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