xref: /openbmc/qemu/hw/scsi/vhost-user-scsi.c (revision c03213fd)
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     VIRTIO_F_IN_ORDER,
40     VIRTIO_F_NOTIFICATION_DATA,
41     VHOST_INVALID_FEATURE_BIT
42 };
43 
vhost_user_scsi_start(VHostUserSCSI * s,Error ** errp)44 static int vhost_user_scsi_start(VHostUserSCSI *s, Error **errp)
45 {
46     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
47     int ret;
48 
49     ret = vhost_scsi_common_start(vsc, errp);
50     s->started_vu = !(ret < 0);
51 
52     return ret;
53 }
54 
vhost_user_scsi_stop(VHostUserSCSI * s)55 static void vhost_user_scsi_stop(VHostUserSCSI *s)
56 {
57     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
58 
59     if (!s->started_vu) {
60         return;
61     }
62     s->started_vu = false;
63 
64     vhost_scsi_common_stop(vsc);
65 }
66 
vhost_user_scsi_set_status(VirtIODevice * vdev,uint8_t status)67 static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
68 {
69     VHostUserSCSI *s = (VHostUserSCSI *)vdev;
70     DeviceState *dev = DEVICE(vdev);
71     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
72     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
73     bool should_start = virtio_device_should_start(vdev, status);
74     Error *local_err = NULL;
75     int ret;
76 
77     if (!s->connected) {
78         return;
79     }
80 
81     if (vhost_dev_is_started(&vsc->dev) == should_start) {
82         return;
83     }
84 
85     if (should_start) {
86         ret = vhost_user_scsi_start(s, &local_err);
87         if (ret < 0) {
88             error_reportf_err(local_err,
89                               "unable to start vhost-user-scsi: %s: ",
90                               strerror(-ret));
91             qemu_chr_fe_disconnect(&vs->conf.chardev);
92         }
93     } else {
94         vhost_user_scsi_stop(s);
95     }
96 }
97 
vhost_user_scsi_handle_output(VirtIODevice * vdev,VirtQueue * vq)98 static void vhost_user_scsi_handle_output(VirtIODevice *vdev, VirtQueue *vq)
99 {
100     VHostUserSCSI *s = (VHostUserSCSI *)vdev;
101     DeviceState *dev = DEVICE(vdev);
102     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
103     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
104 
105     Error *local_err = NULL;
106     int i, ret;
107 
108     if (!vdev->start_on_kick) {
109         return;
110     }
111 
112     if (!s->connected) {
113         return;
114     }
115 
116     if (vhost_dev_is_started(&vsc->dev)) {
117         return;
118     }
119 
120     /*
121      * Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
122      * vhost here instead of waiting for .set_status().
123      */
124     ret = vhost_user_scsi_start(s, &local_err);
125     if (ret < 0) {
126         error_reportf_err(local_err, "vhost-user-scsi: vhost start failed: ");
127         qemu_chr_fe_disconnect(&vs->conf.chardev);
128         return;
129     }
130 
131     /* Kick right away to begin processing requests already in vring */
132     for (i = 0; i < vsc->dev.nvqs; i++) {
133         VirtQueue *kick_vq = virtio_get_queue(vdev, i);
134 
135         if (!virtio_queue_get_desc_addr(vdev, i)) {
136             continue;
137         }
138         event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
139     }
140 }
141 
vhost_user_scsi_connect(DeviceState * dev,Error ** errp)142 static int vhost_user_scsi_connect(DeviceState *dev, Error **errp)
143 {
144     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
145     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
146     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
147     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
148     int ret = 0;
149 
150     if (s->connected) {
151         return 0;
152     }
153 
154     vsc->dev.num_queues = vs->conf.num_queues;
155     vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
156     vsc->dev.vqs = s->vhost_vqs;
157     vsc->dev.vq_index = 0;
158     vsc->dev.backend_features = 0;
159 
160     ret = vhost_dev_init(&vsc->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
161                          errp);
162     if (ret < 0) {
163         return ret;
164     }
165 
166     s->connected = true;
167 
168     /* restore vhost state */
169     if (virtio_device_started(vdev, vdev->status)) {
170         ret = vhost_user_scsi_start(s, errp);
171     }
172 
173     return ret;
174 }
175 
176 static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event);
177 
vhost_user_scsi_disconnect(DeviceState * dev)178 static void vhost_user_scsi_disconnect(DeviceState *dev)
179 {
180     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
181     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
