xref: /openbmc/qemu/hw/scsi/vhost-scsi.c (revision 7183128b) 
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 #include "linux/vhost.h"
30 
31 /* Features supported by host kernel. */
32 static const int kernel_feature_bits[] = {
33     VIRTIO_F_NOTIFY_ON_EMPTY,
34     VIRTIO_RING_F_INDIRECT_DESC,
35     VIRTIO_RING_F_EVENT_IDX,
36     VIRTIO_SCSI_F_HOTPLUG,
37     VHOST_INVALID_FEATURE_BIT
38 };
39 
40 static int vhost_scsi_set_endpoint(VHostSCSI *s)
41 {
42     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
43     const VhostOps *vhost_ops = s->dev.vhost_ops;
44     struct vhost_scsi_target backend;
45     int ret;
46 
47     memset(&backend, 0, sizeof(backend));
48     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
49     ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
50     if (ret < 0) {
51         return -errno;
52     }
53     return 0;
54 }
55 
56 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
57 {
58     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
59     struct vhost_scsi_target backend;
60     const VhostOps *vhost_ops = s->dev.vhost_ops;
61 
62     memset(&backend, 0, sizeof(backend));
63     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
64     vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
65 }
66 
67 static int vhost_scsi_start(VHostSCSI *s)
68 {
69     int ret, abi_version, i;
70     VirtIODevice *vdev = VIRTIO_DEVICE(s);
71     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
72     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
73     const VhostOps *vhost_ops = s->dev.vhost_ops;
74 
75     if (!k->set_guest_notifiers) {
76         error_report("binding does not support guest notifiers");
77         return -ENOSYS;
78     }
79 
80     ret = vhost_ops->vhost_call(&s->dev,
81                                 VHOST_SCSI_GET_ABI_VERSION, &abi_version);
82     if (ret < 0) {
83         return -errno;
84     }
85     if (abi_version > VHOST_SCSI_ABI_VERSION) {
86         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
87                      " %d is greater than vhost_scsi userspace supports: %d, please"
88                      " upgrade your version of QEMU", abi_version,
89                      VHOST_SCSI_ABI_VERSION);
90         return -ENOSYS;
91     }
92 
93     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
94     if (ret < 0) {
95         return ret;
96     }
97 
98     s->dev.acked_features = vdev->guest_features;
99     ret = vhost_dev_start(&s->dev, vdev);
100     if (ret < 0) {
101         error_report("Error start vhost dev");
102         goto err_notifiers;
103     }
104 
105     ret = vhost_scsi_set_endpoint(s);
106     if (ret < 0) {
107         error_report("Error set vhost-scsi endpoint");
108         goto err_vhost_stop;
109     }
110 
111     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
112     if (ret < 0) {
113         error_report("Error binding guest notifier");
114         goto err_endpoint;
115     }
116 
117     /* guest_notifier_mask/pending not used yet, so just unmask
118      * everything here.  virtio-pci will do the right thing by
119      * enabling/disabling irqfd.
120      */
121     for (i = 0; i < s->dev.nvqs; i++) {
122         vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
123     }
124 
125     return ret;
126 
127 err_endpoint:
128     vhost_scsi_clear_endpoint(s);
129 err_vhost_stop:
130     vhost_dev_stop(&s->dev, vdev);
131 err_notifiers:
132     vhost_dev_disable_notifiers(&s->dev, vdev);
133     return ret;
134 }
135 
136 static void vhost_scsi_stop(VHostSCSI *s)
137 {
138     VirtIODevice *vdev = VIRTIO_DEVICE(s);
139     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
140     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
141     int ret = 0;
142 
143     if (k->set_guest_notifiers) {
144         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
145         if (ret < 0) {
146                 error_report("vhost guest notifier cleanup failed: %d", ret);
147         }
148     }
149     assert(ret >= 0);
150 
151     vhost_scsi_clear_endpoint(s);
152     vhost_dev_stop(&s->dev, vdev);
153     vhost_dev_disable_notifiers(&s->dev, vdev);
154 }
155 
156 static uint64_t vhost_scsi_get_features(VirtIODevice *vdev,
157                                         uint64_t features,
158                                         Error **errp)
159 {
160     VHostSCSI *s = VHOST_SCSI(vdev);
161 
162     return vhost_get_features(&s->dev, kernel_feature_bits, features);
163 }
164 
165 static void vhost_scsi_set_config(VirtIODevice *vdev,
166                                   const uint8_t *config)
167 {
168     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
169     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
170 
171     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size ||
172         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) {
173         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
174         exit(1);
175     }
176 }
177 
178 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
179 {
180     VHostSCSI *s = (VHostSCSI *)vdev;
181     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
182 
183     if (s->dev.started == start) {
184         return;
185     }
186 
187     if (start) {
188         int ret;
189 
190         ret = vhost_scsi_start(s);
191         if (ret < 0) {
192             error_report("virtio-scsi: unable to start vhost: %s",
193                          strerror(-ret));
194 
