xref: /openbmc/qemu/hw/virtio/vhost-vsock.c (revision 2f93d8b0)
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     return vhost_vsock_common_get_features(vdev, requested_features, errp);
112 }
113 
114 static 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 
126 static 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         /*
175          * vhostfd is closed by vhost_dev_cleanup, which is called
176          * by vhost_dev_init on initialization error.
177          */
178         goto err_virtio;
179     }
180 
181     ret = vhost_vsock_set_guest_cid(vdev);
182     if (ret < 0) {
183         error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
184         goto err_vhost_dev;
185     }
186 
187     return;
188 
189 err_vhost_dev:
190     /* vhost_dev_cleanup() closes the vhostfd passed to vhost_dev_init() */
191     vhost_dev_cleanup(&vvc->vhost_dev);
192 err_virtio:
193     vhost_vsock_common_unrealize(vdev);
194 }
195 
196 static void vhost_vsock_device_unrealize(DeviceState *dev)
197 {
198     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(dev);
199     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
200 
201     /* This will stop vhost backend if appropriate. */
202     vhost_vsock_set_status(vdev, 0);
203 
204     vhost_dev_cleanup(&vvc->vhost_dev);
205     vhost_vsock_common_unrealize(vdev);
206 }
207 
208 static Property vhost_vsock_properties[] = {
209     DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
210     DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
211     DEFINE_PROP_END_OF_LIST(),
212 };
213 
214 static void vhost_vsock_class_init(ObjectClass *klass, 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 
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