xref: /openbmc/qemu/hw/scsi/vhost-scsi.c (revision 327d4b7f)
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. */
36 static 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 
44 static 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 
61 static 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 
73 static 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 
105 static 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 
113 static 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 
140 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
141 {
142 }
143 
144 static 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 
155 static 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 
166 static 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(monitor_cur(), 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         if (migrate_add_blocker(vsc->migration_blocker, errp) < 0) {
211             error_free(vsc->migration_blocker);
212             goto free_virtio;
213         }
214     }
215 
216     vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
217     vsc->dev.vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
218     vsc->dev.vq_index = 0;
219     vsc->dev.backend_features = 0;
220 
221     ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
222                          VHOST_BACKEND_TYPE_KERNEL, 0, errp);
223     if (ret < 0) {
224         goto free_vqs;
225     }
226 
227     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
228     vsc->channel = 0;
229     vsc->lun = 0;
230     /* Note: we can also get the minimum tpgt from kernel */
231     vsc->target = vs->conf.boot_tpgt;
232 
233     return;
234 
235  free_vqs:
236     if (!vsc->migratable) {
237         migrate_del_blocker(vsc->migration_blocker);
238     }
239     g_free(vsc->dev.vqs);
240  free_virtio:
241     virtio_scsi_common_unrealize(dev);
242  close_fd:
243     close(vhostfd);
244     return;
245 }
246 
247 static void vhost_scsi_unrealize(DeviceState *dev)
248 {
249     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
250     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
251     struct vhost_virtqueue *vqs = vsc->dev.vqs;
252 
253     if (!vsc->migratable) {
254         migrate_del_blocker(vsc->migration_blocker);
255         error_free(vsc->migration_blocker);
256     }
257 
258     /* This will stop vhost backend. */
259     vhost_scsi_set_status(vdev, 0);
260 
261     vhost_dev_cleanup(&vsc->dev);
262     g_free(vqs);
263 
264     virtio_scsi_common_unrealize(dev);
265 }
266 
267 static Property vhost_scsi_properties[] = {
268     DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
269     DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
270     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
271     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
272                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
273     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
274                        128),
275     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust,
276                       true),
277     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
278                        0xFFFF),
279     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
280     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
281                                                  VIRTIO_SCSI_F_T10_PI,
282                                                  false),
283     DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
284     DEFINE_PROP_END_OF_LIST(),
285 };
286 
287 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
288 {
289     DeviceClass *dc = DEVICE_CLASS(klass);
290     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
291     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
292 
293     device_class_set_props(dc, vhost_scsi_properties);
294     dc->vmsd = &vmstate_virtio_vhost_scsi;
295     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
296     vdc->realize = vhost_scsi_realize;
297     vdc->unrealize = vhost_scsi_unrealize;
298     vdc->get_features = vhost_scsi_common_get_features;
299     vdc->set_config = vhost_scsi_common_set_config;
300     vdc->set_status = vhost_scsi_set_status;
301     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
302 }
303 
304 static void vhost_scsi_instance_init(Object *obj)
305 {
306     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
307 
308     vsc->feature_bits = kernel_feature_bits;
309 
310     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
311                                   DEVICE(vsc));
312 }
313 
314 static const TypeInfo vhost_scsi_info = {
315     .name = TYPE_VHOST_SCSI,
316     .parent = TYPE_VHOST_SCSI_COMMON,
317     .instance_size = sizeof(VHostSCSI),
318     .class_init = vhost_scsi_class_init,
319     .instance_init = vhost_scsi_instance_init,
320     .interfaces = (InterfaceInfo[]) {
321         { TYPE_FW_PATH_PROVIDER },
322         { }
323     },
324 };
325 
326 static void virtio_register_types(void)
327 {
328     type_register_static(&vhost_scsi_info);
329 }
330 
331 type_init(virtio_register_types)
332