v4.19.13 snapshot.
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
new file mode 100644
index 0000000..ad14fbf
--- /dev/null
+++ b/drivers/net/virtio_net.c
@@ -0,0 +1,3199 @@
+/* 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)
+
+/* 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];
+};
+
+/* 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, 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 xdp_frame *xdpf_sent;
+ struct bpf_prog *xdp_prog;
+ struct send_queue *sq;
+ unsigned int len;
+ int drops = 0;
+ int kicks = 0;
+ int ret, err;
+ int i;
+
+ sq = virtnet_xdp_sq(vi);
+
+ if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
+ ret = -EINVAL;
+ drops = n;
+ goto out;
+ }
+
+ /* 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) {
+ ret = -ENXIO;
+ drops = n;
+ goto out;
+ }
+
+ /* Free up any pending old buffers before queueing new ones. */
+ while ((xdpf_sent = virtqueue_get_buf(sq->vq, &len)) != NULL)
+ xdp_return_frame(xdpf_sent);
+
+ 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.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)) {
+ 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 > 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)
+{
+ struct sk_buff *skb;
+ unsigned int len;
+ unsigned int packets = 0;
+ unsigned int bytes = 0;
+
+ while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
+ pr_debug("Sent skb %p\n", skb);
+
+ bytes += skb->len;
+ packets++;
+
+ dev_consume_skb_any(skb);
+ }
+
+ /* 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 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)
+ return;
+
+ if (__netif_tx_trylock(txq)) {
+ free_old_xmit_skbs(sq);
+ __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;
+ struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq));
+
+ __netif_tx_lock(txq, raw_smp_processor_id());
+ free_old_xmit_skbs(sq);
+ __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);
+
+ 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);
+ 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;
+ }
+
+ 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);
+
+ netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
+ err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
+ if (err)
+ goto err;
+ vi->xdp_queue_pairs = xdp_qp;
+
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
+ rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
+ if (i == 0) {
+ if (!old_prog)
+ virtnet_clear_guest_offloads(vi);
+ if (!prog)
+ virtnet_restore_guest_offloads(vi);
+ }
+ if (old_prog)
+ bpf_prog_put(old_prog);
+ if (netif_running(dev))
+ virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
+ }
+
+ return 0;
+
+err:
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ virtnet_napi_enable(vi->rq[i].vq, &vi->rq[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 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 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_raw_buffer_queue(vi, i))
+ dev_kfree_skb(buf);
+ else
+ put_page(virt_to_head_page(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");