qemu/hw/virtio/vhost-vsock.c

419 lines
11 KiB
C

/*
* Virtio vsock device
*
* Copyright 2015 Red Hat, Inc.
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* (at your option) any later version. See the COPYING file in the
* top-level directory.
*/
#include "qemu/osdep.h"
#include <sys/ioctl.h>
#include "standard-headers/linux/virtio_vsock.h"
#include "qapi/error.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
#include "qemu/error-report.h"
#include "hw/virtio/vhost-vsock.h"
#include "qemu/iov.h"
#include "monitor/monitor.h"
enum {
VHOST_VSOCK_SAVEVM_VERSION = 0,
VHOST_VSOCK_QUEUE_SIZE = 128,
};
static void vhost_vsock_get_config(VirtIODevice *vdev, uint8_t *config)
{
VHostVSock *vsock = VHOST_VSOCK(vdev);
struct virtio_vsock_config vsockcfg = {};
virtio_stq_p(vdev, &vsockcfg.guest_cid, vsock->conf.guest_cid);
memcpy(config, &vsockcfg, sizeof(vsockcfg));
}
static int vhost_vsock_set_guest_cid(VHostVSock *vsock)
{
const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
int ret;
if (!vhost_ops->vhost_vsock_set_guest_cid) {
return -ENOSYS;
}
ret = vhost_ops->vhost_vsock_set_guest_cid(&vsock->vhost_dev,
vsock->conf.guest_cid);
if (ret < 0) {
return -errno;
}
return 0;
}
static int vhost_vsock_set_running(VHostVSock *vsock, int start)
{
const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
int ret;
if (!vhost_ops->vhost_vsock_set_running) {
return -ENOSYS;
}
ret = vhost_ops->vhost_vsock_set_running(&vsock->vhost_dev, start);
if (ret < 0) {
return -errno;
}
return 0;
}
static void vhost_vsock_start(VirtIODevice *vdev)
{
VHostVSock *vsock = VHOST_VSOCK(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int ret;
int i;
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
return;
}
ret = vhost_dev_enable_notifiers(&vsock->vhost_dev, vdev);
if (ret < 0) {
error_report("Error enabling host notifiers: %d", -ret);
return;
}
ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, true);
if (ret < 0) {
error_report("Error binding guest notifier: %d", -ret);
goto err_host_notifiers;
}
vsock->vhost_dev.acked_features = vdev->guest_features;
ret = vhost_dev_start(&vsock->vhost_dev, vdev);
if (ret < 0) {
error_report("Error starting vhost: %d", -ret);
goto err_guest_notifiers;
}
ret = vhost_vsock_set_running(vsock, 1);
if (ret < 0) {
error_report("Error starting vhost vsock: %d", -ret);
goto err_dev_start;
}
/* 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 < vsock->vhost_dev.nvqs; i++) {
vhost_virtqueue_mask(&vsock->vhost_dev, vdev, i, false);
}
return;
err_dev_start:
vhost_dev_stop(&vsock->vhost_dev, vdev);
err_guest_notifiers:
k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
err_host_notifiers:
vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
}
static void vhost_vsock_stop(VirtIODevice *vdev)
{
VHostVSock *vsock = VHOST_VSOCK(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;
}
ret = vhost_vsock_set_running(vsock, 0);
if (ret < 0) {
error_report("vhost vsock set running failed: %d", ret);
return;
}
vhost_dev_stop(&vsock->vhost_dev, vdev);
ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
if (ret < 0) {
error_report("vhost guest notifier cleanup failed: %d", ret);
return;
}
vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
}
static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
{
VHostVSock *vsock = VHOST_VSOCK(vdev);
bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
if (!vdev->vm_running) {
should_start = false;
}
if (vsock->vhost_dev.started == should_start) {
return;
}
if (should_start) {
vhost_vsock_start(vdev);
} else {
vhost_vsock_stop(vdev);
}
}
static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
uint64_t requested_features,
Error **errp)
{
/* No feature bits used yet */
return requested_features;
}
static void vhost_vsock_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
/* Do nothing */
}
static void vhost_vsock_guest_notifier_mask(VirtIODevice *vdev, int idx,
bool mask)
{
VHostVSock *vsock = VHOST_VSOCK(vdev);
vhost_virtqueue_mask(&vsock->vhost_dev, vdev, idx, mask);
}
static bool vhost_vsock_guest_notifier_pending(VirtIODevice *vdev, int idx)
{
VHostVSock *vsock = VHOST_VSOCK(vdev);
return vhost_virtqueue_pending(&vsock->vhost_dev, idx);
}
static void vhost_vsock_send_transport_reset(VHostVSock *vsock)
{
VirtQueueElement *elem;
VirtQueue *vq = vsock->event_vq;
struct virtio_vsock_event event = {
.id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
};
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
error_report("vhost-vsock missed transport reset event");
return;
}
if (elem->out_num) {
error_report("invalid vhost-vsock event virtqueue element with "
"out buffers");
goto out;
}
if (iov_from_buf(elem->in_sg, elem->in_num, 0,
&event, sizeof(event)) != sizeof(event)) {
error_report("vhost-vsock event virtqueue element is too short");
goto out;
}
virtqueue_push(vq, elem, sizeof(event));
virtio_notify(VIRTIO_DEVICE(vsock), vq);
out:
g_free(elem);
}
static void vhost_vsock_post_load_timer_cleanup(VHostVSock *vsock)
{
if (!vsock->post_load_timer) {
return;
}
timer_del(vsock->post_load_timer);
timer_free(vsock->post_load_timer);
vsock->post_load_timer = NULL;
}
static void vhost_vsock_post_load_timer_cb(void *opaque)
{
VHostVSock *vsock = opaque;
vhost_vsock_post_load_timer_cleanup(vsock);
vhost_vsock_send_transport_reset(vsock);
}
static int vhost_vsock_pre_save(void *opaque)
{
VHostVSock *vsock = opaque;
/* At this point, backend must be stopped, otherwise
* it might keep writing to memory. */
assert(!vsock->vhost_dev.started);
return 0;
}
static int vhost_vsock_post_load(void *opaque, int version_id)
{
VHostVSock *vsock = opaque;
VirtIODevice *vdev = VIRTIO_DEVICE(vsock);
if (virtio_queue_get_addr(vdev, 2)) {
/* Defer transport reset event to a vm clock timer so that virtqueue
* changes happen after migration has completed.
