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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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1138 lines
28 KiB
C
1138 lines
28 KiB
C
/* Copyright (C) 2009 Red Hat, Inc.
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* Author: Michael S. Tsirkin <mst@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2.
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*
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* virtio-net server in host kernel.
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*/
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#include <linux/compat.h>
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#include <linux/eventfd.h>
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#include <linux/vhost.h>
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#include <linux/virtio_net.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/mutex.h>
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#include <linux/workqueue.h>
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#include <linux/file.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/net.h>
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#include <linux/if_packet.h>
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#include <linux/if_arp.h>
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#include <linux/if_tun.h>
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#include <linux/if_macvlan.h>
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#include <linux/if_vlan.h>
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#include <net/sock.h>
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#include "vhost.h"
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static int experimental_zcopytx = 1;
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module_param(experimental_zcopytx, int, 0444);
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MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
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" 1 -Enable; 0 - Disable");
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/* Max number of bytes transferred before requeueing the job.
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* Using this limit prevents one virtqueue from starving others. */
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#define VHOST_NET_WEIGHT 0x80000
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/* MAX number of TX used buffers for outstanding zerocopy */
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#define VHOST_MAX_PEND 128
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#define VHOST_GOODCOPY_LEN 256
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/*
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* For transmit, used buffer len is unused; we override it to track buffer
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* status internally; used for zerocopy tx only.
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*/
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/* Lower device DMA failed */
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#define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)
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/* Lower device DMA done */
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#define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
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/* Lower device DMA in progress */
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#define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
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/* Buffer unused */
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#define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
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#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
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enum {
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VHOST_NET_FEATURES = VHOST_FEATURES |
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(1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
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(1ULL << VIRTIO_NET_F_MRG_RXBUF) |
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(1ULL << VIRTIO_F_VERSION_1),
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};
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enum {
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VHOST_NET_VQ_RX = 0,
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VHOST_NET_VQ_TX = 1,
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VHOST_NET_VQ_MAX = 2,
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};
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struct vhost_net_ubuf_ref {
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/* refcount follows semantics similar to kref:
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* 0: object is released
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* 1: no outstanding ubufs
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* >1: outstanding ubufs
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*/
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atomic_t refcount;
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wait_queue_head_t wait;
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struct vhost_virtqueue *vq;
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};
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struct vhost_net_virtqueue {
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struct vhost_virtqueue vq;
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size_t vhost_hlen;
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size_t sock_hlen;
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/* vhost zerocopy support fields below: */
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/* last used idx for outstanding DMA zerocopy buffers */
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int upend_idx;
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/* first used idx for DMA done zerocopy buffers */
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int done_idx;
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/* an array of userspace buffers info */
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struct ubuf_info *ubuf_info;
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/* Reference counting for outstanding ubufs.
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* Protected by vq mutex. Writers must also take device mutex. */
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struct vhost_net_ubuf_ref *ubufs;
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};
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struct vhost_net {
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struct vhost_dev dev;
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struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX];
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struct vhost_poll poll[VHOST_NET_VQ_MAX];
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/* Number of TX recently submitted.
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* Protected by tx vq lock. */
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unsigned tx_packets;
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/* Number of times zerocopy TX recently failed.
