qemu-e2k/hw/virtio/vhost-user-i2c.c

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/*
* Vhost-user i2c virtio device
*
* Copyright (c) 2021 Viresh Kumar <viresh.kumar@linaro.org>
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/qdev-properties.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/vhost-user-i2c.h"
#include "qemu/error-report.h"
#include "standard-headers/linux/virtio_ids.h"
/* Remove this once the header is updated in Linux kernel */
#ifndef VIRTIO_ID_I2C_ADAPTER
#define VIRTIO_ID_I2C_ADAPTER 34
#endif
static const int feature_bits[] = {
VIRTIO_I2C_F_ZERO_LENGTH_REQUEST,
VHOST_INVALID_FEATURE_BIT
};
static void vu_i2c_start(VirtIODevice *vdev)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
int ret, i;
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
return;
}
ret = vhost_dev_enable_notifiers(&i2c->vhost_dev, vdev);
if (ret < 0) {
error_report("Error enabling host notifiers: %d", -ret);
return;
}
ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, true);
if (ret < 0) {
error_report("Error binding guest notifier: %d", -ret);
goto err_host_notifiers;
}
i2c->vhost_dev.acked_features = vdev->guest_features;
ret = vhost_dev_start(&i2c->vhost_dev, vdev);
if (ret < 0) {
error_report("Error starting vhost-user-i2c: %d", -ret);
goto err_guest_notifiers;
}
/*
* guest_notifier_mask/pending not used yet, so just unmask
* everything here. virtio-pci will do the right thing by
* enabling/disabling irqfd.
*/
for (i = 0; i < i2c->vhost_dev.nvqs; i++) {
vhost_virtqueue_mask(&i2c->vhost_dev, vdev, i, false);
}
return;
err_guest_notifiers:
k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false);
err_host_notifiers:
vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev);
}
static void vu_i2c_stop(VirtIODevice *vdev)
{
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int ret;
if (!k->set_guest_notifiers) {
return;
}
vhost_dev_stop(&i2c->vhost_dev, vdev);
ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false);
if (ret < 0) {
error_report("vhost guest notifier cleanup failed: %d", ret);
return;
}
vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev);
}
static void vu_i2c_set_status(VirtIODevice *vdev, uint8_t status)
{
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
if (!vdev->vm_running) {
should_start = false;
}
if (i2c->vhost_dev.started == should_start) {
return;
}
if (should_start) {
vu_i2c_start(vdev);
} else {
vu_i2c_stop(vdev);
}
}
static uint64_t vu_i2c_get_features(VirtIODevice *vdev,
uint64_t requested_features, Error **errp)
{
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
virtio_add_feature(&requested_features, VIRTIO_I2C_F_ZERO_LENGTH_REQUEST);
return vhost_get_features(&i2c->vhost_dev, feature_bits, requested_features);
}
static void vu_i2c_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
/*
* Not normally called; it's the daemon that handles the queue;
* however virtio's cleanup path can call this.
*/
}
static void vu_i2c_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask)
{
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
vhost_virtqueue_mask(&i2c->vhost_dev, vdev, idx, mask);
}
static bool vu_i2c_guest_notifier_pending(VirtIODevice *vdev, int idx)
{
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
return vhost_virtqueue_pending(&i2c->vhost_dev, idx);
}
static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserI2C *i2c)
{
vhost_user_cleanup(&i2c->vhost_user);
virtio_delete_queue(i2c->vq);
virtio_cleanup(vdev);
g_free(i2c->vhost_dev.vqs);
i2c->vhost_dev.vqs = NULL;
}
static int vu_i2c_connect(DeviceState *dev)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
if (i2c->connected) {
return 0;
}
i2c->connected = true;
/* restore vhost state */
if (virtio_device_started(vdev, vdev->status)) {
vu_i2c_start(vdev);
}
return 0;
}
static void vu_i2c_disconnect(DeviceState *dev)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
if (!i2c->connected) {
return;
}
i2c->connected = false;
if (i2c->vhost_dev.started) {
vu_i2c_stop(vdev);
}
}
static void vu_i2c_event(void *opaque, QEMUChrEvent event)
{
DeviceState *dev = opaque;
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
switch (event) {
case CHR_EVENT_OPENED:
if (vu_i2c_connect(dev) < 0) {
qemu_chr_fe_disconnect(&i2c->chardev);
return;
}
break;
case CHR_EVENT_CLOSED:
vu_i2c_disconnect(dev);
break;
case CHR_EVENT_BREAK:
case CHR_EVENT_MUX_IN:
case CHR_EVENT_MUX_OUT:
/* Ignore */
break;
}
}
static void vu_i2c_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserI2C *i2c = VHOST_USER_I2C(dev);
int ret;
if (!i2c->chardev.chr) {
error_setg(errp, "vhost-user-i2c: missing chardev");
return;
}
if (!vhost_user_init(&i2c->vhost_user, &i2c->chardev, errp)) {
return;
}
virtio_init(vdev, "vhost-user-i2c", VIRTIO_ID_I2C_ADAPTER, 0);
i2c->vhost_dev.nvqs = 1;
i2c->vq = virtio_add_queue(vdev, 4, vu_i2c_handle_output);
i2c->vhost_dev.vqs = g_new0(struct vhost_virtqueue, i2c->vhost_dev.nvqs);
ret = vhost_dev_init(&i2c->vhost_dev, &i2c->vhost_user,
VHOST_BACKEND_TYPE_USER, 0, errp);
if (ret < 0) {
do_vhost_user_cleanup(vdev, i2c);
}
qemu_chr_fe_set_handlers(&i2c->chardev, NULL, NULL, vu_i2c_event, NULL,
dev, NULL, true);
}
static void vu_i2c_device_unrealize(DeviceState *dev)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserI2C *i2c = VHOST_USER_I2C(dev);
/* This will stop vhost backend if appropriate. */
vu_i2c_set_status(vdev, 0);
vhost_dev_cleanup(&i2c->vhost_dev);
do_vhost_user_cleanup(vdev, i2c);
}
static const VMStateDescription vu_i2c_vmstate = {
.name = "vhost-user-i2c",
.unmigratable = 1,
};
static Property vu_i2c_properties[] = {
DEFINE_PROP_CHR("chardev", VHostUserI2C, chardev),
DEFINE_PROP_END_OF_LIST(),
};
static void vu_i2c_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
device_class_set_props(dc, vu_i2c_properties);
dc->vmsd = &vu_i2c_vmstate;
set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
vdc->realize = vu_i2c_device_realize;
vdc->unrealize = vu_i2c_device_unrealize;
vdc->get_features = vu_i2c_get_features;
vdc->set_status = vu_i2c_set_status;
vdc->guest_notifier_mask = vu_i2c_guest_notifier_mask;
vdc->guest_notifier_pending = vu_i2c_guest_notifier_pending;
}
static const TypeInfo vu_i2c_info = {
.name = TYPE_VHOST_USER_I2C,
.parent = TYPE_VIRTIO_DEVICE,
.instance_size = sizeof(VHostUserI2C),
.class_init = vu_i2c_class_init,
};
static void vu_i2c_register_types(void)
{
type_register_static(&vu_i2c_info);
}
type_init(vu_i2c_register_types)