xref: /openbmc/qemu/hw/virtio/vhost-vsock.c (revision 701bff24)
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)
240