xref: /openbmc/qemu/hw/scsi/vhost-scsi.c (revision 21f5826a)
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 #include "hw/virtio/virtio-access.h"
27 
28 /* Features supported by host kernel. */
29 static const int kernel_feature_bits[] = {
30     VIRTIO_F_NOTIFY_ON_EMPTY,
31     VIRTIO_RING_F_INDIRECT_DESC,
32     VIRTIO_RING_F_EVENT_IDX,
33     VIRTIO_SCSI_F_HOTPLUG,
34     VHOST_INVALID_FEATURE_BIT
35 };
36 
37 static int vhost_scsi_set_endpoint(VHostSCSI *s)
38 {
39     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
40     const VhostOps *vhost_ops = s->dev.vhost_ops;
41     struct vhost_scsi_target backend;
42     int ret;
43 
44     memset(&backend, 0, sizeof(backend));
45     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
46     ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
47     if (ret < 0) {
48         return -errno;
49     }
50     return 0;
51 }
52 
53 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
54 {
55     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
56     struct vhost_scsi_target backend;
57     const VhostOps *vhost_ops = s->dev.vhost_ops;
58 
59     memset(&backend, 0, sizeof(backend));
60     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
61     vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
62 }
63 
64 static int vhost_scsi_start(VHostSCSI *s)
65 {
66     int ret, abi_version, i;
67     VirtIODevice *vdev = VIRTIO_DEVICE(s);
68     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
69     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
70     const VhostOps *vhost_ops = s->dev.vhost_ops;
71 
72     if (!k->set_guest_notifiers) {
73         error_report("binding does not support guest notifiers");
74         return -ENOSYS;
75     }
76 
77     ret = vhost_ops->vhost_call(&s->dev,
78                                 VHOST_SCSI_GET_ABI_VERSION, &abi_version);
79     if (ret < 0) {
80         return -errno;
81     }
82     if (abi_version > VHOST_SCSI_ABI_VERSION) {
83         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
84                      " %d is greater than vhost_scsi userspace supports: %d, please"
85                      " upgrade your version of QEMU\n", abi_version,
86                      VHOST_SCSI_ABI_VERSION);
87         return -ENOSYS;
88     }
89 
90     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
91     if (ret < 0) {
92         return ret;
93     }
94 
95     s->dev.acked_features = vdev->guest_features;
96     ret = vhost_dev_start(&s->dev, vdev);
97     if (ret < 0) {
98         error_report("Error start vhost dev");
99         goto err_notifiers;
100     }
101 
102     ret = vhost_scsi_set_endpoint(s);
103     if (ret < 0) {
104         error_report("Error set vhost-scsi endpoint");
105         goto err_vhost_stop;
106     }
107 
108     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
109     if (ret < 0) {
110         error_report("Error binding guest notifier");
111         goto err_endpoint;
112     }
113 
114     /* guest_notifier_mask/pending not used yet, so just unmask
115      * everything here.  virtio-pci will do the right thing by
116      * enabling/disabling irqfd.
117      */
118     for (i = 0; i < s->dev.nvqs; i++) {
119         vhost_virtqueue_mask(&s->dev, vdev, i, false);
120     }
121 
122     return ret;
123 
124 err_endpoint:
125     vhost_scsi_clear_endpoint(s);
126 err_vhost_stop:
127     vhost_dev_stop(&s->dev, vdev);
128 err_notifiers:
129     vhost_dev_disable_notifiers(&s->dev, vdev);
130     return ret;
131 }
132 
133 static void vhost_scsi_stop(VHostSCSI *s)
134 {
135     VirtIODevice *vdev = VIRTIO_DEVICE(s);
136     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
137     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
138     int ret = 0;
139 
140     if (k->set_guest_notifiers) {
141         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
142         if (ret < 0) {
143                 error_report("vhost guest notifier cleanup failed: %d\n", ret);
144         }
145     }
146     assert(ret >= 0);
147 
148     vhost_scsi_clear_endpoint(s);
149     vhost_dev_stop(&s->dev, vdev);
150     vhost_dev_disable_notifiers(&s->dev, vdev);
151 }
152 
153 static uint32_t vhost_scsi_get_features(VirtIODevice *vdev,
154                                         uint32_t features)
155 {
156     VHostSCSI *s = VHOST_SCSI(vdev);
157 
158     return vhost_get_features(&s->dev, kernel_feature_bits, 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) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size ||
168         (uint32_t) virtio_ldl_p(vdev, &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_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
200 {
201 }
202 
203 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
204 {
205     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
206     VHostSCSI *s = VHOST_SCSI(dev);
207     Error *err = NULL;
208     int vhostfd = -1;
209     int ret;
210 
211     if (!vs->conf.wwpn) {
212         error_setg(errp, "vhost-scsi: missing wwpn");
213         return;
214     }
215 
216     if (vs->conf.vhostfd) {
217         vhostfd = monitor_handle_fd_param(cur_mon, vs->conf.vhostfd);
218         if (vhostfd == -1) {
219             error_setg(errp, "vhost-scsi: unable to parse vhostfd");
220             return;
221         }
222     } else {
223         vhostfd = open("/dev/vhost-scsi", O_RDWR);
224         if (vhostfd < 0) {
225             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
226                        strerror(errno));
227             return;
228         }
229     }
230 
231     virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
232                                vhost_dummy_handle_output,
233                                vhost_dummy_handle_output);
234     if (err != NULL) {
235         error_propagate(errp, err);
236         close(vhostfd);
237         return;
238     }
239 
240     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
241     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
242     s->dev.vq_index = 0;
243     s->dev.backend_features = 0;
244 
245     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
246                          VHOST_BACKEND_TYPE_KERNEL, true);
247     if (ret < 0) {
248         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
249                    strerror(-ret));
250         return;
251     }
252 
253     error_setg(&s->migration_blocker,
254             "vhost-scsi does not support migration");
255     migrate_add_blocker(s->migration_blocker);
256 }
257 
258 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
259 {
260     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
261     VHostSCSI *s = VHOST_SCSI(dev);
262 
263     migrate_del_blocker(s->migration_blocker);
264     error_free(s->migration_blocker);
265 
266     /* This will stop vhost backend. */
267     vhost_scsi_set_status(vdev, 0);
268 
269     g_free(s->dev.vqs);
270 
271     virtio_scsi_common_unrealize(dev, errp);
272 }
273 
274 static Property vhost_scsi_properties[] = {
275     DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent_obj.conf),
276     DEFINE_PROP_END_OF_LIST(),
277 };
278 
279 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
280 {
281     DeviceClass *dc = DEVICE_CLASS(klass);
282     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
283 
284     dc->props = vhost_scsi_properties;
285     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
286     vdc->realize = vhost_scsi_realize;
287     vdc->unrealize = vhost_scsi_unrealize;
288     vdc->get_features = vhost_scsi_get_features;
289     vdc->set_config = vhost_scsi_set_config;
290     vdc->set_status = vhost_scsi_set_status;
291 }
292 
293 static const TypeInfo vhost_scsi_info = {
294     .name = TYPE_VHOST_SCSI,
295     .parent = TYPE_VIRTIO_SCSI_COMMON,
296     .instance_size = sizeof(VHostSCSI),
297     .class_init = vhost_scsi_class_init,
298 };
299 
300 static void virtio_register_types(void)
301 {
302     type_register_static(&vhost_scsi_info);
303 }
304 
305 type_init(virtio_register_types)
306