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qemu/hw/virtio/virtio-bus.c

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/*
* VirtioBus
*
* Copyright (C) 2012 : GreenSocs Ltd
* http://www.greensocs.com/ , email: info@greensocs.com
*
* Developed by :
* Frederic Konrad <fred.konrad@greensocs.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "qemu/error-report.h"
#include "hw/qdev.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio.h"
/* #define DEBUG_VIRTIO_BUS */
#ifdef DEBUG_VIRTIO_BUS
#define DPRINTF(fmt, ...) \
do { printf("virtio_bus: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) do { } while (0)
#endif
/* A VirtIODevice is being plugged */
void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp)
{
DeviceState *qdev = DEVICE(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(qdev));
VirtioBusState *bus = VIRTIO_BUS(qbus);
VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
DPRINTF("%s: plug device.\n", qbus->name);
if (klass->device_plugged != NULL) {
klass->device_plugged(qbus->parent, errp);
}
/* Get the features of the plugged device. */
assert(vdc->get_features != NULL);
vdev->host_features = vdc->get_features(vdev, vdev->host_features,
errp);
if (klass->post_plugged != NULL) {
klass->post_plugged(qbus->parent, errp);
}
}
/* Reset the virtio_bus */
void virtio_bus_reset(VirtioBusState *bus)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
DPRINTF("%s: reset device.\n", BUS(bus)->name);
if (vdev != NULL) {
virtio_reset(vdev);
}
}
/* A VirtIODevice is being unplugged */
void virtio_bus_device_unplugged(VirtIODevice *vdev)
{
DeviceState *qdev = DEVICE(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(qdev));
VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
DPRINTF("%s: remove device.\n", qbus->name);
if (vdev != NULL) {
if (klass->device_unplugged != NULL) {
klass->device_unplugged(qbus->parent);
}
}
}
/* Get the device id of the plugged device. */
uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
assert(vdev != NULL);
return vdev->device_id;
}
/* Get the config_len field of the plugged device. */
size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
assert(vdev != NULL);
return vdev->config_len;
}
/* Get bad features of the plugged device. */
uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *k;
assert(vdev != NULL);
k = VIRTIO_DEVICE_GET_CLASS(vdev);
if (k->bad_features != NULL) {
return k->bad_features(vdev);
} else {
return 0;
}
}
/* Get config of the plugged device. */
void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *k;
assert(vdev != NULL);
k = VIRTIO_DEVICE_GET_CLASS(vdev);
if (k->get_config != NULL) {
k->get_config(vdev, config);
}
}
/* Set config of the plugged device. */
void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *k;
assert(vdev != NULL);
k = VIRTIO_DEVICE_GET_CLASS(vdev);
if (k->set_config != NULL) {
k->set_config(vdev, config);
}
}
/*
* This function handles both assigning the ioeventfd handler and
* registering it with the kernel.
* assign: register/deregister ioeventfd with the kernel
* set_handler: use the generic ioeventfd handler
*/
static int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
int n, bool assign, bool set_handler)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
VirtQueue *vq = virtio_get_queue(vdev, n);
EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
int r = 0;
if (assign) {
r = event_notifier_init(notifier, 1);
if (r < 0) {
error_report("%s: unable to init event notifier: %d", __func__, r);
return r;
}
virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler);
r = k->ioeventfd_assign(proxy, notifier, n, assign);
if (r < 0) {
error_report("%s: unable to assign ioeventfd: %d", __func__, r);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
return r;
}
} else {
k->ioeventfd_assign(proxy, notifier, n, assign);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
}
return r;
}
void virtio_bus_start_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtIODevice *vdev;
int n, r;
if (!k->ioeventfd_started || k->ioeventfd_started(proxy)) {
return;
}
if (k->ioeventfd_disabled(proxy)) {
return;
}
vdev = virtio_bus_get_device(bus);
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, true, true);
if (r < 0) {
goto assign_error;
}
}
k->ioeventfd_set_started(proxy, true, false);
return;
assign_error:
while (--n >= 0) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, false, false);
assert(r >= 0);
}
k->ioeventfd_set_started(proxy, false, true);
error_report("%s: failed. Fallback to userspace (slower).", __func__);
}
void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtIODevice *vdev;
int n, r;
if (!k->ioeventfd_started || !k->ioeventfd_started(proxy)) {
return;
}
vdev = virtio_bus_get_device(bus);
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, false, false);
assert(r >= 0);
}
k->ioeventfd_set_started(proxy, false, false);
}
/*
* This function switches from/to the generic ioeventfd handler.
* assign==false means 'use generic ioeventfd handler'.
*/
int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
if (!k->ioeventfd_started) {
return -ENOSYS;
}
k->ioeventfd_set_disabled(proxy, assign);
if (assign) {
/*
* Stop using the generic ioeventfd, we are doing eventfd handling
* ourselves below
*
* FIXME: We should just switch the handler and not deassign the
* ioeventfd.
* Otherwise, there's a window where we don't have an
* ioeventfd and we may end up with a notification where
* we don't expect one.
*/
virtio_bus_stop_ioeventfd(bus);
}
return set_host_notifier_internal(proxy, bus, n, assign, false);
}
static char *virtio_bus_get_dev_path(DeviceState *dev)
{
BusState *bus = qdev_get_parent_bus(dev);
DeviceState *proxy = DEVICE(bus->parent);
return qdev_get_dev_path(proxy);
}
static char *virtio_bus_get_fw_dev_path(DeviceState *dev)
{
return NULL;
}
static void virtio_bus_class_init(ObjectClass *klass, void *data)
{
BusClass *bus_class = BUS_CLASS(klass);
bus_class->get_dev_path = virtio_bus_get_dev_path;
bus_class->get_fw_dev_path = virtio_bus_get_fw_dev_path;
}
static const TypeInfo virtio_bus_info = {
.name = TYPE_VIRTIO_BUS,
.parent = TYPE_BUS,
.instance_size = sizeof(VirtioBusState),
.abstract = true,
.class_size = sizeof(VirtioBusClass),
.class_init = virtio_bus_class_init
};
static void virtio_register_types(void)
{
type_register_static(&virtio_bus_info);
}
type_init(virtio_register_types)
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