| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jason (Hui) Wang | 3858 | 42.42% | 48 | 33.80% |
| Michael S. Tsirkin | 3212 | 35.32% | 40 | 28.17% |
| Asias He | 782 | 8.60% | 8 | 5.63% |
| David L Stevens | 398 | 4.38% | 1 | 0.70% |
| Tonghao Zhang | 380 | 4.18% | 3 | 2.11% |
| Toshiaki Makita | 106 | 1.17% | 4 | 2.82% |
| Al Viro | 75 | 0.82% | 4 | 2.82% |
| Tejun Heo | 42 | 0.46% | 2 | 1.41% |
| Wei Xu | 41 | 0.45% | 1 | 0.70% |
| Arnd Bergmann | 28 | 0.31% | 3 | 2.11% |
| Willem de Bruijn | 28 | 0.31% | 2 | 1.41% |
| Stephen Hemminger | 20 | 0.22% | 1 | 0.70% |
| Takuya Yoshikawa | 17 | 0.19% | 1 | 0.70% |
| Basil Gor | 15 | 0.16% | 1 | 0.70% |
| Jeff Dike | 15 | 0.16% | 2 | 1.41% |
| haibinzhang(张海斌) | 12 | 0.13% | 1 | 0.70% |
| Alexander Potapenko | 11 | 0.12% | 1 | 0.70% |
| Paolo Abeni | 11 | 0.12% | 1 | 0.70% |
| Jesper Dangaard Brouer | 8 | 0.09% | 1 | 0.70% |
| Ingo Molnar | 6 | 0.07% | 2 | 1.41% |
| Kees Cook | 5 | 0.05% | 1 | 0.70% |
| Dan Carpenter | 4 | 0.04% | 1 | 0.70% |
| Sainath Grandhi | 4 | 0.04% | 1 | 0.70% |
| Michal Hocko | 2 | 0.02% | 2 | 1.41% |
| Denys Vlasenko | 2 | 0.02% | 1 | 0.70% |
| Stefan Hajnoczi | 2 | 0.02% | 1 | 0.70% |
| Linus Torvalds | 2 | 0.02% | 1 | 0.70% |
| Christoph Hellwig | 2 | 0.02% | 1 | 0.70% |
| Romain Francoise | 2 | 0.02% | 1 | 0.70% |
| Greg Kurz | 1 | 0.01% | 1 | 0.70% |
| Paul E. McKenney | 1 | 0.01% | 1 | 0.70% |
| Eric Dumazet | 1 | 0.01% | 1 | 0.70% |
| Jiri Pirko | 1 | 0.01% | 1 | 0.70% |
| Tobias Klauser | 1 | 0.01% | 1 | 0.70% |
| Total | 9095 | 142 |
/* 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. */ #include <linux/compat.h> #include <linux/eventfd.h> #include <linux/vhost.h> #include <linux/virtio_net.h> #include <linux/miscdevice.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/mutex.h> #include <linux/workqueue.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; module_param(experimental_zcopytx, int, 0444); MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" " 1 -Enable; 0 - Disable"); /* Max number of bytes transferred before requeueing the job. * 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 /* * For transmit, used buffer len is unused; we override it to track buffer * status internally; used for zerocopy tx only. */ /* Lower device DMA failed */ #define VHOST_DMA_FAILED_LEN ((__force __virtio32)3) /* Lower device DMA done */ #define VHOST_DMA_DONE_LEN ((__force __virtio32)2) /* Lower device DMA in progress */ #define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1) /* Buffer unused */ #define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0) #define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN) enum { VHOST_NET_FEATURES = VHOST_FEATURES | (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | (1ULL << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VIRTIO_F_IOMMU_PLATFORM) }; enum { VHOST_NET_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) }; enum { VHOST_NET_VQ_RX = 0, VHOST_NET_VQ_TX = 1, VHOST_NET_VQ_MAX = 2, }; struct vhost_net_ubuf_ref { /* 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; }; #define VHOST_NET_BATCH 64 struct vhost_net_buf { void **queue; int tail; int head; }; struct vhost_net_virtqueue { struct vhost_virtqueue vq; size_t vhost_hlen; size_t sock_hlen; /* vhost zerocopy support fields below: */ /* last used idx for outstanding DMA zerocopy buffers */ int upend_idx; /* 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; /* 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 { struct vhost_dev dev; struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX]; struct vhost_poll poll[VHOST_NET_VQ_MAX]; /* Number of TX recently submitted. * Protected by tx vq lock. */ unsigned tx_packets; /* Number of times zerocopy TX recently failed. * Protected by tx vq lock. */ unsigned tx_zcopy_err; /* Flush in progress. Protected by tx vq lock. */ bool tx_flush; /* Private page frag */ struct page_frag page_frag; /* Refcount bias of page frag */ int refcnt_bias; }; static unsigned vhost_net_zcopy_mask __read_mostly; static void *vhost_net_buf_get_ptr(struct vhost_net_buf *rxq) { if (rxq->tail != rxq->head) return rxq->queue[rxq->head]; else return NULL; } static int vhost_net_buf_get_size(struct vhost_net_buf *rxq) { return rxq->tail - rxq->head; } 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 * vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy) { struct vhost_net_ubuf_ref *ubufs; /* No zero copy backend? Nothing to count. */ if (!zcopy) return NULL; ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL); if (!ubufs) return ERR_PTR(-ENOMEM); atomic_set(&ubufs->refcount, 1); init_waitqueue_head(&ubufs->wait); ubufs->vq = vq; return ubufs; } static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs) { int r = atomic_sub_return(1, &ubufs->refcount); if (unlikely(!r)) wake_up(&ubufs->wait); return r; } static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs) { 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); } static void vhost_net_clear_ubuf_info(struct vhost_net *n) { int i; for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { kfree(n->vqs[i].ubuf_info); n->vqs[i].ubuf_info = NULL; } } static int vhost_net_set_ubuf_info(struct vhost_net *n) { bool zcopy; int i; for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { zcopy = vhost_net_zcopy_mask & (0x1 << i); if (!zcopy) continue; 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; } return 0; err: vhost_net_clear_ubuf_info(n); return -ENOMEM; } static void vhost_net_vq_reset(struct vhost_net *n) { int i; vhost_net_clear_ubuf_info(n); for (i = 0; i < VHOST_NET_VQ_MAX; i++) { n->vqs[i].done_idx = 0; n->vqs[i].upend_idx = 0; 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); } } static void vhost_net_tx_packet(struct vhost_net *net) { ++net->tx_packets; if (net->tx_packets < 1024) return; net->tx_packets = 0; net->tx_zcopy_err = 0; } static void vhost_net_tx_err(struct vhost_net *net) { ++net->tx_zcopy_err; } static bool vhost_net_tx_select_zcopy(struct vhost_net *net) { /* TX flush waits for outstanding DMAs to be done. * Don't start new DMAs. */ return !net->tx_flush && net->tx_packets / 64 >= net->tx_zcopy_err; } static bool vhost_sock_zcopy(struct socket *sock) { return unlikely(experimental_zcopytx) && sock_flag(sock->sk, SOCK_ZEROCOPY); } static bool vhost_sock_xdp(struct socket *sock) { return sock_flag(sock->sk, SOCK_XDP); } /* In case of DMA done not in order in lower device driver for some reason. * upend_idx is used to track end of used idx, done_idx is used to track head * of used idx. Once lower device DMA done contiguously, we will signal KVM * guest used idx. */ 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, add; int j = 0; for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) { if (vq->heads[i].len == VHOST_DMA_FAILED_LEN) vhost_net_tx_err(net); if (VHOST_DMA_IS_DONE(vq->heads[i].len)) { vq->heads[i].len = VHOST_DMA_CLEAR_LEN; ++j; } else break; } while (j) { add = min(UIO_MAXIOV - nvq->done_idx, j); vhost_add_used_and_signal_n(vq->dev, vq, &vq->heads[nvq->done_idx], add); nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV; j -= add; } } static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) { struct vhost_net_ubuf_ref *ubufs = ubuf->ctx; struct vhost_virtqueue *vq = ubufs->vq; 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. * 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 <= 1 || !(cnt % 16)) vhost_poll_queue(&vq->poll); rcu_read_unlock_bh(); } 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 (!