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/module.h"
23#include "monitor/monitor.h"
24#include "migration/blocker.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 "hw/qdev-properties.h"
32#include "qemu/cutils.h"
33#include "sysemu/sysemu.h"
34
35/* Features supported by host kernel. */
36static const int kernel_feature_bits[] = {
37 VIRTIO_F_NOTIFY_ON_EMPTY,
38 VIRTIO_RING_F_INDIRECT_DESC,
39 VIRTIO_RING_F_EVENT_IDX,
40 VIRTIO_SCSI_F_HOTPLUG,
41 VHOST_INVALID_FEATURE_BIT
42};
43
44static int vhost_scsi_set_endpoint(VHostSCSI *s)
45{
46 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
47 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
48 const VhostOps *vhost_ops = vsc->dev.vhost_ops;
49 struct vhost_scsi_target backend;
50 int ret;
51
52 memset(&backend, 0, sizeof(backend));
53 pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
54 ret = vhost_ops->vhost_scsi_set_endpoint(&vsc->dev, &backend);
55 if (ret < 0) {
56 return -errno;
57 }
58 return 0;
59}
60
61static void vhost_scsi_clear_endpoint(VHostSCSI *s)
62{
63 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
64 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
65 struct vhost_scsi_target backend;
66 const VhostOps *vhost_ops = vsc->dev.vhost_ops;
67
68 memset(&backend, 0, sizeof(backend));
69 pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
70 vhost_ops->vhost_scsi_clear_endpoint(&vsc->dev, &backend);
71}
72
73static int vhost_scsi_start(VHostSCSI *s)
74{
75 int ret, abi_version;
76 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
77 const VhostOps *vhost_ops = vsc->dev.vhost_ops;
78
79 ret = vhost_ops->vhost_scsi_get_abi_version(&vsc->dev, &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,"
86 " please upgrade your version of QEMU", abi_version,
87 VHOST_SCSI_ABI_VERSION);
88 return -ENOSYS;
89 }
90
91 ret = vhost_scsi_common_start(vsc);
92 if (ret < 0) {
93 return ret;
94 }
95
96 ret = vhost_scsi_set_endpoint(s);
97 if (ret < 0) {
98 error_report("Error setting vhost-scsi endpoint");
99 vhost_scsi_common_stop(vsc);
100 }
101
102 return ret;
103}
104
105static void vhost_scsi_stop(VHostSCSI *s)
106{
107 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
108
109 vhost_scsi_clear_endpoint(s);
110 vhost_scsi_common_stop(vsc);
111}
112
113static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
114{
115 VHostSCSI *s = VHOST_SCSI(vdev);
116 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
117 bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
118
119 if (!vdev->vm_running) {
120 start = false;
121 }
122
123 if (vsc->dev.started == start) {
124 return;
125 }
126
127 if (start) {
128 int ret;
129
130 ret = vhost_scsi_start(s);
131 if (ret < 0) {
132 error_report("unable to start vhost-scsi: %s", strerror(-ret));
133 exit(1);
134 }
135 } else {
136 vhost_scsi_stop(s);
137 }
138}
139
140static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
141{
142}
143
144static int vhost_scsi_pre_save(void *opaque)
145{
146 VHostSCSICommon *vsc = opaque;
147
148 /* At this point, backend must be stopped, otherwise
149 * it might keep writing to memory. */
150 assert(!vsc->dev.started);
151
152 return 0;
153}
154
155static const VMStateDescription vmstate_virtio_vhost_scsi = {
156 .name = "virtio-vhost_scsi",
157 .minimum_version_id = 1,
158 .version_id = 1,
159 .fields = (VMStateField[]) {
160 VMSTATE_VIRTIO_DEVICE,
161 VMSTATE_END_OF_LIST()
162 },
163 .pre_save = vhost_scsi_pre_save,
164};
165
166static void vhost_scsi_realize(DeviceState *dev, Error **errp)
167{
168 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
169 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
170 Error *err = NULL;
171 int vhostfd = -1;
172 int ret;
173
174 if (!vs->conf.wwpn) {
175 error_setg(errp, "vhost-scsi: missing wwpn");
176 return;
177 }
178
179 if (vs->conf.vhostfd) {
180 vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, errp);
181 if (vhostfd == -1) {
182 error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
183 return;
184 }
185 } else {
186 vhostfd = open("/dev/vhost-scsi", O_RDWR);
187 if (vhostfd < 0) {
188 error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
189 strerror(errno));
190 return;
191 }
192 }
193
194 virtio_scsi_common_realize(dev,
