| 1 | /* |
| 2 | * Vhost-user SCMI virtio device |
| 3 | * |
| 4 | * SPDX-FileCopyrightText: Red Hat, Inc. |
| 5 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 6 | * |
| 7 | * Implementation based on other vhost-user devices in QEMU. |
| 8 | */ |
| 9 | |
| 10 | #include "qemu/osdep.h" |
| 11 | #include "qapi/error.h" |
| 12 | #include "qemu/error-report.h" |
| 13 | #include "hw/virtio/virtio-bus.h" |
| 14 | #include "hw/virtio/vhost-user-scmi.h" |
| 15 | #include "standard-headers/linux/virtio_ids.h" |
| 16 | #include "standard-headers/linux/virtio_scmi.h" |
| 17 | #include "trace.h" |
| 18 | |
| 19 | /* |
| 20 | * In this version, we don't support VIRTIO_SCMI_F_SHARED_MEMORY. |
| 21 | * Note that VIRTIO_SCMI_F_SHARED_MEMORY is currently not supported in |
| 22 | * Linux VirtIO SCMI guest driver. |
| 23 | */ |
| 24 | static const int feature_bits[] = { |
| 25 | VIRTIO_F_VERSION_1, |
| 26 | VIRTIO_F_NOTIFY_ON_EMPTY, |
| 27 | VIRTIO_RING_F_INDIRECT_DESC, |
| 28 | VIRTIO_RING_F_EVENT_IDX, |
| 29 | VIRTIO_F_RING_RESET, |
| 30 | VIRTIO_SCMI_F_P2A_CHANNELS, |
| 31 | VHOST_INVALID_FEATURE_BIT |
| 32 | }; |
| 33 | |
| 34 | static int vu_scmi_start(VirtIODevice *vdev) |
| 35 | { |
| 36 | VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev); |
| 37 | BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); |
| 38 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); |
| 39 | struct vhost_dev *vhost_dev = &scmi->vhost_dev; |
| 40 | int ret, i; |
| 41 | |
| 42 | if (!k->set_guest_notifiers) { |
| 43 | error_report("binding does not support guest notifiers"); |
| 44 | return -ENOSYS; |
| 45 | } |
| 46 | |
| 47 | ret = vhost_dev_enable_notifiers(vhost_dev, vdev); |
| 48 | if (ret < 0) { |
| 49 | error_report("Error enabling host notifiers: %d", ret); |
| 50 | return ret; |
| 51 | } |
| 52 | |
| 53 | ret = k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, true); |
| 54 | if (ret < 0) { |
| 55 | error_report("Error binding guest notifier: %d", ret); |
| 56 | goto err_host_notifiers; |
| 57 | } |
| 58 | |
| 59 | vhost_ack_features(vhost_dev, feature_bits, vdev->guest_features); |
| 60 | |
| 61 | ret = vhost_dev_start(vhost_dev, vdev, true); |
| 62 | if (ret < 0) { |
| 63 | error_report("Error starting vhost-user-scmi: %d", ret); |
| 64 | goto err_guest_notifiers; |
| 65 | } |
| 66 | scmi->started_vu = true; |
| 67 | |
| 68 | /* |
| 69 | * guest_notifier_mask/pending not used yet, so just unmask |
| 70 | * everything here. virtio-pci will do the right thing by |
| 71 | * enabling/disabling irqfd. |
| 72 | */ |
| 73 | for (i = 0; i < scmi->vhost_dev.nvqs; i++) { |
| 74 | vhost_virtqueue_mask(vhost_dev, vdev, i, false); |
| 75 | } |
| 76 | return 0; |
| 77 | |
| 78 | err_guest_notifiers: |
| 79 | k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, false); |
| 80 | err_host_notifiers: |
| 81 | vhost_dev_disable_notifiers(vhost_dev, vdev); |
| 82 | |
| 83 | return ret; |
| 84 | } |
| 85 | |
| 86 | static int vu_scmi_stop(VirtIODevice *vdev) |
| 87 | { |
| 88 | VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev); |
| 89 | BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); |
| 90 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); |
| 91 | struct vhost_dev *vhost_dev = &scmi->vhost_dev; |
| 92 | int ret, err; |
| 93 | |
| 94 | /* vhost_dev_is_started() check in the callers is not fully reliable. */ |
| 95 | if (!scmi->started_vu) { |
| 96 | return 0; |
| 97 | } |
| 98 | scmi->started_vu = false; |
| 99 | |
| 100 | if (!k->set_guest_notifiers) { |
| 101 | return 0; |
| 102 | } |
| 103 | |
| 104 | ret = vhost_dev_stop(vhost_dev, vdev, true); |
| 105 | |
