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1805 lines
44 KiB
1805 lines
44 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* Copyright (C) 2009 Red Hat, Inc. |
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* Author: Michael S. Tsirkin <[email protected]> |
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* |
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* virtio-net server in host kernel. |
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*/ |
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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/sched/clock.h> |
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#include <linux/sched/signal.h> |
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#include <linux/vmalloc.h> |
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|
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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_tap.h> |
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#include <linux/if_vlan.h> |
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#include <linux/skb_array.h> |
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#include <linux/skbuff.h> |
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|
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#include <net/sock.h> |
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#include <net/xdp.h> |
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|
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#include "vhost.h" |
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|
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static int experimental_zcopytx = 0; |
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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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|
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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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|
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/* Max number of packets transferred before requeueing the job. |
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* Using this limit prevents one virtqueue from starving others with small |
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* pkts. |
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*/ |
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#define VHOST_NET_PKT_WEIGHT 256 |
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|
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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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/* |
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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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|
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#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN) |
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|
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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_ACCESS_PLATFORM) |
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}; |
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|
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enum { |
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VHOST_NET_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
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}; |
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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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|
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#define VHOST_NET_BATCH 64 |
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struct vhost_net_buf { |
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void **queue; |
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int tail; |
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int head; |
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}; |
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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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/* For TX, first used idx for DMA done zerocopy buffers |
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* For RX, number of batched heads |
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*/ |
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int done_idx; |
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/* Number of XDP frames batched */ |
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int batched_xdp; |
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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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struct ptr_ring *rx_ring; |
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struct vhost_net_buf rxq; |
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/* Batched XDP buffs */ |
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struct xdp_buff *xdp; |
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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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/* Private page frag */ |
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struct page_frag page_frag; |
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/* Refcount bias of page frag */ |
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int refcnt_bias; |
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}; |
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|
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static unsigned vhost_net_zcopy_mask __read_mostly; |
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|
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static void *vhost_net_buf_get_ptr(struct vhost_net_buf *rxq) |
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{ |
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if (rxq->tail != rxq->head) |
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return rxq->queue[rxq->head]; |
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else |
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return NULL; |
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} |
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static int vhost_net_buf_get_size(struct vhost_net_buf *rxq) |
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{ |
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return rxq->tail - rxq->head; |
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} |
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|
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static int vhost_net_buf_is_empty(struct vhost_net_buf *rxq) |
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{ |
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return rxq->tail == rxq->head; |
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} |
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|
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static void *vhost_net_buf_consume(struct vhost_net_buf *rxq) |
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{ |
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void *ret = vhost_net_buf_get_ptr(rxq); |
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++rxq->head; |
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return ret; |
