1 /* 2 * Vhost-user filesystem virtio device 3 * 4 * Copyright 2018-2019 Red Hat, Inc. 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or 10 * (at your option) any later version. See the COPYING file in the 11 * top-level directory. 12 */ 13 14 #include "qemu/osdep.h" 15 #include <sys/ioctl.h> 16 #include "standard-headers/linux/virtio_fs.h" 17 #include "qapi/error.h" 18 #include "hw/qdev-properties.h" 19 #include "hw/qdev-properties-system.h" 20 #include "hw/virtio/virtio-bus.h" 21 #include "hw/virtio/virtio-access.h" 22 #include "qemu/error-report.h" 23 #include "hw/virtio/vhost-user-fs.h" 24 #include "monitor/monitor.h" 25 #include "sysemu/sysemu.h" 26 27 static void vuf_get_config(VirtIODevice *vdev, uint8_t *config) 28 { 29 VHostUserFS *fs = VHOST_USER_FS(vdev); 30 struct virtio_fs_config fscfg = {}; 31 32 memcpy((char *)fscfg.tag, fs->conf.tag, 33 MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag))); 34 35 virtio_stl_p(vdev, &fscfg.num_request_queues, fs->conf.num_request_queues); 36 37 memcpy(config, &fscfg, sizeof(fscfg)); 38 } 39 40 static void vuf_start(VirtIODevice *vdev) 41 { 42 VHostUserFS *fs = VHOST_USER_FS(vdev); 43 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 44 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 45 int ret; 46 int i; 47 48 if (!k->set_guest_notifiers) { 49 error_report("binding does not support guest notifiers"); 50 return; 51 } 52 53 ret = vhost_dev_enable_notifiers(&fs->vhost_dev, vdev); 54 if (ret < 0) { 55 error_report("Error enabling host notifiers: %d", -ret); 56 return; 57 } 58 59 ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, true); 60 if (ret < 0) { 61 error_report("Error binding guest notifier: %d", -ret); 62 goto err_host_notifiers; 63 } 64 65 fs->vhost_dev.acked_features = vdev->guest_features; 66 ret = vhost_dev_start(&fs->vhost_dev, vdev); 67 if (ret < 0) { 68 error_report("Error starting vhost: %d", -ret); 69 goto err_guest_notifiers; 70 } 71 72 /* 73 * guest_notifier_mask/pending not used yet, so just unmask 74 * everything here. virtio-pci will do the right thing by 75 * enabling/disabling irqfd. 76 */ 77 for (i = 0; i < fs->vhost_dev.nvqs; i++) { 78 vhost_virtqueue_mask(&fs->vhost_dev, vdev, i, false); 79 } 80 81 return; 82 83 err_guest_notifiers: 84 k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false); 85 err_host_notifiers: 86 vhost_dev_disable_notifiers(&fs->vhost_dev, vdev); 87 } 88 89 static void vuf_stop(VirtIODevice *vdev) 90 { 91 VHostUserFS *fs = VHOST_USER_FS(vdev); 92 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 93 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 94 int ret; 95 96 if (!k->set_guest_notifiers) { 97 return; 98 } 99 100 vhost_dev_stop(&fs->vhost_dev, vdev); 101 102 ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false); 103 if (ret < 0) { 104 error_report("vhost guest notifier cleanup failed: %d", ret); 105 return; 106 } 107 108 vhost_dev_disable_notifiers(&fs->vhost_dev, vdev); 109 } 110 111 static void vuf_set_status(VirtIODevice *vdev, uint8_t status) 112 { 113 VHostUserFS *fs = VHOST_USER_FS(vdev); 114 bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK; 115 116 if (!vdev->vm_running) { 117 should_start = false; 118 } 119 120 if (fs->vhost_dev.started == should_start) { 121 return; 122 } 123 124 if (should_start) { 125 vuf_start(vdev); 126 } else { 127 vuf_stop(vdev); 128 } 129 } 130 131 static uint64_t vuf_get_features(VirtIODevice *vdev, 132 uint64_t requested_features, 133 Error **errp) 134 { 135 /* No feature bits used yet */ 136 return requested_features; 137 } 138 139 static void vuf_handle_output(VirtIODevice *vdev, VirtQueue *vq) 140 { 141 /* 142 * Not normally called; it's the daemon that handles the queue; 143 * however virtio's cleanup path can call this. 144 */ 145 } 146 147 static void vuf_guest_notifier_mask(VirtIODevice *vdev, int idx, 148 bool mask) 149 { 150 VHostUserFS *fs = VHOST_USER_FS(vdev); 151 152 vhost_virtqueue_mask(&fs->vhost_dev, vdev, idx, mask); 153 } 154 155 static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx) 156 { 157 VHostUserFS *fs = VHOST_USER_FS(vdev); 158 159 return vhost_virtqueue_pending(&fs->vhost_dev, idx); 160 } 161 162 static void vuf_device_realize(DeviceState *dev, Error **errp) 163 { 164 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 165 VHostUserFS *fs = VHOST_USER_FS(dev); 166 unsigned int i; 167 size_t len; 168 int ret; 169 170 if (!fs->conf.chardev.chr) { 171 