| 106 | err = k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, false); |
| 107 | if (err < 0) { |
| 108 | error_report("vhost guest notifier cleanup failed: %d", err); |
| 109 | return err; |
| 110 | } |
| 111 | vhost_dev_disable_notifiers(vhost_dev, vdev); |
| 112 | return ret; |
| 113 | } |
| 114 | |
| 115 | static int vu_scmi_set_status(VirtIODevice *vdev, uint8_t status) |
| 116 | { |
| 117 | VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev); |
| 118 | bool should_start = virtio_device_should_start(vdev, status); |
| 119 | |
| 120 | if (!scmi->connected) { |
| 121 | return -1; |
| 122 | } |
| 123 | if (vhost_dev_is_started(&scmi->vhost_dev) == should_start) { |
| 124 | return 0; |
| 125 | } |
| 126 | |
| 127 | if (should_start) { |
| 128 | vu_scmi_start(vdev); |
| 129 | } else { |
| 130 | int ret; |
| 131 | ret = vu_scmi_stop(vdev); |
| 132 | if (ret < 0) { |
| 133 | return ret; |
| 134 | } |
| 135 | } |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | static uint64_t vu_scmi_get_features(VirtIODevice *vdev, uint64_t features, |
| 140 | Error **errp) |
| 141 | { |
| 142 | VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev); |
| 143 | |
| 144 | return vhost_get_features(&scmi->vhost_dev, feature_bits, features); |
| 145 | } |
| 146 | |
| 147 | static void vu_scmi_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
| 148 | { |
| 149 | /* |
| 150 | * Not normally called; it's the daemon that handles the queue; |
| 151 | * however virtio's cleanup path can call this. |
| 152 | */ |
| 153 | } |
| 154 | |
| 155 | static void vu_scmi_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask) |
| 156 | { |
| 157 | VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev); |
| 158 | |
| 159 | if (idx == VIRTIO_CONFIG_IRQ_IDX) { |
| 160 | return; |
| 161 | } |
| 162 | |
| 163 | vhost_virtqueue_mask(&scmi->vhost_dev, vdev, idx, mask); |
| 164 | } |
| 165 | |
| 166 | static bool vu_scmi_guest_notifier_pending(VirtIODevice *vdev, int idx) |
| 167 | { |
| 168 | VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev); |
| 169 | |
| 170 | return vhost_virtqueue_pending(&scmi->vhost_dev, idx); |
| 171 | } |
| 172 | |
| 173 | static void vu_scmi_connect(DeviceState *dev) |
| 174 | { |
| 175 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 176 | VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev); |
| 177 | |
| 178 | if (scmi->connected) { |
| 179 | return; |
| 180 | } |
| 181 | scmi->connected = true; |
| 182 | |
| 183 | /* restore vhost state */ |
| 184 | if (virtio_device_started(vdev, vdev->status)) { |
| 185 | vu_scmi_start(vdev); |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | static void vu_scmi_disconnect(DeviceState *dev) |
| 190 | { |
| 191 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 192 | VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev); |
| 193 | |
| 194 | if (!scmi->connected) { |
| 195 | return; |
| 196 | } |
| 197 | scmi->connected = false; |
| 198 | |
| 199 | if (vhost_dev_is_started(&scmi->vhost_dev)) { |
| 200 | vu_scmi_stop(vdev); |
| 201 | } |
| 202 | } |
| 203 | |
| 204 | static void vu_scmi_event(void *opaque, QEMUChrEvent event) |
| 205 | { |
| 206 | DeviceState *dev = opaque; |
| 207 | |
| 208 | switch (event) { |
| 209 | case CHR_EVENT_OPENED: |
| 210 | vu_scmi_connect(dev); |
| 211 | break; |
| 212 | case CHR_EVENT_CLOSED: |
| 213 | vu_scmi_disconnect(dev); |
| 214 | break; |
| 215 | case CHR_EVENT_BREAK: |
| 216 | case CHR_EVENT_MUX_IN: |
| 217 | case CHR_EVENT_MUX_OUT: |
| 218 | /* Ignore */ |
| 219 | break; |
| 220 | } |
| 221 | } |
| 222 | |
| 223 | static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserSCMI *scmi, |
