xref: /qemu/hw/scsi/vhost-scsi.c (revision 63d2ada2) 
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 #include "hw/fw-path-provider.h"
28 
29 /* Features supported by host kernel. */
30 static const int kernel_feature_bits[] = {
31     VIRTIO_F_NOTIFY_ON_EMPTY,
32     VIRTIO_RING_F_INDIRECT_DESC,
33     VIRTIO_RING_F_EVENT_IDX,
34     VIRTIO_SCSI_F_HOTPLUG,
35     VHOST_INVALID_FEATURE_BIT
36 };
37 
38 static int vhost_scsi_set_endpoint(VHostSCSI *s)
39 {
40     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
41     const VhostOps *vhost_ops = s->dev.vhost_ops;
42     struct vhost_scsi_target backend;
43     int ret;
44 
45     memset(&backend, 0, sizeof(backend));
46     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
47     ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
48     if (ret < 0) {
49         return -errno;
50     }
51     return 0;
52 }
53 
54 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
55 {
56     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
57     struct vhost_scsi_target backend;
58     const VhostOps *vhost_ops = s->dev.vhost_ops;
59 
60     memset(&backend, 0, sizeof(backend));
61     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
62     vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
63 }
64 
65 static int vhost_scsi_start(VHostSCSI *s)
66 {
67     int ret, abi_version, i;
68     VirtIODevice *vdev = VIRTIO_DEVICE(s);
69     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
70     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
71     const VhostOps *vhost_ops = s->dev.vhost_ops;
72 
73     if (!k->set_guest_notifiers) {
74         error_report("binding does not support guest notifiers");
75         return -ENOSYS;
76     }
77 
78     ret = vhost_ops->vhost_call(&s->dev,
79                                 VHOST_SCSI_GET_ABI_VERSION, &abi_version);
80     if (ret < 0) {
81         return -errno;
82     }
83     if (abi_version > VHOST_SCSI_ABI_VERSION) {
84         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
85                      " %d is greater than vhost_scsi userspace supports: %d, please"
86                      " upgrade your version of QEMU", abi_version,
87                      VHOST_SCSI_ABI_VERSION);
88         return -ENOSYS;
89     }
90 
91     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
92     if (ret < 0) {
93         return ret;
94     }
95 
96     s->dev.acked_features = vdev->guest_features;
97     ret = vhost_dev_start(&s->dev, vdev);
98     if (ret < 0) {
99         error_report("Error start vhost dev");
100         goto err_notifiers;
101     }
102 
103     ret = vhost_scsi_set_endpoint(s);
104     if (ret < 0) {
105         error_report("Error set vhost-scsi endpoint");
106         goto err_vhost_stop;
107     }
108 
109     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
110     if (ret < 0) {
111         error_report("Error binding guest notifier");
112         goto err_endpoint;
113     }
114 
115     /* guest_notifier_mask/pending not used yet, so just unmask
116      * everything here.  virtio-pci will do the right thing by
117      * enabling/disabling irqfd.
118      */
119     for (i = 0; i < s->dev.nvqs; i++) {
120         vhost_virtqueue_mask(&s->dev, vdev, i, false);
121     }
122 
123     return ret;
124 
125 err_endpoint:
126     vhost_scsi_clear_endpoint(s);
127 err_vhost_stop:
128     vhost_dev_stop(&s->dev, vdev);
129 err_notifiers:
130     vhost_dev_disable_notifiers(&s->dev, vdev);
131     return ret;
132 }
133 
134 static void vhost_scsi_stop(VHostSCSI *s)
135 {
136     VirtIODevice *vdev = VIRTIO_DEVICE(s);
137     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
138     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
139     int ret = 0;
140 
141     if (k->set_guest_notifiers) {
142         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
143         if (ret < 0) {
144                 error_report("vhost guest notifier cleanup failed: %d", ret);
145         }
146     }
147     assert(ret >= 0);
148 
149     vhost_scsi_clear_endpoint(s);
150     vhost_dev_stop(&s->dev, vdev);
151     vhost_dev_disable_notifiers(&s->dev, vdev);
152 }
153 
154 static uint32_t vhost_scsi_get_features(VirtIODevice *vdev,
155                                         uint32_t features)
156 {
157     VHostSCSI *s = VHOST_SCSI(vdev);
158 
159     return vhost_get_features(&s->dev, kernel_feature_bits, features);
160 }
161 
162 static void vhost_scsi_set_config(VirtIODevice *vdev,
163                                   const uint8_t *config)
164 {
165     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
166     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
167 
168     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size ||
169         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) {
170         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
171         exit(1);
172     }
173 }
174 
175 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
176 {
177     VHostSCSI *s = (VHostSCSI *)vdev;
178     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
179 
180     if (s->dev.started == start) {
181         return;
182     }
183 