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* Protected by tx vq lock. */
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unsigned tx_zcopy_err;
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/* Flush in progress. Protected by tx vq lock. */
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bool tx_flush;
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};
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static unsigned vhost_net_zcopy_mask __read_mostly;
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static void vhost_net_enable_zcopy(int vq)
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{
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vhost_net_zcopy_mask |= 0x1 << vq;
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}
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static struct vhost_net_ubuf_ref *
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vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
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{
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struct vhost_net_ubuf_ref *ubufs;
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/* No zero copy backend? Nothing to count. */
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if (!zcopy)
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return NULL;
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ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
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if (!ubufs)
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return ERR_PTR(-ENOMEM);
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atomic_set(&ubufs->refcount, 1);
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init_waitqueue_head(&ubufs->wait);
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ubufs->vq = vq;
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return ubufs;
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}
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static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
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{
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int r = atomic_sub_return(1, &ubufs->refcount);
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if (unlikely(!r))
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wake_up(&ubufs->wait);
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return r;
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}
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static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
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{
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vhost_net_ubuf_put(ubufs);
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wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
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}
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static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
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{
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vhost_net_ubuf_put_and_wait(ubufs);
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kfree(ubufs);
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}
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static void vhost_net_clear_ubuf_info(struct vhost_net *n)
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{
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int i;
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for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
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kfree(n->vqs[i].ubuf_info);
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n->vqs[i].ubuf_info = NULL;
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}
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}
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static int vhost_net_set_ubuf_info(struct vhost_net *n)
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{
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bool zcopy;
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int i;
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for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
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zcopy = vhost_net_zcopy_mask & (0x1 << i);
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if (!zcopy)
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continue;
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n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
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UIO_MAXIOV, GFP_KERNEL);
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if (!n->vqs[i].ubuf_info)
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goto err;
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}
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return 0;
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err:
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vhost_net_clear_ubuf_info(n);
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return -ENOMEM;
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}
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static void vhost_net_vq_reset(struct vhost_net *n)
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{
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int i;
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vhost_net_clear_ubuf_info(n);
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for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
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n->vqs[i].done_idx = 0;
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n->vqs[i].upend_idx = 0;
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n->vqs[i].ubufs = NULL;
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n->vqs[i].vhost_hlen = 0;
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n->vqs[i].sock_hlen = 0;
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}
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}
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static void vhost_net_tx_packet(struct vhost_net *net)
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{
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++net->tx_packets;
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if (net->tx_packets < 1024)
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return;
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net->tx_packets = 0;
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net->tx_zcopy_err = 0;
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}
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static void vhost_net_tx_err(struct vhost_net *net)
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{
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++net->tx_zcopy_err;
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}
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static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
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{
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/* TX flush waits for outstanding DMAs to be done.
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* Don't start new DMAs.
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*/
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return !net->tx_flush &&
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net->tx_packets / 64 >= net->tx_zcopy_err;
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}
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static bool vhost_sock_zcopy(struct socket *sock)
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{
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return unlikely(experimental_zcopytx) &&
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sock_flag(sock->sk, SOCK_ZEROCOPY);
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}
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/* In case of DMA done not in order in lower device driver for some reason.
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* upend_idx is used to track end of used idx, done_idx is used to track head
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* of used idx. Once lower device DMA done contiguously, we will signal KVM
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* guest used idx.
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*/
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static void vhost_zerocopy_signal_used(struct vhost_net *net,
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struct vhost_virtqueue *vq)
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{
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struct vhost_net_virtqueue *nvq =
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container_of(vq, struct vhost_net_virtqueue, vq);
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int i, add;
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int j = 0;
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for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
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if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
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vhost_net_tx_err(net);
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if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
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vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
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++j;
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} else
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break;
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}
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while (j) {
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add = min(UIO_MAXIOV - nvq->done_idx, j);
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vhost_add_used_and_signal_n(vq->dev, vq,
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&vq->heads[nvq->done_idx], add);
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nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV;
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j -= add;
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}
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}
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static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
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{
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struct vhost_net_ubuf_ref *ubufs = ubuf->ctx;
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struct vhost_virtqueue *vq = ubufs->vq;
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int cnt;
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rcu_read_lock_bh();
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/* set len to mark this desc buffers done DMA */
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vq->heads[ubuf->desc].len = success ?
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VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
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cnt = vhost_net_ubuf_put(ubufs);
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/*
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* Trigger polling thread if guest stopped submitting new buffers:
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* in this case, the refcount after decrement will eventually reach 1.
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* We also trigger polling periodically after each 16 packets
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* (the value 16 here is more or less arbitrary, it's tuned to trigger
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* less than 10% of times).
