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 "qemu/osdep.h"
18 #include <linux/vhost.h>
19 #include <sys/ioctl.h>
20 #include "qapi/error.h"
21 #include "qemu/error-report.h"
22 #include "qemu/module.h"
23 #include "monitor/monitor.h"
24 #include "migration/blocker.h"
25 #include "hw/virtio/vhost-scsi.h"
26 #include "hw/virtio/vhost.h"
27 #include "hw/virtio/virtio-scsi.h"
28 #include "hw/virtio/virtio-bus.h"
29 #include "hw/fw-path-provider.h"
30 #include "hw/qdev-properties.h"
31 #include "qemu/cutils.h"
32 #include "sysemu/sysemu.h"
33
34 /* Features supported by host kernel. */
35 static const int kernel_feature_bits[] = {
36 VIRTIO_F_NOTIFY_ON_EMPTY,
37 VIRTIO_RING_F_INDIRECT_DESC,
38 VIRTIO_RING_F_EVENT_IDX,
39 VIRTIO_SCSI_F_HOTPLUG,
40 VIRTIO_F_RING_RESET,
41 VIRTIO_F_IN_ORDER,
42 VIRTIO_F_NOTIFICATION_DATA,
43 VHOST_INVALID_FEATURE_BIT
44 };
45
vhost_scsi_set_endpoint(VHostSCSI * s)46 static int vhost_scsi_set_endpoint(VHostSCSI *s)
47 {
48 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
49 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
50 const VhostOps *vhost_ops = vsc->dev.vhost_ops;
51 struct vhost_scsi_target backend;
52 int ret;
53
54 memset(&backend, 0, sizeof(backend));
55 pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
56 ret = vhost_ops->vhost_scsi_set_endpoint(&vsc->dev, &backend);
57 if (ret < 0) {
58 return -errno;
59 }
60 return 0;
61 }
62
vhost_scsi_clear_endpoint(VHostSCSI * s)63 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
64 {
65 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
66 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
67 struct vhost_scsi_target backend;
68 const VhostOps *vhost_ops = vsc->dev.vhost_ops;
69
70 memset(&backend, 0, sizeof(backend));
71 pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
72 vhost_ops->vhost_scsi_clear_endpoint(&vsc->dev, &backend);
73 }
74
vhost_scsi_start(VHostSCSI * s)75 static int vhost_scsi_start(VHostSCSI *s)
76 {
77 int ret, abi_version;
78 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
79 const VhostOps *vhost_ops = vsc->dev.vhost_ops;
80 Error *local_err = NULL;
81
82 ret = vhost_ops->vhost_scsi_get_abi_version(&vsc->dev, &abi_version);
83 if (ret < 0) {
84 return -errno;
85 }
86 if (abi_version > VHOST_SCSI_ABI_VERSION) {
87 error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
88 " %d is greater than vhost_scsi userspace supports: %d,"
89 " please upgrade your version of QEMU", abi_version,
90 VHOST_SCSI_ABI_VERSION);
91 return -ENOSYS;
92 }
93
94 ret = vhost_scsi_common_start(vsc, &local_err);
95 if (ret < 0) {
96 error_reportf_err(local_err, "Error starting vhost-scsi: ");
97 return ret;
98 }
99
100 ret = vhost_scsi_set_endpoint(s);
101 if (ret < 0) {
102 error_report("Error setting vhost-scsi endpoint");
103 vhost_scsi_common_stop(vsc);
104 }
105
106 return ret;
107 }
108
vhost_scsi_stop(VHostSCSI * s)109 static void vhost_scsi_stop(VHostSCSI *s)
110 {
111 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
112
113 vhost_scsi_clear_endpoint(s);
114 vhost_scsi_common_stop(vsc);
115 }
116
vhost_scsi_set_status(VirtIODevice * vdev,uint8_t val)117 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
118 {
119 VHostSCSI *s = VHOST_SCSI(vdev);
120 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
121 bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
122
123 if (!vdev->vm_running) {
124 start = false;
125 }
126
127 if (vhost_dev_is_started(&vsc->dev) == start) {
128 return;
129 }
130
131 if (start) {
132 int ret;
133
134 ret = vhost_scsi_start(s);
135 if (ret < 0) {
136 error_report("unable to start vhost-scsi: %s", strerror(-ret));
137 exit(1);
138 }
139 } else {
140 vhost_scsi_stop(s);
141 }
142 }
143
vhost_dummy_handle_output(VirtIODevice * vdev,VirtQueue * vq)144 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
145 {
146 }
147
vhost_scsi_pre_save(void * opaque)148 static int vhost_scsi_pre_save(void *opaque)
149 {
