qemu/hw/virtio/vhost-user-fs.c

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/*
* Vhost-user filesystem virtio device
*
* Copyright 2018-2019 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_fs.h"
#include "qapi/error.h"
#include "hw/qdev-properties.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
#include "qemu/error-report.h"
#include "hw/virtio/vhost-user-fs.h"
#include "monitor/monitor.h"
static void vuf_get_config(VirtIODevice *vdev, uint8_t *config)
{
VHostUserFS *fs = VHOST_USER_FS(vdev);
struct virtio_fs_config fscfg = {};
memcpy((char *)fscfg.tag, fs->conf.tag,
MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag)));
virtio_stl_p(vdev, &fscfg.num_request_queues, fs->conf.num_request_queues);
memcpy(config, &fscfg, sizeof(fscfg));
}
static void vuf_start(VirtIODevice *vdev)
{
VHostUserFS *fs = VHOST_USER_FS(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(&fs->vhost_dev, vdev);
if (ret < 0) {
error_report("Error enabling host notifiers: %d", -ret);
return;
}
ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, true);
if (ret < 0) {
error_report("Error binding guest notifier: %d", -ret);
goto err_host_notifiers;
}
fs->vhost_dev.acked_features = vdev->guest_features;
ret = vhost_dev_start(&fs->vhost_dev, vdev);
if (ret < 0) {
error_report("Error starting vhost: %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 < fs->vhost_dev.nvqs; i++) {
vhost_virtqueue_mask(&fs->vhost_dev, vdev, i, false);
}
return;
err_guest_notifiers:
k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false);
err_host_notifiers:
vhost_dev_disable_notifiers(&fs->vhost_dev, vdev);
}
static void vuf_stop(VirtIODevice *vdev)
{
VHostUserFS *fs = VHOST_USER_FS(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(&fs->vhost_dev, vdev);
ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false);
if (ret < 0) {
error_report("vhost guest notifier cleanup failed: %d", ret);
return;
}
vhost_dev_disable_notifiers(&fs->vhost_dev, vdev);
}
static void vuf_set_status(VirtIODevice *vdev, uint8_t status)
{
VHostUserFS *fs = VHOST_USER_FS(vdev);
bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
if (!vdev->vm_running) {
should_start = false;
}
if (fs->vhost_dev.started == should_start) {
return;
}
if (should_start) {
vuf_start(vdev);
} else {
vuf_stop(vdev);
}
}
static uint64_t vuf_get_features(VirtIODevice *vdev,
uint64_t requested_features,
Error **errp)
{
/* No feature bits used yet */
return requested_features;
}
static void vuf_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 vuf_guest_notifier_mask(VirtIODevice *vdev, int idx,
bool mask)
{
VHostUserFS *fs = VHOST_USER_FS(vdev);
vhost_virtqueue_mask(&fs->vhost_dev, vdev, idx, mask);
}
static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx)
{
VHostUserFS *fs = VHOST_USER_FS(vdev);
return vhost_virtqueue_pending(&fs->vhost_dev, idx);
}
static void vuf_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserFS *fs = VHOST_USER_FS(dev);
unsigned int i;
size_t len;
int ret;
if (!fs->conf.chardev.chr) {
error_setg(errp, "missing chardev");
return;
}
if (!fs->conf.tag) {
error_setg(errp, "missing tag property");
return;
}
len = strlen(fs->conf.tag);
if (len == 0) {
error_setg(errp, "tag property cannot be empty");
return;
}
if (len > sizeof_field(struct virtio_fs_config, tag)) {
error_setg(errp, "tag property must be %zu bytes or less",
sizeof_field(struct virtio_fs_config, tag));
return;
}
if (fs->conf.num_request_queues == 0) {
error_setg(errp, "num-request-queues property must be larger than 0");
return;
}
if (!is_power_of_2(fs->conf.queue_size)) {
error_setg(errp, "queue-size property must be a power of 2");
return;
}
if (fs->conf.queue_size > VIRTQUEUE_MAX_SIZE) {
error_setg(errp, "queue-size property must be %u or smaller",
VIRTQUEUE_MAX_SIZE);
return;
}
if (!vhost_user_init(&fs->vhost_user, &fs->conf.chardev, errp)) {
return;
}
virtio_init(vdev, "vhost-user-fs", VIRTIO_ID_FS,
sizeof(struct virtio_fs_config));
/* Hiprio queue */
virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
/* Request queues */
for (i = 0; i < fs->conf.num_request_queues; i++) {
virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
}
/* 1 high prio queue, plus the number configured */
fs->vhost_dev.nvqs = 1 + fs->conf.num_request_queues;
fs->vhost_dev.vqs = g_new0(struct vhost_virtqueue, fs->vhost_dev.nvqs);
ret = vhost_dev_init(&fs->vhost_dev, &fs->vhost_user,
VHOST_BACKEND_TYPE_USER, 0);
if (ret < 0) {
error_setg_errno(errp, -ret, "vhost_dev_init failed");
goto err_virtio;
}
return;
err_virtio:
vhost_user_cleanup(&fs->vhost_user);
virtio_cleanup(vdev);
g_free(fs->vhost_dev.vqs);
return;
}
static void vuf_device_unrealize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserFS *fs = VHOST_USER_FS(dev);
/* This will stop vhost backend if appropriate. */
vuf_set_status(vdev, 0);
vhost_dev_cleanup(&fs->vhost_dev);
vhost_user_cleanup(&fs->vhost_user);
virtio_cleanup(vdev);
g_free(fs->vhost_dev.vqs);
fs->vhost_dev.vqs = NULL;
}
static const VMStateDescription vuf_vmstate = {
.name = "vhost-user-fs",
.unmigratable = 1,
};
static Property vuf_properties[] = {
DEFINE_PROP_CHR("chardev", VHostUserFS, conf.chardev),
DEFINE_PROP_STRING("tag", VHostUserFS, conf.tag),
DEFINE_PROP_UINT16("num-request-queues", VHostUserFS,
conf.num_request_queues, 1),
DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128),
DEFINE_PROP_END_OF_LIST(),
};
static void vuf_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
dc->props = vuf_properties;
dc->vmsd = &vuf_vmstate;
set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
vdc->realize = vuf_device_realize;
vdc->unrealize = vuf_device_unrealize;
vdc->get_features = vuf_get_features;
vdc->get_config = vuf_get_config;
vdc->set_status = vuf_set_status;
vdc->guest_notifier_mask = vuf_guest_notifier_mask;
vdc->guest_notifier_pending = vuf_guest_notifier_pending;
}
static const TypeInfo vuf_info = {
.name = TYPE_VHOST_USER_FS,
.parent = TYPE_VIRTIO_DEVICE,
.instance_size = sizeof(VHostUserFS),
.class_init = vuf_class_init,
};
static void vuf_register_types(void)
{
type_register_static(&vuf_info);
}
type_init(vuf_register_types)