xref: /qemu/hw/scsi/vhost-scsi.c (revision f2ad72b3) 
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 "qemu/osdep.h"
18 #include <sys/ioctl.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_scsi_set_endpoint(&s->dev, &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_scsi_clear_endpoint(&s->dev, &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_scsi_get_abi_version(&s->dev, &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, errp);
221         if (vhostfd == -1) {
222             error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
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);
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     vhost_dev_cleanup(&s->dev);
279     g_free(s->dev.vqs);
280 
281     virtio_scsi_common_unrealize(dev, errp);
282 }
283 
284 /*
285  * Implementation of an interface to adjust firmware path
286  * for the bootindex property handling.
287  */
288 static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus,
289                                         DeviceState *dev)
290 {
291     VHostSCSI *s = VHOST_SCSI(dev);
292     /* format: channel@channel/vhost-scsi@target,lun */
293     return g_strdup_printf("/channel@%x/%s@%x,%x", s->channel,
294                            qdev_fw_name(dev), s->target, s->lun);
295 }
296 
297 static Property vhost_scsi_properties[] = {
298     DEFINE_PROP_STRING("vhostfd", VHostSCSI, parent_obj.conf.vhostfd),
299     DEFINE_PROP_STRING("wwpn", VHostSCSI, parent_obj.conf.wwpn),
300     DEFINE_PROP_UINT32("boot_tpgt", VHostSCSI, parent_obj.conf.boot_tpgt, 0),
301     DEFINE_PROP_UINT32("num_queues", VHostSCSI, parent_obj.conf.num_queues, 1),
302     DEFINE_PROP_UINT32("max_sectors", VHostSCSI, parent_obj.conf.max_sectors,
303                                                  0xFFFF),
304     DEFINE_PROP_UINT32("cmd_per_lun", VHostSCSI, parent_obj.conf.cmd_per_lun,
305                                                  128),
306     DEFINE_PROP_END_OF_LIST(),
307 };
308 
309 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
310 {
311     DeviceClass *dc = DEVICE_CLASS(klass);
312     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
313     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
314 
315     dc->props = vhost_scsi_properties;
316     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
317     vdc->realize = vhost_scsi_realize;
318     vdc->unrealize = vhost_scsi_unrealize;
319     vdc->get_features = vhost_scsi_get_features;
320     vdc->set_config = vhost_scsi_set_config;
321     vdc->set_status = vhost_scsi_set_status;
322     fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
323 }
324 
325 static void vhost_scsi_instance_init(Object *obj)
326 {
327     VHostSCSI *dev = VHOST_SCSI(obj);
328 
329     device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
330                                   DEVICE(dev), NULL);
331 }
332 
333 static const TypeInfo vhost_scsi_info = {
334     .name = TYPE_VHOST_SCSI,
335     .parent = TYPE_VIRTIO_SCSI_COMMON,
336     .instance_size = sizeof(VHostSCSI),
337     .class_init = vhost_scsi_class_init,
338     .instance_init = vhost_scsi_instance_init,
339     .interfaces = (InterfaceInfo[]) {
340         { TYPE_FW_PATH_PROVIDER },
341         { }
342     },
343 };
344 
345 static void virtio_register_types(void)
346 {
347     type_register_static(&vhost_scsi_info);
348 }
349 
350 type_init(virtio_register_types)
351