xref: /openbmc/qemu/hw/scsi/vhost-user-scsi.c (revision 55abfc1f)
1 /*
2  * vhost-user-scsi host device
3  *
4  * Copyright (c) 2016 Nutanix Inc. All rights reserved.
5  *
6  * Author:
7  *  Felipe Franciosi <felipe@nutanix.com>
8  *
9  * This work is largely based on the "vhost-scsi" implementation by:
10  *  Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
11  *  Nicholas Bellinger <nab@risingtidesystems.com>
12  *
13  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
14  * See the COPYING.LIB file in the top-level directory.
15  *
16  */
17 
18 #include "qemu/osdep.h"
19 #include "qapi/error.h"
20 #include "qemu/error-report.h"
21 #include "hw/fw-path-provider.h"
22 #include "hw/qdev-core.h"
23 #include "hw/qdev-properties.h"
24 #include "hw/qdev-properties-system.h"
25 #include "hw/virtio/vhost.h"
26 #include "hw/virtio/vhost-backend.h"
27 #include "hw/virtio/vhost-user-scsi.h"
28 #include "hw/virtio/virtio.h"
29 #include "chardev/char-fe.h"
30 #include "sysemu/sysemu.h"
31 
32 /* Features supported by the host application */
33 static const int user_feature_bits[] = {
34     VIRTIO_F_NOTIFY_ON_EMPTY,
35     VIRTIO_RING_F_INDIRECT_DESC,
36     VIRTIO_RING_F_EVENT_IDX,
37     VIRTIO_SCSI_F_HOTPLUG,
38     VIRTIO_F_RING_RESET,
39     VHOST_INVALID_FEATURE_BIT
40 };
41 
42 static int vhost_user_scsi_start(VHostUserSCSI *s, Error **errp)
43 {
44     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
45     int ret;
46 
47     ret = vhost_scsi_common_start(vsc, errp);
48     s->started_vu = !(ret < 0);
49 
50     return ret;
51 }
52 
53 static void vhost_user_scsi_stop(VHostUserSCSI *s)
54 {
55     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
56 
57     if (!s->started_vu) {
58         return;
59     }
60     s->started_vu = false;
61 
62     vhost_scsi_common_stop(vsc);
63 }
64 
65 static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
66 {
67     VHostUserSCSI *s = (VHostUserSCSI *)vdev;
68     DeviceState *dev = DEVICE(vdev);
69     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
70     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
71     bool should_start = virtio_device_should_start(vdev, status);
72     Error *local_err = NULL;
73     int ret;
74 
75     if (!s->connected) {
76         return;
77     }
78 
79     if (vhost_dev_is_started(&vsc->dev) == should_start) {
80         return;
81     }
82 
83     if (should_start) {
84         ret = vhost_user_scsi_start(s, &local_err);
85         if (ret < 0) {
86             error_reportf_err(local_err, "unable to start vhost-user-scsi: %s",
87                               strerror(-ret));
88             qemu_chr_fe_disconnect(&vs->conf.chardev);
89         }
90     } else {
91         vhost_user_scsi_stop(s);
92     }
93 }
94 
95 static void vhost_user_scsi_handle_output(VirtIODevice *vdev, VirtQueue *vq)
96 {
97     VHostUserSCSI *s = (VHostUserSCSI *)vdev;
98     DeviceState *dev = DEVICE(vdev);
99     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
100     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
101 
102     Error *local_err = NULL;
103     int i, ret;
104 
105     if (!vdev->start_on_kick) {
106         return;
107     }
108 
109     if (!s->connected) {
110         return;
111     }
112 
113     if (vhost_dev_is_started(&vsc->dev)) {
114         return;
115     }
116 
117     /*
118      * Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
119      * vhost here instead of waiting for .set_status().
