diff options
Diffstat (limited to 'drivers/vhost/net.c')
| -rw-r--r-- | drivers/vhost/net.c | 1440 |
1 files changed, 1090 insertions, 350 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 027be91db139..7f886d3dba7d 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1,8 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-only /* Copyright (C) 2009 Red Hat, Inc. * Author: Michael S. Tsirkin <mst@redhat.com> * - * This work is licensed under the terms of the GNU GPL, version 2. - * * virtio-net server in host kernel. */ @@ -15,22 +14,28 @@ #include <linux/moduleparam.h> #include <linux/mutex.h> #include <linux/workqueue.h> -#include <linux/rcupdate.h> #include <linux/file.h> #include <linux/slab.h> +#include <linux/sched/clock.h> +#include <linux/sched/signal.h> +#include <linux/vmalloc.h> #include <linux/net.h> #include <linux/if_packet.h> #include <linux/if_arp.h> #include <linux/if_tun.h> #include <linux/if_macvlan.h> +#include <linux/if_tap.h> #include <linux/if_vlan.h> +#include <linux/skb_array.h> +#include <linux/skbuff.h> #include <net/sock.h> +#include <net/xdp.h> #include "vhost.h" -static int experimental_zcopytx = 1; +static int experimental_zcopytx = 0; module_param(experimental_zcopytx, int, 0444); MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" " 1 -Enable; 0 - Disable"); @@ -39,6 +44,12 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" * Using this limit prevents one virtqueue from starving others. */ #define VHOST_NET_WEIGHT 0x80000 +/* Max number of packets transferred before requeueing the job. + * Using this limit prevents one virtqueue from starving others with small + * pkts. + */ +#define VHOST_NET_PKT_WEIGHT 256 + /* MAX number of TX used buffers for outstanding zerocopy */ #define VHOST_MAX_PEND 128 #define VHOST_GOODCOPY_LEN 256 @@ -48,20 +59,29 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" * status internally; used for zerocopy tx only. */ /* Lower device DMA failed */ -#define VHOST_DMA_FAILED_LEN 3 +#define VHOST_DMA_FAILED_LEN ((__force __virtio32)3) /* Lower device DMA done */ -#define VHOST_DMA_DONE_LEN 2 +#define VHOST_DMA_DONE_LEN ((__force __virtio32)2) /* Lower device DMA in progress */ -#define VHOST_DMA_IN_PROGRESS 1 +#define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1) /* Buffer unused */ -#define VHOST_DMA_CLEAR_LEN 0 - -#define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN) +#define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0) + +#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN) + +static const int vhost_net_bits[] = { + VHOST_FEATURES, + VHOST_NET_F_VIRTIO_NET_HDR, + VIRTIO_NET_F_MRG_RXBUF, + VIRTIO_F_ACCESS_PLATFORM, + VIRTIO_F_RING_RESET, + VIRTIO_F_IN_ORDER, + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO +}; enum { - VHOST_NET_FEATURES = VHOST_FEATURES | - (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | - (1ULL << VIRTIO_NET_F_MRG_RXBUF), + VHOST_NET_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) }; enum { @@ -71,29 +91,46 @@ enum { }; struct vhost_net_ubuf_ref { - struct kref kref; + /* refcount follows semantics similar to kref: + * 0: object is released + * 1: no outstanding ubufs + * >1: outstanding ubufs + */ + atomic_t refcount; wait_queue_head_t wait; struct vhost_virtqueue *vq; + struct rcu_head rcu; +}; + +#define VHOST_NET_BATCH 64 +struct vhost_net_buf { + void **queue; + int tail; + int head; }; struct vhost_net_virtqueue { struct vhost_virtqueue vq; - /* hdr is used to store the virtio header. - * Since each iovec has >= 1 byte length, we never need more than - * header length entries to store the header. */ - struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)]; size_t vhost_hlen; size_t sock_hlen; /* vhost zerocopy support fields below: */ /* last used idx for outstanding DMA zerocopy buffers */ int upend_idx; - /* first used idx for DMA done zerocopy buffers */ + /* For TX, first used idx for DMA done zerocopy buffers + * For RX, number of batched heads + */ int done_idx; + /* Number of XDP frames batched */ + int batched_xdp; /* an array of userspace buffers info */ - struct ubuf_info *ubuf_info; + struct ubuf_info_msgzc *ubuf_info; /* Reference counting for outstanding ubufs. * Protected by vq mutex. Writers must also take device mutex. */ struct vhost_net_ubuf_ref *ubufs; + struct ptr_ring *rx_ring; + struct vhost_net_buf rxq; + /* Batched XDP buffs */ + struct xdp_buff *xdp; }; struct vhost_net { @@ -108,21 +145,92 @@ struct vhost_net { unsigned tx_zcopy_err; /* Flush in progress. Protected by tx vq lock. */ bool tx_flush; + /* Private page frag cache */ + struct page_frag_cache pf_cache; }; static unsigned vhost_net_zcopy_mask __read_mostly; -static void vhost_net_enable_zcopy(int vq) +static void *vhost_net_buf_get_ptr(struct vhost_net_buf *rxq) { - vhost_net_zcopy_mask |= 0x1 << vq; + if (rxq->tail != rxq->head) + return rxq->queue[rxq->head]; + else + return NULL; } -static void vhost_net_zerocopy_done_signal(struct kref *kref) +static int vhost_net_buf_get_size(struct vhost_net_buf *rxq) { - struct vhost_net_ubuf_ref *ubufs; + return rxq->tail - rxq->head; +} - ubufs = container_of(kref, struct vhost_net_ubuf_ref, kref); - wake_up(&ubufs->wait); +static int vhost_net_buf_is_empty(struct vhost_net_buf *rxq) +{ + return rxq->tail == rxq->head; +} + +static void *vhost_net_buf_consume(struct vhost_net_buf *rxq) +{ + void *ret = vhost_net_buf_get_ptr(rxq); + ++rxq->head; + return ret; +} + +static int vhost_net_buf_produce(struct vhost_net_virtqueue *nvq) +{ + struct vhost_net_buf *rxq = &nvq->rxq; + + rxq->head = 0; + rxq->tail = ptr_ring_consume_batched(nvq->rx_ring, rxq->queue, + VHOST_NET_BATCH); + return rxq->tail; +} + +static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq) +{ + struct vhost_net_buf *rxq = &nvq->rxq; + + if (nvq->rx_ring && !vhost_net_buf_is_empty(rxq)) { + ptr_ring_unconsume(nvq->rx_ring, rxq->queue + rxq->head, + vhost_net_buf_get_size(rxq), + tun_ptr_free); + rxq->head = rxq->tail = 0; + } +} + +static int vhost_net_buf_peek_len(void *ptr) +{ + if (tun_is_xdp_frame(ptr)) { + struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr); + + return xdpf->len; + } + + return __skb_array_len_with_tag(ptr); +} + +static int vhost_net_buf_peek(struct vhost_net_virtqueue *nvq) +{ + struct vhost_net_buf *rxq = &nvq->rxq; + + if (!vhost_net_buf_is_empty(rxq)) + goto out; + + if (!vhost_net_buf_produce(nvq)) + return 0; + +out: + return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq)); +} + +static void vhost_net_buf_init(struct vhost_net_buf *rxq) +{ + rxq->head = rxq->tail = 0; +} + +static void vhost_net_enable_zcopy(int vq) +{ + vhost_net_zcopy_mask |= 0x1 << vq; } static struct vhost_net_ubuf_ref * @@ -135,27 +243,34 @@ vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy) ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL); if (!ubufs) return ERR_PTR(-ENOMEM); - kref_init(&ubufs->kref); + atomic_set(&ubufs->refcount, 1); init_waitqueue_head(&ubufs->wait); ubufs->vq = vq; return ubufs; } -static void vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs) +static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs) { - kref_put(&ubufs->kref, vhost_net_zerocopy_done_signal); + int r; + + rcu_read_lock(); + r = atomic_sub_return(1, &ubufs->refcount); + if (unlikely(!r)) + wake_up(&ubufs->wait); + rcu_read_unlock(); + return r; } static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs) { - kref_put(&ubufs->kref, vhost_net_zerocopy_done_signal); - wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount)); + vhost_net_ubuf_put(ubufs); + wait_event(ubufs->wait, !atomic_read(&ubufs->refcount)); } static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs) { vhost_net_ubuf_put_and_wait(ubufs); - kfree(ubufs); + kfree_rcu(ubufs, rcu); } static void vhost_net_clear_ubuf_info(struct vhost_net *n) @@ -177,8 +292,10 @@ static int vhost_net_set_ubuf_info(struct vhost_net *n) zcopy = vhost_net_zcopy_mask & (0x1 << i); if (!zcopy) continue; - n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) * - UIO_MAXIOV, GFP_KERNEL); + n->vqs[i].ubuf_info = + kmalloc_array(UIO_MAXIOV, + sizeof(*n->vqs[i].ubuf_info), + GFP_KERNEL); if (!n->vqs[i].ubuf_info) goto err; } @@ -201,6 +318,7 @@ static void vhost_net_vq_reset(struct vhost_net *n) n->vqs[i].ubufs = NULL; n->vqs[i].vhost_hlen = 0; n->vqs[i].sock_hlen = 0; + vhost_net_buf_init(&n->vqs[i].rxq); } } @@ -234,42 +352,9 @@ static bool vhost_sock_zcopy(struct socket *sock) sock_flag(sock->sk, SOCK_ZEROCOPY); } -/* Pop first len bytes from iovec. Return number of segments used. */ -static int move_iovec_hdr(struct iovec *from, struct iovec *to, - size_t len, int iov_count) -{ - int seg = 0; - size_t size; - - while (len && seg < iov_count) { - size = min(from->iov_len, len); - to->iov_base = from->iov_base; - to->iov_len = size; - from->iov_len -= size; - from->iov_base += size; - len -= size; - ++from; - ++to; - ++seg; - } - return seg; -} -/* Copy iovec entries for len bytes from iovec. */ -static void copy_iovec_hdr(const struct iovec *from, struct iovec *to, - size_t len, int iovcount) +static bool vhost_sock_xdp(struct socket *sock) { - int seg = 0; - size_t size; - - while (len && seg < iovcount) { - size = min(from->iov_len, len); - to->iov_base = from->iov_base; - to->iov_len = size; - len -= size; - ++from; - ++to; - ++seg; - } + return sock_flag(sock->sk, SOCK_XDP); } /* In case of DMA done not in order in lower device driver for some reason. @@ -277,12 +362,12 @@ static void copy_iovec_hdr(const struct iovec *from, struct iovec *to, * of used idx. Once lower device DMA done contiguously, we will signal KVM * guest used idx. */ -static int vhost_zerocopy_signal_used(struct vhost_net *net, - struct vhost_virtqueue *vq) +static void vhost_zerocopy_signal_used(struct vhost_net *net, + struct vhost_virtqueue *vq) { struct vhost_net_virtqueue *nvq = container_of(vq, struct vhost_net_virtqueue, vq); - int i; + int i, add; int j = 0; for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) { @@ -290,192 +375,635 @@ static int vhost_zerocopy_signal_used(struct vhost_net *net, vhost_net_tx_err(net); if (VHOST_DMA_IS_DONE(vq->heads[i].len)) { vq->heads[i].len = VHOST_DMA_CLEAR_LEN; - vhost_add_used_and_signal(vq->dev, vq, - vq->heads[i].id, 0); ++j; } else break; } - if (j) - nvq->done_idx = i; - return j; + while (j) { + add = min(UIO_MAXIOV - nvq->done_idx, j); + vhost_add_used_and_signal_n(vq->dev, vq, + &vq->heads[nvq->done_idx], + NULL, add); + nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV; + j -= add; + } } -static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) +static void vhost_zerocopy_complete(struct sk_buff *skb, + struct ubuf_info *ubuf_base, bool success) { + struct ubuf_info_msgzc *ubuf = uarg_to_msgzc(ubuf_base); struct vhost_net_ubuf_ref *ubufs = ubuf->ctx; struct vhost_virtqueue *vq = ubufs->vq; - int cnt = atomic_read(&ubufs->kref.refcount); + int cnt; + + rcu_read_lock_bh(); + + /* set len to mark this desc buffers done DMA */ + vq->heads[ubuf->desc].len = success ? + VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN; + cnt = vhost_net_ubuf_put(ubufs); /* * Trigger polling thread if guest stopped submitting new buffers: - * in this case, the refcount after decrement will eventually reach 1 - * so here it is 2. + * in this case, the refcount after decrement will eventually reach 1. * We also trigger polling periodically after each 16 packets * (the value 16 here is more or less arbitrary, it's tuned to trigger * less than 10% of times). */ - if (cnt <= 2 || !(cnt % 16)) + if (cnt <= 1 || !(cnt % 16)) vhost_poll_queue(&vq->poll); - /* set len to mark this desc buffers done DMA */ - vq->heads[ubuf->desc].len = success ? - VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN; - vhost_net_ubuf_put(ubufs); + + rcu_read_unlock_bh(); } -/* Expects to be always run from workqueue - which acts as - * read-size critical section for our kind of RCU. */ -static void handle_tx(struct vhost_net *net) +static const struct ubuf_info_ops vhost_ubuf_ops = { + .complete = vhost_zerocopy_complete, +}; + +static inline unsigned long busy_clock(void) +{ + return local_clock() >> 10; +} + +static bool vhost_can_busy_poll(unsigned long endtime) +{ + return likely(!need_resched() && !time_after(busy_clock(), endtime) && + !signal_pending(current)); +} + +static void vhost_net_disable_vq(struct vhost_net *n, + struct vhost_virtqueue *vq) +{ + struct vhost_net_virtqueue *nvq = + container_of(vq, struct vhost_net_virtqueue, vq); + struct vhost_poll *poll = n->poll + (nvq - n->vqs); + if (!vhost_vq_get_backend(vq)) + return; + vhost_poll_stop(poll); +} + +static int vhost_net_enable_vq(struct vhost_net *n, + struct vhost_virtqueue *vq) +{ + struct vhost_net_virtqueue *nvq = + container_of(vq, struct vhost_net_virtqueue, vq); + struct vhost_poll *poll = n->poll + (nvq - n->vqs); + struct socket *sock; + + sock = vhost_vq_get_backend(vq); + if (!sock) + return 0; + + return vhost_poll_start(poll, sock->file); +} + +static void vhost_net_signal_used(struct vhost_net_virtqueue *nvq, + unsigned int count) +{ + struct vhost_virtqueue *vq = &nvq->vq; + struct vhost_dev *dev = vq->dev; + + if (!nvq->done_idx) + return; + + vhost_add_used_and_signal_n(dev, vq, vq->heads, + vq->nheads, count); + nvq->done_idx = 0; +} + +static void vhost_tx_batch(struct vhost_net *net, + struct vhost_net_virtqueue *nvq, + struct socket *sock, + struct msghdr *msghdr) +{ + struct vhost_virtqueue *vq = &nvq->vq; + bool in_order = vhost_has_feature(vq, VIRTIO_F_IN_ORDER); + struct tun_msg_ctl ctl = { + .type = TUN_MSG_PTR, + .num = nvq->batched_xdp, + .ptr = nvq->xdp, + }; + int i, err; + + if (in_order) { + vq->heads[0].len = 0; + vq->nheads[0] = nvq->done_idx; + } + + if (nvq->batched_xdp == 0) + goto signal_used; + + msghdr->msg_control = &ctl; + msghdr->msg_controllen = sizeof(ctl); + err = sock->ops->sendmsg(sock, msghdr, 0); + if (unlikely(err < 0)) { + vq_err(&nvq->vq, "Fail to batch sending packets\n"); + + /* free pages owned by XDP; since this is an unlikely error path, + * keep it simple and avoid more complex bulk update for the + * used pages + */ + for (i = 0; i < nvq->batched_xdp; ++i) + put_page(virt_to_head_page(nvq->xdp[i].data)); + nvq->batched_xdp = 0; + nvq->done_idx = 0; + return; + } + +signal_used: + vhost_net_signal_used(nvq, in_order ? 