1 /*
2  * vhost-user-scsi host device
3  *
4  * Copyright (c) 2016 Nutanix Inc. All rights reserved.
5  *
6  * Author:
7  *  Felipe Franciosi <felipe@nutanix.com>
8  *
9  * This work is largely based on the "vhost-scsi" implementation by:
10  *  Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
11  *  Nicholas Bellinger <nab@risingtidesystems.com>
12  *
13  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
14  * See the COPYING.LIB file in the top-level directory.
15  *
16  */
17 
18 #include "qemu/osdep.h"
19 #include "qapi/error.h"
20 #include "qemu/error-report.h"
21 #include "hw/fw-path-provider.h"
22 #include "hw/qdev-core.h"
23 #include "hw/qdev-properties.h"
24 #include "hw/qdev-properties-system.h"
25 #include "hw/virtio/vhost.h"
26 #include "hw/virtio/vhost-backend.h"
27 #include "hw/virtio/vhost-user-scsi.h"
28 #include "hw/virtio/virtio.h"
29 #include "hw/virtio/virtio-access.h"
30 #include "chardev/char-fe.h"
31 #include "sysemu/sysemu.h"
32 
33 /* Features supported by the host application */
34 static const int user_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 enum VhostUserProtocolFeature {
43     VHOST_USER_PROTOCOL_F_RESET_DEVICE = 13,
44 };
45 
vhost_user_scsi_set_status(VirtIODevice * vdev,uint8_t status)46 static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
47 {
48     VHostUserSCSI *s = (VHostUserSCSI *)vdev;
49     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
50     bool start = (status & VIRTIO_CONFIG_S_DRIVER_OK) && vdev->vm_running;
51 
52     if (vsc->dev.started == start) {
53         return;
54     }
55 
56     if (start) {
57         int ret;
58 
59         ret = vhost_scsi_common_start(vsc);
60         if (ret < 0) {
61             error_report("unable to start vhost-user-scsi: %s", strerror(-ret));
62             exit(1);
63         }
64     } else {
65         vhost_scsi_common_stop(vsc);
66     }
67 }
68 
vhost_user_scsi_reset(VirtIODevice * vdev)69 static void vhost_user_scsi_reset(VirtIODevice *vdev)
70 {
71     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(vdev);
72     struct vhost_dev *dev = &vsc->dev;
73 
74     /*
75      * Historically, reset was not implemented so only reset devices
76      * that are expecting it.
77      */
78     if (!virtio_has_feature(dev->protocol_features,
79                             VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
80         return;
81     }
82 
83     if (dev->vhost_ops->vhost_reset_device) {
84         dev->vhost_ops->vhost_reset_device(dev);
85     }
86 }
87 
vhost_dummy_handle_output(VirtIODevice * vdev,VirtQueue * vq)88 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
89 {
90 }
91 
vhost_user_scsi_realize(DeviceState * dev,Error ** errp)92 static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
93 {
94     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
95     VHostUserSCSI *s = VHOST_USER_SCSI(dev);
96     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
97     struct vhost_virtqueue *vqs = NULL;
98     Error *err = NULL;
99     int ret;
100 
101     if (!vs->conf.chardev.chr) {
102         error_setg(errp, "vhost-user-scsi: missing chardev");
103         return;
104     }
105 
106     virtio_scsi_common_realize(dev, vhost_dummy_handle_output,
107                                vhost_dummy_handle_output,
108                                vhost_dummy_handle_output, &err);
109     if (err != NULL) {
110         error_propagate(errp, err);
111         return;
112     }
113 
114     if (!vhost_user_init(&s->vhost_user, &vs->conf.chardev, errp)) {
115         goto free_virtio;
116     }
117 
118     vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
119     vsc->dev.vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
120     vsc->dev.vq_index = 0;
121     vsc->dev.backend_features = 0;
122     vqs = vsc->dev.vqs;
123 
124     ret = vhost_dev_init(&vsc->dev, &s->vhost_user,
125                          VHOST_BACKEND_TYPE_USER, 0);
126     if (ret < 0) {
127         error_setg(errp, "vhost-user-scsi: vhost initialization failed: %s",
128                    strerror(-ret));
129         goto free_vhost;
130     }
131 
132     /* Channel and lun both are 0 for bootable vhost-user-scsi disk */
133     vsc->channel = 0;