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} |
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|
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static int vhost_net_buf_produce(struct vhost_net_virtqueue *nvq) |
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{ |
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struct vhost_net_buf *rxq = &nvq->rxq; |
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|
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rxq->head = 0; |
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rxq->tail = ptr_ring_consume_batched(nvq->rx_ring, rxq->queue, |
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VHOST_NET_BATCH); |
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return rxq->tail; |
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} |
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static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq) |
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{ |
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struct vhost_net_buf *rxq = &nvq->rxq; |
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|
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if (nvq->rx_ring && !vhost_net_buf_is_empty(rxq)) { |
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ptr_ring_unconsume(nvq->rx_ring, rxq->queue + rxq->head, |
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vhost_net_buf_get_size(rxq), |
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tun_ptr_free); |
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rxq->head = rxq->tail = 0; |
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} |
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} |
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|
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static int vhost_net_buf_peek_len(void *ptr) |
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{ |
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if (tun_is_xdp_frame(ptr)) { |
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struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr); |
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|
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return xdpf->len; |
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} |
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return __skb_array_len_with_tag(ptr); |
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} |
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static int vhost_net_buf_peek(struct vhost_net_virtqueue *nvq) |
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{ |
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struct vhost_net_buf *rxq = &nvq->rxq; |
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|
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if (!vhost_net_buf_is_empty(rxq)) |
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goto out; |
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|
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if (!vhost_net_buf_produce(nvq)) |
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return 0; |
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|
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out: |
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return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq)); |
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} |
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|
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static void vhost_net_buf_init(struct vhost_net_buf *rxq) |
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{ |
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rxq->head = rxq->tail = 0; |
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} |
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|
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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 = |
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kmalloc_array(UIO_MAXIOV, |
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sizeof(*n->vqs[i].ubuf_info), |
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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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vhost_net_buf_init(&n->vqs[i].rxq); |
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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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|
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static bool vhost_sock_xdp(struct socket *sock) |
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{ |
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return sock_flag(sock->sk, SOCK_XDP); |
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} |
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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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|
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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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|
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static void vhost_zerocopy_callback(struct sk_buff *skb, |
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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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|
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rcu_read_lock_bh(); |
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|
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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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/* |
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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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|
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rcu_read_unlock_bh(); |
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} |
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|
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static inline unsigned long busy_clock(void) |
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{ |
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return local_clock() >> 10; |
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} |
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|
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static bool vhost_can_busy_poll(unsigned long endtime) |
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{ |
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return likely(!need_resched() && !time_after(busy_clock(), endtime) && |
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!signal_pending(current)); |
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} |
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|
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static void vhost_net_disable_vq(struct vhost_net *n, |
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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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struct vhost_poll *poll = n->poll + (nvq - n->vqs); |
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if (!vhost_vq_get_backend(vq)) |
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return; |
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vhost_poll_stop(poll); |
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} |