1 : nvq->done_idx); + nvq->batched_xdp = 0; +} + +static int sock_has_rx_data(struct socket *sock) +{ + if (unlikely(!sock)) + return 0; + + if (sock->ops->peek_len) + return sock->ops->peek_len(sock); + + return skb_queue_empty(&sock->sk->sk_receive_queue); +} + +static void vhost_net_busy_poll_try_queue(struct vhost_net *net, + struct vhost_virtqueue *vq) +{ + if (!vhost_vq_avail_empty(&net->dev, vq)) { + vhost_poll_queue(&vq->poll); + } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { + vhost_disable_notify(&net->dev, vq); + vhost_poll_queue(&vq->poll); + } +} + +static void vhost_net_busy_poll(struct vhost_net *net, + struct vhost_virtqueue *rvq, + struct vhost_virtqueue *tvq, + bool *busyloop_intr, + bool poll_rx) +{ + unsigned long busyloop_timeout; + unsigned long endtime; + struct socket *sock; + struct vhost_virtqueue *vq = poll_rx ? tvq : rvq; + + /* Try to hold the vq mutex of the paired virtqueue. We can't + * use mutex_lock() here since we could not guarantee a + * consistenet lock ordering. + */ + if (!mutex_trylock(&vq->mutex)) + return; + + vhost_disable_notify(&net->dev, vq); + sock = vhost_vq_get_backend(rvq); + + busyloop_timeout = poll_rx ? rvq->busyloop_timeout: + tvq->busyloop_timeout; + + preempt_disable(); + endtime = busy_clock() + busyloop_timeout; + + while (vhost_can_busy_poll(endtime)) { + if (vhost_vq_has_work(vq)) { + *busyloop_intr = true; + break; + } + + if ((sock_has_rx_data(sock) && + !vhost_vq_avail_empty(&net->dev, rvq)) || + !vhost_vq_avail_empty(&net->dev, tvq)) + break; + + cpu_relax(); + } + + preempt_enable(); + + if (poll_rx || sock_has_rx_data(sock)) + vhost_net_busy_poll_try_queue(net, vq); + else if (!poll_rx) /* On tx here, sock has no rx data. */ + vhost_enable_notify(&net->dev, rvq); + + mutex_unlock(&vq->mutex); +} + +static int vhost_net_tx_get_vq_desc(struct vhost_net *net, + struct vhost_net_virtqueue *tnvq, + unsigned int *out_num, unsigned int *in_num, + struct msghdr *msghdr, bool *busyloop_intr, + unsigned int *ndesc) +{ + struct vhost_net_virtqueue *rnvq = &net->vqs[VHOST_NET_VQ_RX]; + struct vhost_virtqueue *rvq = &rnvq->vq; + struct vhost_virtqueue *tvq = &tnvq->vq; + + int r = vhost_get_vq_desc_n(tvq, tvq->iov, ARRAY_SIZE(tvq->iov), + out_num, in_num, NULL, NULL, ndesc); + + if (r == tvq->num && tvq->busyloop_timeout) { + /* Flush batched packets first */ + if (!vhost_sock_zcopy(vhost_vq_get_backend(tvq))) + vhost_tx_batch(net, tnvq, + vhost_vq_get_backend(tvq), + msghdr); + + vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, false); + + r = vhost_get_vq_desc_n(tvq, tvq->iov, ARRAY_SIZE(tvq->iov), + out_num, in_num, NULL, NULL, ndesc); + } + + return r; +} + +static bool vhost_exceeds_maxpend(struct vhost_net *net) { struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; struct vhost_virtqueue *vq = &nvq->vq; - unsigned out, in, s; + + return (nvq->upend_idx + UIO_MAXIOV - nvq->done_idx) % UIO_MAXIOV > + min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2); +} + +static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter, + size_t hdr_size, int out) +{ + /* Skip header. TODO: support TSO. */ + size_t len = iov_length(vq->iov, out); + + iov_iter_init(iter, ITER_SOURCE, vq->iov, out, len); + iov_iter_advance(iter, hdr_size); + + return iov_iter_count(iter); +} + +static int get_tx_bufs(struct vhost_net *net, + struct vhost_net_virtqueue *nvq, + struct msghdr *msg, + unsigned int *out, unsigned int *in, + size_t *len, bool *busyloop_intr, + unsigned int *ndesc) +{ + struct vhost_virtqueue *vq = &nvq->vq; + int ret; + + ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, msg, + busyloop_intr, ndesc); + + if (ret < 0 || ret == vq->num) + return ret; + + if (*in) { + vq_err(vq, "Unexpected descriptor format for TX: out %d, int %d\n", + *out, *in); + return -EFAULT; + } + + /* Sanity check */ + *len = init_iov_iter(vq, &msg->msg_iter, nvq->vhost_hlen, *out); + if (*len == 0) { + vq_err(vq, "Unexpected header len for TX: %zd expected %zd\n", + *len, nvq->vhost_hlen); + return -EFAULT; + } + + return ret; +} + +static bool tx_can_batch(struct vhost_virtqueue *vq, size_t total_len) +{ + return total_len < VHOST_NET_WEIGHT && + !vhost_vq_avail_empty(vq->dev, vq); +} + +#define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD) + +static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq, + struct iov_iter *from) +{ + struct vhost_virtqueue *vq = &nvq->vq; + struct vhost_net *net = container_of(vq->dev, struct vhost_net, + dev); + struct socket *sock = vhost_vq_get_backend(vq); + struct virtio_net_hdr *gso; + struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp]; + size_t len = iov_iter_count(from); + int headroom = vhost_sock_xdp(sock) ? XDP_PACKET_HEADROOM : 0; + int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + int pad = SKB_DATA_ALIGN(VHOST_NET_RX_PAD + headroom + nvq->sock_hlen); + int sock_hlen = nvq->sock_hlen; + void *buf; + int copied; + int ret; + + if (unlikely(len < nvq->sock_hlen)) + return -EFAULT; + + if (SKB_DATA_ALIGN(len + pad) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE) + return -ENOSPC; + + buflen += SKB_DATA_ALIGN(len + pad); + buf = page_frag_alloc_align(&net->pf_cache, buflen, GFP_KERNEL, + SMP_CACHE_BYTES); + if (unlikely(!buf)) + return -ENOMEM; + + copied = copy_from_iter(buf + pad - sock_hlen, len, from); + if (copied != len) { + ret = -EFAULT; + goto err; + } + + gso = buf + pad - sock_hlen; + + if (!sock_hlen) + memset(buf, 0, pad); + + if ((gso->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && + vhost16_to_cpu(vq, gso->csum_start) + + vhost16_to_cpu(vq, gso->csum_offset) + 2 > + vhost16_to_cpu(vq, gso->hdr_len)) { + gso->hdr_len = cpu_to_vhost16(vq, + vhost16_to_cpu(vq, gso->csum_start) + + vhost16_to_cpu(vq, gso->csum_offset) + 2); + + if (vhost16_to_cpu(vq, gso->hdr_len) > len) { + ret = -EINVAL; + goto err; + } + } + + /* pad contains sock_hlen */ + memcpy(buf, buf + pad - sock_hlen, sock_hlen); + + xdp_init_buff(xdp, buflen, NULL); + xdp_prepare_buff(xdp, buf, pad, len - sock_hlen, true); + + ++nvq->batched_xdp; + + return 0; + +err: + page_frag_free(buf); + return ret; +} + +static void handle_tx_copy(struct vhost_net *net, struct socket *sock) +{ + struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; + struct vhost_virtqueue *vq = &nvq->vq; + unsigned out, in; int head; struct msghdr msg = { .msg_name = NULL, .msg_namelen = 0, .msg_control = NULL, .msg_controllen = 0, - .msg_iov = vq->iov, .msg_flags = MSG_DONTWAIT, }; size_t len, total_len = 0; int err; - size_t hdr_size; - struct socket *sock; - struct vhost_net_ubuf_ref *uninitialized_var(ubufs); - bool zcopy, zcopy_used; - - /* TODO: check that we are running from vhost_worker? */ - sock = rcu_dereference_check(vq->private_data, 1); - if (!sock) - return; + int sent_pkts = 0; + bool sock_can_batch = (sock->sk->sk_sndbuf == INT_MAX); + bool in_order = vhost_has_feature(vq, VIRTIO_F_IN_ORDER); + unsigned int ndesc = 0; - mutex_lock(&vq->mutex); - vhost_disable_notify(&net->dev, vq); + do { + bool busyloop_intr = false; - hdr_size = nvq->vhost_hlen; - zcopy = nvq->ubufs; - - for (;;) { - /* Release DMAs done buffers first */ - if (zcopy) - vhost_zerocopy_signal_used(net, vq); + if (nvq->done_idx == VHOST_NET_BATCH) + vhost_tx_batch(net, nvq, sock, &msg); - head = vhost_get_vq_desc(&net->dev, vq, vq->iov, - ARRAY_SIZE(vq->iov), - &out, &in, - NULL, NULL); + head = get_tx_bufs(net, nvq, &msg, &out, &in, &len, + &busyloop_intr, &ndesc); /* On error, stop handling until the next kick. */ if (unlikely(head < 0)) break; /* Nothing new? Wait for eventfd to tell us they refilled. */ if (head == vq->num) { - int num_pends; - - /* If more outstanding DMAs, queue the work. - * Handle upend_idx wrap around + /* Flush batched packets to handle pending RX + * work (if busyloop_intr is set) and to avoid + * unnecessary virtqueue kicks. */ - num_pends = likely(nvq->upend_idx >= nvq->done_idx) ? - (nvq->upend_idx - nvq->done_idx) : - (nvq->upend_idx + UIO_MAXIOV - - nvq->done_idx); - if (unlikely(num_pends > VHOST_MAX_PEND)) - break; - if (unlikely(vhost_enable_notify(&net->dev, vq))) { + vhost_tx_batch(net, nvq, sock, &msg); + if (unlikely(busyloop_intr)) { + vhost_poll_queue(&vq->poll); + } else if (unlikely(vhost_enable_notify(&net->dev, + vq))) { vhost_disable_notify(&net->dev, vq); continue; } break; } - if (in) { - vq_err(vq, "Unexpected descriptor format for TX: " - "out %d, int %d\n", out, in); - break; + + total_len += len; + + /* For simplicity, TX batching is only enabled if + * sndbuf is unlimited. + */ + if (sock_can_batch) { + err = vhost_net_build_xdp(nvq, &msg.msg_iter); + if (!err) { + goto done; + } else if (unlikely(err != -ENOSPC)) { + vhost_tx_batch(net, nvq, sock, &msg); + vhost_discard_vq_desc(vq, 1, ndesc); + vhost_net_enable_vq(net, vq); + break; + } + + if (nvq->batched_xdp) { + /* We can't build XDP buff, go for single + * packet path but let's flush batched + * packets. + */ + vhost_tx_batch(net, nvq, sock, &msg); + } + msg.msg_control = NULL; + } else { + if (tx_can_batch(vq, total_len)) + msg.msg_flags |= MSG_MORE; + else + msg.msg_flags &= ~MSG_MORE; + } + + err = sock->ops->sendmsg(sock, &msg, len); + if (unlikely(err < 0)) { + if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) { + vhost_discard_vq_desc(vq, 1, ndesc); + vhost_net_enable_vq(net, vq); + break; + } + pr_debug("Fail to send packet: err %d", err); + } else if (unlikely(err != len)) + pr_debug("Truncated TX packet: len %d != %zd\n", + err, len); +done: + if (in_order) { + vq->heads[0].id = cpu_to_vhost32(vq, head); + } else { + vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head); + vq->heads[nvq->done_idx].len = 0; } - /* Skip header. TODO: support TSO. */ - s = move_iovec_hdr(vq->iov, nvq->hdr, hdr_size, out); - msg.msg_iovlen = out; - len = iov_length(vq->iov, out); - /* Sanity check */ - if (!len) { - vq_err(vq, "Unexpected header len for TX: " - "%zd expected %zd\n", - iov_length(nvq->hdr, s), hdr_size); + ++nvq->done_idx; + } while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len))); + + vhost_tx_batch(net, nvq, sock, &msg); +} + +static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) +{ + struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; + struct vhost_virtqueue *vq = &nvq->vq; + unsigned out, in; + int head; + struct msghdr msg = { + .msg_name = NULL, + .msg_namelen = 0, + .msg_control = NULL, + .msg_controllen = 0, + .msg_flags = MSG_DONTWAIT, + }; + struct tun_msg_ctl ctl; + size_t len, total_len = 0; + int err; + struct vhost_net_ubuf_ref *ubufs; + struct ubuf_info_msgzc *ubuf; + unsigned int ndesc = 0; + bool zcopy_used; + int sent_pkts = 0; + + do { + bool busyloop_intr; + + /* Release DMAs done buffers first */ + vhost_zerocopy_signal_used(net, vq); + + busyloop_intr = false; + head = get_tx_bufs(net, nvq, &msg, &out, &in, &len, + &busyloop_intr, &ndesc); + /* On error, stop handling until the next kick. */ + if (unlikely(head < 0)) + break; + /* Nothing new? Wait for eventfd to tell us they refilled. */ + if (head == vq->num) { + if (unlikely(busyloop_intr)) { + vhost_poll_queue(&vq->poll); + } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { + vhost_disable_notify(&net->dev, vq); + continue; + } break; } - zcopy_used = zcopy && (len >= VHOST_GOODCOPY_LEN || - nvq->upend_idx != nvq->done_idx); + + zcopy_used = len >= VHOST_GOODCOPY_LEN + && !vhost_exceeds_maxpend(net) + && vhost_net_tx_select_zcopy(net); /* use msg_control to pass vhost zerocopy ubuf info to skb */ if (zcopy_used) { - vq->heads[nvq->upend_idx].id = head; - if (!vhost_net_tx_select_zcopy(net) || - len < VHOST_GOODCOPY_LEN) { - /* copy don't need to wait for DMA done */ - vq->heads[nvq->upend_idx].len = - VHOST_DMA_DONE_LEN; - msg.msg_control = NULL; - msg.msg_controllen = 0; - ubufs = NULL; - } else { - struct ubuf_info *ubuf; - ubuf = nvq->ubuf_info + nvq->upend_idx; - - vq->heads[nvq->upend_idx].len = - VHOST_DMA_IN_PROGRESS; - ubuf->callback = vhost_zerocopy_callback; - ubuf->ctx = nvq->ubufs; - ubuf->desc = nvq->upend_idx; - msg.msg_control = ubuf; - msg.msg_controllen = sizeof(ubuf); - ubufs = nvq->ubufs; - kref_get(&ubufs->kref); - } + ubuf = nvq->ubuf_info + nvq->upend_idx; + vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head); + vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS; + ubuf->ctx = nvq->ubufs; + ubuf->desc = nvq->upend_idx; + ubuf->ubuf.ops = &vhost_ubuf_ops; + ubuf->ubuf.flags = SKBFL_ZEROCOPY_FRAG; + refcount_set(&ubuf->ubuf.refcnt, 1); + msg.msg_control = &ctl; + ctl.type = TUN_MSG_UBUF; + ctl.ptr = &ubuf->ubuf; + msg.msg_controllen = sizeof(ctl); + ubufs = nvq->ubufs; + atomic_inc(&ubufs->refcount); nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV; - } else + } else { msg.msg_control = NULL; - /* TODO: Check specific error and bomb out unless ENOBUFS? */ - err = sock->ops->sendmsg(NULL, sock, &msg, len); + ubufs = NULL; + } + total_len += len; + if (tx_can_batch(vq, total_len) && + likely(!vhost_exceeds_maxpend(net))) { + msg.msg_flags |= MSG_MORE; + } else { + msg.msg_flags &= ~MSG_MORE; + } + + err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { + bool retry = err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS; + if (zcopy_used) { - if (ubufs) + if (vq->heads[ubuf->desc].len == VHOST_DMA_IN_PROGRESS) vhost_net_ubuf_put(ubufs); - nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) - % UIO_MAXIOV; + if (retry) + nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) + % UIO_MAXIOV; + else + vq->heads[ubuf->desc].len = VHOST_DMA_DONE_LEN; } - vhost_discard_vq_desc(vq, 1); - break; - } - if (err != len) + if (retry) { + vhost_discard_vq_desc(vq, 1, ndesc); + vhost_net_enable_vq(net, vq); + break; + } + pr_debug("Fail to send packet: err %d", err); + } else if (unlikely(err != len)) pr_debug("Truncated TX packet: " " len %d != %zd\n", err, len); if (!zcopy_used) vhost_add_used_and_signal(&net->dev, vq, head, 0); else vhost_zerocopy_signal_used(net, vq); - total_len += len; vhost_net_tx_packet(net); - if (unlikely(total_len >= VHOST_NET_WEIGHT)) { - vhost_poll_queue(&vq->poll); - break; - } - } + } while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len))); +} +/* Expects to be always run from workqueue - which acts as + * read-size critical section for our kind of RCU. */ +static void handle_tx(struct vhost_net *net) +{ + struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; + struct vhost_virtqueue *vq = &nvq->vq; + struct socket *sock; + + mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX); + sock = vhost_vq_get_backend(vq); + if (!sock) + goto out; + + if (!vq_meta_prefetch(vq)) + goto out; + + vhost_disable_notify(&net->dev, vq); + vhost_net_disable_vq(net, vq); + + if (vhost_sock_zcopy(sock)) + handle_tx_zerocopy(net, sock); + else + handle_tx_copy(net, sock); + +out: mutex_unlock(&vq->mutex); } -static int peek_head_len(struct sock *sk) +static int peek_head_len(struct vhost_net_virtqueue *rvq, struct sock *sk) { struct sk_buff *head; int len = 0; unsigned long flags; + if (rvq->rx_ring) + return vhost_net_buf_peek(rvq); + spin_lock_irqsave(&sk->sk_receive_queue.lock, flags); head = skb_peek(&sk->sk_receive_queue); if (likely(head)) { len = head->len; - if (vlan_tx_tag_present(head)) + if (skb_vlan_tag_present(head)) len += VLAN_HLEN; } @@ -483,9 +1011,31 @@ static int peek_head_len(struct sock *sk) return len; } +static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk, + bool *busyloop_intr, unsigned int *count) +{ + struct vhost_net_virtqueue *rnvq = &net->vqs[VHOST_NET_VQ_RX]; + struct vhost_net_virtqueue *tnvq = &net->vqs[VHOST_NET_VQ_TX]; + struct vhost_virtqueue *rvq = &rnvq->vq; + struct vhost_virtqueue *tvq = &tnvq->vq; + int len = peek_head_len(rnvq, sk); + + if (!len && rvq->busyloop_timeout) { + /* Flush batched heads first */ + vhost_net_signal_used(rnvq, *count); + *count = 0; + /* Both tx vq and rx socket were polled here */ + vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, true); + + len = peek_head_len(rnvq, sk); + } + + return len; +} + /* This is a multi-buffer version of vhost_get_desc, that works if * vq has read descriptors only. - * @vq - the relevant virtqueue + * @nvq - the relevant vhost_net virtqueue * @datalen - data length we'll be reading * @iovcount - returned count of io vectors we fill * @log - vhost log @@ -493,28 +1043,40 @@ static int peek_head_len(struct sock *sk) * @quota - headcount quota, 1 for big buffer * returns number of buffer heads allocated, negative on error */ -static int get_rx_bufs(struct vhost_virtqueue *vq, +static int get_rx_bufs(struct vhost_net_virtqueue *nvq, struct vring_used_elem *heads, + u16 *nheads, int datalen, unsigned *iovcount, struct vhost_log *log, unsigned *log_num, - unsigned int quota) + unsigned int quota, + unsigned int *ndesc) { - unsigned int out, in; + struct vhost_virtqueue *vq = &nvq->vq; + bool in_order = vhost_has_feature(vq, VIRTIO_F_IN_ORDER); + unsigned int out, in, desc_num, n = 0; int seg = 0; int headcount = 0; unsigned d; int r, nlogs = 0; + /* len is always initialized before use since we are always called with + * datalen > 0. + */ + u32 len; while (datalen > 0 && headcount < quota) { if (unlikely(seg >= UIO_MAXIOV)) { r = -ENOBUFS; goto err; } - d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg, - ARRAY_SIZE(vq->iov) - seg, &out, - &in, log, log_num); + r = vhost_get_vq_desc_n(vq, vq->iov + seg, + ARRAY_SIZE(vq->iov) - seg, &out, + &in, log, log_num, &desc_num); + if (unlikely(r < 0)) + goto err; + + d = r; if (d == vq->num) { r = 0; goto err; @@ -529,19 +1091,40 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, nlogs += *log_num; log += *log_num; } - heads[headcount].id = d; - heads[headcount].len = iov_length(vq->iov + seg, in); - datalen -= heads[headcount].len; + len = iov_length(vq->iov + seg, in); + if (!in_order) { + heads[headcount].id = cpu_to_vhost32(vq, d); + heads[headcount].len = cpu_to_vhost32(vq, len); + } ++headcount; + datalen -= len; seg += in; + n += desc_num; } - heads[headcount - 1].len += datalen; + *iovcount = seg; if (unlikely(log)) *log_num = nlogs; + + /* Detect overrun */ + if (unlikely(datalen > 0)) { + r = UIO_MAXIOV + 1; + goto err; + } + + if (!in_order) + heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen); + else { + heads[0].len = cpu_to_vhost32(vq, len + datalen); + heads[0].id = cpu_to_vhost32(vq, d); + nheads[0] = headcount; + } + + *ndesc = n; + return headcount; err: - vhost_discard_vq_desc(vq, headcount); + vhost_discard_vq_desc(vq, headcount, n); return r; } @@ -551,52 +1134,74 @@ static void handle_rx(struct vhost_net *net) { struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX]; struct vhost_virtqueue *vq = &nvq->vq; - unsigned uninitialized_var(in), log; + bool in_order = vhost_has_feature(vq, VIRTIO_F_IN_ORDER); + unsigned int count = 0; + unsigned in, log; struct vhost_log *vq_log; struct msghdr msg = { .msg_name = NULL, .msg_namelen = 0, .msg_control = NULL, /* FIXME: get and handle RX aux data. */ .msg_controllen = 0, - .msg_iov = vq->iov, .msg_flags = MSG_DONTWAIT, }; - struct virtio_net_hdr_mrg_rxbuf hdr = { - .hdr.flags = 0, - .