error_setg(errp, "missing chardev"); 172 return; 173 } 174 175 if (!fs->conf.tag) { 176 error_setg(errp, "missing tag property"); 177 return; 178 } 179 len = strlen(fs->conf.tag); 180 if (len == 0) { 181 error_setg(errp, "tag property cannot be empty"); 182 return; 183 } 184 if (len > sizeof_field(struct virtio_fs_config, tag)) { 185 error_setg(errp, "tag property must be %zu bytes or less", 186 sizeof_field(struct virtio_fs_config, tag)); 187 return; 188 } 189 190 if (fs->conf.num_request_queues == 0) { 191 error_setg(errp, "num-request-queues property must be larger than 0"); 192 return; 193 } 194 195 if (!is_power_of_2(fs->conf.queue_size)) { 196 error_setg(errp, "queue-size property must be a power of 2"); 197 return; 198 } 199 200 if (fs->conf.queue_size > VIRTQUEUE_MAX_SIZE) { 201 error_setg(errp, "queue-size property must be %u or smaller", 202 VIRTQUEUE_MAX_SIZE); 203 return; 204 } 205 206 if (!vhost_user_init(&fs->vhost_user, &fs->conf.chardev, errp)) { 207 return; 208 } 209 210 virtio_init(vdev, "vhost-user-fs", VIRTIO_ID_FS, 211 sizeof(struct virtio_fs_config)); 212 213 /* Hiprio queue */ 214 fs->hiprio_vq = virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output); 215 216 /* Request queues */ 217 fs->req_vqs = g_new(VirtQueue *, fs->conf.num_request_queues); 218 for (i = 0; i < fs->conf.num_request_queues; i++) { 219 fs->req_vqs[i] = virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output); 220 } 221 222 /* 1 high prio queue, plus the number configured */ 223 fs->vhost_dev.nvqs = 1 + fs->conf.num_request_queues; 224 fs->vhost_dev.vqs = g_new0(struct vhost_virtqueue, fs->vhost_dev.nvqs); 225 ret = vhost_dev_init(&fs->vhost_dev, &fs->vhost_user, 226 VHOST_BACKEND_TYPE_USER, 0); 227 if (ret < 0) { 228 error_setg_errno(errp, -ret, "vhost_dev_init failed"); 229 goto err_virtio; 230 } 231 232 return; 233 234 err_virtio: 235 vhost_user_cleanup(&fs->vhost_user); 236 virtio_delete_queue(fs->hiprio_vq); 237 for (i = 0; i < fs->conf.num_request_queues; i++) { 238 virtio_delete_queue(fs->req_vqs[i]); 239 } 240 g_free(fs->req_vqs); 241 virtio_cleanup(vdev); 242 g_free(fs->vhost_dev.vqs); 243 return; 244 } 245 246 static void vuf_device_unrealize(DeviceState *dev) 247 { 248 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 249 VHostUserFS *fs = VHOST_USER_FS(dev); 250 int i; 251 252 /* This will stop vhost backend if appropriate. */ 253 vuf_set_status(vdev, 0); 254 255 vhost_dev_cleanup(&fs->vhost_dev); 256 257 vhost_user_cleanup(&fs->vhost_user); 258 259 virtio_delete_queue(fs->hiprio_vq); 260 for (i = 0; i < fs->conf.num_request_queues; i++) { 261 virtio_delete_queue(fs->req_vqs[i]); 262 } 263 g_free(fs->req_vqs); 264 virtio_cleanup(vdev); 265 g_free(fs->vhost_dev.vqs); 266 fs->vhost_dev.vqs = NULL; 267 } 268 269 static const VMStateDescription vuf_vmstate = { 270 .name = "vhost-user-fs", 271 .unmigratable = 1, 272 }; 273 274 static Property vuf_properties[] = { 275 DEFINE_PROP_CHR("chardev", VHostUserFS, conf.chardev), 276 DEFINE_PROP_STRING("tag", VHostUserFS, conf.tag), 277 DEFINE_PROP_UINT16("num-request-queues", VHostUserFS, 278 conf.num_request_queues, 1), 279 DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128), 280 DEFINE_PROP_END_OF_LIST(), 281 }; 282 283 static void vuf_instance_init(Object *obj) 284 { 285 VHostUserFS *fs = VHOST_USER_FS(obj); 286 287 device_add_bootindex_property(obj, &fs->bootindex, "bootindex", 288 "/filesystem@0", DEVICE(obj)); 289 } 290 291 static void vuf_class_init(ObjectClass *klass, void *data) 292 { 293 DeviceClass *dc = DEVICE_CLASS(klass); 294 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 295 296 device_class_set_props(dc, vuf_properties); 297 dc->vmsd = &vuf_vmstate; 298 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 299 vdc->realize = vuf_device_realize; 300 vdc->unrealize = vuf_device_unrealize; 301 vdc->get_features = vuf_get_features; 302 vdc->get_config = vuf_get_config; 303 vdc->set_status = vuf_set_status; 304 vdc->guest_notifier_mask = vuf_guest_notifier_mask; 305 vdc->guest_notifier_pending = vuf_guest_notifier_pending; 306 } 307 308 static const TypeInfo vuf_info = { 309 .name = TYPE_VHOST_USER_FS, 310 .parent = TYPE_VIRTIO_DEVICE, 311 .instance_size = sizeof(VHostUserFS), 312 .instance_init = vuf_instance_init, 313 .class_init = vuf_class_init, 314 }; 315 316 static void vuf_register_types(void) 317 { 318 type_register_static(&vuf_info); 319 } 320 321 type_init(vuf_register_types) 322