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 = vq->private_data; if (!sock) return 0; return vhost_poll_start(poll, sock->file); } static void vhost_net_signal_used(struct vhost_net_virtqueue *nvq) { 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, nvq->done_idx); 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 tun_msg_ctl ctl = { .type = TUN_MSG_PTR, .num = nvq->batched_xdp, .ptr = nvq->xdp, }; int err; if (nvq->batched_xdp == 0) goto signal_used; msghdr->msg_control = &ctl; err = sock->ops->sendmsg(sock, msghdr, 0); if (unlikely(err < 0)) { vq_err(&nvq->vq, "Fail to batch sending packets\n"); return; } signal_used: vhost_net_signal_used(nvq); 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 = rvq->private_data; 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_has_work(&net->dev)) { *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) { 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(tvq, tvq->iov, ARRAY_SIZE(tvq->iov), out_num, in_num, NULL, NULL); if (r == tvq->num && tvq->busyloop_timeout) { /* Flush batched packets first */ if (!vhost_sock_zcopy(tvq->private_data)) vhost_tx_batch(net, tnvq, tvq->private_data, msghdr); vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, false); r = vhost_get_vq_desc(tvq, tvq->iov, ARRAY_SIZE(tvq->iov), out_num, in_num, NULL, NULL); } 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; 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, WRITE, vq->iov, out, len); iov_iter_advance(iter, hdr_size); return iov_iter_count(iter); } static bool vhost_exceeds_weight(int pkts, int total_len) { return total_len >= VHOST_NET_WEIGHT || pkts >= VHOST_NET_PKT_WEIGHT; } 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) { struct vhost_virtqueue *vq = &nvq->vq; int ret; ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, msg, busyloop_intr); 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 SKB_FRAG_PAGE_ORDER get_order(32768) static bool vhost_net_page_frag_refill(struct vhost_net *net, unsigned int sz, struct page_frag *pfrag, gfp_t gfp) { if (pfrag->page) { if (pfrag->offset + sz <= pfrag->size) return true; __page_frag_cache_drain(pfrag->page, net->refcnt_bias); } pfrag->offset = 0; net->refcnt_bias = 0; if (SKB_FRAG_PAGE_ORDER) { /* Avoid direct reclaim but allow kswapd to wake */ pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY, SKB_FRAG_PAGE_ORDER); if (likely(pfrag->page)) { pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER; goto done; } } pfrag->page = alloc_page(gfp); if (likely(pfrag->page)) { pfrag->size = PAGE_SIZE; goto done; } return false; done: net->refcnt_bias = USHRT_MAX; page_ref_add(pfrag->page, USHRT_MAX - 1); return true; } #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 = vq->private_data; struct page_frag *alloc_frag = &net->page_frag; struct virtio_net_hdr *gso; struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp]; struct tun_xdp_hdr *hdr; 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; 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); alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES); if (unlikely(!vhost_net_page_frag_refill(net, buflen, alloc_frag, GFP_KERNEL))) return -ENOMEM; buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset; copied = copy_page_from_iter(alloc_frag->page, alloc_frag->offset + offsetof(struct tun_xdp_hdr, gso), sock_hlen, from); if (copied != sock_hlen) return -EFAULT; hdr = buf; gso = &hdr->gso; 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) return -EINVAL; } len -= sock_hlen; copied = copy_page_from_iter(alloc_frag->page, alloc_frag->offset + pad, len, from); if (copied != len) return -EFAULT; xdp->data_hard_start = buf; xdp->data = buf + pad; xdp->data_end = xdp->data + len; hdr->buflen = buflen; --net->refcnt_bias; alloc_frag->offset += buflen; ++nvq->batched_xdp; return 0; } 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_flags = MSG_DONTWAIT, }; size_t len, total_len = 0; int err; int sent_pkts = 0; bool sock_can_batch = (sock->sk->sk_sndbuf == INT_MAX); for (;;) { bool busyloop_intr = false; if (nvq->done_idx == VHOST_NET_BATCH) vhost_tx_batch(net, nvq, sock, &msg); head = get_tx_bufs(net, nvq, &msg, &out, &in, &len, &busyloop_intr); /* 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; } 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); vhost_net_enable_vq(net, vq); break; } /* 