summaryrefslogtreecommitdiffstats
path: root/src/vnet/devices/virtio/virtio.c
blob: 02ded3f5f52d569ec82c0911be488835b2a46228 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
/*
 *------------------------------------------------------------------
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *------------------------------------------------------------------
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <net/if.h>
#include <linux/if_tun.h>
#include <sys/ioctl.h>
#include <linux/virtio_net.h>
#include <linux/vhost.h>
#include <sys/eventfd.h>

#include <vlib/vlib.h>
#include <vlib/unix/unix.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/ip/ip4_packet.h>
#include <vnet/ip/ip6_packet.h>
#include <vnet/devices/virtio/virtio.h>

virtio_main_t virtio_main;

#define _IOCTL(fd,a,...) \
  if (ioctl (fd, a, __VA_ARGS__) < 0) \
    { \
      err = clib_error_return_unix (0, "ioctl(" #a ")"); \
      goto error; \
    }

static clib_error_t *
call_read_ready (clib_file_t * uf)
{
  virtio_main_t *nm = &virtio_main;
  vnet_main_t *vnm = vnet_get_main ();
  u16 qid = uf->private_data & 0xFFFF;
  virtio_if_t *vif =
    vec_elt_at_index (nm->interfaces, uf->private_data >> 16);
  u64 b;

  CLIB_UNUSED (ssize_t size) = read (uf->file_descriptor, &b, sizeof (b));
  if ((qid & 1) == 0)
    vnet_device_input_set_interrupt_pending (vnm, vif->hw_if_index, qid);

  return 0;
}


clib_error_t *
virtio_vring_init (vlib_main_t * vm, virtio_if_t * vif, u16 idx, u16 sz)
{
  clib_error_t *err = 0;
  virtio_vring_t *vring;
  struct vhost_vring_state state = { 0 };
  struct vhost_vring_addr addr = { 0 };
  struct vhost_vring_file file = { 0 };
  clib_file_t t = { 0 };
  int i;

  if (!is_pow2 (sz))
    return clib_error_return (0, "ring size must be power of 2");

  if (sz > 32768)
    return clib_error_return (0, "ring size must be 32768 or lower");

  if (sz == 0)
    sz = 256;

  vec_validate_aligned (vif->vrings, idx, CLIB_CACHE_LINE_BYTES);
  vring = vec_elt_at_index (vif->vrings, idx);

  i = sizeof (struct vring_desc) * sz;
  i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
  vring->desc = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
  memset (vring->desc, 0, i);

  i = sizeof (struct vring_avail) + sz * sizeof (vring->avail->ring[0]);
  i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
  vring->avail = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
  memset (vring->avail, 0, i);
  // tell kernel that we don't need interrupt
  vring->avail->flags = VIRTIO_RING_FLAG_MASK_INT;

  i = sizeof (struct vring_used) + sz * sizeof (struct vring_used_elem);
  i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
  vring->used = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
  memset (vring->used, 0, i);

  ASSERT (vring->buffers == 0);
  vec_validate_aligned (vring->buffers, sz, CLIB_CACHE_LINE_BYTES);

  vring->size = sz;
  vring->call_fd = eventfd (0, EFD_NONBLOCK | EFD_CLOEXEC);
  vring->kick_fd = eventfd (0, EFD_CLOEXEC);

  t.read_function = call_read_ready;
  t.file_descriptor = vring->call_fd;
  t.private_data = vif->dev_instance << 16 | idx;
  vring->call_file_index = clib_file_add (&file_main, &t);

  state.index = idx;
  state.num = sz;
  _IOCTL (vif->fd, VHOST_SET_VRING_NUM, &state);

  addr.index = idx;
  addr.flags = 0;
  addr.desc_user_addr = pointer_to_uword (vring->desc);
  addr.avail_user_addr = pointer_to_uword (vring->avail);
  addr.used_user_addr = pointer_to_uword (vring->used);
  _IOCTL (vif->fd, VHOST_SET_VRING_ADDR, &addr);

  file.index = idx;
  file.fd = vring->kick_fd;
  _IOCTL (vif->fd, VHOST_SET_VRING_KICK, &file);
  file.fd = vring->call_fd;
  _IOCTL (vif->fd, VHOST_SET_VRING_CALL, &file);
  file.fd = vif->tap_fd;
  _IOCTL (vif->fd, VHOST_NET_SET_BACKEND, &file);

error:
  return err;
}

static_always_inline void
virtio_free_rx_buffers (vlib_main_t * vm, virtio_vring_t * vring)
{
  u16 used = vring->desc_in_use;
  u16 next = vring->desc_next;
  u16 mask = vring->size - 1;

  while (used)
    {
      vlib_buffer_free (vm, &vring->buffers[next], 1);
      next = (next + 1) & mask;
      used--;
    }
}

clib_error_t *
virtio_vring_free (vlib_main_t * vm, virtio_if_t * vif, u32 idx)
{
  virtio_vring_t *vring = vec_elt_at_index (vif->vrings, idx);

  clib_file_del_by_index (&file_main, vring->call_file_index);
  close (vring->kick_fd);
  close (vring->call_fd);
  if (vring->used)
    {
      if ((idx & 1) == 1)
	virtio_free_used_desc (vm, vring);
      else
	virtio_free_rx_buffers (vm, vring);
      clib_mem_free (vring->used);
    }
  if (vring->desc)
    clib_mem_free (vring->desc);
  if (vring->avail)
    clib_mem_free (vring->avail);
  vec_free (vring->buffers);
  return 0;
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */