hw/virtio/vhost-vsock.c

   1 /*
   2  * Virtio vsock device
   3  *
   4  * Copyright 2015 Red Hat, Inc.
   5  *
   6  * Authors:
   7  *  Stefan Hajnoczi <stefanha@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or
  10  * (at your option) any later version.  See the COPYING file in the
  11  * top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include "standard-headers/linux/virtio_vsock.h"
  16 #include "qapi/error.h"
  17 #include "hw/virtio/virtio-access.h"
  18 #include "qemu/error-report.h"
  19 #include "qemu/sockets.h"
  20 #include "hw/qdev-properties.h"
  21 #include "hw/virtio/vhost-vsock.h"
  22 #include "monitor/monitor.h"
  23
  24 static void vhost_vsock_get_config(VirtIODevice *vdev, uint8_t *config)
  25 {
  26     VHostVSock *vsock = VHOST_VSOCK(vdev);
  27     struct virtio_vsock_config vsockcfg = {};
  28
  29     virtio_stq_p(vdev, &vsockcfg.guest_cid, vsock->conf.guest_cid);
  30     memcpy(config, &vsockcfg, sizeof(vsockcfg));
  31 }
  32
  33 static int vhost_vsock_set_guest_cid(VirtIODevice *vdev)
  34 {
  35     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
  36     VHostVSock *vsock = VHOST_VSOCK(vdev);
  37     const VhostOps *vhost_ops = vvc->vhost_dev.vhost_ops;
  38     int ret;
  39
  40     if (!vhost_ops->vhost_vsock_set_guest_cid) {
  41         return -ENOSYS;
  42     }
  43
  44     ret = vhost_ops->vhost_vsock_set_guest_cid(&vvc->vhost_dev,
  45                                                vsock->conf.guest_cid);
  46     if (ret < 0) {
  47         return -errno;
  48     }
  49     return 0;
  50 }
  51
  52 static int vhost_vsock_set_running(VirtIODevice *vdev, int start)
  53 {
  54     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
  55     const VhostOps *vhost_ops = vvc->vhost_dev.vhost_ops;
  56     int ret;
  57
  58     if (!vhost_ops->vhost_vsock_set_running) {
  59         return -ENOSYS;
  60     }
  61
  62     ret = vhost_ops->vhost_vsock_set_running(&vvc->vhost_dev, start);
  63     if (ret < 0) {
  64         return -errno;
  65     }
  66     return 0;
  67 }
  68
  69
  70 static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
  71 {
  72     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
  73     bool should_start = virtio_device_started(vdev, status);
  74     int ret;
  75
  76     if (vhost_dev_is_started(&vvc->vhost_dev) == should_start) {
  77         return;
  78     }
  79
  80     if (should_start) {
  81         ret = vhost_vsock_common_start(vdev);
  82         if (ret < 0) {
  83             return;
  84         }
  85
  86         ret = vhost_vsock_set_running(vdev, 1);
  87         if (ret < 0) {
  88             vhost_vsock_common_stop(vdev);
  89             error_report("Error starting vhost vsock: %d", -ret);
  90             return;
  91         }
  92     } else {
  93         ret = vhost_vsock_set_running(vdev, 0);
  94         if (ret < 0) {
  95             error_report("vhost vsock set running failed: %d", ret);
  96             return;
  97         }
  98
  99         vhost_vsock_common_stop(vdev);
 100     }
 101 }
 102
 103 static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
 104                                          uint64_t requested_features,
 105                                          Error **errp)
 106 {
 107     return vhost_vsock_common_get_features(vdev, requested_features, errp);
 108 }
 109
 110 static const VMStateDescription vmstate_virtio_vhost_vsock = {
 111     .name = "virtio-vhost_vsock",
 112     .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION,
 113     .version_id = VHOST_VSOCK_SAVEVM_VERSION,
 114     .fields = (VMStateField[]) {
 115         VMSTATE_VIRTIO_DEVICE,
 116         VMSTATE_END_OF_LIST()
 117     },
 118     .pre_save = vhost_vsock_common_pre_save,
 119     .post_load = vhost_vsock_common_post_load,
 120 };
 121
 122 static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
 123 {
 124     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(dev);