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*/
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if (cnt <= 1 || !(cnt % 16))
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vhost_poll_queue(&vq->poll);
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rcu_read_unlock_bh();
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}
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/* Expects to be always run from workqueue - which acts as
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* read-size critical section for our kind of RCU. */
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static void handle_tx(struct vhost_net *net)
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{
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struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
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struct vhost_virtqueue *vq = &nvq->vq;
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unsigned out, in;
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int head;
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struct msghdr msg = {
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.msg_name = NULL,
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.msg_namelen = 0,
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.msg_control = NULL,
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.msg_controllen = 0,
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.msg_flags = MSG_DONTWAIT,
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};
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size_t len, total_len = 0;
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int err;
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size_t hdr_size;
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struct socket *sock;
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struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
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bool zcopy, zcopy_used;
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mutex_lock(&vq->mutex);
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sock = vq->private_data;
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if (!sock)
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goto out;
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vhost_disable_notify(&net->dev, vq);
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hdr_size = nvq->vhost_hlen;
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zcopy = nvq->ubufs;
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for (;;) {
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/* Release DMAs done buffers first */
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if (zcopy)
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vhost_zerocopy_signal_used(net, vq);
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/* If more outstanding DMAs, queue the work.
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* Handle upend_idx wrap around
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*/
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if (unlikely((nvq->upend_idx + vq->num - VHOST_MAX_PEND)
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% UIO_MAXIOV == nvq->done_idx))
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break;
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head = vhost_get_vq_desc(vq, vq->iov,
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ARRAY_SIZE(vq->iov),
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&out, &in,
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NULL, NULL);
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/* On error, stop handling until the next kick. */
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if (unlikely(head < 0))
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break;
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/* Nothing new? Wait for eventfd to tell us they refilled. */
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if (head == vq->num) {
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if (unlikely(vhost_enable_notify(&net->dev, vq))) {
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vhost_disable_notify(&net->dev, vq);
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continue;
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}
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break;
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}
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if (in) {
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vq_err(vq, "Unexpected descriptor format for TX: "
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"out %d, int %d\n", out, in);
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break;
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}
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/* Skip header. TODO: support TSO. */
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len = iov_length(vq->iov, out);
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iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len);
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iov_iter_advance(&msg.msg_iter, hdr_size);
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/* Sanity check */
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if (!msg_data_left(&msg)) {
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vq_err(vq, "Unexpected header len for TX: "
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"%zd expected %zd\n",
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len, hdr_size);
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break;
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}
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len = msg_data_left(&msg);
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zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
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&& (nvq->upend_idx + 1) % UIO_MAXIOV !=
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nvq->done_idx
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&& vhost_net_tx_select_zcopy(net);
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/* use msg_control to pass vhost zerocopy ubuf info to skb */
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if (zcopy_used) {
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struct ubuf_info *ubuf;
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ubuf = nvq->ubuf_info + nvq->upend_idx;
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vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
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vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
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ubuf->callback = vhost_zerocopy_callback;
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ubuf->ctx = nvq->ubufs;
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ubuf->desc = nvq->upend_idx;
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msg.msg_control = ubuf;
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msg.msg_controllen = sizeof(ubuf);
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ubufs = nvq->ubufs;
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atomic_inc(&ubufs->refcount);
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nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
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} else {
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msg.msg_control = NULL;
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ubufs = NULL;
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}
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/* TODO: Check specific error and bomb out unless ENOBUFS? */
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err = sock->ops->sendmsg(sock, &msg, len);
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if (unlikely(err < 0)) {
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if (zcopy_used) {
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vhost_net_ubuf_put(ubufs);
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nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
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% UIO_MAXIOV;
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}
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vhost_discard_vq_desc(vq, 1);
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break;
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}
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if (err != len)
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pr_debug("Truncated TX packet: "
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" len %d != %zd\n", err, len);
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if (!zcopy_used)
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vhost_add_used_and_signal(&net->dev, vq, head, 0);
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else
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vhost_zerocopy_signal_used(net, vq);
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total_len += len;
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vhost_net_tx_packet(net);
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if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
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vhost_poll_queue(&vq->poll);
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break;
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}
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}
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out:
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mutex_unlock(&vq->mutex);
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}
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|
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static int peek_head_len(struct sock *sk)
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{
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struct sk_buff *head;
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int len = 0;
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unsigned long flags;
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|
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spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
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head = skb_peek(&sk->sk_receive_queue);
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if (likely(head)) {
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len = head->len;
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if (skb_vlan_tag_present(head))
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len += VLAN_HLEN;
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}
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|
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spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
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return len;
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}
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|
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/* This is a multi-buffer version of vhost_get_desc, that works if
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* vq has read descriptors only.