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|
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static int vhost_net_enable_vq(struct vhost_net *n, |
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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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struct vhost_poll *poll = n->poll + (nvq - n->vqs); |
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struct socket *sock; |
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|
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sock = vhost_vq_get_backend(vq); |
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if (!sock) |
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return 0; |
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|
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return vhost_poll_start(poll, sock->file); |
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} |
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|
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static void vhost_net_signal_used(struct vhost_net_virtqueue *nvq) |
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{ |
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struct vhost_virtqueue *vq = &nvq->vq; |
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struct vhost_dev *dev = vq->dev; |
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|
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if (!nvq->done_idx) |
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return; |
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|
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vhost_add_used_and_signal_n(dev, vq, vq->heads, nvq->done_idx); |
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nvq->done_idx = 0; |
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} |
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|
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static void vhost_tx_batch(struct vhost_net *net, |
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struct vhost_net_virtqueue *nvq, |
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struct socket *sock, |
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struct msghdr *msghdr) |
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{ |
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struct tun_msg_ctl ctl = { |
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.type = TUN_MSG_PTR, |
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.num = nvq->batched_xdp, |
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.ptr = nvq->xdp, |
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}; |
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int err; |
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|
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if (nvq->batched_xdp == 0) |
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goto signal_used; |
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|
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msghdr->msg_control = &ctl; |
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err = sock->ops->sendmsg(sock, msghdr, 0); |
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if (unlikely(err < 0)) { |
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vq_err(&nvq->vq, "Fail to batch sending packets\n"); |
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return; |
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} |
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|
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signal_used: |
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vhost_net_signal_used(nvq); |
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nvq->batched_xdp = 0; |
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} |
|
|
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static int sock_has_rx_data(struct socket *sock) |
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{ |
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if (unlikely(!sock)) |
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return 0; |
|
|
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if (sock->ops->peek_len) |
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return sock->ops->peek_len(sock); |
|
|
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return skb_queue_empty(&sock->sk->sk_receive_queue); |
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} |
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|
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static void vhost_net_busy_poll_try_queue(struct vhost_net *net, |
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struct vhost_virtqueue *vq) |
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{ |
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if (!vhost_vq_avail_empty(&net->dev, vq)) { |
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vhost_poll_queue(&vq->poll); |
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} else if (unlikely(vhost_enable_notify(&net->dev, vq))) { |
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vhost_disable_notify(&net->dev, vq); |
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vhost_poll_queue(&vq->poll); |
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} |
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} |
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|
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static void vhost_net_busy_poll(struct vhost_net *net, |
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struct vhost_virtqueue *rvq, |
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struct vhost_virtqueue *tvq, |
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bool *busyloop_intr, |
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bool poll_rx) |
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{ |
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unsigned long busyloop_timeout; |
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unsigned long endtime; |
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struct socket *sock; |
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struct vhost_virtqueue *vq = poll_rx ? tvq : rvq; |
|
|
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/* Try to hold the vq mutex of the paired virtqueue. We can't |
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* use mutex_lock() here since we could not guarantee a |
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* consistenet lock ordering. |
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*/ |
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if (!mutex_trylock(&vq->mutex)) |
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return; |
|
|
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vhost_disable_notify(&net->dev, vq); |
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sock = vhost_vq_get_backend(rvq); |
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|
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busyloop_timeout = poll_rx ? rvq->busyloop_timeout: |
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tvq->busyloop_timeout; |
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|
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preempt_disable(); |
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endtime = busy_clock() + busyloop_timeout; |
|
|
