vhost-user-i2c.c (7653B)
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 g_free(i2c->vhost_dev.vqs); 147 i2c->vhost_dev.vqs = NULL; 148 } 149 150 static int vu_i2c_connect(DeviceState *dev) 151 { 152 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 153 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 154 155 if (i2c->connected) { 156 return 0; 157 } 158 i2c->connected = true; 159 160 /* restore vhost state */ 161 if (virtio_device_started(vdev, vdev->status)) { 162 vu_i2c_start(vdev); 163 } 164 165 return 0; 166 } 167 168 static void vu_i2c_disconnect(DeviceState *dev) 169 { 170 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 171 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 172 173 if (!i2c->connected) { 174 return; 175 } 176 i2c->connected = false; 177 178 if (vhost_dev_is_started(&i2c->vhost_dev)) { 179 vu_i2c_stop(vdev); 180 } 181 } 182 183 static void vu_i2c_event(void *opaque, QEMUChrEvent event) 184 { 185 DeviceState *dev = opaque; 186 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 187 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 188 189 switch (event) { 190 case CHR_EVENT_OPENED: 191 if (vu_i2c_connect(dev) < 0) { 192 qemu_chr_fe_disconnect(&i2c->chardev); 193 return; 194 } 195 break; 196 case CHR_EVENT_CLOSED: 197 vu_i2c_disconnect(dev); 198 break; 199 case CHR_EVENT_BREAK: 200 case CHR_EVENT_MUX_IN: 201 case CHR_EVENT_MUX_OUT: 202 /* Ignore */ 203 break; 204 } 205 } 206 207 static void vu_i2c_device_realize(DeviceState *dev, Error **errp) 208 { 209 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 210 VHostUserI2C *i2c = VHOST_USER_I2C(dev); 211 int ret; 212 213 if (!i2c->chardev.chr) { 214 error_setg(errp, "vhost-user-i2c: missing chardev"); 215 return; 216 } 217 218 if (!vhost_user_init(&i2c->vhost_user, &i2c->chardev, errp)) { 219 return; 220 } 221 222 virtio_init(vdev, VIRTIO_ID_I2C_ADAPTER, 0); 223 224 i2c->vhost_dev.nvqs = 1; 225 i2c->vq = virtio_add_queue(vdev, 4, vu_i2c_handle_output); 226 i2c->vhost_dev.vqs = g_new0(struct vhost_virtqueue, i2c->vhost_dev.nvqs); 227 228 ret = vhost_dev_init(&i2c->vhost_dev, &i2c->vhost_user, 229 VHOST_BACKEND_TYPE_USER, 0, errp); 230 if (ret < 0) { 231 do_vhost_user_cleanup(vdev, i2c); 232 } 233 234 qemu_chr_fe_set_handlers(&i2c->chardev, NULL, NULL, vu_i2c_event, NULL, 235 dev, NULL, true); 236 } 237 238 static void vu_i2c_device_unrealize(DeviceState *dev) 239 { 240 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 241 VHostUserI2C *i2c = VHOST_USER_I2C(dev); 242 243 /* This will stop vhost backend if appropriate. */ 244 vu_i2c_set_status(vdev, 0); 245 vhost_dev_cleanup(&i2c->vhost_dev); 246 do_vhost_user_cleanup(vdev, i2c); 247 } 248 249 static const VMStateDescription vu_i2c_vmstate = { 250 .name = "vhost-user-i2c", 251 .unmigratable = 1, 252 }; 253 254 static Property vu_i2c_properties[] = { 255 DEFINE_PROP_CHR("chardev", VHostUserI2C, chardev), 256 DEFINE_PROP_END_OF_LIST(), 257 }; 258 259 static void vu_i2c_class_init(ObjectClass *klass, void *data) 260 { 261 DeviceClass *dc = DEVICE_CLASS(klass); 262 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 263 264 device_class_set_props(dc, vu_i2c_properties); 265 dc->vmsd = &vu_i2c_vmstate; 266 set_bit(DEVICE_CATEGORY_INPUT, dc->categories); 267 vdc->realize = vu_i2c_device_realize; 268 vdc->unrealize = vu_i2c_device_unrealize; 269 vdc->get_features = vu_i2c_get_features; 270 vdc->set_status = vu_i2c_set_status; 271 vdc->guest_notifier_mask = vu_i2c_guest_notifier_mask; 272 vdc->guest_notifier_pending = vu_i2c_guest_notifier_pending; 273 } 274 275 static const TypeInfo vu_i2c_info = { 276 .name = TYPE_VHOST_USER_I2C, 277 .parent = TYPE_VIRTIO_DEVICE, 278 .instance_size = sizeof(VHostUserI2C), 279 .class_init = vu_i2c_class_init, 280 }; 281 282 static void vu_i2c_register_types(void) 283 { 284 type_register_static(&vu_i2c_info); 285 } 286 287 type_init(vu_i2c_register_types)