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 "system/system.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 int 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 0;
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 return 0;
143 }
144
vhost_dummy_handle_output(VirtIODevice * vdev,VirtQueue * vq)145 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
146 {
147 }
148
vhost_scsi_pre_save(void * opaque)149 static int vhost_scsi_pre_save(void *opaque)
150 {
151 VHostSCSICommon *vsc = opaque;
152
153 /* At this point, backend must be stopped, otherwise
154 * it might keep writing to memory. */
155 assert(!vhost_dev_is_started(&vsc->dev));
156
157 return 0;
158 }
159
160 static const VMStateDescription vmstate_virtio_vhost_scsi = {
161 .name = "virtio-vhost_scsi",
162 .minimum_version_id = 1,
163 .version_id = 1,
164 .fields = (const VMStateField[]) {
165 VMSTATE_VIRTIO_DEVICE,
166 VMSTATE_END_OF_LIST()
167 },
168 .pre_save = vhost_scsi_pre_save,
169 };
170
vhost_scsi_set_workers(VHostSCSICommon * vsc,bool per_virtqueue)171 static int vhost_scsi_set_workers(VHostSCSICommon *vsc, bool per_virtqueue)
172 {
173 struct vhost_dev *dev = &vsc->dev;
174 struct vhost_vring_worker vq_worker;
175 struct vhost_worker_state worker;
176 int i, ret = 0;
177
178 /* Use default worker */
179 if (!per_virtqueue || dev->nvqs == VHOST_SCSI_VQ_NUM_FIXED + 1) {
180 return 0;
181 }
182
183 /*
184 * ctl/evt share the first worker since it will be rare for them
185 * to send cmds while IO is running.
186 */
187 for (i = VHOST_SCSI_VQ_NUM_FIXED + 1; i < dev->nvqs; i++) {
188 memset(&worker, 0, sizeof(worker));
189
190 ret = dev->vhost_ops->vhost_new_worker(dev, &worker);
191 if (ret == -ENOTTY) {
192 /*
193 * worker ioctls are not implemented so just ignore and
194 * and continue device setup.
195 */
196 warn_report("vhost-scsi: Backend supports a single worker. "
197 "Ignoring worker_per_virtqueue=true setting.");
198 ret = 0;
199 break;
200 } else if (ret) {
201 break;
202 }
203
204 memset(&vq_worker, 0, sizeof(vq_worker));
205 vq_worker.worker_id = worker.worker_id;
206 vq_worker.index = i;
207
208 ret = dev->vhost_ops->vhost_attach_vring_worker(dev, &vq_worker);
209 if (ret == -ENOTTY) {
210 /*
211 * It's a bug for the kernel to have supported the worker creation
212 * ioctl but not attach.
213 */
214 dev->vhost_ops->vhost_free_worker(dev, &worker);
215 break;
216 } else if (ret) {
217 break;
218 }
219 }
220
221 return ret;
222 }
223
vhost_scsi_realize(DeviceState * dev,Error ** errp)224 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
225 {
226 ERRP_GUARD();
227 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
228 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
229 Error *err = NULL;
230 int vhostfd = -1;
231 int ret;
232 struct vhost_virtqueue *vqs = NULL;
233
234 if (!vs->conf.wwpn) {
235 error_setg(errp, "vhost-scsi: missing wwpn");
236 return;
237 }
238
239 if (vs->conf.vhostfd) {
240 vhostfd = monitor_fd_param(monitor_cur(), vs->conf.vhostfd, errp);
241 if (vhostfd == -1) {
242 error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
243 return;
244 }
245 } else {
246 vhostfd = open("/dev/vhost-scsi", O_RDWR);
247 if (vhostfd < 0) {
248 error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
249 strerror(errno));
250 return;
251 }
252 }
253
254 virtio_scsi_common_realize(dev,
255 vhost_dummy_handle_output,
256 vhost_dummy_handle_output,
257 vhost_dummy_handle_output,
258 &err);
259 if (err != NULL) {
260 error_propagate(errp, err);
261 goto close_fd;
262 }
263
264 if (!vsc->migratable) {
265 error_setg(&vsc->migration_blocker,
266 "vhost-scsi does not support migration in all cases. "
267 "When external environment supports it (Orchestrator migrates "
268 "target SCSI device state or use shared storage over network), "
269 "set 'migratable' property to true to enable migration.");
270 if (migrate_add_blocker_normal(&vsc->migration_blocker, errp) < 0) {
271 goto free_virtio;
272 }
273 }
274
275 vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
276 vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
277 vsc->dev.vqs = vqs;
278 vsc->dev.vq_index = 0;
279 vsc->dev.backend_features = 0;
280
281 ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
282 VHOST_BACKEND_TYPE_KERNEL, 0, errp);
283 if (ret < 0) {
284 /*
285 * vhost_dev_init calls vhost_dev_cleanup on error, which closes
286 * vhostfd, don't double close it.
