mirror of
https://github.com/Motorhead1991/qemu.git
synced 2025-07-29 05:13:54 -06:00
virtio: add vhost-user-base and a generic vhost-user-device
In theory we shouldn't need to repeat so much boilerplate to support vhost-user backends. This provides a generic vhost-user-base QOM object and a derived vhost-user-device for which the user needs to provide the few bits of information that aren't currently provided by the vhost-user protocol. This should provide a baseline implementation from which the other vhost-user stub can specialise. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230710153522.3469097-8-alex.bennee@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Alex Bennée
Michael S. Tsirkin
parent
f05356f84d
commit
eee7780973
4 changed files with 443 additions and 0 deletions
324
hw/virtio/vhost-user-device.c
Normal file
324
hw/virtio/vhost-user-device.c
Normal file
|
|
@ -0,0 +1,324 @@
|
|||
/*
|
||||
* Generic vhost-user stub. This can be used to connect to any
|
||||
* vhost-user backend. All configuration details must be handled by
|
||||
* the vhost-user daemon itself
|
||||
*
|
||||
* Copyright (c) 2023 Linaro Ltd
|
||||
* Author: Alex Bennée <alex.bennee@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-device.h"
|
||||
#include "qemu/error-report.h"
|
||||
|
||||
static void vub_start(VirtIODevice *vdev)
|
||||
{
|
||||
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
|
||||
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
|
||||
VHostUserBase *vub = VHOST_USER_BASE(vdev);
|
||||
int ret, i;
|
||||
|
||||
if (!k->set_guest_notifiers) {
|
||||
error_report("binding does not support guest notifiers");
|
||||
return;
|
||||
}
|
||||
|
||||
ret = vhost_dev_enable_notifiers(&vub->vhost_dev, vdev);
|
||||
if (ret < 0) {
|
||||
error_report("Error enabling host notifiers: %d", -ret);
|
||||
return;
|
||||
}
|
||||
|
||||
ret = k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, true);
|
||||
if (ret < 0) {
|
||||
error_report("Error binding guest notifier: %d", -ret);
|
||||
goto err_host_notifiers;
|
||||
}
|
||||
|
||||
vub->vhost_dev.acked_features = vdev->guest_features;
|
||||
|
||||
ret = vhost_dev_start(&vub->vhost_dev, vdev, true);
|
||||
if (ret < 0) {
|
||||
error_report("Error starting vhost-user-device: %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 < vub->vhost_dev.nvqs; i++) {
|
||||
vhost_virtqueue_mask(&vub->vhost_dev, vdev, i, false);
|
||||
}
|
||||
|
||||
return;
|
||||
|
||||
err_guest_notifiers:
|
||||
k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false);
|
||||
err_host_notifiers:
|
||||
vhost_dev_disable_notifiers(&vub->vhost_dev, vdev);
|
||||
}
|
||||
|
||||
static void vub_stop(VirtIODevice *vdev)
|
||||
{
|
||||
VHostUserBase *vub = VHOST_USER_BASE(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(&vub->vhost_dev, vdev, true);
|
||||
|
||||
ret = k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false);
|
||||
if (ret < 0) {
|
||||
error_report("vhost guest notifier cleanup failed: %d", ret);
|
||||
return;
|
||||
}
|
||||
|
||||
vhost_dev_disable_notifiers(&vub->vhost_dev, vdev);
|
||||
}
|
||||
|
||||
static void vub_set_status(VirtIODevice *vdev, uint8_t status)
|
||||
{
|
||||
VHostUserBase *vub = VHOST_USER_BASE(vdev);
|
||||
bool should_start = virtio_device_should_start(vdev, status);
|
||||
|
||||
if (vhost_dev_is_started(&vub->vhost_dev) == should_start) {
|
||||
return;
|
||||
}
|
||||
|
||||
if (should_start) {
|
||||
vub_start(vdev);
|
||||
} else {
|
||||
vub_stop(vdev);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* For an implementation where everything is delegated to the backend
|
||||
* we don't do anything other than return the full feature set offered
|
||||
* by the daemon (module the reserved feature bit).