| 224 | struct vhost_virtqueue *vhost_vqs) |
| 225 | { |
| 226 | virtio_delete_queue(scmi->cmd_vq); |
| 227 | virtio_delete_queue(scmi->event_vq); |
| 228 | g_free(vhost_vqs); |
| 229 | virtio_cleanup(vdev); |
| 230 | vhost_user_cleanup(&scmi->vhost_user); |
| 231 | } |
| 232 | |
| 233 | static void vu_scmi_device_realize(DeviceState *dev, Error **errp) |
| 234 | { |
| 235 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 236 | VHostUserSCMI *scmi = VHOST_USER_SCMI(dev); |
| 237 | struct vhost_virtqueue *vhost_vqs; |
| 238 | int ret; |
| 239 | |
| 240 | if (!scmi->chardev.chr) { |
| 241 | error_setg(errp, "vhost-user-scmi: chardev is mandatory"); |
| 242 | return; |
| 243 | } |
| 244 | |
| 245 | vdev->host_features |= (1ULL << VIRTIO_SCMI_F_P2A_CHANNELS); |
| 246 | |
| 247 | if (!vhost_user_init(&scmi->vhost_user, &scmi->chardev, errp)) { |
| 248 | return; |
| 249 | } |
| 250 | |
| 251 | virtio_init(vdev, VIRTIO_ID_SCMI, 0); |
| 252 | |
| 253 | scmi->cmd_vq = virtio_add_queue(vdev, 256, vu_scmi_handle_output); |
| 254 | scmi->event_vq = virtio_add_queue(vdev, 256, vu_scmi_handle_output); |
| 255 | scmi->vhost_dev.nvqs = 2; |
| 256 | scmi->vhost_dev.vqs = g_new0(struct vhost_virtqueue, scmi->vhost_dev.nvqs); |
| 257 | vhost_vqs = scmi->vhost_dev.vqs; |
| 258 | |
| 259 | ret = vhost_dev_init(&scmi->vhost_dev, &scmi->vhost_user, |
| 260 | VHOST_BACKEND_TYPE_USER, 0, errp); |
| 261 | if (ret < 0) { |
| 262 | error_setg_errno(errp, -ret, |
| 263 | "vhost-user-scmi: vhost_dev_init() failed"); |
| 264 | do_vhost_user_cleanup(vdev, scmi, vhost_vqs); |
| 265 | return; |
| 266 | } |
| 267 | |
| 268 | qemu_chr_fe_set_handlers(&scmi->chardev, NULL, NULL, vu_scmi_event, NULL, |
| 269 | dev, NULL, true); |
| 270 | } |
| 271 | |
| 272 | static void vu_scmi_device_unrealize(DeviceState *dev) |
| 273 | { |
| 274 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
| 275 | VHostUserSCMI *scmi = VHOST_USER_SCMI(dev); |
| 276 | struct vhost_virtqueue *vhost_vqs = scmi->vhost_dev.vqs; |
| 277 | |
| 278 | vu_scmi_set_status(vdev, 0); |
| 279 | vhost_dev_cleanup(&scmi->vhost_dev); |
| 280 | do_vhost_user_cleanup(vdev, scmi, vhost_vqs); |
| 281 | } |
| 282 | |
| 283 | static const VMStateDescription vu_scmi_vmstate = { |
| 284 | .name = "vhost-user-scmi", |
| 285 | .unmigratable = 1, |
| 286 | }; |
| 287 | |
| 288 | static const Property vu_scmi_properties[] = { |
| 289 | DEFINE_PROP_CHR("chardev", VHostUserSCMI, chardev), |
| 290 | }; |
| 291 | |
| 292 | static void vu_scmi_class_init(ObjectClass *klass, const void *data) |
| 293 | { |
| 294 | DeviceClass *dc = DEVICE_CLASS(klass); |
| 295 | VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); |
| 296 | |
| 297 | device_class_set_props(dc, vu_scmi_properties); |
| 298 | dc->vmsd = &vu_scmi_vmstate; |
| 299 | set_bit(DEVICE_CATEGORY_INPUT, dc->categories); |
| 300 | vdc->realize = vu_scmi_device_realize; |
| 301 | vdc->unrealize = vu_scmi_device_unrealize; |
| 302 | vdc->get_features = vu_scmi_get_features; |
| 303 | vdc->set_status = vu_scmi_set_status; |
| 304 | vdc->guest_notifier_mask = vu_scmi_guest_notifier_mask; |
| 305 | vdc->guest_notifier_pending = vu_scmi_guest_notifier_pending; |
| 306 | } |
| 307 | |
| 308 | static const TypeInfo vu_scmi_info = { |
| 309 | .name = TYPE_VHOST_USER_SCMI, |
| 310 | .parent = TYPE_VIRTIO_DEVICE, |
| 311 | .instance_size = sizeof(VHostUserSCMI), |
| 312 | .class_init = vu_scmi_class_init, |
| 313 | }; |
| 314 | |
| 315 | static void vu_scmi_register_types(void) |
| 316 | { |
| 317 | type_register_static(&vu_scmi_info); |
| 318 | } |
| 319 | |
| 320 | type_init(vu_scmi_register_types) |