184     if (start) {
185         int ret;
186 
187         ret = vhost_scsi_start(s);
188         if (ret < 0) {
189             error_report("virtio-scsi: unable to start vhost: %s",
190                          strerror(-ret));
191 
192             /* There is no userspace virtio-scsi fallback so exit */
193             exit(1);
194         }
195     } else {
196         vhost_scsi_stop(s);
197     }
198 }
199 
200 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
201 {
202 }
203 
204 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
205 {
206     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
207     VHostSCSI *s = VHOST_SCSI(dev);
208     Error *err = NULL;
209     int vhostfd = -1;
210     int ret;
211 
212     if (!vs->conf.wwpn) {
213         error_setg(errp, "vhost-scsi: missing wwpn");
214         return;
215     }
216 
217     if (vs->conf.vhostfd) {
218         vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, &err);
219         if (vhostfd == -1) {
220             error_setg(errp, "vhost-scsi: unable to parse vhostfd: %s",
221                        error_get_pretty(err));
222             error_free(err);
223             return;
224         }
225     } else {
226         vhostfd = open("/dev/vhost-scsi", O_RDWR);
227         if (vhostfd < 0) {
228             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
229                        strerror(errno));
230             return;
231         }
232     }
233 
234     virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
235                                vhost_dummy_handle_output,
236                                vhost_dummy_handle_output);
237     if (err != NULL) {
238         error_propagate(errp, err);
239         close(vhostfd);
240         return;
241     }
242 
243     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
244     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
245     s->dev.vq_index = 0;
246     s->dev.backend_features = 0;
247 
248     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
249                          VHOST_BACKEND_TYPE_KERNEL, true);
250     if (ret < 0) {
251         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
252                    strerror(-ret));
253         return;
254     }
255 
256     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
257     s->channel = 0;
258     s->lun = 0;
259     /* Note: we can also get the minimum tpgt from kernel */
260     s->target = vs->conf.boot_tpgt;
261 
262     error_setg(&s->migration_blocker,
263             "vhost-scsi does not support migration");
264     migrate_add_blocker(s->migration_blocker);
265 }
266 
267 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
268 {
269     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
270     VHostSCSI *s = VHOST_SCSI(dev);
271 
272     migrate_del_blocker(s->migration_blocker);
273     error_free(s->migration_blocker);
274 
275     /* This will stop vhost backend. */
276     vhost_scsi_set_status(vdev, 0);
277 
278     g_free(s->dev.vqs);
279 
280     virtio_scsi_common_unrealize(dev, errp);
281 }
282 
283 /*
284  * Implementation of an interface to adjust firmware path
285  * for the bootindex property handling.
286  */
287 static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus,
288                                         DeviceState *dev)
289 {
290     VHostSCSI *s = VHOST_SCSI(dev);
291     /* format: channel@channel/vhost-scsi@target,lun */
292     return g_strdup_printf("channel@%x/%s@%x,%x", s->channel,
293                            qdev_fw_name(dev), s->target, s->lun);
294 }
295 
296 static Property vhost_scsi_properties[] = {
297     DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent_obj.conf),
298     DEFINE_PROP_END_OF_LIST(),
299 };
300 
301 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
302 {
303     DeviceClass *dc = DEVICE_CLASS(klass);
304     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
305     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
306 
307     dc->props = vhost_scsi_properties;
308     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
309     vdc->realize = vhost_scsi_realize;
310     vdc->unrealize = vhost_scsi_unrealize;
311     vdc->get_features = vhost_scsi_get_features;
312     vdc->set_config = vhost_scsi_set_config;
313     vdc->set_status = vhost_scsi_set_status;
314     fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
315 }
316 
317 static void vhost_scsi_instance_init(Object *obj)
318 {
319     VHostSCSI *dev = VHOST_SCSI(obj);
320 
321     device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
322                                   DEVICE(dev), NULL);
323 }
324 
325 static const TypeInfo vhost_scsi_info = {
326     .name = TYPE_VHOST_SCSI,
327     .parent = TYPE_VIRTIO_SCSI_COMMON,
328     .instance_size = sizeof(VHostSCSI),
329     .class_init = vhost_scsi_class_init,
330     .instance_init = vhost_scsi_instance_init,
331     .interfaces = (InterfaceInfo[]) {
332         { TYPE_FW_PATH_PROVIDER },
333         { }
334     },
335 };
336 
337 static void virtio_register_types(void)
338 {
339     type_register_static(&vhost_scsi_info);
340 }
341 
342 type_init(virtio_register_types)
343