|
||||
*/
|
||||
static uint64_t vub_get_features(VirtIODevice *vdev,
|
||||
uint64_t requested_features, Error **errp)
|
||||
{
|
||||
VHostUserBase *vub = VHOST_USER_BASE(vdev);
|
||||
/* This should be set when the vhost connection initialises */
|
||||
g_assert(vub->vhost_dev.features);
|
||||
return vub->vhost_dev.features & ~(1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
|
||||
}
|
||||
|
||||
static void vub_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 do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserBase *vub)
|
||||
{
|
||||
vhost_user_cleanup(&vub->vhost_user);
|
||||
|
||||
for (int i = 0; i < vub->num_vqs; i++) {
|
||||
VirtQueue *vq = g_ptr_array_index(vub->vqs, i);
|
||||
virtio_delete_queue(vq);
|
||||
}
|
||||
|
||||
virtio_cleanup(vdev);
|
||||
}
|
||||
|
||||
static int vub_connect(DeviceState *dev)
|
||||
{
|
||||
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
||||
VHostUserBase *vub = VHOST_USER_BASE(vdev);
|
||||
|
||||
if (vub->connected) {
|
||||
return 0;
|
||||
}
|
||||
vub->connected = true;
|
||||
|
||||
/* restore vhost state */
|
||||
if (virtio_device_started(vdev, vdev->status)) {
|
||||
vub_start(vdev);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void vub_disconnect(DeviceState *dev)
|
||||
{
|
||||
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
||||
VHostUserBase *vub = VHOST_USER_BASE(vdev);
|
||||
|
||||
if (!vub->connected) {
|
||||
return;
|
||||
}
|
||||
vub->connected = false;
|
||||
|
||||
if (vhost_dev_is_started(&vub->vhost_dev)) {
|
||||
vub_stop(vdev);
|
||||
}
|
||||
}
|
||||
|
||||
static void vub_event(void *opaque, QEMUChrEvent event)
|
||||
{
|
||||
DeviceState *dev = opaque;
|
||||
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
||||
VHostUserBase *vub = VHOST_USER_BASE(vdev);
|
||||
|
||||
switch (event) {
|
||||
case CHR_EVENT_OPENED:
|
||||
if (vub_connect(dev) < 0) {
|
||||
qemu_chr_fe_disconnect(&vub->chardev);
|
||||
return;
|
||||
}
|
||||
break;
|
||||
case CHR_EVENT_CLOSED:
|
||||
vub_disconnect(dev);
|
||||
break;
|
||||
case CHR_EVENT_BREAK:
|
||||
case CHR_EVENT_MUX_IN:
|
||||
case CHR_EVENT_MUX_OUT:
|
||||
/* Ignore */
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
static void vub_device_realize(DeviceState *dev, Error **errp)
|
||||
{
|
||||
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
||||
VHostUserBase *vub = VHOST_USER_BASE(dev);
|
||||
int ret;
|
||||
|
||||
if (!vub->chardev.chr) {
|
||||
error_setg(errp, "vhost-user-device: missing chardev");
|
||||
return;
|
||||
}
|
||||
|
||||
if (!vub->virtio_id) {
|
||||
error_setg(errp, "vhost-user-device: need to define device id");
|
||||
return;
|
||||
}
|
||||
|
||||
if (!vub->num_vqs) {
|
||||
vub->num_vqs = 1; /* reasonable default? */
|
||||
}
|
||||
|
||||
if (!vhost_user_init(&vub->vhost_user, &vub->chardev, errp)) {
|
||||
return;
|
||||
}
|
||||
|
||||
virtio_init(vdev, vub->virtio_id, 0);
|
||||
|
||||
/*
|
||||
* Disable guest notifiers, by default all notifications will be via the
|
||||
* asynchronous vhost-user socket.