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while (vhost_can_busy_poll(endtime)) { |
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if (vhost_has_work(&net->dev)) { |
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*busyloop_intr = true; |
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break; |
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} |
|
|
|
if ((sock_has_rx_data(sock) && |
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!vhost_vq_avail_empty(&net->dev, rvq)) || |
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!vhost_vq_avail_empty(&net->dev, tvq)) |
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break; |
|
|
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cpu_relax(); |
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} |
|
|
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preempt_enable(); |
|
|
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if (poll_rx || sock_has_rx_data(sock)) |
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vhost_net_busy_poll_try_queue(net, vq); |
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else if (!poll_rx) /* On tx here, sock has no rx data. */ |
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vhost_enable_notify(&net->dev, rvq); |
|
|
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mutex_unlock(&vq->mutex); |
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} |
|
|
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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(vhost_vq_get_backend(tvq))) |
|
vhost_tx_batch(net, tnvq, |
|
vhost_vq_get_backend(tvq), |
|
msghdr); |
|
|
|
vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, false); |
|
|
|
r = vhost_get_vq_desc(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 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 = vhost_vq_get_backend(vq); |
|
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; |
|
xdp->frame_sz = 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); |
|
|
|
do { |
|
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; |
|
} |
|
|
|
err = sock->ops->sendmsg(sock, &msg, len); |
|
if (unlikely(err < 0)) { |
|
if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) { |
|
vhost_discard_vq_desc(vq, 1); |
|
vhost_net_enable_vq(net, vq); |
|
break; |
|
} |
|
pr_debug("Fail to send packet: err %d", err); |
|
} else if (unlikely(err != len)) |
|
pr_debug("Truncated TX packet: len %d != %zd\n", |
|
err, len); |
|
done: |
|
vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head); |
|
vq->heads[nvq->done_idx].len = 0; |
|
++nvq->done_idx; |
|
} while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len))); |
|
|
|
vhost_tx_batch(net, nvq, sock, &msg); |
|
} |
|
|
|
static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) |
|
{ |
|
struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; |
|
struct vhost_virtqueue *vq = &nvq->vq; |
|
unsigned out, in; |
|
int head; |
|
struct msghdr msg = { |
|
.msg_name = NULL, |
|
.msg_namelen = 0, |
|
.msg_control = NULL, |
|
.msg_controllen = 0, |
|
.msg_flags = MSG_DONTWAIT, |
|
}; |
|
struct tun_msg_ctl ctl; |
|
size_t len, total_len = 0; |
|
int err; |
|
struct vhost_net_ubuf_ref *ubufs; |
|
struct ubuf_info *ubuf; |
|
bool zcopy_used; |
|
int sent_pkts = 0; |
|
|
|
do { |
|
bool busyloop_intr; |
|
|
|
/* Release DMAs done buffers first */ |
|
vhost_zerocopy_signal_used(net, vq); |
|
|
|
busyloop_intr = false; |
|
head = get_tx_bufs(net, nvq, &msg, &out, &in, &len, |
|
&busyloop_intr); |
|
/* 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) { |
|
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; |
|
ubuf->flags = SKBFL_ZEROCOPY_FRAG; |
|
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; |
|
} |
|
|
|
err = sock->ops->sendmsg(sock, &msg, len); |
|
if (unlikely(err < 0)) { |
|
if (zcopy_used) { |
|
if (vq->heads[ubuf->desc].len == VHOST_DMA_IN_PROGRESS) |
|
vhost_net_ubuf_put(ubufs); |
|
nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) |
|
% UIO_MAXIOV; |
|
} |
|
if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) { |
|
vhost_discard_vq_desc(vq, 1); |
|
vhost_net_enable_vq(net, vq); |
|
break; |
|
} |
|
pr_debug("Fail to send packet: err %d", err); |
|
} else if (unlikely(err != len)) |
|
pr_debug("Truncated TX packet: " |
|
" len %d != %zd\n", err, len); |
|
if (!zcopy_used) |
|
vhost_add_used_and_signal(&net->dev, vq, head, 0); |
|
else |
|
vhost_zerocopy_signal_used(net, vq); |
|
vhost_net_tx_packet(net); |
|
} while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len))); |
|
} |
|
|
|
/* Expects to be always run from workqueue - which acts as |
|
* read-size critical section for our kind of RCU. */ |
|
static void handle_tx(struct vhost_net *net) |
|
{ |
|
struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; |
|
struct vhost_virtqueue *vq = &nvq->vq; |
|
struct socket *sock; |
|
|
|
mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX); |
|
sock = vhost_vq_get_backend(vq); |
|
if (!sock) |
|
goto out; |
|
|
|
if (!vq_meta_prefetch(vq)) |
|
goto out; |
|
|
|
vhost_disable_notify(&net->dev, vq); |
|
vhost_net_disable_vq(net, vq); |
|
|
|
if (vhost_sock_zcopy(sock)) |
|
handle_tx_zerocopy(net, sock); |
|
else |
|
handle_tx_copy(net, sock); |
|
|
|
out: |
|
mutex_unlock(&vq->mutex); |
|
} |
|
|
|
static int peek_head_len(struct 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 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 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 = vhost_vq_get_backend(vq); |
|
if (!sock) |
|
goto out; |
|
|
|
if (!vq_meta_prefetch(vq)) |
|
goto out; |
|
|
|
vhost_disable_notify(&net->dev, vq); |
|
vhost_net_disable_vq(net, vq); |
|
|
|
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); |
|
|
|
do { |
|
sock_len = vhost_net_rx_peek_head_len(net, sock->sk, |
|
&busyloop_intr); |
|
if (!sock_len) |
|
break; |
|
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; |
|
} while (likely(!vhost_exceeds_weight(vq, ++recv_pkts, total_len))); |
|
|
|
if (unlikely(busyloop_intr)) |
|
vhost_poll_queue(&vq->poll); |
|
else if (!sock_len) |
|
vhost_net_enable_vq(net, vq); |
|
out: |
|
vhost_net_signal_used(nvq); |
|
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_NET_PKT_WEIGHT, VHOST_NET_WEIGHT, true, |
|
NULL); |
|
|
|
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 = vhost_vq_get_backend(vq); |
|
vhost_net_disable_vq(n, vq); |
|
vhost_vq_set_backend(vq, 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) |
|
{ |
|
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; |
|
} |
|
|
|
if (sock->sk->sk_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 = vhost_vq_get_backend(vq); |
|
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); |
|
vhost_vq_set_backend(vq, sock); |
|
vhost_net_buf_unproduce(nvq); |
|
r = vhost_vq_init_access(vq); |
|
if (r) |
|
goto err_used; |
|
r = vhost_net_enable_vq(n, vq); |
|
if (r) |
|
goto err_used; |
|
if (index == VHOST_NET_VQ_RX) |
|
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: |
|
vhost_vq_set_backend(vq, 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_iotlb *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_ACCESS_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; |
|
vhost_set_backend_features(&n->dev, features); |
|
return 0; |
|
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; |
|
} |
|
} |
|
|
|
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, |
|
.compat_ioctl = compat_ptr_ioctl, |
|
.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");
|
|
|