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 = status & VIRTIO_CONFIG_S_DRIVER_OK;
  74     int ret;
  75
  76     if (!vdev->vm_running) {
  77         should_start = false;
  78     }
  79
  80     if (vvc->vhost_dev.started == should_start) {
  81         return;
  82     }
  83
  84     if (should_start) {
  85         ret = vhost_vsock_common_start(vdev);
  86         if (ret < 0) {
  87             return;
  88         }
  89
  90         ret = vhost_vsock_set_running(vdev, 1);
  91         if (ret < 0) {
  92             vhost_vsock_common_stop(vdev);
  93             error_report("Error starting vhost vsock: %d", -ret);
  94             return;
  95         }
  96     } else {
  97         ret = vhost_vsock_set_running(vdev, 0);
  98         if (ret < 0) {
  99             error_report("vhost vsock set running failed: %d", ret);
 100             return;
 101         }
 102
 103         vhost_vsock_common_stop(vdev);
 104     }
 105 }
 106
 107 static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
 108                                          uint64_t requested_features,
 109                                          Error **errp)
 110 {
 111     /* No feature bits used yet */
 112     return requested_features;
 113 }
 114
 115 static const VMStateDescription vmstate_virtio_vhost_vsock = {
 116     .name = "virtio-vhost_vsock",
 117     .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION,
 118     .version_id = VHOST_VSOCK_SAVEVM_VERSION,
 119     .fields = (VMStateField[]) {
 120         VMSTATE_VIRTIO_DEVICE,
 121         VMSTATE_END_OF_LIST()
 122     },
 123     .pre_save = vhost_vsock_common_pre_save,
 124     .post_load = vhost_vsock_common_post_load,
 125 };
 126
 127 static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
 128 {
 129     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(dev);
 130     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 131     VHostVSock *vsock = VHOST_VSOCK(dev);
 132     int vhostfd;
 133     int ret;
 134
 135     /* Refuse to use reserved CID numbers */
 136     if (vsock->conf.guest_cid <= 2) {
 137         error_setg(errp, "guest-cid property must be greater than 2");
 138         return;
 139     }
 140
 141     if (vsock->conf.guest_cid > UINT32_MAX) {
 142         error_setg(errp, "guest-cid property must be a 32-bit number");
 143         return;
 144     }
 145
 146     if (vsock->conf.vhostfd) {
 147         vhostfd = monitor_fd_param(monitor_cur(), vsock->conf.vhostfd, errp);
 148         if (vhostfd == -1) {
 149             error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
 150             return;
 151         }
 152
 153         ret = qemu_try_set_nonblock(vhostfd);
 154         if (ret < 0) {
 155             error_setg_errno(errp, -ret,
 156                              "vhost-vsock: unable to set non-blocking mode");
 157             return;
 158         }
 159     } else {
 160         vhostfd = open("/dev/vhost-vsock", O_RDWR);
 161         if (vhostfd < 0) {
 162             error_setg_errno(errp, errno,
 163                              "vhost-vsock: failed to open vhost device");
 164             return;
 165         }
 166
 167         qemu_set_nonblock(vhostfd);
 168     }
 169
 170     vhost_vsock_common_realize(vdev, "vhost-vsock");
 171
 172     ret = vhost_dev_init(&vvc->vhost_dev, (void *)(uintptr_t)vhostfd,
 173                          VHOST_BACKEND_TYPE_KERNEL, 0);
 174     if (ret < 0) {
 175         error_setg_errno(errp, -ret, "vhost-vsock: vhost_dev_init failed");
 176         goto err_virtio;
 177     }
 178
 179     ret = vhost_vsock_set_guest_cid(vdev);
 180     if (ret < 0) {
 181         error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
 182         goto err_vhost_dev;
 183     }
 184
 185     return;
 186
 187 err_vhost_dev:
 188     vhost_dev_cleanup(&vvc->vhost_dev);
 189     /* vhost_dev_cleanup() closes the vhostfd passed to vhost_dev_init() */
 190     vhostfd = -1;
 191 err_virtio:
 192     vhost_vsock_common_unrealize(vdev);
 193     if (vhostfd >= 0) {
 194         close(vhostfd);
 195     }
 196     return;
 197 }
 198
 199 static void vhost_vsock_device_unrealize(DeviceState *dev)
 200 {
 201     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(dev);
 202     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 203
 204     /* This will stop vhost backend if appropriate. */
 205     vhost_vsock_set_status(vdev, 0);
 206
 207     vhost_dev_cleanup(&vvc->vhost_dev);
 208     vhost_vsock_common_unrealize(vdev);
 209 }
 210
 211 static Property vhost_vsock_properties[] = {
 212     DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
 213     DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
 214     DEFINE_PROP_END_OF_LIST(),
 215 };
 216
 217 static void vhost_vsock_class_init(ObjectClass *klass, void *data)
 218 {
 219     DeviceClass *dc = DEVICE_CLASS(klass);
 220     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 221
 222     device_class_set_props(dc, vhost_vsock_properties);
 223     dc->vmsd = &vmstate_virtio_vhost_vsock;
 224     vdc->realize = vhost_vsock_device_realize;
 225     vdc->unrealize = vhost_vsock_device_unrealize;
 226     vdc->get_features = vhost_vsock_get_features;
 227     vdc->get_config = vhost_vsock_get_config;
 228     vdc->set_status = vhost_vsock_set_status;
 229 }
 230
 231 static const TypeInfo vhost_vsock_info = {
 232     .name = TYPE_VHOST_VSOCK,
 233     .parent = TYPE_VHOST_VSOCK_COMMON,
 234     .instance_size = sizeof(VHostVSock),
 235     .class_init = vhost_vsock_class_init,
 236 };
 237
 238 static void vhost_vsock_register_types(void)
 239 {
 240     type_register_static(&vhost_vsock_info);
 241 }
 242
 243 type_init(vhost_vsock_register_types)