xref: /openbmc/qemu/hw/scsi/vhost-scsi.c (revision fe44dc91) 
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 <linux/vhost.h>
19 #include <sys/ioctl.h>
20 #include "qapi/error.h"
21 #include "qemu/error-report.h"
22 #include "qemu/queue.h"
23 #include "monitor/monitor.h"
24 #include "migration/migration.h"
25 #include "hw/virtio/vhost-scsi.h"
26 #include "hw/virtio/vhost.h"
27 #include "hw/virtio/virtio-scsi.h"
28 #include "hw/virtio/virtio-bus.h"
29 #include "hw/virtio/virtio-access.h"
30 #include "hw/fw-path-provider.h"
31 #include "qemu/cutils.h"
32 
33 /* Features supported by host kernel. */
34 static const int kernel_feature_bits[] = {
35     VIRTIO_F_NOTIFY_ON_EMPTY,
36     VIRTIO_RING_F_INDIRECT_DESC,
37     VIRTIO_RING_F_EVENT_IDX,
38     VIRTIO_SCSI_F_HOTPLUG,
39     VHOST_INVALID_FEATURE_BIT
40 };
41 
42 static int vhost_scsi_set_endpoint(VHostSCSI *s)
43 {
44     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
45     const VhostOps *vhost_ops = s->dev.vhost_ops;
46     struct vhost_scsi_target backend;
47     int ret;
48 
49     memset(&backend, 0, sizeof(backend));
50     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
51     ret = vhost_ops->vhost_scsi_set_endpoint(&s->dev, &backend);
52     if (ret < 0) {
53         return -errno;
54     }
55     return 0;
56 }
57 
58 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
59 {
60     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
61     struct vhost_scsi_target backend;
62     const VhostOps *vhost_ops = s->dev.vhost_ops;
63 
64     memset(&backend, 0, sizeof(backend));
65     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
66     vhost_ops->vhost_scsi_clear_endpoint(&s->dev, &backend);
67 }
68 
69 static int vhost_scsi_start(VHostSCSI *s)
70 {
71     int ret, abi_version, i;
72     VirtIODevice *vdev = VIRTIO_DEVICE(s);
73     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
74     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
75     const VhostOps *vhost_ops = s->dev.vhost_ops;
76 
77     if (!k->set_guest_notifiers) {
78         error_report("binding does not support guest notifiers");
79         return -ENOSYS;
80     }
81 
82     ret = vhost_ops->vhost_scsi_get_abi_version(&s->dev, &abi_version);
83     if (ret < 0) {
84         return -errno;
85     }
86     if (abi_version > VHOST_SCSI_ABI_VERSION) {
87         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
88                      " %d is greater than vhost_scsi userspace supports: %d, please"
89                      " upgrade your version of QEMU", abi_version,
90                      VHOST_SCSI_ABI_VERSION);
91         return -ENOSYS;
92     }
93 
94     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
95     if (ret < 0) {
96         return ret;
97     }
98 
99     s->dev.acked_features = vdev->guest_features;
100     ret = vhost_dev_start(&s->dev, vdev);
101     if (ret < 0) {
102         error_report("Error start vhost dev");
103         goto err_notifiers;
104     }
105 
106     ret = vhost_scsi_set_endpoint(s);
107     if (ret < 0) {
108         error_report("Error set vhost-scsi endpoint");
109         goto err_vhost_stop;
110     }
111 
112     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
113     if (ret < 0) {
114         error_report("Error binding guest notifier");
115         goto err_endpoint;
116     }
117 
118     /* guest_notifier_mask/pending not used yet, so just unmask
119      * everything here.  virtio-pci will do the right thing by
120      * enabling/disabling irqfd.
121      */
122     for (i = 0; i < s->dev.nvqs; i++) {
123         vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
124     }
125 
126     return ret;
127 
128 err_endpoint:
129     vhost_scsi_clear_endpoint(s);
130 err_vhost_stop:
131     vhost_dev_stop(&s->dev, vdev);
132 err_notifiers:
133     vhost_dev_disable_notifiers(&s->dev, vdev);
134     return ret;
135 }
136 
137 static void vhost_scsi_stop(VHostSCSI *s)
138 {
139     VirtIODevice *vdev = VIRTIO_DEVICE(s);
140     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
141     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
142     int ret = 0;
143 
144     if (k->set_guest_notifiers) {
145         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
146         if (ret < 0) {
147                 error_report("vhost guest notifier cleanup failed: %d", ret);
148         }
149     }
150     assert(ret >= 0);
151 
152     vhost_scsi_clear_endpoint(s);
153     vhost_dev_stop(&s->dev, vdev);
154     vhost_dev_disable_notifiers(&s->dev, vdev);
155 }
156 
157 static uint64_t vhost_scsi_get_features(VirtIODevice *vdev,
158                                         uint64_t features,
159                                         Error **errp)
160 {
161     VHostSCSI *s = VHOST_SCSI(vdev);
162 
163     return vhost_get_features(&s->dev, kernel_feature_bits, features);
164 }
165 
166 static void vhost_scsi_set_config(VirtIODevice *vdev,
167                                   const uint8_t *config)
168 {
169     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
170     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
171 
172     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size ||
173         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) {
174         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
175         exit(1);
176     }
177 }
178 
179 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
180 {
181     VHostSCSI *s = (VHostSCSI *)vdev;
182     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