182     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
183     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
184 
185     if (!s->connected) {
186         goto done;
187     }
188     s->connected = false;
189 
190     vhost_user_scsi_stop(s);
191 
192     vhost_dev_cleanup(&vsc->dev);
193 
194 done:
195     /* Re-instate the event handler for new connections */
196     qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL,
197                              vhost_user_scsi_event, NULL, dev, NULL, true);
198 }
199 
vhost_user_scsi_event(void * opaque,QEMUChrEvent event)200 static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event)
201 {
202     DeviceState *dev = opaque;
203     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
204     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
205     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
206     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
207     Error *local_err = NULL;
208 
209     switch (event) {
210     case CHR_EVENT_OPENED:
211         if (vhost_user_scsi_connect(dev, &local_err) < 0) {
212             error_report_err(local_err);
213             qemu_chr_fe_disconnect(&vs->conf.chardev);
214             return;
215         }
216         break;
217     case CHR_EVENT_CLOSED:
218         /* defer close until later to avoid circular close */
219         vhost_user_async_close(dev, &vs->conf.chardev, &vsc->dev,
220                                vhost_user_scsi_disconnect);
221         break;
222     case CHR_EVENT_BREAK:
223     case CHR_EVENT_MUX_IN:
224     case CHR_EVENT_MUX_OUT:
225         /* Ignore */
226         break;
227     }
228 }
229 
vhost_user_scsi_realize_connect(VHostUserSCSI * s,Error ** errp)230 static int vhost_user_scsi_realize_connect(VHostUserSCSI *s, Error **errp)
231 {
232     DeviceState *dev = DEVICE(s);
233     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
234     int ret;
235 
236     s->connected = false;
237 
238     ret = qemu_chr_fe_wait_connected(&vs->conf.chardev, errp);
239     if (ret < 0) {
240         return ret;
241     }
242 
243     ret = vhost_user_scsi_connect(dev, errp);
244     if (ret < 0) {
245         qemu_chr_fe_disconnect(&vs->conf.chardev);
246         return ret;
247     }
248     assert(s->connected);
249 
250     return 0;
251 }
252 
vhost_user_scsi_realize(DeviceState * dev,Error ** errp)253 static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
254 {
255     ERRP_GUARD();
256     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
257     VHostUserSCSI *s = VHOST_USER_SCSI(dev);
258     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
259     Error *err = NULL;
260     int ret;
261     int retries = VU_REALIZE_CONN_RETRIES;
262 
263     if (!vs->conf.chardev.chr) {
264         error_setg(errp, "vhost-user-scsi: missing chardev");
265         return;
266     }
267 
268     virtio_scsi_common_realize(dev, vhost_user_scsi_handle_output,
269                                vhost_user_scsi_handle_output,
270                                vhost_user_scsi_handle_output, &err);
271     if (err != NULL) {
272         error_propagate(errp, err);
273         return;
274     }
275 
276     if (!vhost_user_init(&s->vhost_user, &vs->conf.chardev, errp)) {
277         goto free_virtio;
278     }
279 
280     vsc->inflight = g_new0(struct vhost_inflight, 1);
281     s->vhost_vqs = g_new0(struct vhost_virtqueue,
282                           VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues);
283 
284     assert(!*errp);
285     do {
286         if (*errp) {
287             error_prepend(errp, "Reconnecting after error: ");
288             error_report_err(*errp);
289             *errp = NULL;
290         }
291         ret = vhost_user_scsi_realize_connect(s, errp);
292     } while (ret < 0 && retries--);
293 
294     if (ret < 0) {
295         goto free_vhost;
296     }
297 
298     /* we're fully initialized, now we can operate, so add the handler */
299     qemu_chr_fe_set_handlers(&vs->conf.chardev,  NULL, NULL,
300                              vhost_user_scsi_event, NULL, (void *)dev,
301                              NULL, true);
302     /* Channel and lun both are 0 for bootable vhost-user-scsi disk */
303     vsc->channel = 0;
304     vsc->lun = 0;
305     vsc->target = vs->conf.boot_tpgt;
306 
307     return;
308 
309 free_vhost:
310     g_free(s->vhost_vqs);
311     s->vhost_vqs = NULL;
312     g_free(vsc->inflight);
313     vsc->inflight = NULL;
314     vhost_user_cleanup(&s->vhost_user);
315 
316 free_virtio:
317     virtio_scsi_common_unrealize(dev);
318 }
319 
vhost_user_scsi_unrealize(DeviceState * dev)320 static void vhost_user_scsi_unrealize(DeviceState *dev)
321 {
