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