vi->sq[0].napi.weight)
ec->tx_max_coalesced_frames = 1;
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 = {
.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES,
.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,
.set_coalesce = virtnet_set_coalesce,
.get_coalesce = virtnet_get_coalesce,
};
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)
bpf_prog_add(prog, vi->max_queue_pairs - 1);
/* 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 int virtnet_set_features(struct net_device *dev,
netdev_features_t features)
{
struct virtnet_info *vi = netdev_priv(dev);
u64 offloads;
int err;
if ((dev->features ^ features) & NETIF_F_LRO) {
if (vi->xdp_queue_pairs)
return -EBUSY;
if (features & NETIF_F_LRO)
offloads = vi->guest_offloads_capable;
else
offloads = 0;
err = virtnet_set_guest_offloads(vi, offloads);
if (err)
return err;
vi->guest_offloads = offloads;
}
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,
.ndo_set_features = virtnet_set_features,
};
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);
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;
if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
dev->features |= NETIF_F_LRO;
if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
dev->hw_features |= NETIF_F_LRO;
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);
vi->guest_offloads_capable = 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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