134     vsc->lun = 0;
135     vsc->target = vs->conf.boot_tpgt;
136 
137     return;
138 
139 free_vhost:
140     vhost_user_cleanup(&s->vhost_user);
141     g_free(vqs);
142 free_virtio:
143     virtio_scsi_common_unrealize(dev);
144 }
145 
vhost_user_scsi_unrealize(DeviceState * dev)146 static void vhost_user_scsi_unrealize(DeviceState *dev)
147 {
148     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
149     VHostUserSCSI *s = VHOST_USER_SCSI(dev);
150     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
151     struct vhost_virtqueue *vqs = vsc->dev.vqs;
152 
153     /* This will stop the vhost backend. */
154     vhost_user_scsi_set_status(vdev, 0);
155 
156     vhost_dev_cleanup(&vsc->dev);
157     g_free(vqs);
158 
159     virtio_scsi_common_unrealize(dev);
160     vhost_user_cleanup(&s->vhost_user);
161 }
162 
163 static Property vhost_user_scsi_properties[] = {
164     DEFINE_PROP_CHR("chardev", VirtIOSCSICommon, conf.chardev),
165     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
166     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
167                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
168     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
169                        128),
170     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
171                        0xFFFF),
172     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
173     DEFINE_PROP_BIT64("hotplug", VHostSCSICommon, host_features,
174                                                   VIRTIO_SCSI_F_HOTPLUG,
175                                                   true),
176     DEFINE_PROP_BIT64("param_change", VHostSCSICommon, host_features,
177                                                        VIRTIO_SCSI_F_CHANGE,
178                                                        true),
179     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
180                                                  VIRTIO_SCSI_F_T10_PI,
181                                                  false),
182     DEFINE_PROP_END_OF_LIST(),
183 };
184 
185 static const VMStateDescription vmstate_vhost_scsi = {
186     .name = "virtio-scsi",
187     .minimum_version_id = 1,
188     .version_id = 1,
189     .fields = (VMStateField[]) {
190         VMSTATE_VIRTIO_DEVICE,
191         VMSTATE_END_OF_LIST()
192     },
193 };
194 
vhost_user_scsi_class_init(ObjectClass * klass,void * data)195 static void vhost_user_scsi_class_init(ObjectClass *klass, void *data)
196 {
197     DeviceClass *dc = DEVICE_CLASS(klass);
198     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
199     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
200 
201     device_class_set_props(dc, vhost_user_scsi_properties);
202     dc->vmsd = &vmstate_vhost_scsi;
203     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
204     vdc->realize = vhost_user_scsi_realize;
205     vdc->unrealize = vhost_user_scsi_unrealize;
206     vdc->get_features = vhost_scsi_common_get_features;
207     vdc->set_config = vhost_scsi_common_set_config;
208     vdc->set_status = vhost_user_scsi_set_status;
209     vdc->reset = vhost_user_scsi_reset;
210     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
211 }
212 
vhost_user_scsi_instance_init(Object * obj)213 static void vhost_user_scsi_instance_init(Object *obj)
214 {
215     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
216 
217     vsc->feature_bits = user_feature_bits;
218 
219     /* Add the bootindex property for this object */
220     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
221                                   DEVICE(vsc));
222 }
223 
224 static const TypeInfo vhost_user_scsi_info = {
225     .name = TYPE_VHOST_USER_SCSI,
226     .parent = TYPE_VHOST_SCSI_COMMON,
227     .instance_size = sizeof(VHostUserSCSI),
228     .class_init = vhost_user_scsi_class_init,
229     .instance_init = vhost_user_scsi_instance_init,
230     .interfaces = (InterfaceInfo[]) {
231         { TYPE_FW_PATH_PROVIDER },
232         { }
233     },
234 };
235 
virtio_register_types(void)236 static void virtio_register_types(void)
237 {
238     type_register_static(&vhost_user_scsi_info);
239 }
240 
241 type_init(virtio_register_types)
242