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