xref: /qemu/hw/scsi/vhost-scsi.c (revision 67cc32eb) 
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/error-report.h"
20 #include "qemu/queue.h"
21 #include "monitor/monitor.h"
22 #include "migration/migration.h"
23 #include "hw/virtio/vhost-scsi.h"
24 #include "hw/virtio/vhost.h"
25 #include "hw/virtio/virtio-scsi.h"
26 #include "hw/virtio/virtio-bus.h"
27 #include "hw/virtio/virtio-access.h"
28 #include "hw/fw-path-provider.h"
29 
30 /* Features supported by host kernel. */
31 static const int kernel_feature_bits[] = {
32     VIRTIO_F_NOTIFY_ON_EMPTY,
33     VIRTIO_RING_F_INDIRECT_DESC,
34     VIRTIO_RING_F_EVENT_IDX,
35     VIRTIO_SCSI_F_HOTPLUG,
36     VHOST_INVALID_FEATURE_BIT
37 };
38 
39 static int vhost_scsi_set_endpoint(VHostSCSI *s)
40 {
41     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
42     const VhostOps *vhost_ops = s->dev.vhost_ops;
43     struct vhost_scsi_target backend;
44     int ret;
45 
46     memset(&backend, 0, sizeof(backend));
47     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
48     ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
49     if (ret < 0) {
50         return -errno;
51     }
52     return 0;
53 }
54 
55 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
56 {
57     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
58     struct vhost_scsi_target backend;
59     const VhostOps *vhost_ops = s->dev.vhost_ops;
60 
61     memset(&backend, 0, sizeof(backend));
62     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
63     vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
64 }
65 
66 static int vhost_scsi_start(VHostSCSI *s)
67 {
68     int ret, abi_version, i;
69     VirtIODevice *vdev = VIRTIO_DEVICE(s);
70     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
71     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
72     const VhostOps *vhost_ops = s->dev.vhost_ops;
73 
74     if (!k->set_guest_notifiers) {
75         error_report("binding does not support guest notifiers");
76         return -ENOSYS;
77     }
78 
79     ret = vhost_ops->vhost_call(&s->dev,
80                                 VHOST_SCSI_GET_ABI_VERSION, &abi_version);
81     if (ret < 0) {
82         return -errno;
83     }
84     if (abi_version > VHOST_SCSI_ABI_VERSION) {
85         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
86                      " %d is greater than vhost_scsi userspace supports: %d, please"
87                      " upgrade your version of QEMU", abi_version,
88                      VHOST_SCSI_ABI_VERSION);
89         return -ENOSYS;
90     }
91 
92     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
93     if (ret < 0) {
94         return ret;
95     }
96 
97     s->dev.acked_features = vdev->guest_features;
98     ret = vhost_dev_start(&s->dev, vdev);
99     if (ret < 0) {
100         error_report("Error start vhost dev");
101         goto err_notifiers;
102     }
103 
104     ret = vhost_scsi_set_endpoint(s);
105     if (ret < 0) {
106         error_report("Error set vhost-scsi endpoint");
107         goto err_vhost_stop;
108     }
109 
110     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
111     if (ret < 0) {
112         error_report("Error binding guest notifier");
113         goto err_endpoint;
114     }
115 
116     /* guest_notifier_mask/pending not used yet, so just unmask
117      * everything here.  virtio-pci will do the right thing by
118      * enabling/disabling irqfd.
119      */
120     for (i = 0; i < s->dev.nvqs; i++) {
121         vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
122     }
123 
124     return ret;
125 
126 err_endpoint:
127     vhost_scsi_clear_endpoint(s);
128 err_vhost_stop:
129     vhost_dev_stop(&s->dev, vdev);
130 err_notifiers:
131     vhost_dev_disable_notifiers(&s->dev, vdev);
132     return ret;
133 }
134 
135 static void vhost_scsi_stop(VHostSCSI *s)
136 {
137     VirtIODevice *vdev = VIRTIO_DEVICE(s);
138     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
139     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
140     int ret = 0;
141 
142     if (k->set_guest_notifiers) {
143         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
144         if (ret < 0) {
145                 error_report("vhost guest notifier cleanup failed: %d", ret);
146         }
147     }
148     assert(ret >= 0);
149 
150     vhost_scsi_clear_endpoint(s);
151     vhost_dev_stop(&s->dev, vdev);
152     vhost_dev_disable_notifiers(&s->dev, vdev);
153 }
154 
155 static uint64_t vhost_scsi_get_features(VirtIODevice *vdev,
156                                         uint64_t features,
157                                         Error **errp)
158 {
159     VHostSCSI *s = VHOST_SCSI(vdev);
160 
161     return vhost_get_features(&s->dev, kernel_feature_bits, features);
162 }
163 
164 static void vhost_scsi_set_config(VirtIODevice *vdev,
165                                   const uint8_t *config)
166 {
167     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
168     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
169 
170     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size ||
171         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) {
172         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
173         exit(1);
174     }
175 }
176 
177 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
178 {
179     VHostSCSI *s = (VHostSCSI *)vdev;
180     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
181 
182     if (s->dev.started == start) {
183         return;
184     }
185 
186     if (start) {
187         int ret;
188 
189         ret = vhost_scsi_start(s);
