hw/virtio/vhost-backend.c

   1 /*
   2  * vhost-backend
   3  *
   4  * Copyright (c) 2013 Virtual Open Systems Sarl.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include <linux/vhost.h>
  13 #include <sys/ioctl.h>
  14 #include "hw/virtio/vhost.h"
  15 #include "hw/virtio/vhost-backend.h"
  16 #include "qemu/error-report.h"
  17
  18 static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
  19                              void *arg)
  20 {
  21     int fd = (uintptr_t) dev->opaque;
  22
  23     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  24
  25     return ioctl(fd, request, arg);
  26 }
  27
  28 static int vhost_kernel_init(struct vhost_dev *dev, void *opaque)
  29 {
  30     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  31
  32     dev->opaque = opaque;
  33
  34     return 0;
  35 }
  36
  37 static int vhost_kernel_cleanup(struct vhost_dev *dev)
  38 {
  39     int fd = (uintptr_t) dev->opaque;
  40
  41     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  42
  43     return close(fd);
  44 }
  45
  46 static int vhost_kernel_memslots_limit(struct vhost_dev *dev)
  47 {
  48     int limit = 64;
  49     char *s;
  50
  51     if (g_file_get_contents("/sys/module/vhost/parameters/max_mem_regions",
  52                             &s, NULL, NULL)) {
  53         uint64_t val = g_ascii_strtoull(s, NULL, 10);
  54         if (!((val == G_MAXUINT64 || !val) && errno)) {
  55             return val;
  56         }
  57         error_report("ignoring invalid max_mem_regions value in vhost module:"
  58                      " %s", s);
  59     }
  60     return limit;
  61 }
  62
  63 static int vhost_kernel_net_set_backend(struct vhost_dev *dev,
  64                                         struct vhost_vring_file *file)
  65 {
  66     return vhost_kernel_call(dev, VHOST_NET_SET_BACKEND, file);
  67 }
  68
  69 static int vhost_kernel_scsi_set_endpoint(struct vhost_dev *dev,
  70                                           struct vhost_scsi_target *target)
  71 {
  72     return vhost_kernel_call(dev, VHOST_SCSI_SET_ENDPOINT, target);
  73 }
  74
  75 static int vhost_kernel_scsi_clear_endpoint(struct vhost_dev *dev,
  76                                             struct vhost_scsi_target *target)
  77 {
  78     return vhost_kernel_call(dev, VHOST_SCSI_CLEAR_ENDPOINT, target);
  79 }
  80
  81 static int vhost_kernel_scsi_get_abi_version(struct vhost_dev *dev, int *version)
  82 {
  83     return vhost_kernel_call(dev, VHOST_SCSI_GET_ABI_VERSION, version);
  84 }
  85
  86 static int vhost_kernel_set_log_base(struct vhost_dev *dev, uint64_t base,
  87                                      struct vhost_log *log)
  88 {
  89     return vhost_kernel_call(dev, VHOST_SET_LOG_BASE, &base);
  90 }
  91
  92 static int vhost_kernel_set_mem_table(struct vhost_dev *dev,
  93                                       struct vhost_memory *mem)
  94 {
  95     return vhost_kernel_call(dev, VHOST_SET_MEM_TABLE, mem);
  96 }
  97
  98 static int vhost_kernel_set_vring_addr(struct vhost_dev *dev,
  99                                        struct vhost_vring_addr *addr)
 100 {
 101     return vhost_kernel_call(dev, VHOST_SET_VRING_ADDR, addr);
 102 }
 103
 104 static int vhost_kernel_set_vring_endian(struct vhost_dev *dev,
 105                                          struct vhost_vring_state *ring)
 106 {
 107     return vhost_kernel_call(dev, VHOST_SET_VRING_ENDIAN, ring);
 108 }
 109
 110 static int vhost_kernel_set_vring_num(struct vhost_dev *dev,
 111                                       struct vhost_vring_state *ring)
 112 {
 113     return vhost_kernel_call(dev, VHOST_SET_VRING_NUM, ring);
 114 }
 115
 116 static int vhost_kernel_set_vring_base(struct vhost_dev *dev,
 117                                        struct vhost_vring_state *ring)
 118 {
 119     return vhost_kernel_call(dev, VHOST_SET_VRING_BASE, ring);
 120 }
 121
 122 static int vhost_kernel_get_vring_base(struct vhost_dev *dev,
 123                                        struct vhost_vring_state *ring)
 124 {
 125     return vhost_kernel_call(dev, VHOST_GET_VRING_BASE, ring);
 126 }
 127
 128 static int vhost_kernel_set_vring_kick(struct vhost_dev *dev,
 129                                        struct vhost_vring_file *file)