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE + struct virtio_net_hdr hdr = { + .flags = 0, + .gso_type = VIRTIO_NET_HDR_GSO_NONE }; size_t total_len = 0; int err, mergeable; s16 headcount; size_t vhost_hlen, sock_hlen; size_t vhost_len, sock_len; - /* TODO: check that we are running from vhost_worker? */ - struct socket *sock = rcu_dereference_check(vq->private_data, 1); + bool busyloop_intr = false; + bool set_num_buffers; + struct socket *sock; + struct iov_iter fixup; + __virtio16 num_buffers; + int recv_pkts = 0; + unsigned int ndesc; + mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX); + sock = vhost_vq_get_backend(vq); if (!sock) - return; + goto out; + + if (!vq_meta_prefetch(vq)) + goto out; - mutex_lock(&vq->mutex); vhost_disable_notify(&net->dev, vq); + vhost_net_disable_vq(net, vq); + vhost_hlen = nvq->vhost_hlen; sock_hlen = nvq->sock_hlen; - vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ? + vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ? vq->log : NULL; - mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF); - - while ((sock_len = peek_head_len(sock->sk))) { + mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF); + set_num_buffers = mergeable || + vhost_has_feature(vq, VIRTIO_F_VERSION_1); + + do { + sock_len = vhost_net_rx_peek_head_len(net, sock->sk, + &busyloop_intr, &count); + if (!sock_len) + break; sock_len += sock_hlen; vhost_len = sock_len + vhost_hlen; - headcount = get_rx_bufs(vq, vq->heads, vhost_len, - &in, vq_log, &log, - likely(mergeable) ? UIO_MAXIOV : 1); + headcount = get_rx_bufs(nvq, vq->heads + count, + vq->nheads + count, + vhost_len, &in, vq_log, &log, + likely(mergeable) ? UIO_MAXIOV : 1, + &ndesc); /* On error, stop handling until the next kick. */ if (unlikely(headcount < 0)) - break; + goto out; /* OK, now we need to know about added descriptors. */ if (!headcount) { - if (unlikely(vhost_enable_notify(&net->dev, vq))) { + if (unlikely(busyloop_intr)) { + vhost_poll_queue(&vq->poll); + } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { /* They have slipped one in as we were * doing that: check again. */ vhost_disable_notify(&net->dev, vq); @@ -604,18 +1209,29 @@ static void handle_rx(struct vhost_net *net) } /* Nothing new? Wait for eventfd to tell us * they refilled. */ - break; + goto out; + } + busyloop_intr = false; + if (nvq->rx_ring) + msg.msg_control = vhost_net_buf_consume(&nvq->rxq); + /* On overrun, truncate and discard */ + if (unlikely(headcount > UIO_MAXIOV)) { + iov_iter_init(&msg.msg_iter, ITER_DEST, vq->iov, 1, 1); + err = sock->ops->recvmsg(sock, &msg, + 1, MSG_DONTWAIT | MSG_TRUNC); + pr_debug("Discarded rx packet: len %zd\n", sock_len); + continue; } /* We don't need to be notified again. */ - if (unlikely((vhost_hlen))) - /* Skip header. TODO: support TSO. */ - move_iovec_hdr(vq->iov, nvq->hdr, vhost_hlen, in); - else - /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF: - * needed because recvmsg can modify msg_iov. */ - copy_iovec_hdr(vq->iov, nvq->hdr, sock_hlen, in); - msg.msg_iovlen = in; - err = sock->ops->recvmsg(NULL, sock, &msg, + iov_iter_init(&msg.msg_iter, ITER_DEST, vq->iov, in, vhost_len); + fixup = msg.msg_iter; + if (unlikely((vhost_hlen))) { + /* We will supply the header ourselves + * TODO: support TSO. + */ + iov_iter_advance(&msg.msg_iter, vhost_hlen); + } + err = sock->ops->recvmsg(sock, &msg, sock_len, MSG_DONTWAIT | MSG_TRUNC); /* Userspace might have consumed the packet meanwhile: * it's not supposed to do this usually, but might be hard @@ -623,36 +1239,51 @@ static void handle_rx(struct vhost_net *net) if (unlikely(err != sock_len)) { pr_debug("Discarded rx packet: " " len %d, expected %zd\n", err, sock_len); - vhost_discard_vq_desc(vq, headcount); + vhost_discard_vq_desc(vq, headcount, ndesc); continue; } - if (unlikely(vhost_hlen) && - memcpy_toiovecend(nvq->hdr, (unsigned char *)&hdr, 0, - vhost_hlen)) { - vq_err(vq, "Unable to write vnet_hdr at addr %p\n", - vq->iov->iov_base); - break; + /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */ + if (unlikely(vhost_hlen)) { + if (copy_to_iter(&hdr, sizeof(hdr), + &fixup) != sizeof(hdr)) { + vq_err(vq, "Unable to write vnet_hdr " + "at addr %p\n", vq->iov->iov_base); + goto out; + } + } else { + /* Header came from socket; we'll need to patch + * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF + */ + iov_iter_advance(&fixup, sizeof(hdr)); } /* TODO: Should check and handle checksum. */ - if (likely(mergeable) && - memcpy_toiovecend(nvq->hdr, (unsigned char *)&headcount, - offsetof(typeof(hdr), num_buffers), - sizeof hdr.num_buffers)) { + + num_buffers = cpu_to_vhost16(vq, headcount); + if (likely(set_num_buffers) && + copy_to_iter(&num_buffers, sizeof num_buffers, + &fixup) != sizeof num_buffers) { vq_err(vq, "Failed num_buffers write"); - vhost_discard_vq_desc(vq, headcount); - break; + vhost_discard_vq_desc(vq, headcount, ndesc); + goto out; + } + nvq->done_idx += headcount; + count += in_order ? 1 : headcount; + if (nvq->done_idx > VHOST_NET_BATCH) { + vhost_net_signal_used(nvq, count); + count = 0; } - vhost_add_used_and_signal_n(&net->dev, vq, vq->heads, - headcount); if (unlikely(vq_log)) - vhost_log_write(vq, vq_log, log, vhost_len); + vhost_log_write(vq, vq_log, log, vhost_len, + vq->iov, in); total_len += vhost_len; - if (unlikely(total_len >= VHOST_NET_WEIGHT)) { - vhost_poll_queue(&vq->poll); - break; - } - } + } while (likely(!vhost_exceeds_weight(vq, ++recv_pkts, total_len))); + if (unlikely(busyloop_intr)) + vhost_poll_queue(&vq->poll); + else if (!sock_len) + vhost_net_enable_vq(net, vq); +out: + vhost_net_signal_used(nvq, count); mutex_unlock(&vq->mutex); } @@ -690,18 +1321,39 @@ static void handle_rx_net(struct vhost_work *work) static int vhost_net_open(struct inode *inode, struct file *f) { - struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL); + struct vhost_net *n; struct vhost_dev *dev; struct vhost_virtqueue **vqs; - int r, i; + void **queue; + struct xdp_buff *xdp; + int i; + n = kvmalloc(sizeof *n, GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!n) return -ENOMEM; - vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL); + vqs = kmalloc_array(VHOST_NET_VQ_MAX, sizeof(*vqs), GFP_KERNEL); if (!vqs) { - kfree(n); + kvfree(n); + return -ENOMEM; + } + + queue = kmalloc_array(VHOST_NET_BATCH, sizeof(void *), + GFP_KERNEL); + if (!queue) { + kfree(vqs); + kvfree(n); return -ENOMEM; } + n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue; + + xdp = kmalloc_array(VHOST_NET_BATCH, sizeof(*xdp), GFP_KERNEL); + if (!xdp) { + kfree(vqs); + kvfree(n); + kfree(queue); + return -ENOMEM; + } + n->vqs[VHOST_NET_VQ_TX].xdp = xdp; dev = &n->dev; vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq; @@ -713,61 +1365,41 @@ static int vhost_net_open(struct inode *inode, struct file *f) n->vqs[i].ubuf_info = NULL; n->vqs[i].upend_idx = 0; n->vqs[i].done_idx = 0; + n->vqs[i].batched_xdp = 0; n->vqs[i].vhost_hlen = 0; n->vqs[i].sock_hlen = 0; + n->vqs[i].rx_ring = NULL; + vhost_net_buf_init(&n->vqs[i].rxq); } - r = vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX); - if (r < 0) { - kfree(n); - kfree(vqs); - return r; - } + vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX, + UIO_MAXIOV + VHOST_NET_BATCH, + VHOST_NET_PKT_WEIGHT, VHOST_NET_WEIGHT, true, + NULL); - vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev); - vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev); + vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev, + vqs[VHOST_NET_VQ_TX]); + vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev, + vqs[VHOST_NET_VQ_RX]); f->private_data = n; + page_frag_cache_init(&n->pf_cache); return 0; } -static void vhost_net_disable_vq(struct vhost_net *n, - struct vhost_virtqueue *vq) -{ - struct vhost_net_virtqueue *nvq = - container_of(vq, struct vhost_net_virtqueue, vq); - struct vhost_poll *poll = n->poll + (nvq - n->vqs); - if (!vq->private_data) - return; - vhost_poll_stop(poll); -} - -static int vhost_net_enable_vq(struct vhost_net *n, - struct vhost_virtqueue *vq) -{ - struct vhost_net_virtqueue *nvq = - container_of(vq, struct vhost_net_virtqueue, vq); - struct vhost_poll *poll = n->poll + (nvq - n->vqs); - struct socket *sock; - - sock = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); - if (!sock) - return 0; - - return vhost_poll_start(poll, sock->file); -} - static struct socket *vhost_net_stop_vq(struct vhost_net *n, struct vhost_virtqueue *vq) { struct socket *sock; + struct vhost_net_virtqueue *nvq = + container_of(vq, struct vhost_net_virtqueue, vq); mutex_lock(&vq->mutex); - sock = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); + sock = vhost_vq_get_backend(vq); vhost_net_disable_vq(n, vq); - rcu_assign_pointer(vq->private_data, NULL); + vhost_vq_set_backend(vq, NULL); + vhost_net_buf_unproduce(nvq); + nvq->rx_ring = NULL; mutex_unlock(&vq->mutex); return sock; } @@ -779,16 +1411,9 @@ static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock, *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq); } -static void vhost_net_flush_vq(struct vhost_net *n, int index) -{ - vhost_poll_flush(n->poll + index); - vhost_poll_flush(&n->vqs[index].vq.poll); -} - static void vhost_net_flush(struct vhost_net *n) { - vhost_net_flush_vq(n, VHOST_NET_VQ_TX); - vhost_net_flush_vq(n, VHOST_NET_VQ_RX); + vhost_dev_flush(&n->dev); if (n->vqs[VHOST_NET_VQ_TX].ubufs) { mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); n->tx_flush = true; @@ -797,7 +1422,7 @@ static void vhost_net_flush(struct vhost_net *n) vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs); mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); n->tx_flush = false; - kref_init(&n->vqs[VHOST_NET_VQ_TX].ubufs->kref); + atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1); mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); } } @@ -811,27 +1436,28 @@ static int vhost_net_release(struct inode *inode, struct file *f) vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); vhost_dev_stop(&n->dev); - vhost_dev_cleanup(&n->dev, false); + vhost_dev_cleanup(&n->dev); vhost_net_vq_reset(n); if (tx_sock) - fput(tx_sock->file); + sockfd_put(tx_sock); if (rx_sock) - fput(rx_sock->file); + sockfd_put(rx_sock); + /* Make sure no callbacks are outstanding */ + synchronize_rcu(); /* We do an extra flush before freeing memory, * since jobs can re-queue themselves. */ vhost_net_flush(n); + kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue); + kfree(n->vqs[VHOST_NET_VQ_TX].xdp); kfree(n->dev.vqs); - kfree(n); + page_frag_cache_drain(&n->pf_cache); + kvfree(n); return 0; } static struct socket *get_raw_socket(int fd) { - struct { - struct sockaddr_ll sa; - char buf[MAX_ADDR_LEN]; - } uaddr; - int uaddr_len = sizeof uaddr, r; + int r; struct socket *sock = sockfd_lookup(fd, &r); if (!sock) @@ -843,21 +1469,30 @@ static struct socket *get_raw_socket(int fd) goto err; } - r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, - &uaddr_len, 0); - if (r) - goto err; - - if (uaddr.sa.sll_family != AF_PACKET) { + if (sock->sk->sk_family != AF_PACKET) { r = -EPFNOSUPPORT; goto err; } return sock; err: - fput(sock->file); + sockfd_put(sock); return ERR_PTR(r); } +static struct ptr_ring *get_tap_ptr_ring(struct file *file) +{ + struct ptr_ring *ring; + ring = tun_get_tx_ring(file); + if (!IS_ERR(ring)) + goto out; + ring = tap_get_ptr_ring(file); + if (!IS_ERR(ring)) + goto out; + ring = NULL; +out: + return ring; +} + static struct socket *get_tap_socket(int fd) { struct file *file = fget(fd); @@ -868,7 +1503,7 @@ static struct socket *get_tap_socket(int fd) sock = tun_get_socket(file); if (!IS_ERR(sock)) return sock; - sock = macvtap_get_socket(file); + sock = tap_get_socket(file); if (IS_ERR(sock)) fput(file); return sock; @@ -911,6 +1546,9 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) nvq = &n->vqs[index]; mutex_lock(&vq->mutex); + if (fd == -1) + vhost_clear_msg(&n->dev); + /* Verify that ring has been setup correctly. */ if (!vhost_vq_access_ok(vq)) { r = -EFAULT; @@ -923,8 +1561,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) } /* start polling new socket */ - oldsock = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); + oldsock = vhost_vq_get_backend(vq); if (sock != oldsock) { ubufs = vhost_net_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock)); @@ -934,13 +1571,20 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) } vhost_net_disable_vq(n, vq); - rcu_assign_pointer(vq->private_data, sock); - r = vhost_init_used(vq); + vhost_vq_set_backend(vq, sock); + vhost_net_buf_unproduce(nvq); + r = vhost_vq_init_access(vq); if (r) goto err_used; r = vhost_net_enable_vq(n, vq); if (r) goto err_used; + if (index == VHOST_NET_VQ_RX) { + if (sock) + nvq->rx_ring = get_tap_ptr_ring(sock->file); + else + nvq->rx_ring = NULL; + } oldubufs = nvq->ubufs; nvq->ubufs = ubufs; @@ -960,20 +1604,21 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) } if (oldsock) { - vhost_net_flush_vq(n, index); - fput(oldsock->file); + vhost_dev_flush(&n->dev); + sockfd_put(oldsock); } mutex_unlock(&n->dev.mutex); return 0; err_used: - rcu_assign_pointer(vq->private_data, oldsock); + vhost_vq_set_backend(vq, oldsock); vhost_net_enable_vq(n, vq); if (ubufs) vhost_net_ubuf_put_wait_and_free(ubufs); err_ubufs: - fput(sock->file); + if (sock) + sockfd_put(sock); err_vq: mutex_unlock(&vq->mutex); err: @@ -986,39 +1631,48 @@ static long vhost_net_reset_owner(struct vhost_net *n) struct socket *tx_sock = NULL; struct socket *rx_sock = NULL; long err; - struct vhost_memory *memory; + struct vhost_iotlb *umem; mutex_lock(&n->dev.mutex); err = vhost_dev_check_owner(&n->dev); if (err) goto done; - memory = vhost_dev_reset_owner_prepare(); - if (!memory) { + umem = vhost_dev_reset_owner_prepare(); + if (!umem) { err = -ENOMEM; goto done; } vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); - vhost_dev_reset_owner(&n->dev, memory); + vhost_dev_stop(&n->dev); + vhost_dev_reset_owner(&n->dev, umem); vhost_net_vq_reset(n); done: mutex_unlock(&n->dev.mutex); if (tx_sock) - fput(tx_sock->file); + sockfd_put(tx_sock); if (rx_sock) - fput(rx_sock->file); + sockfd_put(rx_sock); return err; } -static int vhost_net_set_features(struct vhost_net *n, u64 features) +static int vhost_net_set_features(struct vhost_net *n, const u64 *features) { size_t vhost_hlen, sock_hlen, hdr_len; int i; - hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ? - sizeof(struct virtio_net_hdr_mrg_rxbuf) : - sizeof(struct virtio_net_hdr); - if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) { + hdr_len = virtio_features_test_bit(features, VIRTIO_NET_F_MRG_RXBUF) || + virtio_features_test_bit(features, VIRTIO_F_VERSION_1) ? + sizeof(struct virtio_net_hdr_mrg_rxbuf) : + sizeof(struct virtio_net_hdr); + + if (virtio_features_test_bit(features, + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO) || + virtio_features_test_bit(features, + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO)) + hdr_len = sizeof(struct virtio_net_hdr_v1_hash_tunnel); + + if (virtio_features_test_bit(features, VHOST_NET_F_VIRTIO_NET_HDR)) { /* vhost provides vnet_hdr */ vhost_hlen = hdr_len; sock_hlen = 0; @@ -1028,22 +1682,29 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features) sock_hlen = hdr_len; } mutex_lock(&n->dev.mutex); - if ((features & (1 << VHOST_F_LOG_ALL)) && - !vhost_log_access_ok(&n->dev)) { - mutex_unlock(&n->dev.mutex); - return -EFAULT; + if (virtio_features_test_bit(features, VHOST_F_LOG_ALL) && + !vhost_log_access_ok(&n->dev)) + goto out_unlock; + + if (virtio_features_test_bit(features, VIRTIO_F_ACCESS_PLATFORM)) { + if (vhost_init_device_iotlb(&n->dev)) + goto out_unlock; } - n->dev.acked_features = features; - smp_wmb(); + for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { mutex_lock(&n->vqs[i].vq.mutex); + virtio_features_copy(n->vqs[i].vq.acked_features_array, + features); n->vqs[i].vhost_hlen = vhost_hlen; n->vqs[i].sock_hlen = sock_hlen; mutex_unlock(&n->vqs[i].vq.mutex); } - vhost_net_flush(n); mutex_unlock(&n->dev.mutex); return 0; + +out_unlock: + mutex_unlock(&n->dev.mutex); + return -EFAULT; } static long vhost_net_set_owner(struct vhost_net *n) @@ -1070,12 +1731,14 @@ out: static long vhost_net_ioctl(struct file *f, unsigned int ioctl, unsigned long arg) { + const DEFINE_VHOST_FEATURES_ARRAY(vhost_net_features, vhost_net_bits); + u64 all_features[VIRTIO_FEATURES_U64S]; struct vhost_net *n = f->private_data; void __user *argp = (void __user *)arg; u64 __user *featurep = argp; struct vhost_vring_file backend; - u64 features; - int r; + u64 features, count, copied; + int r, i; switch (ioctl) { case VHOST_NET_SET_BACKEND: @@ -1083,16 +1746,72 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl, return -EFAULT; return vhost_net_set_backend(n, backend.index, backend.fd); case VHOST_GET_FEATURES: - features = VHOST_NET_FEATURES; + features = vhost_net_features[0]; if (copy_to_user(featurep, &features, sizeof features)) return -EFAULT; return 0; case VHOST_SET_FEATURES: if (copy_from_user(&features, featurep, sizeof features)) return -EFAULT; - if (features & ~VHOST_NET_FEATURES) + if (features & ~vhost_net_features[0]) return -EOPNOTSUPP; - return vhost_net_set_features(n, features); + + virtio_features_from_u64(all_features, features); + return vhost_net_set_features(n, all_features); + case VHOST_GET_FEATURES_ARRAY: + if (copy_from_user(&count, featurep, sizeof(count))) + return -EFAULT; + + /* Copy the net features, up to the user-provided buffer size */ + argp += sizeof(u64); + copied = min(count, (u64)VIRTIO_FEATURES_U64S); + if (copy_to_user(argp, vhost_net_features, + copied * sizeof(u64))) + return -EFAULT; + + /* Zero the trailing space provided by user-space, if any */ + if (clear_user(argp, size_mul(count - copied, sizeof(u64)))) + return -EFAULT; + return 0; + case VHOST_SET_FEATURES_ARRAY: + if (copy_from_user(&count, featurep, sizeof(count))) + return -EFAULT; + + virtio_features_zero(all_features); + argp += sizeof(u64); + copied = min(count, (u64)VIRTIO_FEATURES_U64S); + if (copy_from_user(all_features, argp, copied * sizeof(u64))) + return -EFAULT; + + /* + * Any feature specified by user-space above + * VIRTIO_FEATURES_BITS is not supported by definition. + */ + for (i = copied; i < count; ++i) { + if (copy_from_user(&features, featurep + 1 + i, + sizeof(features))) + return -EFAULT; + if (features) + return -EOPNOTSUPP; + } + + for (i = 0; i < VIRTIO_FEATURES_U64S; i++) + if (all_features[i] & ~vhost_net_features[i]) + return -EOPNOTSUPP; + + return vhost_net_set_features(n, all_features); + case VHOST_GET_BACKEND_FEATURES: + features = VHOST_NET_BACKEND_FEATURES; + if (copy_to_user(featurep, &features, sizeof(features))) + return -EFAULT; + return 0; + case VHOST_SET_BACKEND_FEATURES: + if (copy_from_user(&features, featurep, sizeof(features))) + return -EFAULT; + if (features & ~VHOST_NET_BACKEND_FEATURES) + return -EOPNOTSUPP; + vhost_set_backend_features(&n->dev, features); + return 0; case VHOST_RESET_OWNER: return vhost_net_reset_owner(n); case VHOST_SET_OWNER: @@ -1109,21 +1828,42 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl, } } -#ifdef CONFIG_COMPAT -static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl, - unsigned long arg) +static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct file *file = iocb->ki_filp; + struct vhost_net *n = file->private_data; + struct vhost_dev *dev = &n->dev; + int noblock = file->f_flags & O_NONBLOCK; + + return vhost_chr_read_iter(dev, to, noblock); +} + +static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb, + struct iov_iter *from) { - return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); + struct file *file = iocb->ki_filp; + struct vhost_net *n = file->private_data; + struct vhost_dev *dev = &n->dev; + + return vhost_chr_write_iter(dev, from); +} + +static __poll_t vhost_net_chr_poll(struct file *file, poll_table *wait) +{ + struct vhost_net *n = file->private_data; + struct vhost_dev *dev = &n->dev; + + return vhost_chr_poll(file, dev, wait); } -#endif static const struct file_operations vhost_net_fops = { .owner = THIS_MODULE, .release = vhost_net_release, + .read_iter = vhost_net_chr_read_iter, + .write_iter = vhost_net_chr_write_iter, + .poll = vhost_net_chr_poll, .unlocked_ioctl = vhost_net_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = vhost_net_compat_ioctl, -#endif + .compat_ioctl = compat_ptr_ioctl, .open = vhost_net_open, .llseek = noop_llseek, }; @@ -1134,7 +1874,7 @@ static struct miscdevice vhost_net_misc = { .fops = &vhost_net_fops, }; -static int vhost_net_init(void) +static int __init vhost_net_init(void) { if (experimental_zcopytx) vhost_net_enable_zcopy(VHOST_NET_VQ_TX); @@ -1142,7 +1882,7 @@ static int vhost_net_init(void) } module_init(vhost_net_init); -static void vhost_net_exit(void) +static void __exit vhost_net_exit(void) { misc_deregister(&vhost_net_misc); } |