120      */
121     ret = vhost_user_scsi_start(s, &local_err);
122     if (ret < 0) {
123         error_reportf_err(local_err, "vhost-user-scsi: vhost start failed: ");
124         qemu_chr_fe_disconnect(&vs->conf.chardev);
125         return;
126     }
127 
128     /* Kick right away to begin processing requests already in vring */
129     for (i = 0; i < vsc->dev.nvqs; i++) {
130         VirtQueue *kick_vq = virtio_get_queue(vdev, i);
131 
132         if (!virtio_queue_get_desc_addr(vdev, i)) {
133             continue;
134         }
135         event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
136     }
137 }
138 
139 static int vhost_user_scsi_connect(DeviceState *dev, Error **errp)
140 {
141     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
142     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
143     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
144     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
145     int ret = 0;
146 
147     if (s->connected) {
148         return 0;
149     }
150 
151     vsc->dev.num_queues = vs->conf.num_queues;
152     vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
153     vsc->dev.vqs = s->vhost_vqs;
154     vsc->dev.vq_index = 0;
155     vsc->dev.backend_features = 0;
156 
157     ret = vhost_dev_init(&vsc->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
158                          errp);
159     if (ret < 0) {
160         return ret;
161     }
162 
163     s->connected = true;
164 
165     /* restore vhost state */
166     if (virtio_device_started(vdev, vdev->status)) {
167         ret = vhost_user_scsi_start(s, errp);
168     }
169 
170     return ret;
171 }
172 
173 static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event);
174 
175 static void vhost_user_scsi_disconnect(DeviceState *dev)
176 {
177     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
178     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
179     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
180     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
181 
182     if (!s->connected) {
183         return;
184     }
185     s->connected = false;
186 
187     vhost_user_scsi_stop(s);
188 
189     vhost_dev_cleanup(&vsc->dev);
190 
191     /* Re-instate the event handler for new connections */
192     qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL,
193                              vhost_user_scsi_event, NULL, dev, NULL, true);
194 }
195 
196 static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event)
197 {
198     DeviceState *dev = opaque;
199     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
200     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
201     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
202     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
203     Error *local_err = NULL;
204 
205     switch (event) {
206     case CHR_EVENT_OPENED:
207         if (vhost_user_scsi_connect(dev, &local_err) < 0) {
208             error_report_err(local_err);
209             qemu_chr_fe_disconnect(&vs->conf.chardev);
210             return;
211         }
212         break;
213     case CHR_EVENT_CLOSED:
214         /* defer close until later to avoid circular close */
215         vhost_user_async_close(dev, &vs->conf.chardev, &vsc->dev,
216                                vhost_user_scsi_disconnect,
217                                vhost_user_scsi_event);
218         break;
219     case CHR_EVENT_BREAK:
220     case CHR_EVENT_MUX_IN:
221     case CHR_EVENT_MUX_OUT:
222         /* Ignore */
223         break;
224     }
225 }
226 
227 static int vhost_user_scsi_realize_connect(VHostUserSCSI *s, Error **errp)
228 {
229     DeviceState *dev = DEVICE(s);
230     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
231     int ret;
232 
233     s->connected = false;
234 
235     ret = qemu_chr_fe_wait_connected(&vs->conf.chardev, errp);
236     if (ret < 0) {
237         return ret;
238     }
239 
240     ret = vhost_user_scsi_connect(dev, errp);
241     if (ret < 0) {
242         qemu_chr_fe_disconnect(&vs->conf.chardev);
243         return ret;
244     }
245     assert(s->connected);
246 
247     return 0;
248 }
249 
250 static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
251 {
252     ERRP_GUARD();
253     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
254     VHostUserSCSI *s = VHOST_USER_SCSI(dev);
255     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
256     Error *err = NULL;
257     int ret;
258     int retries = VU_REALIZE_CONN_RETRIES;
259 
260     if (!vs->conf.chardev.chr) {
261         error_setg(errp, "vhost-user-scsi: missing chardev");
262         return;
263     }
264 
265     virtio_scsi_common_realize(dev, vhost_user_scsi_handle_output,
266                                vhost_user_scsi_handle_output,
267                                vhost_user_scsi_handle_output, &err);
268     if (err != NULL) {
269         error_propagate(errp, err);
270         return;
271     }
272 
273     if (!vhost_user_init(&s->vhost_user, &vs->conf.chardev, errp)) {
274         goto free_virtio;
275     }
276 
277     vsc->inflight = g_new0(struct vhost_inflight, 1);
278     s->vhost_vqs = g_new0(struct vhost_virtqueue,
279                           VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues);
280 
281     assert(!*errp);
282     do {
283         if (*errp) {
284             error_prepend(errp, "Reconnecting after error: ");
285             error_report_err(*errp);