 125     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 126     VHostVSock *vsock = VHOST_VSOCK(dev);
 127     int vhostfd;
 128     int ret;
 129
 130     /* Refuse to use reserved CID numbers */
 131     if (vsock->conf.guest_cid <= 2) {
 132         error_setg(errp, "guest-cid property must be greater than 2");
 133         return;
 134     }
 135
 136     if (vsock->conf.guest_cid > UINT32_MAX) {
 137         error_setg(errp, "guest-cid property must be a 32-bit number");
 138         return;
 139     }
 140
 141     if (vsock->conf.vhostfd) {
 142         vhostfd = monitor_fd_param(monitor_cur(), vsock->conf.vhostfd, errp);
 143         if (vhostfd == -1) {
 144             error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
 145             return;
 146         }
 147
 148         if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
 149             error_setg_errno(errp, errno,
 150                              "vhost-vsock: unable to set non-blocking mode");
 151             return;
 152         }
 153     } else {
 154         vhostfd = open("/dev/vhost-vsock", O_RDWR);
 155         if (vhostfd < 0) {
 156             error_setg_errno(errp, errno,
 157                              "vhost-vsock: failed to open vhost device");
 158             return;
 159         }
 160
 161         if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
 162             error_setg_errno(errp, errno,
 163                              "Failed to set FD nonblocking");
 164             return;
 165         }
 166     }
 167
 168     vhost_vsock_common_realize(vdev);
 169
 170     ret = vhost_dev_init(&vvc->vhost_dev, (void *)(uintptr_t)vhostfd,
 171                          VHOST_BACKEND_TYPE_KERNEL, 0, errp);
 172     if (ret < 0) {
 173         /*
 174          * vhostfd is closed by vhost_dev_cleanup, which is called
 175          * by vhost_dev_init on initialization error.
 176          */
 177         goto err_virtio;
 178     }
 179
 180     ret = vhost_vsock_set_guest_cid(vdev);
 181     if (ret < 0) {
 182         error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
 183         goto err_vhost_dev;
 184     }
 185
 186     return;
 187
 188 err_vhost_dev:
 189     /* vhost_dev_cleanup() closes the vhostfd passed to vhost_dev_init() */
 190     vhost_dev_cleanup(&vvc->vhost_dev);
 191 err_virtio:
 192     vhost_vsock_common_unrealize(vdev);
 193 }
 194
 195 static void vhost_vsock_device_unrealize(DeviceState *dev)
 196 {
 197     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(dev);
 198     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 199
 200     /* This will stop vhost backend if appropriate. */
 201     vhost_vsock_set_status(vdev, 0);
 202
 203     vhost_dev_cleanup(&vvc->vhost_dev);
 204     vhost_vsock_common_unrealize(vdev);
 205 }
 206
 207 static Property vhost_vsock_properties[] = {
 208     DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
 209     DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
 210     DEFINE_PROP_END_OF_LIST(),
 211 };
 212
 213 static void vhost_vsock_class_init(ObjectClass *klass, void *data)
 214 {
 215     DeviceClass *dc = DEVICE_CLASS(klass);
 216     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 217
 218     device_class_set_props(dc, vhost_vsock_properties);
 219     dc->vmsd = &vmstate_virtio_vhost_vsock;
 220     vdc->realize = vhost_vsock_device_realize;
 221     vdc->unrealize = vhost_vsock_device_unrealize;
 222     vdc->get_features = vhost_vsock_get_features;
 223     vdc->get_config = vhost_vsock_get_config;
 224     vdc->set_status = vhost_vsock_set_status;
 225 }
 226
 227 static const TypeInfo vhost_vsock_info = {
 228     .name = TYPE_VHOST_VSOCK,
 229     .parent = TYPE_VHOST_VSOCK_COMMON,
 230     .instance_size = sizeof(VHostVSock),
 231     .class_init = vhost_vsock_class_init,
 232 };
 233
 234 static void vhost_vsock_register_types(void)
 235 {
 236     type_register_static(&vhost_vsock_info);
 237 }
 238
 239 type_init(vhost_vsock_register_types)