*/
assert(!vsock->post_load_timer);
vsock->post_load_timer =
timer_new_ns(QEMU_CLOCK_VIRTUAL,
vhost_vsock_post_load_timer_cb,
vsock);
timer_mod(vsock->post_load_timer, 1);
}
return 0;
}
static const VMStateDescription vmstate_virtio_vhost_vsock = {
.name = "virtio-vhost_vsock",
.minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION,
.version_id = VHOST_VSOCK_SAVEVM_VERSION,
.fields = (VMStateField[]) {
VMSTATE_VIRTIO_DEVICE,
VMSTATE_END_OF_LIST()
},
.pre_save = vhost_vsock_pre_save,
.post_load = vhost_vsock_post_load,
};
static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostVSock *vsock = VHOST_VSOCK(dev);
int vhostfd;
int ret;
/* Refuse to use reserved CID numbers */
if (vsock->conf.guest_cid <= 2) {
error_setg(errp, "guest-cid property must be greater than 2");
return;
}
if (vsock->conf.guest_cid > UINT32_MAX) {
error_setg(errp, "guest-cid property must be a 32-bit number");
return;
}
if (vsock->conf.vhostfd) {
vhostfd = monitor_fd_param(cur_mon, vsock->conf.vhostfd, errp);
if (vhostfd == -1) {
error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
return;
}
} else {
vhostfd = open("/dev/vhost-vsock", O_RDWR);
if (vhostfd < 0) {
error_setg_errno(errp, -errno,
"vhost-vsock: failed to open vhost device");
return;
}
}
virtio_init(vdev, "vhost-vsock", VIRTIO_ID_VSOCK,
sizeof(struct virtio_vsock_config));
/* Receive and transmit queues belong to vhost */
virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
/* The event queue belongs to QEMU */
vsock->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
vhost_vsock_handle_output);
vsock->vhost_dev.nvqs = ARRAY_SIZE(vsock->vhost_vqs);
vsock->vhost_dev.vqs = vsock->vhost_vqs;
ret = vhost_dev_init(&vsock->vhost_dev, (void *)(uintptr_t)vhostfd,
VHOST_BACKEND_TYPE_KERNEL, 0);
if (ret < 0) {
error_setg_errno(errp, -ret, "vhost-vsock: vhost_dev_init failed");
goto err_virtio;
}
ret = vhost_vsock_set_guest_cid(vsock);
if (ret < 0) {
error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
goto err_vhost_dev;
}
vsock->post_load_timer = NULL;
return;
err_vhost_dev:
vhost_dev_cleanup(&vsock->vhost_dev);
err_virtio:
virtio_cleanup(vdev);
close(vhostfd);
return;
}
static void vhost_vsock_device_unrealize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostVSock *vsock = VHOST_VSOCK(dev);
vhost_vsock_post_load_timer_cleanup(vsock);
/* This will stop vhost backend if appropriate. */
vhost_vsock_set_status(vdev, 0);
vhost_dev_cleanup(&vsock->vhost_dev);
virtio_cleanup(vdev);
}
static Property vhost_vsock_properties[] = {
DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
DEFINE_PROP_END_OF_LIST(),
};
static void vhost_vsock_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
dc->props = vhost_vsock_properties;
dc->vmsd = &vmstate_virtio_vhost_vsock;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
vdc->realize = vhost_vsock_device_realize;
vdc->unrealize = vhost_vsock_device_unrealize;
vdc->get_features = vhost_vsock_get_features;
vdc->get_config = vhost_vsock_get_config;
vdc->set_status = vhost_vsock_set_status;
vdc->guest_notifier_mask = vhost_vsock_guest_notifier_mask;
vdc->guest_notifier_pending = vhost_vsock_guest_notifier_pending;
}
static const TypeInfo vhost_vsock_info = {
.name = TYPE_VHOST_VSOCK,
.parent = TYPE_VIRTIO_DEVICE,
.instance_size = sizeof(VHostVSock),
.class_init = vhost_vsock_class_init,
};
static void vhost_vsock_register_types(void)
{
type_register_static(&vhost_vsock_info);
}
type_init(vhost_vsock_register_types)