286             *errp = NULL;
287         }
288         ret = vhost_user_scsi_realize_connect(s, errp);
289     } while (ret < 0 && retries--);
290 
291     if (ret < 0) {
292         goto free_vhost;
293     }
294 
295     /* we're fully initialized, now we can operate, so add the handler */
296     qemu_chr_fe_set_handlers(&vs->conf.chardev,  NULL, NULL,
297                              vhost_user_scsi_event, NULL, (void *)dev,
298                              NULL, true);
299     /* Channel and lun both are 0 for bootable vhost-user-scsi disk */
300     vsc->channel = 0;
301     vsc->lun = 0;
302     vsc->target = vs->conf.boot_tpgt;
303 
304     return;
305 
306 free_vhost:
307     g_free(s->vhost_vqs);
308     s->vhost_vqs = NULL;
309     g_free(vsc->inflight);
310     vsc->inflight = NULL;
311     vhost_user_cleanup(&s->vhost_user);
312 
313 free_virtio:
314     virtio_scsi_common_unrealize(dev);
315 }
316 
317 static void vhost_user_scsi_unrealize(DeviceState *dev)
318 {
319     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
320     VHostUserSCSI *s = VHOST_USER_SCSI(dev);
321     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
322     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
323 
324     /* This will stop the vhost backend. */
325     vhost_user_scsi_set_status(vdev, 0);
326     qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL, NULL, NULL, NULL,
327                              NULL, false);
328 
329     vhost_dev_cleanup(&vsc->dev);
330     g_free(s->vhost_vqs);
331     s->vhost_vqs = NULL;
332 
333     vhost_dev_free_inflight(vsc->inflight);
334     g_free(vsc->inflight);
335     vsc->inflight = NULL;
336 
337     vhost_user_cleanup(&s->vhost_user);
338     virtio_scsi_common_unrealize(dev);
339 }
340 
341 static Property vhost_user_scsi_properties[] = {
342     DEFINE_PROP_CHR("chardev", VirtIOSCSICommon, conf.chardev),
343     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
344     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
345                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
346     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
347                        128),
348     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
349                        0xFFFF),
350     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
351     DEFINE_PROP_BIT64("hotplug", VHostSCSICommon, host_features,
352                                                   VIRTIO_SCSI_F_HOTPLUG,
353                                                   true),
354     DEFINE_PROP_BIT64("param_change", VHostSCSICommon, host_features,
355                                                        VIRTIO_SCSI_F_CHANGE,
356                                                        true),
357     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
358                                                  VIRTIO_SCSI_F_T10_PI,
359                                                  false),
360     DEFINE_PROP_END_OF_LIST(),
361 };
362 
363 static void vhost_user_scsi_reset(VirtIODevice *vdev)
364 {
365     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
366     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
367 
368     vhost_dev_free_inflight(vsc->inflight);
369 }
370 
371 static struct vhost_dev *vhost_user_scsi_get_vhost(VirtIODevice *vdev)
372 {
373     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(vdev);
374     return &vsc->dev;
375 }
376 
377 static const VMStateDescription vmstate_vhost_scsi = {
378     .name = "virtio-scsi",
379     .minimum_version_id = 1,
380     .version_id = 1,
381     .fields = (VMStateField[]) {
382         VMSTATE_VIRTIO_DEVICE,
383         VMSTATE_END_OF_LIST()
384     },
385 };
386 
387 static void vhost_user_scsi_class_init(ObjectClass *klass, void *data)
388 {
389     DeviceClass *dc = DEVICE_CLASS(klass);
390     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
391     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
392 
393     device_class_set_props(dc, vhost_user_scsi_properties);
394     dc->vmsd = &vmstate_vhost_scsi;
395     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
396     vdc->realize = vhost_user_scsi_realize;
397     vdc->unrealize = vhost_user_scsi_unrealize;
398     vdc->get_features = vhost_scsi_common_get_features;
399     vdc->set_config = vhost_scsi_common_set_config;
400     vdc->set_status = vhost_user_scsi_set_status;
401     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
402     vdc->reset = vhost_user_scsi_reset;
403     vdc->get_vhost = vhost_user_scsi_get_vhost;
404 }
405 
406 static void vhost_user_scsi_instance_init(Object *obj)
407 {
408     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
409 
410     vsc->feature_bits = user_feature_bits;
411 
412     /* Add the bootindex property for this object */
413     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
414                                   DEVICE(vsc));
415 }
416 
417 static const TypeInfo vhost_user_scsi_info = {
418     .name = TYPE_VHOST_USER_SCSI,
419     .parent = TYPE_VHOST_SCSI_COMMON,
420     .instance_size = sizeof(VHostUserSCSI),
421     .class_init = vhost_user_scsi_class_init,
422     .instance_init = vhost_user_scsi_instance_init,
423     .interfaces = (InterfaceInfo[]) {
424         { TYPE_FW_PATH_PROVIDER },
425         { }
426     },
427 };
428 
429 static void virtio_register_types(void)
430 {
431     type_register_static(&vhost_user_scsi_info);
432 }
433 
434 type_init(virtio_register_types)
435