xref: /openbmc/qemu/hw/scsi/vhost-scsi.c (revision d6032e06)
1 /*
2  * vhost_scsi host device
3  *
4  * Copyright IBM, Corp. 2011
5  *
6  * Authors:
7  *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
8  *
9  * Changes for QEMU mainline + tcm_vhost kernel upstream:
10  *  Nicholas Bellinger <nab@risingtidesystems.com>
11  *
12  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
13  * See the COPYING.LIB file in the top-level directory.
14  *
15  */
16 
17 #include <sys/ioctl.h>
18 #include "config.h"
19 #include "qemu/queue.h"
20 #include "monitor/monitor.h"
21 #include "migration/migration.h"
22 #include "hw/virtio/vhost-scsi.h"
23 #include "hw/virtio/vhost.h"
24 #include "hw/virtio/virtio-scsi.h"
25 #include "hw/virtio/virtio-bus.h"
26 
27 static int vhost_scsi_set_endpoint(VHostSCSI *s)
28 {
29     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
30     struct vhost_scsi_target backend;
31     int ret;
32 
33     memset(&backend, 0, sizeof(backend));
34     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
35     ret = ioctl(s->dev.control, VHOST_SCSI_SET_ENDPOINT, &backend);
36     if (ret < 0) {
37         return -errno;
38     }
39     return 0;
40 }
41 
42 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
43 {
44     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
45     struct vhost_scsi_target backend;
46 
47     memset(&backend, 0, sizeof(backend));
48     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
49     ioctl(s->dev.control, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
50 }
51 
52 static int vhost_scsi_start(VHostSCSI *s)
53 {
54     int ret, abi_version, i;
55     VirtIODevice *vdev = VIRTIO_DEVICE(s);
56     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
57     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
58 
59     if (!k->set_guest_notifiers) {
60         error_report("binding does not support guest notifiers");
61         return -ENOSYS;
62     }
63 
64     ret = ioctl(s->dev.control, VHOST_SCSI_GET_ABI_VERSION, &abi_version);
65     if (ret < 0) {
66         return -errno;
67     }
68     if (abi_version > VHOST_SCSI_ABI_VERSION) {
69         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
70                      " %d is greater than vhost_scsi userspace supports: %d, please"
71                      " upgrade your version of QEMU\n", abi_version,
72                      VHOST_SCSI_ABI_VERSION);
73         return -ENOSYS;
74     }
75 
76     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
77     if (ret < 0) {
78         return ret;
79     }
80 
81     s->dev.acked_features = vdev->guest_features;
82     ret = vhost_dev_start(&s->dev, vdev);
83     if (ret < 0) {
84         error_report("Error start vhost dev");
85         goto err_notifiers;
86     }
87 
88     ret = vhost_scsi_set_endpoint(s);
89     if (ret < 0) {
90         error_report("Error set vhost-scsi endpoint");
91         goto err_vhost_stop;
92     }
93 
94     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
95     if (ret < 0) {
96         error_report("Error binding guest notifier");
97         goto err_endpoint;
98     }
99 
100     /* guest_notifier_mask/pending not used yet, so just unmask
101      * everything here.  virtio-pci will do the right thing by
102      * enabling/disabling irqfd.