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; } /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { vhost_discard_vq_desc(vq, 1); vhost_net_enable_vq(net, vq); break; } if (err != len) pr_debug("Truncated TX packet: len %d != %zd\n", err, len); done: vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head); vq->heads[nvq->done_idx].len = 0; ++nvq->done_idx; if (vhost_exceeds_weight(++sent_pkts, total_len)) { vhost_poll_queue(&vq->poll); break; } } 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 *uninitialized_var(ubufs); bool zcopy_used; int sent_pkts = 0; for (;;) { 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); /* 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 = 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) { struct ubuf_info *ubuf; 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->callback = vhost_zerocopy_callback; ubuf->ctx = nvq->ubufs; ubuf->desc = nvq->upend_idx; refcount_set(&ubuf->refcnt, 1); msg.msg_control = &ctl; ctl.type = TUN_MSG_UBUF; ctl.ptr = ubuf; msg.msg_controllen = sizeof(ctl); ubufs = nvq->ubufs; atomic_inc(&ubufs->refcount); nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV; } else { msg.msg_control = NULL; 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; } /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { if (zcopy_used) { vhost_net_ubuf_put(ubufs); nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) % UIO_MAXIOV; } vhost_discard_vq_desc(vq, 1); vhost_net_enable_vq(net, vq); break; } if (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); vhost_net_tx_packet(net); if (unlikely(vhost_exceeds_weight(++sent_pkts, total_len))) { vhost_poll_queue(&vq->poll); break; } } } /* 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 = vq->private_data; if (!sock) goto out; if (!vq_iotlb_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 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 (skb_vlan_tag_present(head)) len += VLAN_HLEN; } spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags); return len; } static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk, bool *busyloop_intr) { 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); /* 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 * @datalen - data length we'll be reading * @iovcount - returned count of io vectors we fill * @log - vhost log * @log_num - log offset * @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, struct vring_used_elem *heads, int datalen, unsigned *iovcount, struct vhost_log *log, unsigned *log_num, unsigned int quota) { unsigned int out, in; 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 uninitialized_var(len); while (datalen > 0 && headcount < quota) { if (unlikely(seg >= UIO_MAXIOV)) { r = -ENOBUFS; goto err; } r = vhost_get_vq_desc(vq, vq->iov + seg, ARRAY_SIZE(vq->iov) - seg, &out, &in, log, log_num); if (unlikely(r < 0)) goto err; d = r; if (d == vq->num) { r = 0; goto err; } if (unlikely(out || in <= 0)) { vq_err(vq, "unexpected descriptor format for RX: " "out %d, in %d\n", out, in); r = -EINVAL; goto err; } if (unlikely(log)) { nlogs += *log_num; log += *log_num; } heads[headcount].id = cpu_to_vhost32(vq, d); len = iov_length(vq->iov + seg, in); heads[headcount].len = cpu_to_vhost32(vq, len); datalen -= len; ++headcount; seg += in; } heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen); *iovcount = seg; if (unlikely(log)) *log_num = nlogs; /* Detect overrun */ if (unlikely(datalen > 0)) { r = UIO_MAXIOV + 1; goto err; } return headcount; err: vhost_discard_vq_desc(vq, headcount); return r; } /* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */ 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; 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_flags = MSG_DONTWAIT, }; 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; bool busyloop_intr = false; struct socket *sock; struct iov_iter fixup; __virtio16 num_buffers; int recv_pkts = 0; mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX); sock = vq->private_data; if (!sock) goto out; if (!vq_iotlb_prefetch(vq)) goto out; 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(vq, VHOST_F_LOG_ALL)) ? vq->log : NULL; mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF); while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, &busyloop_intr))) { sock_len += sock_hlen; vhost_len = sock_len + vhost_hlen; headcount = get_rx_bufs(vq, vq->heads + nvq->done_idx, vhost_len, &in, vq_log, &log, likely(mergeable) ? UIO_MAXIOV : 1); /* On error, stop handling until the next kick. */ if (unlikely(headcount < 0)) goto out; /* OK, now we need to know about added descriptors. */ if (!headcount) { 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); continue; } /* Nothing new? Wait for eventfd to tell us * they refilled. */ 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, READ, 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. */ iov_iter_init(&msg.msg_iter, READ, 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 * to prevent. Discard data we got (if any) and keep going. */ if (unlikely(err != sock_len)) { pr_debug("Discarded rx packet: " " len %d, expected %zd\n", err, sock_len); vhost_discard_vq_desc(vq, headcount); continue; } /* 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. */ num_buffers = cpu_to_vhost16(vq, headcount); if (likely(mergeable) && 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); goto out; } nvq->done_idx += headcount; if (nvq->done_idx > VHOST_NET_BATCH) vhost_net_signal_used(nvq); if (unlikely(vq_log)) vhost_log_write(vq, vq_log, log, vhost_len, vq->iov, in); total_len += vhost_len; if (unlikely(vhost_exceeds_weight(++recv_pkts, total_len))) { vhost_poll_queue(&vq->poll); goto out; } } if (unlikely(busyloop_intr)) vhost_poll_queue(&vq->poll); else vhost_net_enable_vq(net, vq); out: vhost_net_signal_used(nvq); mutex_unlock(&vq->mutex); } static void handle_tx_kick(struct vhost_work *work) { struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, poll.work); struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); handle_tx(net); } static void handle_rx_kick(struct vhost_work *work) { struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, poll.work); struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); handle_rx(net); } static void handle_tx_net(struct vhost_work *work) { struct vhost_net *net = container_of(work, struct vhost_net, poll[VHOST_NET_VQ_TX].work); handle_tx(net); } static void handle_rx_net(struct vhost_work *work) { struct vhost_net *net = container_of(work, struct vhost_net, poll[VHOST_NET_VQ_RX].work); handle_rx(net); } static int vhost_net_open(struct inode *inode, struct file *f) { struct vhost_net *n; struct vhost_dev *dev; struct vhost_virtqueue **vqs; void **queue; struct xdp_buff *xdp; int i; n = kvmalloc(sizeof *n, GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!n) return -ENOMEM; vqs = kmalloc_array(VHOST_NET_VQ_MAX, sizeof(*vqs), GFP_KERNEL); if (!vqs) { 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; vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq; n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick; n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick; for (i = 0; i < VHOST_NET_VQ_MAX; i++) { n->vqs[i].ubufs = NULL; 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); } vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX, UIO_MAXIOV + VHOST_NET_BATCH); vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev); vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev); f->private_data = n; n->page_frag.page = NULL; n->refcnt_bias = 0; return 0; } 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 = vq->private_data; vhost_net_disable_vq(n, vq); vq->private_data = NULL; vhost_net_buf_unproduce(nvq); nvq->rx_ring = NULL; mutex_unlock(&vq->mutex); return sock; } static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock, struct socket **rx_sock) { *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq); *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); if (n->vqs[VHOST_NET_VQ_TX].ubufs) { mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); n->tx_flush = true; mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); /* Wait for all lower device DMAs done. */ 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; atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1); mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); } } static int vhost_net_release(struct inode *inode, struct file *f) { struct vhost_net *n = f->private_data; struct socket *tx_sock; struct socket *rx_sock; vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); vhost_dev_stop(&n->dev); vhost_dev_cleanup(&n->dev); vhost_net_vq_reset(n); if (tx_sock) sockfd_put(tx_sock); if (rx_sock) 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); if (n->page_frag.page) __page_frag_cache_drain(n->page_frag.page, n->refcnt_bias); kvfree(n); return 0; } static struct socket *get_raw_socket(int fd) { struct { struct sockaddr_ll sa; char buf[MAX_ADDR_LEN]; } uaddr; int r; struct socket *sock = sockfd_lookup(fd, &r); if (!sock) return ERR_PTR(-ENOTSOCK); /* Parameter checking */ if (sock->sk->sk_type != SOCK_RAW) { r = -ESOCKTNOSUPPORT; goto err; } r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, 0); if (r < 0) goto err; if (uaddr.sa.sll_family != AF_PACKET) { r = -EPFNOSUPPORT; goto err; } return sock; err: sockfd_put(sock); return ERR_PTR(r); } static struct ptr_ring *get_tap_ptr_ring(int fd) { struct ptr_ring *ring; struct file *file = fget(fd); if (!file) return NULL; 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: fput(file); return ring; } static struct socket *get_tap_socket(int fd) { struct file *file = fget(fd); struct socket *sock; if (!file) return ERR_PTR(-EBADF); sock = tun_get_socket(file); if (!IS_ERR(sock)) return sock; sock = tap_get_socket(file); if (IS_ERR(sock)) fput(file); return sock; } static struct socket *get_socket(int fd) { struct socket *sock; /* special case to disable backend */ if (fd == -1) return NULL; sock = get_raw_socket(fd); if (!IS_ERR(sock)) return sock; sock = get_tap_socket(fd); if (!IS_ERR(sock)) return sock; return ERR_PTR(-ENOTSOCK); } static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) { struct socket *sock, *oldsock; struct vhost_virtqueue *vq; struct vhost_net_virtqueue *nvq; struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL; int r; mutex_lock(&n->dev.mutex); r = vhost_dev_check_owner(&n->dev); if (r) goto err; if (index >= VHOST_NET_VQ_MAX) { r = -ENOBUFS; goto err; } vq = &n->vqs[index].vq; nvq = &n->vqs[index]; mutex_lock(&vq->mutex); /* Verify that ring has been setup correctly. */ if (!vhost_vq_access_ok(vq)) { r = -EFAULT; goto err_vq; } sock = get_socket(fd); if (IS_ERR(sock)) { r = PTR_ERR(sock); goto err_vq; } /* start polling new socket */ oldsock = vq->private_data; if (sock != oldsock) { ubufs = vhost_net_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock)); if (IS_ERR(ubufs)) { r = PTR_ERR(ubufs); goto err_ubufs; } vhost_net_disable_vq(n, vq); vq->private_data = 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) nvq->rx_ring = get_tap_ptr_ring(fd); oldubufs = nvq->ubufs; nvq->ubufs = ubufs; n->tx_packets = 0; n->tx_zcopy_err = 0; n->tx_flush = false; } mutex_unlock(&vq->mutex); if (oldubufs) { vhost_net_ubuf_put_wait_and_free(oldubufs); mutex_lock(&vq->mutex); vhost_zerocopy_signal_used(n, vq); mutex_unlock(&vq->mutex); } if (oldsock) { vhost_net_flush_vq(n, index); sockfd_put(oldsock); } mutex_unlock(&n->dev.mutex); return 0; err_used: vq->private_data = oldsock; vhost_net_enable_vq(n, vq); if (ubufs) vhost_net_ubuf_put_wait_and_free(ubufs); err_ubufs: if (sock) sockfd_put(sock); err_vq: mutex_unlock(&vq->mutex); err: mutex_unlock(&n->dev.mutex); return r; } static long vhost_net_reset_owner(struct vhost_net *n) { struct socket *tx_sock = NULL; struct socket *rx_sock = NULL; long