|
||||
*/
|
||||
vdev->use_guest_notifier_mask = false;
|
||||
|
||||
/* Allocate queues */
|
||||
vub->vqs = g_ptr_array_sized_new(vub->num_vqs);
|
||||
for (int i = 0; i < vub->num_vqs; i++) {
|
||||
g_ptr_array_add(vub->vqs,
|
||||
virtio_add_queue(vdev, 4, vub_handle_output));
|
||||
}
|
||||
|
||||
vub->vhost_dev.nvqs = vub->num_vqs;
|
||||
vub->vhost_dev.vqs = g_new0(struct vhost_virtqueue, vub->vhost_dev.nvqs);
|
||||
|
||||
/* connect to backend */
|
||||
ret = vhost_dev_init(&vub->vhost_dev, &vub->vhost_user,
|
||||
VHOST_BACKEND_TYPE_USER, 0, errp);
|
||||
|
||||
if (ret < 0) {
|
||||
do_vhost_user_cleanup(vdev, vub);
|
||||
}
|
||||
|
||||
qemu_chr_fe_set_handlers(&vub->chardev, NULL, NULL, vub_event, NULL,
|
||||
dev, NULL, true);
|
||||
}
|
||||
|
||||
static void vub_device_unrealize(DeviceState *dev)
|
||||
{
|
||||
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
|
||||
VHostUserBase *vub = VHOST_USER_BASE(dev);
|
||||
struct vhost_virtqueue *vhost_vqs = vub->vhost_dev.vqs;
|
||||
|
||||
/* This will stop vhost backend if appropriate. */
|
||||
vub_set_status(vdev, 0);
|
||||
vhost_dev_cleanup(&vub->vhost_dev);
|
||||
g_free(vhost_vqs);
|
||||
do_vhost_user_cleanup(vdev, vub);
|
||||
}
|
||||
|
||||
static void vub_class_init(ObjectClass *klass, void *data)
|
||||
{
|
||||
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
|
||||
|
||||
vdc->realize = vub_device_realize;
|
||||
vdc->unrealize = vub_device_unrealize;
|
||||
vdc->get_features = vub_get_features;
|
||||
vdc->set_status = vub_set_status;
|
||||
}
|
||||
|
||||
static const TypeInfo vub_info = {
|
||||
.name = TYPE_VHOST_USER_BASE,
|
||||
.parent = TYPE_VIRTIO_DEVICE,
|
||||
.instance_size = sizeof(VHostUserBase),
|
||||
.class_init = vub_class_init,
|
||||
.class_size = sizeof(VHostUserBaseClass),
|
||||
.abstract = true
|
||||
};
|
||||
|
||||
|
||||
/*
|
||||
* The following is a concrete implementation of the base class which
|
||||
* allows the user to define the key parameters via the command line.
|
||||
*/
|
||||
|
||||
static const VMStateDescription vud_vmstate = {
|
||||
.name = "vhost-user-device",
|
||||
.unmigratable = 1,
|
||||
};
|
||||
|
||||
static Property vud_properties[] = {
|
||||
DEFINE_PROP_CHR("chardev", VHostUserBase, chardev),
|
||||
DEFINE_PROP_UINT16("virtio-id", VHostUserBase, virtio_id, 0),
|
||||
DEFINE_PROP_UINT32("num_vqs", VHostUserBase, num_vqs, 1),
|
||||
DEFINE_PROP_END_OF_LIST(),
|
||||
};
|
||||
|
||||
static void vud_class_init(ObjectClass *klass, void *data)
|
||||
{
|
||||
DeviceClass *dc = DEVICE_CLASS(klass);
|
||||
|
||||
device_class_set_props(dc, vud_properties);
|
||||
dc->vmsd = &vud_vmstate;
|
||||
set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
|
||||
}
|
||||
|
||||
static const TypeInfo vud_info = {
|
||||
.name = TYPE_VHOST_USER_DEVICE,
|
||||
.parent = TYPE_VHOST_USER_BASE,
|
||||
.instance_size = sizeof(VHostUserBase),
|
||||
.class_init = vud_class_init,
|
||||
.class_size = sizeof(VHostUserBaseClass),
|
||||
};
|
||||
|
||||
static void vu_register_types(void)
|
||||
{
|
||||
type_register_static(&vub_info);
|
||||
type_register_static(&vud_info);
|
||||
}
|
||||
|
||||
type_init(vu_register_types)
|
||||
Loading…
Add table
Add a link
Reference in a new issue