287 */
288 vhostfd = -1;
289 goto free_vqs;
290 }
291
292 ret = vhost_scsi_set_workers(vsc, vs->conf.worker_per_virtqueue);
293 if (ret < 0) {
294 error_setg(errp, "vhost-scsi: vhost worker setup failed: %s",
295 strerror(-ret));
296 goto free_vqs;
297 }
298
299 /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
300 vsc->channel = 0;
301 vsc->lun = 0;
302 /* Note: we can also get the minimum tpgt from kernel */
303 vsc->target = vs->conf.boot_tpgt;
304
305 return;
306
307 free_vqs:
308 g_free(vqs);
309 if (!vsc->migratable) {
310 migrate_del_blocker(&vsc->migration_blocker);
311 }
312 free_virtio:
313 virtio_scsi_common_unrealize(dev);
314 close_fd:
315 if (vhostfd >= 0) {
316 close(vhostfd);
317 }
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 const 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_BIT64("hotplug", VHostSCSICommon, host_features,
363 VIRTIO_SCSI_F_HOTPLUG,
364 false),
365 DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
366 DEFINE_PROP_BOOL("worker_per_virtqueue", VirtIOSCSICommon,
367 conf.worker_per_virtqueue, false),
368 };
369
vhost_scsi_class_init(ObjectClass * klass,const void * data)370 static void vhost_scsi_class_init(ObjectClass *klass, const void *data)
371 {
372 DeviceClass *dc = DEVICE_CLASS(klass);
373 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
374 FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
375
376 device_class_set_props(dc, vhost_scsi_properties);
377 dc->vmsd = &vmstate_virtio_vhost_scsi;
378 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
379 vdc->realize = vhost_scsi_realize;
380 vdc->unrealize = vhost_scsi_unrealize;
381 vdc->get_features = vhost_scsi_common_get_features;
382 vdc->set_config = vhost_scsi_common_set_config;
383 vdc->set_status = vhost_scsi_set_status;
384 vdc->get_vhost = vhost_scsi_get_vhost;
385 fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
386 }
387
vhost_scsi_instance_init(Object * obj)388 static void vhost_scsi_instance_init(Object *obj)
389 {
390 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
391
392 vsc->feature_bits = kernel_feature_bits;
393
394 device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
395 DEVICE(vsc));
396 }
397
398 static const TypeInfo vhost_scsi_info = {
399 .name = TYPE_VHOST_SCSI,
400 .parent = TYPE_VHOST_SCSI_COMMON,
401 .instance_size = sizeof(VHostSCSI),
402 .class_init = vhost_scsi_class_init,
403 .instance_init = vhost_scsi_instance_init,
404 .interfaces = (const InterfaceInfo[]) {
405 { TYPE_FW_PATH_PROVIDER },
406 { }
407 },
408 };
409
virtio_register_types(void)410 static void virtio_register_types(void)
411 {
412 type_register_static(&vhost_scsi_info);
413 }
414
415 type_init(virtio_register_types)
416