err; struct vhost_umem *umem; mutex_lock(&n->dev.mutex); err = vhost_dev_check_owner(&n->dev); if (err) goto done; 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_stop(&n->dev); vhost_dev_reset_owner(&n->dev, umem); vhost_net_vq_reset(n); done: mutex_unlock(&n->dev.mutex); if (tx_sock) sockfd_put(tx_sock); if (rx_sock) sockfd_put(rx_sock); return err; } static int vhost_net_set_backend_features(struct vhost_net *n, u64 features) { int i; mutex_lock(&n->dev.mutex); for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { mutex_lock(&n->vqs[i].vq.mutex); n->vqs[i].vq.acked_backend_features = features; mutex_unlock(&n->vqs[i].vq.mutex); } mutex_unlock(&n->dev.mutex); return 0; } static int vhost_net_set_features(struct vhost_net *n, u64 features) { size_t vhost_hlen, sock_hlen, hdr_len; int i; hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VIRTIO_F_VERSION_1))) ? sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr); if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) { /* vhost provides vnet_hdr */ vhost_hlen = hdr_len; sock_hlen = 0; } else { /* socket provides vnet_hdr */ vhost_hlen = 0; sock_hlen = hdr_len; } mutex_lock(&n->dev.mutex); if ((features & (1 << VHOST_F_LOG_ALL)) && !vhost_log_access_ok(&n->dev)) goto out_unlock; if ((features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) { if (vhost_init_device_iotlb(&n->dev, true)) goto out_unlock; } for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { mutex_lock(&n->vqs[i].vq.mutex); n->vqs[i].vq.acked_features = features; n->vqs[i].vhost_hlen = vhost_hlen; n->vqs[i].sock_hlen = sock_hlen; mutex_unlock(&n->vqs[i].vq.mutex); } 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) { int r; mutex_lock(&n->dev.mutex); if (vhost_dev_has_owner(&n->dev)) { r = -EBUSY; goto out; } r = vhost_net_set_ubuf_info(n); if (r) goto out; r = vhost_dev_set_owner(&n->dev); if (r) vhost_net_clear_ubuf_info(n); vhost_net_flush(n); out: mutex_unlock(&n->dev.mutex); return r; } static long vhost_net_ioctl(struct file *f, unsigned int ioctl, unsigned long arg) { 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; switch (ioctl) { case VHOST_NET_SET_BACKEND: if (copy_from_user(&backend, argp, sizeof backend)) return -EFAULT; return vhost_net_set_backend(n, backend.index, backend.fd); case VHOST_GET_FEATURES: features = VHOST_NET_FEATURES; 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) return -EOPNOTSUPP; return vhost_net_set_features(n, 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; return vhost_net_set_backend_features(n, features); case VHOST_RESET_OWNER: return vhost_net_reset_owner(n); case VHOST_SET_OWNER: return vhost_net_set_owner(n); default: mutex_lock(&n->dev.mutex); r = vhost_dev_ioctl(&n->dev, ioctl, argp); if (r == -ENOIOCTLCMD) r = vhost_vring_ioctl(&n->dev, ioctl, argp); else vhost_net_flush(n); mutex_unlock(&n->dev.mutex); return r; } } #ifdef CONFIG_COMPAT static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl, unsigned long arg) { return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); } #endif 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) { 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); } 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 .open = vhost_net_open, .llseek = noop_llseek, }; static struct miscdevice vhost_net_misc = { .minor = VHOST_NET_MINOR, .name = "vhost-net", .fops = &vhost_net_fops, }; static int vhost_net_init(void) { if (experimental_zcopytx) vhost_net_enable_zcopy(VHOST_NET_VQ_TX); return misc_register(&vhost_net_misc); } module_init(vhost_net_init); static void vhost_net_exit(void) { misc_deregister(&vhost_net_misc); } module_exit(vhost_net_exit); MODULE_VERSION("0.0.1"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Michael S. Tsirkin"); MODULE_DESCRIPTION("Host kernel accelerator for virtio net"); MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR); MODULE_ALIAS("devname:vhost-net");
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