| /* 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 "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 rx. */ |
| #define VHOST_NET_PKT_WEIGHT(vq) ((vq)->num * 2) |
| |
| /* 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_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_RX_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; |
| /* 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; |
| }; |
| |
| 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; |
| }; |
| |
| 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_RX_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_buff(ptr)) { |
| struct xdp_buff *xdp = tun_ptr_to_xdp(ptr); |
| |
| return xdp->data_end - xdp->data; |
| } |
| |
| 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(sizeof(*n->vqs[i].ubuf_info) * |
| UIO_MAXIOV, 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); |
| } |
| |
| /* 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(struct vhost_dev *dev, |
| unsigned long endtime) |
| { |
| return likely(!need_resched()) && |
| likely(!time_after(busy_clock(), endtime)) && |
| likely(!signal_pending(current)) && |
| !vhost_has_work(dev); |
| } |
| |
| 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 int vhost_net_tx_get_vq_desc(struct vhost_net *net, |
| struct vhost_virtqueue *vq, |
| struct iovec iov[], unsigned int iov_size, |
| unsigned int *out_num, unsigned int *in_num) |
| { |
| unsigned long uninitialized_var(endtime); |
| int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), |
| out_num, in_num, NULL, NULL); |
| |
| if (r == vq->num && vq->busyloop_timeout) { |
| preempt_disable(); |
| endtime = busy_clock() + vq->busyloop_timeout; |
| while (vhost_can_busy_poll(vq->dev, endtime) && |
| vhost_vq_avail_empty(vq->dev, vq)) |
| cpu_relax(); |
| preempt_enable(); |
| r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->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); |
| } |
| |
| /* 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; |
| 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; |
| size_t hdr_size; |
| struct socket *sock; |
| struct vhost_net_ubuf_ref *uninitialized_var(ubufs); |
| bool zcopy, zcopy_used; |
| int sent_pkts = 0; |
| |
| mutex_lock(&vq->mutex); |
| 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); |
| |
| hdr_size = nvq->vhost_hlen; |
| zcopy = nvq->ubufs; |
| |
| for (;;) { |
| /* Release DMAs done buffers first */ |
| if (zcopy) |
| vhost_zerocopy_signal_used(net, vq); |
| |
| |
| head = vhost_net_tx_get_vq_desc(net, vq, vq->iov, |
| ARRAY_SIZE(vq->iov), |
| &out, &in); |
| /* 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(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; |
| } |
| /* Skip header. TODO: support TSO. */ |
| len = iov_length(vq->iov, out); |
| iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len); |
| iov_iter_advance(&msg.msg_iter, hdr_size); |
| /* Sanity check */ |
| if (!msg_data_left(&msg)) { |
| vq_err(vq, "Unexpected header len for TX: " |
| "%zd expected %zd\n", |
| len, hdr_size); |
| break; |
| } |
| len = msg_data_left(&msg); |
| |
| zcopy_used = zcopy && 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 = ubuf; |
| msg.msg_controllen = sizeof(ubuf); |
| 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 (total_len < VHOST_NET_WEIGHT && |
| !vhost_vq_avail_empty(&net->dev, vq) && |
| 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(total_len >= VHOST_NET_WEIGHT) || |
| unlikely(++sent_pkts >= VHOST_NET_PKT_WEIGHT(vq))) { |
| vhost_poll_queue(&vq->poll); |
| break; |
| } |
| } |
| 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 sk_has_rx_data(struct sock *sk) |
| { |
| struct socket *sock = sk->sk_socket; |
| |
| if (sock->ops->peek_len) |
| return sock->ops->peek_len(sock); |
| |
| return skb_queue_empty(&sk->sk_receive_queue); |
| } |
| |
| static void vhost_rx_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 int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) |
| { |
| struct vhost_net_virtqueue *rvq = &net->vqs[VHOST_NET_VQ_RX]; |
| struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; |
| struct vhost_virtqueue *vq = &nvq->vq; |
| unsigned long uninitialized_var(endtime); |
| int len = peek_head_len(rvq, sk); |
| |
| if (!len && vq->busyloop_timeout) { |
| /* Flush batched heads first */ |
| vhost_rx_signal_used(rvq); |
| /* Both tx vq and rx socket were polled here */ |
| mutex_lock_nested(&vq->mutex, 1); |
| vhost_disable_notify(&net->dev, vq); |
| |
| preempt_disable(); |
| endtime = busy_clock() + vq->busyloop_timeout; |
| |
| while (vhost_can_busy_poll(&net->dev, endtime) && |
| !sk_has_rx_data(sk) && |
| vhost_vq_avail_empty(&net->dev, vq)) |
| cpu_relax(); |
| |
| preempt_enable(); |
| |
| 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); |
| } |
| |
| mutex_unlock(&vq->mutex); |
| |
| len = peek_head_len(rvq, 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; |
| struct socket *sock; |
| struct iov_iter fixup; |
| __virtio16 num_buffers; |
| |
| mutex_lock_nested(&vq->mutex, 0); |
| 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))) { |
| 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(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; |
| } |
| 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_RX_BATCH) |
| vhost_rx_signal_used(nvq); |
| if (unlikely(vq_log)) |
| vhost_log_write(vq, vq_log, log, vhost_len); |
| total_len += vhost_len; |
| if (unlikely(total_len >= VHOST_NET_WEIGHT)) { |
| vhost_poll_queue(&vq->poll); |
| goto out; |
| } |
| } |
| vhost_net_enable_vq(net, vq); |
| out: |
| vhost_rx_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; |
| 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); |
| if (!vqs) { |
| kvfree(n); |
| return -ENOMEM; |
| } |
| |
| queue = kmalloc_array(VHOST_RX_BATCH, sizeof(void *), |
| GFP_KERNEL); |
| if (!queue) { |
| kfree(vqs); |
| kvfree(n); |
| return -ENOMEM; |
| } |
| n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue; |
| |
| 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].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); |
| |
| 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; |
| |
| 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_bh(); |
| /* 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->dev.vqs); |
| 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: |
| 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_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_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"); |