 130 {
 131     return vhost_kernel_call(dev, VHOST_SET_VRING_KICK, file);
 132 }
 133
 134 static int vhost_kernel_set_vring_call(struct vhost_dev *dev,
 135                                        struct vhost_vring_file *file)
 136 {
 137     return vhost_kernel_call(dev, VHOST_SET_VRING_CALL, file);
 138 }
 139
 140 static int vhost_kernel_set_vring_busyloop_timeout(struct vhost_dev *dev,
 141                                                    struct vhost_vring_state *s)
 142 {
 143     return vhost_kernel_call(dev, VHOST_SET_VRING_BUSYLOOP_TIMEOUT, s);
 144 }
 145
 146 static int vhost_kernel_set_features(struct vhost_dev *dev,
 147                                      uint64_t features)
 148 {
 149     return vhost_kernel_call(dev, VHOST_SET_FEATURES, &features);
 150 }
 151
 152 static int vhost_kernel_get_features(struct vhost_dev *dev,
 153                                      uint64_t *features)
 154 {
 155     return vhost_kernel_call(dev, VHOST_GET_FEATURES, features);
 156 }
 157
 158 static int vhost_kernel_set_owner(struct vhost_dev *dev)
 159 {
 160     return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
 161 }
 162
 163 static int vhost_kernel_reset_device(struct vhost_dev *dev)
 164 {
 165     return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
 166 }
 167
 168 static int vhost_kernel_get_vq_index(struct vhost_dev *dev, int idx)
 169 {
 170     assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
 171
 172     return idx - dev->vq_index;
 173 }
 174
 175 #ifdef CONFIG_VHOST_VSOCK
 176 static int vhost_kernel_vsock_set_guest_cid(struct vhost_dev *dev,
 177                                             uint64_t guest_cid)
 178 {
 179     return vhost_kernel_call(dev, VHOST_VSOCK_SET_GUEST_CID, &guest_cid);
 180 }
 181
 182 static int vhost_kernel_vsock_set_running(struct vhost_dev *dev, int start)
 183 {
 184     return vhost_kernel_call(dev, VHOST_VSOCK_SET_RUNNING, &start);
 185 }
 186 #endif /* CONFIG_VHOST_VSOCK */
 187
 188 static const VhostOps kernel_ops = {
 189         .backend_type = VHOST_BACKEND_TYPE_KERNEL,
 190         .vhost_backend_init = vhost_kernel_init,
 191         .vhost_backend_cleanup = vhost_kernel_cleanup,
 192         .vhost_backend_memslots_limit = vhost_kernel_memslots_limit,
 193         .vhost_net_set_backend = vhost_kernel_net_set_backend,
 194         .vhost_scsi_set_endpoint = vhost_kernel_scsi_set_endpoint,
 195         .vhost_scsi_clear_endpoint = vhost_kernel_scsi_clear_endpoint,
 196         .vhost_scsi_get_abi_version = vhost_kernel_scsi_get_abi_version,
 197         .vhost_set_log_base = vhost_kernel_set_log_base,
 198         .vhost_set_mem_table = vhost_kernel_set_mem_table,
 199         .vhost_set_vring_addr = vhost_kernel_set_vring_addr,
 200         .vhost_set_vring_endian = vhost_kernel_set_vring_endian,
 201         .vhost_set_vring_num = vhost_kernel_set_vring_num,
 202         .vhost_set_vring_base = vhost_kernel_set_vring_base,
 203         .vhost_get_vring_base = vhost_kernel_get_vring_base,
 204         .vhost_set_vring_kick = vhost_kernel_set_vring_kick,
 205         .vhost_set_vring_call = vhost_kernel_set_vring_call,
 206         .vhost_set_vring_busyloop_timeout =
 207                                 vhost_kernel_set_vring_busyloop_timeout,
 208         .vhost_set_features = vhost_kernel_set_features,
 209         .vhost_get_features = vhost_kernel_get_features,
 210         .vhost_set_owner = vhost_kernel_set_owner,
 211         .vhost_reset_device = vhost_kernel_reset_device,
 212         .vhost_get_vq_index = vhost_kernel_get_vq_index,
 213 #ifdef CONFIG_VHOST_VSOCK
 214         .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
 215         .vhost_vsock_set_running = vhost_kernel_vsock_set_running,
 216 #endif /* CONFIG_VHOST_VSOCK */
 217 };
 218
 219 int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
 220 {
 221     int r = 0;
 222
 223     switch (backend_type) {
 224     case VHOST_BACKEND_TYPE_KERNEL:
 225         dev->vhost_ops = &kernel_ops;
 226         break;
 227     case VHOST_BACKEND_TYPE_USER:
 228         dev->vhost_ops = &user_ops;
 229         break;
 230     default:
 231         error_report("Unknown vhost backend type");
 232         r = -1;
 233     }
 234
 235     return r;
 236 }