103      */
104     for (i = 0; i < s->dev.nvqs; i++) {
105         vhost_virtqueue_mask(&s->dev, vdev, i, false);
106     }
107 
108     return ret;
109 
110 err_endpoint:
111     vhost_scsi_clear_endpoint(s);
112 err_vhost_stop:
113     vhost_dev_stop(&s->dev, vdev);
114 err_notifiers:
115     vhost_dev_disable_notifiers(&s->dev, vdev);
116     return ret;
117 }
118 
119 static void vhost_scsi_stop(VHostSCSI *s)
120 {
121     VirtIODevice *vdev = VIRTIO_DEVICE(s);
122     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
123     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
124     int ret = 0;
125 
126     if (k->set_guest_notifiers) {
127         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
128         if (ret < 0) {
129                 error_report("vhost guest notifier cleanup failed: %d\n", ret);
130         }
131     }
132     assert(ret >= 0);
133 
134     vhost_scsi_clear_endpoint(s);
135     vhost_dev_stop(&s->dev, vdev);
136     vhost_dev_disable_notifiers(&s->dev, vdev);
137 }
138 
139 static uint32_t vhost_scsi_get_features(VirtIODevice *vdev,
140                                         uint32_t features)
141 {
142     VHostSCSI *s = VHOST_SCSI(vdev);
143 
144     /* Clear features not supported by host kernel. */
145     if (!(s->dev.features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY))) {
146         features &= ~(1 << VIRTIO_F_NOTIFY_ON_EMPTY);
147     }
148     if (!(s->dev.features & (1 << VIRTIO_RING_F_INDIRECT_DESC))) {
149         features &= ~(1 << VIRTIO_RING_F_INDIRECT_DESC);
150     }
151     if (!(s->dev.features & (1 << VIRTIO_RING_F_EVENT_IDX))) {
152         features &= ~(1 << VIRTIO_RING_F_EVENT_IDX);
153     }
154     if (!(s->dev.features & (1 << VIRTIO_SCSI_F_HOTPLUG))) {
155         features &= ~(1 << VIRTIO_SCSI_F_HOTPLUG);
156     }
157 
158     return features;
159 }
160 
161 static void vhost_scsi_set_config(VirtIODevice *vdev,
162                                   const uint8_t *config)
163 {
164     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
165     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
166 
167     if ((uint32_t) ldl_raw(&scsiconf->sense_size) != vs->sense_size ||
168         (uint32_t) ldl_raw(&scsiconf->cdb_size) != vs->cdb_size) {
169         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
170         exit(1);
171     }
172 }
173 
174 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
175 {
176     VHostSCSI *s = (VHostSCSI *)vdev;
177     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
178 
179     if (s->dev.started == start) {
180         return;
181     }
182 
183     if (start) {
184         int ret;
185 
186         ret = vhost_scsi_start(s);
187         if (ret < 0) {
188             error_report("virtio-scsi: unable to start vhost: %s\n",
189                          strerror(-ret));
190 
191             /* There is no userspace virtio-scsi fallback so exit */
192             exit(1);
193         }
194     } else {
195         vhost_scsi_stop(s);
196     }
197 }
198 
199 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
200 {
201     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
202     VHostSCSI *s = VHOST_SCSI(dev);
203     Error *err = NULL;
204     int vhostfd = -1;
205     int ret;
206 
207     if (!vs->conf.wwpn) {
208         error_setg(errp, "vhost-scsi: missing wwpn");
209         return;
210     }
211 
212     if (vs->conf.vhostfd) {
213         vhostfd = monitor_handle_fd_param(cur_mon, vs->conf.vhostfd);
214         if (vhostfd == -1) {
215             error_setg(errp, "vhost-scsi: unable to parse vhostfd");
216             return;
217         }
218     }
219 
220     virtio_scsi_common_realize(dev, &err);
221     if (err != NULL) {
222         error_propagate(errp, err);
223         return;
224     }
225 
226     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
227     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
228     s->dev.vq_index = 0;
229 
230     ret = vhost_dev_init(&s->dev, vhostfd, "/dev/vhost-scsi", true);
231     if (ret < 0) {
232         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
233                    strerror(-ret));
234         return;
235     }
236     s->dev.backend_features = 0;
237 
238     error_setg(&s->migration_blocker,
239             "vhost-scsi does not support migration");
240     migrate_add_blocker(s->migration_blocker);
241 }
242 
243 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
244 {
245     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
246     VHostSCSI *s = VHOST_SCSI(dev);
247 
248     migrate_del_blocker(s->migration_blocker);
249     error_free(s->migration_blocker);
250 
251     /* This will stop vhost backend. */
252     vhost_scsi_set_status(vdev, 0);
253 
254     g_free(s->dev.vqs);
255 
256     virtio_scsi_common_unrealize(dev, errp);
257 }
258 
259 static Property vhost_scsi_properties[] = {
260     DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent_obj.conf),
261     DEFINE_PROP_END_OF_LIST(),
262 };
263 
264 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
265 {
266     DeviceClass *dc = DEVICE_CLASS(klass);
267     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
268 
269     dc->props = vhost_scsi_properties;
270     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
271     vdc->realize = vhost_scsi_realize;
272     vdc->unrealize = vhost_scsi_unrealize;
273     vdc->get_features = vhost_scsi_get_features;
274     vdc->set_config = vhost_scsi_set_config;
275     vdc->set_status = vhost_scsi_set_status;
276 }
277 
278 static const TypeInfo vhost_scsi_info = {
279     .name = TYPE_VHOST_SCSI,
280     .parent = TYPE_VIRTIO_SCSI_COMMON,
281     .instance_size = sizeof(VHostSCSI),
282     .class_init = vhost_scsi_class_init,
283 };
284 
285 static void virtio_register_types(void)
286 {
287     type_register_static(&vhost_scsi_info);
288 }
289 
290 type_init(virtio_register_types)
291