1 /* 2 * Vhost-user i2c virtio device 3 * 4 * Copyright (c) 2021 Viresh Kumar <viresh.kumar@linaro.org> 5 * 6 * SPDX-License-Identifier: GPL-2.0-or-later 7 */ 8 9 #include "qemu/osdep.h" 10 #include "qapi/error.h" 11 #include "hw/qdev-properties.h" 12 #include "hw/virtio/virtio-bus.h" 13 #include "hw/virtio/vhost-user-i2c.h" 14 #include "qemu/error-report.h" 15 #include "standard-headers/linux/virtio_ids.h" 16 17 static const int feature_bits[] = { 18 VIRTIO_I2C_F_ZERO_LENGTH_REQUEST, 19 VIRTIO_F_RING_RESET, 20 VHOST_INVALID_FEATURE_BIT 21 }; 22 23 static void vu_i2c_start(VirtIODevice *vdev) 24 { 25 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 26 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 27 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 28 int ret, i; 29 30 if (!k->set_guest_notifiers) { 31 error_report("binding does not support guest notifiers"); 32 return; 33 } 34 35 ret = vhost_dev_enable_notifiers(&i2c->vhost_dev, vdev); 36 if (ret < 0) { 37 error_report("Error enabling host notifiers: %d", -ret); 38 return; 39 } 40 41 ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, true); 42 if (ret < 0) { 43 error_report("Error binding guest notifier: %d", -ret); 44 goto err_host_notifiers; 45 } 46 47 i2c->vhost_dev.acked_features = vdev->guest_features; 48 49 ret = vhost_dev_start(&i2c->vhost_dev, vdev, true); 50 if (ret < 0) { 51 error_report("Error starting vhost-user-i2c: %d", -ret); 52 goto err_guest_notifiers; 53 } 54 55 /* 56 * guest_notifier_mask/pending not used yet, so just unmask 57 * everything here. virtio-pci will do the right thing by 58 * enabling/disabling irqfd. 59 */ 60 for (i = 0; i < i2c->vhost_dev.nvqs; i++) { 61 vhost_virtqueue_mask(&i2c->vhost_dev, vdev, i, false); 62 } 63 64 return; 65 66 err_guest_notifiers: 67 k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false); 68 err_host_notifiers: 69 vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev); 70 } 71 72 static void vu_i2c_stop(VirtIODevice *vdev) 73 { 74 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 75 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 76 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 77 int ret; 78 79 if (!k->set_guest_notifiers) { 80 return; 81 } 82 83 vhost_dev_stop(&i2c->vhost_dev, vdev, true); 84 85 ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false); 86 if (ret < 0) { 87 error_report("vhost guest notifier cleanup failed: %d", ret); 88 return; 89 } 90 91 vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev); 92 } 93 94 static void vu_i2c_set_status(VirtIODevice *vdev, uint8_t status) 95 { 96 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 97 bool should_start = virtio_device_should_start(vdev, status); 98 99 if (vhost_dev_is_started(&i2c->vhost_dev) == should_start) { 100 return; 101 } 102 103 if (should_start) { 104 vu_i2c_start(vdev); 105 } else { 106 vu_i2c_stop(vdev); 107 } 108 } 109 110 static uint64_t vu_i2c_get_features(VirtIODevice *vdev, 111 uint64_t requested_features, Error **errp) 112 { 113 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 114 115 virtio_add_feature(&requested_features, VIRTIO_I2C_F_ZERO_LENGTH_REQUEST); 116 return vhost_get_features(&i2c->vhost_dev, feature_bits, requested_features); 117 } 118 119 static void vu_i2c_handle_output(VirtIODevice *vdev, VirtQueue *vq) 120 { 121 /* 122 * Not normally called; it's the daemon that handles the queue; 123 * however virtio's cleanup path can call this. 124 */ 125 } 126 127 static void vu_i2c_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask) 128 { 129 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 130 131 /* 132 * We don't support interrupts, return early if index is set to 133 * VIRTIO_CONFIG_IRQ_IDX. 134 */ 135 if (idx == VIRTIO_CONFIG_IRQ_IDX) { 136 return; 137 } 138 139 vhost_virtqueue_mask(&i2c->vhost_dev, vdev, idx, mask); 140 } 141 142 static bool vu_i2c_guest_notifier_pending(VirtIODevice *vdev, int idx) 143 { 144 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 145 146 /* 147 * We don't support interrupts, return early if index is set to 148 * VIRTIO_CONFIG_IRQ_IDX. 149 */ 150 if (idx == VIRTIO_CONFIG_IRQ_IDX) { 151 