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* @vq - the relevant virtqueue
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* @datalen - data length we'll be reading
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* @iovcount - returned count of io vectors we fill
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* @log - vhost log
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* @log_num - log offset
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* @quota - headcount quota, 1 for big buffer
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* returns number of buffer heads allocated, negative on error
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*/
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static int get_rx_bufs(struct vhost_virtqueue *vq,
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struct vring_used_elem *heads,
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int datalen,
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unsigned *iovcount,
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struct vhost_log *log,
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unsigned *log_num,
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unsigned int quota)
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{
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unsigned int out, in;
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int seg = 0;
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int headcount = 0;
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unsigned d;
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int r, nlogs = 0;
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/* len is always initialized before use since we are always called with
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* datalen > 0.
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*/
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u32 uninitialized_var(len);
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|
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while (datalen > 0 && headcount < quota) {
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if (unlikely(seg >= UIO_MAXIOV)) {
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r = -ENOBUFS;
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goto err;
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}
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r = vhost_get_vq_desc(vq, vq->iov + seg,
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ARRAY_SIZE(vq->iov) - seg, &out,
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&in, log, log_num);
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if (unlikely(r < 0))
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goto err;
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|
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d = r;
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if (d == vq->num) {
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r = 0;
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goto err;
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}
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if (unlikely(out || in <= 0)) {
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vq_err(vq, "unexpected descriptor format for RX: "
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"out %d, in %d\n", out, in);
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r = -EINVAL;
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goto err;
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}
|
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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(&vq->mutex);
|
|
sock = vq->private_data;
|
|
if (!sock)
|
|
goto out;
|
|
vhost_disable_notify(&net->dev, 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 = peek_head_len(sock->sk))) {
|
|
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);
|
|
/* On error, stop handling until the next kick. */
|
|
if (unlikely(headcount < 0))
|
|
break;
|
|
/* 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;
|
|
}
|
|
/* 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. */
|
|
break;
|
|
}
|
|
/* 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);
|
|
break;
|
|
}
|
|
} 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);
|
|
break;
|
|
}
|
|
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);
|
|
total_len += vhost_len;
|
|
if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
|
|
vhost_poll_queue(&vq->poll);
|
|
break;
|
|
}
|
|
}
|
|
out:
|
|
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;
|
|
int i;
|
|
|
|
n = kmalloc(sizeof *n, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
|
|
if (!n) {
|
|
n = vmalloc(sizeof *n);
|
|
if (!n)
|
|
return -ENOMEM;
|
|
}
|
|
vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
|
|
if (!vqs) {
|
|
kvfree(n);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
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;
|
|
}
|
|
vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
|
|
|
|
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);
|
|
|
|
f->private_data = n;
|
|
|
|
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 = vq->private_data;
|
|
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;
|
|
|
|
mutex_lock(&vq->mutex);
|
|
sock = vq->private_data;
|
|
vhost_net_disable_vq(n, vq);
|
|
vq->private_data = 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, false);
|
|
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->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 uaddr_len = sizeof uaddr, 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,
|
|
&uaddr_len, 0);
|
|
if (r)
|
|
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 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 = macvtap_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;
|
|
r = vhost_init_used(vq);
|
|
if (r)
|
|
goto err_used;
|
|
r = vhost_net_enable_vq(n, vq);
|
|
if (r)
|
|
goto err_used;
|
|
|
|
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_memory *memory;
|
|
|
|
mutex_lock(&n->dev.mutex);
|
|
err = vhost_dev_check_owner(&n->dev);
|
|
if (err)
|
|
goto done;
|
|
memory = vhost_dev_reset_owner_prepare();
|
|
if (!memory) {
|
|
err = -ENOMEM;
|
|
goto done;
|
|
}
|
|
vhost_net_stop(n, &tx_sock, &rx_sock);
|
|
vhost_net_flush(n);
|
|
vhost_dev_reset_owner(&n->dev, memory);
|
|
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)) {
|
|
mutex_unlock(&n->dev.mutex);
|
|
return -EFAULT;
|
|
}
|
|
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;
|
|
}
|
|
|
|
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 const struct file_operations vhost_net_fops = {
|
|
.owner = THIS_MODULE,
|
|
.release = vhost_net_release,
|
|
.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");
|