150 VHostSCSICommon *vsc = opaque;
151
152 /* At this point, backend must be stopped, otherwise
153 * it might keep writing to memory. */
154 assert(!vhost_dev_is_started(&vsc->dev));
155
156 return 0;
157 }
158
159 static const VMStateDescription vmstate_virtio_vhost_scsi = {
160 .name = "virtio-vhost_scsi",
161 .minimum_version_id = 1,
162 .version_id = 1,
163 .fields = (const VMStateField[]) {
164 VMSTATE_VIRTIO_DEVICE,
165 VMSTATE_END_OF_LIST()
166 },
167 .pre_save = vhost_scsi_pre_save,
168 };
169
vhost_scsi_set_workers(VHostSCSICommon * vsc,bool per_virtqueue)170 static int vhost_scsi_set_workers(VHostSCSICommon *vsc, bool per_virtqueue)
171 {
172 struct vhost_dev *dev = &vsc->dev;
173 struct vhost_vring_worker vq_worker;
174 struct vhost_worker_state worker;
175 int i, ret = 0;
176
177 /* Use default worker */
178 if (!per_virtqueue || dev->nvqs == VHOST_SCSI_VQ_NUM_FIXED + 1) {
179 return 0;
180 }
181
182 /*
183 * ctl/evt share the first worker since it will be rare for them
184 * to send cmds while IO is running.
185 */
186 for (i = VHOST_SCSI_VQ_NUM_FIXED + 1; i < dev->nvqs; i++) {
187 memset(&worker, 0, sizeof(worker));
188
189 ret = dev->vhost_ops->vhost_new_worker(dev, &worker);
190 if (ret == -ENOTTY) {
191 /*
192 * worker ioctls are not implemented so just ignore and
193 * and continue device setup.
194 */
195 warn_report("vhost-scsi: Backend supports a single worker. "
196 "Ignoring worker_per_virtqueue=true setting.");
197 ret = 0;
198 break;
199 } else if (ret) {
200 break;
201 }
202
203 memset(&vq_worker, 0, sizeof(vq_worker));
204 vq_worker.worker_id = worker.worker_id;
205 vq_worker.index = i;
206
207 ret = dev->vhost_ops->vhost_attach_vring_worker(dev, &vq_worker);
208 if (ret == -ENOTTY) {
209 /*
210 * It's a bug for the kernel to have supported the worker creation
211 * ioctl but not attach.
212 */
213 dev->vhost_ops->vhost_free_worker(dev, &worker);
214 break;
215 } else if (ret) {
216 break;
217 }
218 }
219
220 return ret;
221 }
222
vhost_scsi_realize(DeviceState * dev,Error ** errp)223 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
224 {
225 ERRP_GUARD();
226 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
227 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
228 Error *err = NULL;
229 int vhostfd = -1;
230 int ret;
231 struct vhost_virtqueue *vqs = NULL;
232
233 if (!vs->conf.wwpn) {
234 error_setg(errp, "vhost-scsi: missing wwpn");
235 return;
236 }
237
238 if (vs->conf.vhostfd) {
239 vhostfd = monitor_fd_param(monitor_cur(), vs->conf.vhostfd, errp);
240 if (vhostfd == -1) {
241 error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
242 return;
243 }
244 } else {
245 vhostfd = open("/dev/vhost-scsi", O_RDWR);
246 if (vhostfd < 0) {
247 error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
248 strerror(errno));
249 return;
250 }
251 }
252
253 virtio_scsi_common_realize(dev,
254 vhost_dummy_handle_output,
255 vhost_dummy_handle_output,
256 vhost_dummy_handle_output,
257 &err);
258 if (err != NULL) {
259 error_propagate(errp, err);
260 goto close_fd;
261 }
262
263 if (!vsc->migratable) {
264 error_setg(&vsc->migration_blocker,
265 "vhost-scsi does not support migration in all cases. "
266 "When external environment supports it (Orchestrator migrates "
267 "target SCSI device state or use shared storage over network), "
268 "set 'migratable' property to true to enable migration.");
269 if (migrate_add_blocker_normal(&vsc->migration_blocker, errp) < 0) {
270 goto free_virtio;
271 }
272 }
273
274 vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
275 vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
276 vsc->dev.vqs = vqs;
277 vsc->dev.vq_index = 0;
278 vsc->dev.backend_features = 0;
279
280 ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
281 VHOST_BACKEND_TYPE_KERNEL, 0, errp);
282 if (ret < 0) {
283 /*
284 * vhost_dev_init calls vhost_dev_cleanup on error, which closes
285 * vhostfd, don't double close it.