183 
184     if (s->dev.started == start) {
185         return;
186     }
187 
188     if (start) {
189         int ret;
190 
191         ret = vhost_scsi_start(s);
192         if (ret < 0) {
193             error_report("virtio-scsi: unable to start vhost: %s",
194                          strerror(-ret));
195 
196             /* There is no userspace virtio-scsi fallback so exit */
197             exit(1);
198         }
199     } else {
200         vhost_scsi_stop(s);
201     }
202 }
203 
204 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
205 {
206 }
207 
208 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
209 {
210     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
211     VHostSCSI *s = VHOST_SCSI(dev);
212     Error *err = NULL;
213     int vhostfd = -1;
214     int ret;
215 
216     if (!vs->conf.wwpn) {
217         error_setg(errp, "vhost-scsi: missing wwpn");
218         return;
219     }
220 
221     if (vs->conf.vhostfd) {
222         vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, errp);
223         if (vhostfd == -1) {
224             error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
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         goto close_fd;
242     }
243 
244     error_setg(&s->migration_blocker,
245                "vhost-scsi does not support migration");
246     migrate_add_blocker(s->migration_blocker, &err);
247     if (err) {
248         error_propagate(errp, err);
249         error_free(s->migration_blocker);
250         goto close_fd;
251     }
252 
253     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
254     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
255     s->dev.vq_index = 0;
256     s->dev.backend_features = 0;
257 
258     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
259                          VHOST_BACKEND_TYPE_KERNEL, 0);
260     if (ret < 0) {
261         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
262                    strerror(-ret));
263         goto free_vqs;
264     }
265 
266     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
267     s->channel = 0;
268     s->lun = 0;
269     /* Note: we can also get the minimum tpgt from kernel */
270     s->target = vs->conf.boot_tpgt;
271 
272     return;
273 
274  free_vqs:
275     migrate_del_blocker(s->migration_blocker);
276     g_free(s->dev.vqs);
277  close_fd:
278     close(vhostfd);
279     return;
280 }
281 
282 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
283 {
284     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
285     VHostSCSI *s = VHOST_SCSI(dev);
286 
287     migrate_del_blocker(s->migration_blocker);
288     error_free(s->migration_blocker);
289 
290     /* This will stop vhost backend. */
291     vhost_scsi_set_status(vdev, 0);
292 
293     vhost_dev_cleanup(&s->dev);
294     g_free(s->dev.vqs);
295 
296     virtio_scsi_common_unrealize(dev, errp);
297 }
298 
299 /*
300  * Implementation of an interface to adjust firmware path
301  * for the bootindex property handling.
302  */
303 static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus,
304                                         DeviceState *dev)
305 {
306     VHostSCSI *s = VHOST_SCSI(dev);
307     /* format: channel@channel/vhost-scsi@target,lun */
308     return g_strdup_printf("/channel@%x/%s@%x,%x", s->channel,
309                            qdev_fw_name(dev), s->target, s->lun);
310 }
311 
312 static Property vhost_scsi_properties[] = {
313     DEFINE_PROP_STRING("vhostfd", VHostSCSI, parent_obj.conf.vhostfd),
314     DEFINE_PROP_STRING("wwpn", VHostSCSI, parent_obj.conf.wwpn),
315     DEFINE_PROP_UINT32("boot_tpgt", VHostSCSI, parent_obj.conf.boot_tpgt, 0),
316     DEFINE_PROP_UINT32("num_queues", VHostSCSI, parent_obj.conf.num_queues, 1),
317     DEFINE_PROP_UINT32("max_sectors", VHostSCSI, parent_obj.conf.max_sectors,
318                                                  0xFFFF),
319     DEFINE_PROP_UINT32("cmd_per_lun", VHostSCSI, parent_obj.conf.cmd_per_lun,
320                                                  128),
321     DEFINE_PROP_END_OF_LIST(),
322 };
323 
324 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
325 {
326     DeviceClass *dc = DEVICE_CLASS(klass);
327     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
328     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
329 
330     dc->props = vhost_scsi_properties;
331     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
332     vdc->realize = vhost_scsi_realize;
333     vdc->unrealize = vhost_scsi_unrealize;
334     vdc->get_features = vhost_scsi_get_features;
335     vdc->set_config = vhost_scsi_set_config;
336     vdc->set_status = vhost_scsi_set_status;
337     fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
338 }
339 
340 static void vhost_scsi_instance_init(Object *obj)
341 {
342     VHostSCSI *dev = VHOST_SCSI(obj);
343 
344     device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
345                                   DEVICE(dev), NULL);
346 }
347 
348 static const TypeInfo vhost_scsi_info = {
349     .name = TYPE_VHOST_SCSI,
350     .parent = TYPE_VIRTIO_SCSI_COMMON,
351     .instance_size = sizeof(VHostSCSI),
352     .class_init = vhost_scsi_class_init,
353     .instance_init = vhost_scsi_instance_init,
354     .interfaces = (InterfaceInfo[]) {
355         { TYPE_FW_PATH_PROVIDER },
356         { }
357     },
358 };
359 
360 static void virtio_register_types(void)
361 {
362     type_register_static(&vhost_scsi_info);
363 }
364 
365 type_init(virtio_register_types)
366