vhost-user-i2c.c (7561B)
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 22static 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 65err_guest_notifiers: 66 k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false); 67err_host_notifiers: 68 vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev); 69} 70 71static 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 93static 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 113static uint64_t vu_i2c_get_features(VirtIODevice *vdev, 114 uint64_t requested_features, Error **errp) 115{ 116 /* No feature bits used yet */ 117 return requested_features; 118} 119 120static void vu_i2c_handle_output(VirtIODevice *vdev, VirtQueue *vq) 121{ 122 /* 123 * Not normally called; it's the daemon that handles the queue; 124 * however virtio's cleanup path can call this. 125 */ 126} 127 128static void vu_i2c_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask) 129{ 130 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 131 132 vhost_virtqueue_mask(&i2c->vhost_dev, vdev, idx, mask); 133} 134 135static bool vu_i2c_guest_notifier_pending(VirtIODevice *vdev, int idx) 136{ 137 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 138 139 return vhost_virtqueue_pending(&i2c->vhost_dev, idx); 140} 141 142static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserI2C *i2c) 143{ 144 vhost_user_cleanup(&i2c->vhost_user); 145 virtio_delete_queue(i2c->vq); 146 virtio_cleanup(vdev); 147 g_free(i2c->vhost_dev.vqs); 148 i2c->vhost_dev.vqs = NULL; 149} 150 151static int vu_i2c_connect(DeviceState *dev) 152{ 153 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 154 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 155 156 if (i2c->connected) { 157 return 0; 158 } 159 i2c->connected = true; 160 161 /* restore vhost state */ 162 if (virtio_device_started(vdev, vdev->status)) { 163 vu_i2c_start(vdev); 164 } 165 166 return 0; 167} 168 169static void vu_i2c_disconnect(DeviceState *dev) 170{ 171 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 172 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 173 174 if (!i2c->connected) { 175 return; 176 } 177 i2c->connected = false; 178 179 if (i2c->vhost_dev.started) { 180 vu_i2c_stop(vdev); 181 } 182} 183 184static void vu_i2c_event(void *opaque, QEMUChrEvent event) 185{ 186 DeviceState *dev = opaque; 187 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 188 VHostUserI2C *i2c = VHOST_USER_I2C(vdev); 189 190 switch (event) { 191 case CHR_EVENT_OPENED: 192 if (vu_i2c_connect(dev) < 0) { 193 qemu_chr_fe_disconnect(&i2c->chardev); 194 return; 195 } 196 break; 197 case CHR_EVENT_CLOSED: 198 vu_i2c_disconnect(dev); 199 break; 200 case CHR_EVENT_BREAK: 201 case CHR_EVENT_MUX_IN: 202 case CHR_EVENT_MUX_OUT: 203 /* Ignore */ 204 break; 205 } 206} 207 208static void vu_i2c_device_realize(DeviceState *dev, Error **errp) 209{ 210 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 211 VHostUserI2C *i2c = VHOST_USER_I2C(dev); 212 int ret; 213 214 if (!i2c->chardev.chr) { 215 error_setg(errp, "vhost-user-i2c: missing chardev"); 216 return; 217 } 218 219 if (!vhost_user_init(&i2c->vhost_user, &i2c->chardev, errp)) { 220 return; 221 } 222 223 virtio_init(vdev, "vhost-user-i2c", VIRTIO_ID_I2C_ADAPTER, 0); 224 225 i2c->vhost_dev.nvqs = 1; 226 i2c->vq = virtio_add_queue(vdev, 4, vu_i2c_handle_output); 227 i2c->vhost_dev.vqs = g_new0(struct vhost_virtqueue, i2c->vhost_dev.nvqs); 228 229 ret = vhost_dev_init(&i2c->vhost_dev, &i2c->vhost_user, 230 VHOST_BACKEND_TYPE_USER, 0, errp); 231 if (ret < 0) { 232 do_vhost_user_cleanup(vdev, i2c); 233 } 234 235 qemu_chr_fe_set_handlers(&i2c->chardev, NULL, NULL, vu_i2c_event, NULL, 236 dev, NULL, true); 237} 238 239static void vu_i2c_device_unrealize(DeviceState *dev) 240{ 241 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 242 VHostUserI2C *i2c = VHOST_USER_I2C(dev); 243 244 /* This will stop vhost backend if appropriate. */ 245 vu_i2c_set_status(vdev, 0); 246 vhost_dev_cleanup(&i2c->vhost_dev); 247 do_vhost_user_cleanup(vdev, i2c); 248} 249 250static const VMStateDescription vu_i2c_vmstate = { 251 .name = "vhost-user-i2c", 252 .unmigratable = 1, 253}; 254 255static Property vu_i2c_properties[] = { 256 DEFINE_PROP_CHR("chardev", VHostUserI2C, chardev), 257 DEFINE_PROP_END_OF_LIST(), 258}; 259 260static 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 276static 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 283static void vu_i2c_register_types(void) 284{ 285 type_register_static(&vu_i2c_info); 286} 287 288type_init(vu_i2c_register_types)