qemu/hw/virtio/vhost-vsock.c
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   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
  24static 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
  33static 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
  52static 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
  70static 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
 107static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
 108                                         uint64_t requested_features,
 109                                         Error **errp)
 110{
 111    return vhost_vsock_common_get_features(vdev, requested_features, errp);
 112}
 113
 114static const VMStateDescription vmstate_virtio_vhost_vsock = {
 115    .name = "virtio-vhost_vsock",
 116    .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION,
 117    .version_id = VHOST_VSOCK_SAVEVM_VERSION,
 118    .fields = (VMStateField[]) {
 119        VMSTATE_VIRTIO_DEVICE,
 120        VMSTATE_END_OF_LIST()
 121    },
 122    .pre_save = vhost_vsock_common_pre_save,
 123    .post_load = vhost_vsock_common_post_load,
 124};
 125
 126static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
 127{
 128    VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(dev);
 129    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 130    VHostVSock *vsock = VHOST_VSOCK(dev);
 131    int vhostfd;
 132    int ret;
 133
 134    /* Refuse to use reserved CID numbers */
 135    if (vsock->conf.guest_cid <= 2) {
 136        error_setg(errp, "guest-cid property must be greater than 2");
 137        return;
 138    }
 139
 140    if (vsock->conf.guest_cid > UINT32_MAX) {
 141        error_setg(errp, "guest-cid property must be a 32-bit number");
 142        return;
 143    }
 144
 145    if (vsock->conf.vhostfd) {
 146        vhostfd = monitor_fd_param(monitor_cur(), vsock->conf.vhostfd, errp);
 147        if (vhostfd == -1) {
 148            error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
 149            return;
 150        }
 151
 152        ret = qemu_try_set_nonblock(vhostfd);
 153        if (ret < 0) {
 154            error_setg_errno(errp, -ret,
 155                             "vhost-vsock: unable to set non-blocking mode");
 156            return;
 157        }
 158    } else {
 159        vhostfd = open("/dev/vhost-vsock", O_RDWR);
 160        if (vhostfd < 0) {
 161            error_setg_errno(errp, errno,
 162                             "vhost-vsock: failed to open vhost device");
 163            return;
 164        }
 165
 166        qemu_set_nonblock(vhostfd);
 167    }
 168
 169    vhost_vsock_common_realize(vdev, "vhost-vsock");
 170
 171    ret = vhost_dev_init(&vvc->vhost_dev, (void *)(uintptr_t)vhostfd,
 172                         VHOST_BACKEND_TYPE_KERNEL, 0, errp);
 173    if (ret < 0) {
 174        goto err_virtio;
 175    }
 176
 177    ret = vhost_vsock_set_guest_cid(vdev);
 178    if (ret < 0) {
 179        error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
 180        goto err_vhost_dev;
 181    }
 182
 183    return;
 184
 185err_vhost_dev:
 186    vhost_dev_cleanup(&vvc->vhost_dev);
 187    /* vhost_dev_cleanup() closes the vhostfd passed to vhost_dev_init() */
 188    vhostfd = -1;
 189err_virtio:
 190    vhost_vsock_common_unrealize(vdev);
 191    if (vhostfd >= 0) {
 192        close(vhostfd);
 193    }
 194    return;
 195}
 196
 197static void vhost_vsock_device_unrealize(DeviceState *dev)
 198{
 199    VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(dev);
 200    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 201
 202    /* This will stop vhost backend if appropriate. */
 203    vhost_vsock_set_status(vdev, 0);
 204
 205    vhost_dev_cleanup(&vvc->vhost_dev);
 206    vhost_vsock_common_unrealize(vdev);
 207}
 208
 209static Property vhost_vsock_properties[] = {
 210    DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
 211    DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
 212    DEFINE_PROP_END_OF_LIST(),
 213};
 214
 215static void vhost_vsock_class_init(ObjectClass *klass, void *data)
 216{
 217    DeviceClass *dc = DEVICE_CLASS(klass);
 218    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 219
 220    device_class_set_props(dc, vhost_vsock_properties);
 221    dc->vmsd = &vmstate_virtio_vhost_vsock;
 222    vdc->realize = vhost_vsock_device_realize;
 223    vdc->unrealize = vhost_vsock_device_unrealize;
 224    vdc->get_features = vhost_vsock_get_features;
 225    vdc->get_config = vhost_vsock_get_config;
 226    vdc->set_status = vhost_vsock_set_status;
 227}
 228
 229static const TypeInfo vhost_vsock_info = {
 230    .name = TYPE_VHOST_VSOCK,
 231    .parent = TYPE_VHOST_VSOCK_COMMON,
 232    .instance_size = sizeof(VHostVSock),
 233    .class_init = vhost_vsock_class_init,
 234};
 235
 236static void vhost_vsock_register_types(void)
 237{
 238    type_register_static(&vhost_vsock_info);
 239}
 240
 241type_init(vhost_vsock_register_types)
 242