195             /* There is no userspace virtio-scsi fallback so exit */
196             exit(1);
197         }
198     } else {
199         vhost_scsi_stop(s);
200     }
201 }
202 
203 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
204 {
205 }
206 
207 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
208 {
209     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
210     VHostSCSI *s = VHOST_SCSI(dev);
211     Error *err = NULL;
212     int vhostfd = -1;
213     int ret;
214 
215     if (!vs->conf.wwpn) {
216         error_setg(errp, "vhost-scsi: missing wwpn");
217         return;
218     }
219 
220     if (vs->conf.vhostfd) {
221         vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, &err);
222         if (vhostfd == -1) {
223             error_setg(errp, "vhost-scsi: unable to parse vhostfd: %s",
224                        error_get_pretty(err));
225             error_free(err);
226             return;
227         }
228     } else {
229         vhostfd = open("/dev/vhost-scsi", O_RDWR);
230         if (vhostfd < 0) {
231             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
232                        strerror(errno));
233             return;
234         }
235     }
236 
237     virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
238                                vhost_dummy_handle_output,
239                                vhost_dummy_handle_output);
240     if (err != NULL) {
241         error_propagate(errp, err);
242         close(vhostfd);
243         return;
244     }
245 
246     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
247     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
248     s->dev.vq_index = 0;
249     s->dev.backend_features = 0;
250 
251     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
252                          VHOST_BACKEND_TYPE_KERNEL);
253     if (ret < 0) {
254         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
255                    strerror(-ret));
256         return;
257     }
258 
259     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
260     s->channel = 0;
261     s->lun = 0;
262     /* Note: we can also get the minimum tpgt from kernel */
263     s->target = vs->conf.boot_tpgt;
264 
265     error_setg(&s->migration_blocker,
266             "vhost-scsi does not support migration");
267     migrate_add_blocker(s->migration_blocker);
268 }
269 
270 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
271 {
272     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
273     VHostSCSI *s = VHOST_SCSI(dev);
274 
275     migrate_del_blocker(s->migration_blocker);
276     error_free(s->migration_blocker);
277 
278     /* This will stop vhost backend. */
279     vhost_scsi_set_status(vdev, 0);
280 
281     vhost_dev_cleanup(&s->dev);
282     g_free(s->dev.vqs);
283 
284     virtio_scsi_common_unrealize(dev, errp);
285 }
286 
287 /*
288  * Implementation of an interface to adjust firmware path
289  * for the bootindex property handling.
290  */
291 static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus,
292                                         DeviceState *dev)
293 {
294     VHostSCSI *s = VHOST_SCSI(dev);
295     /* format: channel@channel/vhost-scsi@target,lun */
296     return g_strdup_printf("/channel@%x/%s@%x,%x", s->channel,
297                            qdev_fw_name(dev), s->target, s->lun);
298 }
299 
300 static Property vhost_scsi_properties[] = {
301     DEFINE_PROP_STRING("vhostfd", VHostSCSI, parent_obj.conf.vhostfd),
302     DEFINE_PROP_STRING("wwpn", VHostSCSI, parent_obj.conf.wwpn),
303     DEFINE_PROP_UINT32("boot_tpgt", VHostSCSI, parent_obj.conf.boot_tpgt, 0),
304     DEFINE_PROP_UINT32("num_queues", VHostSCSI, parent_obj.conf.num_queues, 1),
305     DEFINE_PROP_UINT32("max_sectors", VHostSCSI, parent_obj.conf.max_sectors,
306                                                  0xFFFF),
307     DEFINE_PROP_UINT32("cmd_per_lun", VHostSCSI, parent_obj.conf.cmd_per_lun,
308                                                  128),
309     DEFINE_PROP_END_OF_LIST(),
310 };
311 
312 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
313 {
314     DeviceClass *dc = DEVICE_CLASS(klass);
315     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
316     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
317 
318     dc->props = vhost_scsi_properties;
319     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
320     vdc->realize = vhost_scsi_realize;
321     vdc->unrealize = vhost_scsi_unrealize;
322     vdc->get_features = vhost_scsi_get_features;
323     vdc->set_config = vhost_scsi_set_config;
324     vdc->set_status = vhost_scsi_set_status;
325     fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
326 }
327 
328 static void vhost_scsi_instance_init(Object *obj)
329 {
330     VHostSCSI *dev = VHOST_SCSI(obj);
331 
332     device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
333                                   DEVICE(dev), NULL);
334 }
335 
336 static const TypeInfo vhost_scsi_info = {
337     .name = TYPE_VHOST_SCSI,
338     .parent = TYPE_VIRTIO_SCSI_COMMON,
339     .instance_size = sizeof(VHostSCSI),
340     .class_init = vhost_scsi_class_init,
341     .instance_init = vhost_scsi_instance_init,
342     .interfaces = (InterfaceInfo[]) {
343         { TYPE_FW_PATH_PROVIDER },
344         { }
345     },
346 };
347 
348 static void virtio_register_types(void)
349 {
350     type_register_static(&vhost_scsi_info);
351 }
352 
353 type_init(virtio_register_types)
354