xref: /qemu/hw/virtio/vhost-vsock.c (revision 21596064081e8d0c0153f68714981c7f0e040973)
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 
vhost_vsock_get_config(VirtIODevice * vdev,uint8_t * config)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 
vhost_vsock_set_guest_cid(VirtIODevice * vdev)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 
vhost_vsock_set_running(VirtIODevice * vdev,int start)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 
vhost_vsock_set_status(VirtIODevice * vdev,uint8_t status)70 static int vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
71 {
72     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
73     bool should_start = virtio_device_should_start(vdev, status);
74     int ret;
75 
76     if (vhost_dev_is_started(&vvc->vhost_dev) == should_start) {
77         return 0;
78     }
79 
80     if (should_start) {
81         ret = vhost_vsock_common_start(vdev);
82         if (ret < 0) {
83             return 0;
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 0;
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 0;
97         }
98 
99         vhost_vsock_common_stop(vdev);
100     }
101     return 0;
102 }
103 
vhost_vsock_get_features(VirtIODevice * vdev,uint64_t requested_features,Error ** errp)104 static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
105                                          uint64_t requested_features,
106                                          Error **errp)
107 {
108     return vhost_vsock_common_get_features(vdev, requested_features, errp);
109 }
110 
111 static const VMStateDescription vmstate_virtio_vhost_vsock = {
112     .name = "virtio-vhost_vsock",
113     .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION,
114     .version_id = VHOST_VSOCK_SAVEVM_VERSION,
115     .fields = (const VMStateField[]) {
116         VMSTATE_VIRTIO_DEVICE,
117         VMSTATE_END_OF_LIST()
118     },
119     .pre_save = vhost_vsock_common_pre_save,
120     .post_load = vhost_vsock_common_post_load,
121 };
122 
vhost_vsock_device_realize(DeviceState * dev,Error ** errp)123 static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
124 {
125     ERRP_GUARD();
126     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(dev);
127     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
128     VHostVSock *vsock = VHOST_VSOCK(dev);
129     int vhostfd;
130     int ret;
131 
132     /* Refuse to use reserved CID numbers */
133     if (vsock->conf.guest_cid <= 2) {
134         error_setg(errp, "guest-cid property must be greater than 2");
135         return;
136     }
137 
138     if (vsock->conf.guest_cid > UINT32_MAX) {
139         error_setg(errp, "guest-cid property must be a 32-bit number");
140         return;
141     }
142 
143     if (vsock->conf.vhostfd) {
144         vhostfd = monitor_fd_param(monitor_cur(), vsock->conf.vhostfd, errp);
145         if (vhostfd == -1) {
146             error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
147             return;
148         }
149 
150         if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
151             error_setg_errno(errp, errno,
152                              "vhost-vsock: unable to set non-blocking mode");
153             return;
154         }
155     } else {
156         vhostfd = open("/dev/vhost-vsock", O_RDWR);
157         if (vhostfd < 0) {
158             error_setg_errno(errp, errno,
159                              "vhost-vsock: failed to open vhost device");
160             return;
161         }
162 
163         if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
164             error_setg_errno(errp, errno,
165                              "Failed to set FD nonblocking");
166             return;
167         }
168     }
169 
170     vhost_vsock_common_realize(vdev);
171 
172     ret = vhost_dev_init(&vvc->vhost_dev, (void *)(uintptr_t)vhostfd,
173                          VHOST_BACKEND_TYPE_KERNEL, 0, errp);
174     if (ret < 0) {
175         /*
176          * vhostfd is closed by vhost_dev_cleanup, which is called
177          * by vhost_dev_init on initialization error.
178          */
179         goto err_virtio;
180     }
181 
182     ret = vhost_vsock_set_guest_cid(vdev);
183     if (ret < 0) {
184         error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
185         goto err_vhost_dev;
186     }
187 
188     return;
189 
190 err_vhost_dev:
191     /* vhost_dev_cleanup() closes the vhostfd passed to vhost_dev_init() */
192     vhost_dev_cleanup(&vvc->vhost_dev);
193 err_virtio:
194     vhost_vsock_common_unrealize(vdev);
195 }
196 
vhost_vsock_device_unrealize(DeviceState * dev)197 static 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 
209 static const Property vhost_vsock_properties[] = {
210     DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
211     DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
212 };
213 
vhost_vsock_class_init(ObjectClass * klass,const void * data)214 static void vhost_vsock_class_init(ObjectClass *klass, const void *data)
215 {
216     DeviceClass *dc = DEVICE_CLASS(klass);
217     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
218 
219     device_class_set_props(dc, vhost_vsock_properties);
220     dc->vmsd = &vmstate_virtio_vhost_vsock;
221     vdc->realize = vhost_vsock_device_realize;
222     vdc->unrealize = vhost_vsock_device_unrealize;
223     vdc->get_features = vhost_vsock_get_features;
224     vdc->get_config = vhost_vsock_get_config;
225     vdc->set_status = vhost_vsock_set_status;
226 }
227 
228 static const TypeInfo vhost_vsock_info = {
229     .name = TYPE_VHOST_VSOCK,
230     .parent = TYPE_VHOST_VSOCK_COMMON,
231     .instance_size = sizeof(VHostVSock),
232     .class_init = vhost_vsock_class_init,
233 };
234 
vhost_vsock_register_types(void)235 static void vhost_vsock_register_types(void)
236 {
237     type_register_static(&vhost_vsock_info);
238 }
239 
240 type_init(vhost_vsock_register_types)
241