195 vhost_dummy_handle_output,
196 vhost_dummy_handle_output,
197 vhost_dummy_handle_output,
198 &err);
199 if (err != NULL) {
200 error_propagate(errp, err);
201 goto close_fd;
202 }
203
204 if (!vsc->migratable) {
205 error_setg(&vsc->migration_blocker,
206 "vhost-scsi does not support migration in all cases. "
207 "When external environment supports it (Orchestrator migrates "
208 "target SCSI device state or use shared storage over network), "
209 "set 'migratable' property to true to enable migration.");
210 migrate_add_blocker(vsc->migration_blocker, &err);
211 if (err) {
212 error_propagate(errp, err);
213 error_free(vsc->migration_blocker);
214 goto free_virtio;
215 }
216 }
217
218 vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
219 vsc->dev.vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
220 vsc->dev.vq_index = 0;
221 vsc->dev.backend_features = 0;
222
223 ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
224 VHOST_BACKEND_TYPE_KERNEL, 0);
225 if (ret < 0) {
226 error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
227 strerror(-ret));
228 goto free_vqs;
229 }
230
231 /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
232 vsc->channel = 0;
233 vsc->lun = 0;
234 /* Note: we can also get the minimum tpgt from kernel */
235 vsc->target = vs->conf.boot_tpgt;
236
237 return;
238
239 free_vqs:
240 if (!vsc->migratable) {
241 migrate_del_blocker(vsc->migration_blocker);
242 }
243 g_free(vsc->dev.vqs);
244 free_virtio:
245 virtio_scsi_common_unrealize(dev);
246 close_fd:
247 close(vhostfd);
248 return;
249}
250
251static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
252{
253 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
254 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
255 struct vhost_virtqueue *vqs = vsc->dev.vqs;
256
257 if (!vsc->migratable) {
258 migrate_del_blocker(vsc->migration_blocker);
259 error_free(vsc->migration_blocker);
260 }
261
262 /* This will stop vhost backend. */
263 vhost_scsi_set_status(vdev, 0);
264
265 vhost_dev_cleanup(&vsc->dev);
266 g_free(vqs);
267
268 virtio_scsi_common_unrealize(dev);
269}
270
271static Property vhost_scsi_properties[] = {
272 DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
273 DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
274 DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
275 DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1),
276 DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
277 128),
278 DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
279 0xFFFF),
280 DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
281 DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
282 VIRTIO_SCSI_F_T10_PI,
283 false),
284 DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
285 DEFINE_PROP_END_OF_LIST(),
286};
287
288static void vhost_scsi_class_init(ObjectClass *klass, void *data)
289{
290 DeviceClass *dc = DEVICE_CLASS(klass);
291 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
292 FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
293
294 dc->props = vhost_scsi_properties;
295 dc->vmsd = &vmstate_virtio_vhost_scsi;
296 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
297 vdc->realize = vhost_scsi_realize;
298 vdc->unrealize = vhost_scsi_unrealize;
299 vdc->get_features = vhost_scsi_common_get_features;
300 vdc->set_config = vhost_scsi_common_set_config;
301 vdc->set_status = vhost_scsi_set_status;
302 fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
303}
304
305static void vhost_scsi_instance_init(Object *obj)
306{
307 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
308
309 vsc->feature_bits = kernel_feature_bits;
310
311 device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
312 DEVICE(vsc), NULL);
313}
314
315static const TypeInfo vhost_scsi_info = {
316 .name = TYPE_VHOST_SCSI,
317 .parent = TYPE_VHOST_SCSI_COMMON,
318 .instance_size = sizeof(VHostSCSI),
319 .class_init = vhost_scsi_class_init,
320 .instance_init = vhost_scsi_instance_init,
321 .interfaces = (InterfaceInfo[]) {
322 { TYPE_FW_PATH_PROVIDER },
323 { }
324 },
325};
326
327static void virtio_register_types(void)
328{
329 type_register_static(&vhost_scsi_info);
330}
331
332type_init(virtio_register_types)
333