190         if (ret < 0) {
191             error_report("virtio-scsi: unable to start vhost: %s",
192                          strerror(-ret));
193 
194             /* There is no userspace virtio-scsi fallback so exit */
195             exit(1);
196         }
197     } else {
198         vhost_scsi_stop(s);
199     }
200 }
201 
202 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
203 {
204 }
205 
206 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
207 {
208     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
209     VHostSCSI *s = VHOST_SCSI(dev);
210     Error *err = NULL;
211     int vhostfd = -1;
212     int ret;
213 
214     if (!vs->conf.wwpn) {
215         error_setg(errp, "vhost-scsi: missing wwpn");
216         return;
217     }
218 
219     if (vs->conf.vhostfd) {
220         vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, &err);
221         if (vhostfd == -1) {
222             error_setg(errp, "vhost-scsi: unable to parse vhostfd: %s",
223                        error_get_pretty(err));
224             error_free(err);
225             return;
226         }
227     } else {
228         vhostfd = open("/dev/vhost-scsi", O_RDWR);
229         if (vhostfd < 0) {
230             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
231                        strerror(errno));
232             return;
233         }
234     }
235 
236     virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
237                                vhost_dummy_handle_output,
238                                vhost_dummy_handle_output);
239     if (err != NULL) {
240         error_propagate(errp, err);
241         close(vhostfd);
242         return;
243     }
244 
245     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
246     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
247     s->dev.vq_index = 0;
248     s->dev.backend_features = 0;
249 
250     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
251                          VHOST_BACKEND_TYPE_KERNEL);
252     if (ret < 0) {
253         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
254                    strerror(-ret));
255         return;
256     }
257 
258     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
259     s->channel = 0;
260     s->lun = 0;
261     /* Note: we can also get the minimum tpgt from kernel */
262     s->target = vs->conf.boot_tpgt;
263 
264     error_setg(&s->migration_blocker,
265             "vhost-scsi does not support migration");
266     migrate_add_blocker(s->migration_blocker);
267 }
268 
269 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
270 {
271     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
272     VHostSCSI *s = VHOST_SCSI(dev);
273 
274     migrate_del_blocker(s->migration_blocker);
275     error_free(s->migration_blocker);
276 
277     /* This will stop vhost backend. */
278     vhost_scsi_set_status(vdev, 0);
279 
280     vhost_dev_cleanup(&s->dev);
281     g_free(s->dev.vqs);
282 
283     virtio_scsi_common_unrealize(dev, errp);
284 }
285 
286 /*
287  * Implementation of an interface to adjust firmware path
288  * for the bootindex property handling.
289  */
290 static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus,
291                                         DeviceState *dev)
292 {
293     VHostSCSI *s = VHOST_SCSI(dev);
294     /* format: channel@channel/vhost-scsi@target,lun */
295     return g_strdup_printf("channel@%x/%s@%x,%x", s->channel,
296                            qdev_fw_name(dev), s->target, s->lun);
297 }
298 
299 static Property vhost_scsi_properties[] = {
300     DEFINE_PROP_STRING("vhostfd", VHostSCSI, parent_obj.conf.vhostfd),
301     DEFINE_PROP_STRING("wwpn", VHostSCSI, parent_obj.conf.wwpn),
302     DEFINE_PROP_UINT32("boot_tpgt", VHostSCSI, parent_obj.conf.boot_tpgt, 0),
303     DEFINE_PROP_UINT32("num_queues", VHostSCSI, parent_obj.conf.num_queues, 1),
304     DEFINE_PROP_UINT32("max_sectors", VHostSCSI, parent_obj.conf.max_sectors,
305                                                  0xFFFF),
306     DEFINE_PROP_UINT32("cmd_per_lun", VHostSCSI, parent_obj.conf.cmd_per_lun,
307                                                  128),
308     DEFINE_PROP_END_OF_LIST(),
309 };
310 
311 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
312 {
313     DeviceClass *dc = DEVICE_CLASS(klass);
314     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
315     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
316 
317     dc->props = vhost_scsi_properties;
318     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
319     vdc->realize = vhost_scsi_realize;
320     vdc->unrealize = vhost_scsi_unrealize;
321     vdc->get_features = vhost_scsi_get_features;
322     vdc->set_config = vhost_scsi_set_config;
323     vdc->set_status = vhost_scsi_set_status;
324     fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
325 }
326 
327 static void vhost_scsi_instance_init(Object *obj)
328 {
329     VHostSCSI *dev = VHOST_SCSI(obj);
330 
331     device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
332                                   DEVICE(dev), NULL);
333 }
334 
335 static const TypeInfo vhost_scsi_info = {
336     .name = TYPE_VHOST_SCSI,
337     .parent = TYPE_VIRTIO_SCSI_COMMON,
338     .instance_size = sizeof(VHostSCSI),
339     .class_init = vhost_scsi_class_init,
340     .instance_init = vhost_scsi_instance_init,
341     .interfaces = (InterfaceInfo[]) {
342         { TYPE_FW_PATH_PROVIDER },
343         { }
344     },
345 };
346 
347 static void virtio_register_types(void)
348 {
349     type_register_static(&vhost_scsi_info);
350 }
351 
352 type_init(virtio_register_types)
353