286 */
287 vhostfd = -1;
288 goto free_vqs;
289 }
290
291 ret = vhost_scsi_set_workers(vsc, vs->conf.worker_per_virtqueue);
292 if (ret < 0) {
293 error_setg(errp, "vhost-scsi: vhost worker setup failed: %s",
294 strerror(-ret));
295 goto free_vqs;
296 }
297
298 /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
299 vsc->channel = 0;
300 vsc->lun = 0;
301 /* Note: we can also get the minimum tpgt from kernel */
302 vsc->target = vs->conf.boot_tpgt;
303
304 return;
305
306 free_vqs:
307 g_free(vqs);
308 if (!vsc->migratable) {
309 migrate_del_blocker(&vsc->migration_blocker);
310 }
311 free_virtio:
312 virtio_scsi_common_unrealize(dev);
313 close_fd:
314 if (vhostfd >= 0) {
315 close(vhostfd);
316 }
317 return;
318 }
319
vhost_scsi_unrealize(DeviceState * dev)320 static void vhost_scsi_unrealize(DeviceState *dev)
321 {
322 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
323 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
324 struct vhost_virtqueue *vqs = vsc->dev.vqs;
325
326 if (!vsc->migratable) {
327 migrate_del_blocker(&vsc->migration_blocker);
328 }
329
330 /* This will stop vhost backend. */
331 vhost_scsi_set_status(vdev, 0);
332
333 vhost_dev_cleanup(&vsc->dev);
334 g_free(vqs);
335
336 virtio_scsi_common_unrealize(dev);
337 }
338
vhost_scsi_get_vhost(VirtIODevice * vdev)339 static struct vhost_dev *vhost_scsi_get_vhost(VirtIODevice *vdev)
340 {
341 VHostSCSI *s = VHOST_SCSI(vdev);
342 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
343 return &vsc->dev;
344 }
345
346 static Property vhost_scsi_properties[] = {
347 DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
348 DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
349 DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
350 DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
351 VIRTIO_SCSI_AUTO_NUM_QUEUES),
352 DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
353 128),
354 DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust,
355 true),
356 DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
357 0xFFFF),
358 DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
359 DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
360 VIRTIO_SCSI_F_T10_PI,
361 false),
362 DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
363 DEFINE_PROP_BOOL("worker_per_virtqueue", VirtIOSCSICommon,
364 conf.worker_per_virtqueue, false),
365 DEFINE_PROP_END_OF_LIST(),
366 };
367
vhost_scsi_class_init(ObjectClass * klass,void * data)368 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
369 {
370 DeviceClass *dc = DEVICE_CLASS(klass);
371 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
372 FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
373
374 device_class_set_props(dc, vhost_scsi_properties);
375 dc->vmsd = &vmstate_virtio_vhost_scsi;
376 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
377 vdc->realize = vhost_scsi_realize;
378 vdc->unrealize = vhost_scsi_unrealize;
379 vdc->get_features = vhost_scsi_common_get_features;
380 vdc->set_config = vhost_scsi_common_set_config;
381 vdc->set_status = vhost_scsi_set_status;
382 vdc->get_vhost = vhost_scsi_get_vhost;
383 fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
384 }
385
vhost_scsi_instance_init(Object * obj)386 static void vhost_scsi_instance_init(Object *obj)
387 {
388 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
389
390 vsc->feature_bits = kernel_feature_bits;
391
392 device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
393 DEVICE(vsc));
394 }
395
396 static const TypeInfo vhost_scsi_info = {
397 .name = TYPE_VHOST_SCSI,
398 .parent = TYPE_VHOST_SCSI_COMMON,
399 .instance_size = sizeof(VHostSCSI),
400 .class_init = vhost_scsi_class_init,
401 .instance_init = vhost_scsi_instance_init,
402 .interfaces = (InterfaceInfo[]) {
403 { TYPE_FW_PATH_PROVIDER },
404 { }
405 },
406 };
407
virtio_register_types(void)408 static void virtio_register_types(void)
409 {
410 type_register_static(&vhost_scsi_info);
411 }
412
413 type_init(virtio_register_types)
414