return false; 152 } 153 154 return vhost_virtqueue_pending(&i2c->vhost_dev, idx); 155 } 156 157 static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserI2C *i2c) 158 { 159 vhost_user_cleanup(&i2c->vhost_user); 160 virtio_delete_queue(i2c->vq); 161 virtio_cleanup(vdev); 162 } 163 164 static int vu_i2c_connect(DeviceState *dev) 165 { 166 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 167 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 168 169 if (i2c->connected) { 170 return 0; 171 } 172 i2c->connected = true; 173 174 /* restore vhost state */ 175 if (virtio_device_started(vdev, vdev->status)) { 176 vu_i2c_start(vdev); 177 } 178 179 return 0; 180 } 181 182 static void vu_i2c_disconnect(DeviceState *dev) 183 { 184 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 185 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 186 187 if (!i2c->connected) { 188 return; 189 } 190 i2c->connected = false; 191 192 if (vhost_dev_is_started(&i2c->vhost_dev)) { 193 vu_i2c_stop(vdev); 194 } 195 } 196 197 static void vu_i2c_event(void *opaque, QEMUChrEvent event) 198 { 199 DeviceState *dev = opaque; 200 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 201 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 202 203 switch (event) { 204 case CHR_EVENT_OPENED: 205 if (vu_i2c_connect(dev) < 0) { 206 qemu_chr_fe_disconnect(&i2c->chardev); 207 return; 208 } 209 break; 210 case CHR_EVENT_CLOSED: 211 vu_i2c_disconnect(dev); 212 break; 213 case CHR_EVENT_BREAK: 214 case CHR_EVENT_MUX_IN: 215 case CHR_EVENT_MUX_OUT: 216 /* Ignore */ 217 break; 218 } 219 } 220 221 static void vu_i2c_device_realize(DeviceState *dev, Error **errp) 222 { 223 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 224 VHostUserI2C *i2c = VHOST_USER_I2C(dev); 225 int ret; 226 227 if (!i2c->chardev.chr) { 228 error_setg(errp, "vhost-user-i2c: missing chardev"); 229 return; 230 } 231 232 if (!vhost_user_init(&i2c->vhost_user, &i2c->chardev, errp)) { 233 return; 234 } 235 236 virtio_init(vdev, VIRTIO_ID_I2C_ADAPTER, 0); 237 238 i2c->vhost_dev.nvqs = 1; 239 i2c->vq = virtio_add_queue(vdev, 4, vu_i2c_handle_output); 240 i2c->vhost_dev.vqs = g_new0(struct vhost_virtqueue, i2c->vhost_dev.nvqs); 241 242 ret = vhost_dev_init(&i2c->vhost_dev, &i2c->vhost_user, 243 VHOST_BACKEND_TYPE_USER, 0, errp); 244 if (ret < 0) { 245 g_free(i2c->vhost_dev.vqs); 246 do_vhost_user_cleanup(vdev, i2c); 247 } 248 249 qemu_chr_fe_set_handlers(&i2c->chardev, NULL, NULL, vu_i2c_event, NULL, 250 dev, NULL, true); 251 } 252 253 static void vu_i2c_device_unrealize(DeviceState *dev) 254 { 255 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 256 VHostUserI2C *i2c = VHOST_USER_I2C(dev); 257 struct vhost_virtqueue *vhost_vqs = i2c->vhost_dev.vqs; 258 259 /* This will stop vhost backend if appropriate. */ 260 vu_i2c_set_status(vdev, 0); 261 vhost_dev_cleanup(&i2c->vhost_dev); 262 g_free(vhost_vqs); 263 do_vhost_user_cleanup(vdev, i2c); 264 } 265 266 static const VMStateDescription vu_i2c_vmstate = { 267 .name = "vhost-user-i2c", 268 .unmigratable = 1, 269 }; 270 271 static Property vu_i2c_properties[] = { 272 DEFINE_PROP_CHR("chardev", VHostUserI2C, chardev), 273 DEFINE_PROP_END_OF_LIST(), 274 }; 275 276 static void vu_i2c_class_init(ObjectClass *klass, void *data) 277 { 278 DeviceClass *dc = DEVICE_CLASS(klass); 279 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 280 281 device_class_set_props(dc, vu_i2c_properties); 282 dc->vmsd = &vu_i2c_vmstate; 283 set_bit(DEVICE_CATEGORY_INPUT, dc->categories); 284 vdc->realize = vu_i2c_device_realize; 285 vdc->unrealize = vu_i2c_device_unrealize; 286 vdc->get_features = vu_i2c_get_features; 287 vdc->set_status = vu_i2c_set_status; 288 vdc->guest_notifier_mask = vu_i2c_guest_notifier_mask; 289 vdc->guest_notifier_pending = vu_i2c_guest_notifier_pending; 290 } 291 292 static const TypeInfo vu_i2c_info = { 293 .name = TYPE_VHOST_USER_I2C, 294 .parent = TYPE_VIRTIO_DEVICE, 295 .instance_size = sizeof(VHostUserI2C), 296 .class_init = vu_i2c_class_init, 297 }; 298 299 static void vu_i2c_register_types(void) 300 { 301 type_register_static(&vu_i2c_info); 302 } 303 304 type_init(vu_i2c_register_types) 305