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 vhost_virtqueue_mask(&i2c->vhost_dev, vdev, idx, mask); 132 } 133 134 static bool vu_i2c_guest_notifier_pending(VirtIODevice *vdev, int idx) 135 { 136 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 137 138 return vhost_virtqueue_pending(&i2c->vhost_dev, idx); 139 } 140 141 static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserI2C *i2c) 142 { 143 vhost_user_cleanup(&i2c->vhost_user); 144 virtio_delete_queue(i2c->vq); 145 virtio_cleanup(vdev); 146 } 147 148 static int vu_i2c_connect(DeviceState *dev) 149 { 150 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 151 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 152 153 if (i2c->connected) { 154 return 0; 155 } 156 i2c->connected = true; 157 158 /* restore vhost state */ 159 if (virtio_device_started(vdev, vdev->status)) { 160 vu_i2c_start(vdev); 161 } 162 163 return 0; 164 } 165 166 static void vu_i2c_disconnect(DeviceState *dev) 167 { 168 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 169 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 170 171 if (!i2c->connected) { 172 return; 173 } 174 i2c->connected = false; 175 176 if (vhost_dev_is_started(&i2c->vhost_dev)) { 177 vu_i2c_stop(vdev); 178 } 179 } 180 181 static void vu_i2c_event(void *opaque, QEMUChrEvent event) 182 { 183 DeviceState *dev = opaque; 184 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 185 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 186 187 switch (event) { 188 case CHR_EVENT_OPENED: 189 if (vu_i2c_connect(dev) < 0) { 190 qemu_chr_fe_disconnect(&i2c->chardev); 191 return; 192 } 193 break; 194 case CHR_EVENT_CLOSED: 195 vu_i2c_disconnect(dev); 196 break; 197 case CHR_EVENT_BREAK: 198 case CHR_EVENT_MUX_IN: 199 case CHR_EVENT_MUX_OUT: 200 /* Ignore */ 201 break; 202 } 203 } 204 205 static void vu_i2c_device_realize(DeviceState *dev, Error **errp) 206 { 207 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 208 VHostUserI2C *i2c = VHOST_USER_I2C(dev); 209 int ret; 210 211 if (!i2c->chardev.chr) { 212 error_setg(errp, "vhost-user-i2c: missing chardev"); 213 return; 214 } 215 216 if (!vhost_user_init(&i2c->vhost_user, &i2c->chardev, errp)) { 217 return; 218 } 219 220 virtio_init(vdev, VIRTIO_ID_I2C_ADAPTER, 0); 221 222 i2c->vhost_dev.nvqs = 1; 223 i2c->vq = virtio_add_queue(vdev, 4, vu_i2c_handle_output); 224 i2c->vhost_dev.vqs = g_new0(struct vhost_virtqueue, i2c->vhost_dev.nvqs); 225 226 ret = vhost_dev_init(&i2c->vhost_dev, &i2c->vhost_user, 227 VHOST_BACKEND_TYPE_USER, 0, errp); 228 if (ret < 0) { 229 g_free(i2c->vhost_dev.vqs); 230 do_vhost_user_cleanup(vdev, i2c); 231 } 232 233 qemu_chr_fe_set_handlers(&i2c->chardev, NULL, NULL, vu_i2c_event, NULL, 234 dev, NULL, true); 235 } 236 237 static void vu_i2c_device_unrealize(DeviceState *dev) 238 { 239 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 240 VHostUserI2C *i2c = VHOST_USER_I2C(dev); 241 struct vhost_virtqueue *vhost_vqs = i2c->vhost_dev.vqs; 242 243 /* This will stop vhost backend if appropriate. */ 244 vu_i2c_set_status(vdev, 0); 245 vhost_dev_cleanup(&i2c->vhost_dev); 246 g_free(vhost_vqs); 247 do_vhost_user_cleanup(vdev, i2c); 248 } 249 250 static const VMStateDescription vu_i2c_vmstate = { 251 .name = "vhost-user-i2c", 252 .unmigratable = 1, 253 }; 254 255 static Property vu_i2c_properties[] = { 256 DEFINE_PROP_CHR("chardev", VHostUserI2C, chardev), 257 DEFINE_PROP_END_OF_LIST(), 258 }; 259 260 static void vu_i2c_class_init(ObjectClass *klass, void *data) 261 { 262 DeviceClass *dc = DEVICE_CLASS(klass); 263 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 264 265 device_class_set_props(dc, vu_i2c_properties); 266 dc->vmsd = &vu_i2c_vmstate; 267 set_bit(DEVICE_CATEGORY_INPUT, dc->categories); 268 vdc->realize = vu_i2c_device_realize; 269 vdc->unrealize = vu_i2c_device_unrealize; 270 vdc->get_features = vu_i2c_get_features; 271 vdc->set_status = vu_i2c_set_status; 272 vdc->guest_notifier_mask = vu_i2c_guest_notifier_mask; 273 vdc->guest_notifier_pending = vu_i2c_guest_notifier_pending; 274 } 275 276 static const TypeInfo vu_i2c_info = { 277 .name = TYPE_VHOST_USER_I2C, 278 .parent = TYPE_VIRTIO_DEVICE, 279 .instance_size = sizeof(VHostUserI2C), 280 .class_init = vu_i2c_class_init, 281 }; 282 283 static void vu_i2c_register_types(void) 284 { 285 type_register_static(&vu_i2c_info); 286 } 287 288 type_init(vu_i2c_register_types) 289