322     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
323     VHostUserSCSI *s = VHOST_USER_SCSI(dev);
324     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
325     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
326 
327     /* This will stop the vhost backend. */
328     vhost_user_scsi_set_status(vdev, 0);
329     qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL, NULL, NULL, NULL,
330                              NULL, false);
331 
332     vhost_dev_cleanup(&vsc->dev);
333     g_free(s->vhost_vqs);
334     s->vhost_vqs = NULL;
335 
336     vhost_dev_free_inflight(vsc->inflight);
337     g_free(vsc->inflight);
338     vsc->inflight = NULL;
339 
340     vhost_user_cleanup(&s->vhost_user);
341     virtio_scsi_common_unrealize(dev);
342 }
343 
344 static Property vhost_user_scsi_properties[] = {
345     DEFINE_PROP_CHR("chardev", VirtIOSCSICommon, conf.chardev),
346     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
347     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
348                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
349     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
350                        128),
351     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
352                        0xFFFF),
353     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
354     DEFINE_PROP_BIT64("hotplug", VHostSCSICommon, host_features,
355                                                   VIRTIO_SCSI_F_HOTPLUG,
356                                                   true),
357     DEFINE_PROP_BIT64("param_change", VHostSCSICommon, host_features,
358                                                        VIRTIO_SCSI_F_CHANGE,
359                                                        true),
360     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
361                                                  VIRTIO_SCSI_F_T10_PI,
362                                                  false),
363     DEFINE_PROP_END_OF_LIST(),
364 };
365 
vhost_user_scsi_reset(VirtIODevice * vdev)366 static void vhost_user_scsi_reset(VirtIODevice *vdev)
367 {
368     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
369     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
370 
371     vhost_dev_free_inflight(vsc->inflight);
372 }
373 
vhost_user_scsi_get_vhost(VirtIODevice * vdev)374 static struct vhost_dev *vhost_user_scsi_get_vhost(VirtIODevice *vdev)
375 {
376     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(vdev);
377     return &vsc->dev;
378 }
379 
380 static const VMStateDescription vmstate_vhost_scsi = {
381     .name = "virtio-scsi",
382     .minimum_version_id = 1,
383     .version_id = 1,
384     .fields = (const VMStateField[]) {
385         VMSTATE_VIRTIO_DEVICE,
386         VMSTATE_END_OF_LIST()
387     },
388 };
389 
vhost_user_scsi_class_init(ObjectClass * klass,void * data)390 static void vhost_user_scsi_class_init(ObjectClass *klass, void *data)
391 {
392     DeviceClass *dc = DEVICE_CLASS(klass);
393     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
394     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
395 
396     device_class_set_props(dc, vhost_user_scsi_properties);
397     dc->vmsd = &vmstate_vhost_scsi;
398     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
399     vdc->realize = vhost_user_scsi_realize;
400     vdc->unrealize = vhost_user_scsi_unrealize;
401     vdc->get_features = vhost_scsi_common_get_features;
402     vdc->set_config = vhost_scsi_common_set_config;
403     vdc->set_status = vhost_user_scsi_set_status;
404     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
405     vdc->reset = vhost_user_scsi_reset;
406     vdc->get_vhost = vhost_user_scsi_get_vhost;
407 }
408 
vhost_user_scsi_instance_init(Object * obj)409 static void vhost_user_scsi_instance_init(Object *obj)
410 {
411     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
412 
413     vsc->feature_bits = user_feature_bits;
414 
415     /* Add the bootindex property for this object */
416     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
417                                   DEVICE(vsc));
418 }
419 
420 static const TypeInfo vhost_user_scsi_info = {
421     .name = TYPE_VHOST_USER_SCSI,
422     .parent = TYPE_VHOST_SCSI_COMMON,
423     .instance_size = sizeof(VHostUserSCSI),
424     .class_init = vhost_user_scsi_class_init,
425     .instance_init = vhost_user_scsi_instance_init,
426     .interfaces = (InterfaceInfo[]) {
427         { TYPE_FW_PATH_PROVIDER },
428         { }
429     },
430 };
431 
virtio_register_types(void)432 static void virtio_register_types(void)
433 {
434     type_register_static(&vhost_user_scsi_info);
435 }
436 
437 type_init(virtio_register_types)
438