qemu/include/hw/virtio/virtio-bus.h
Cornelia Huck 11380b3619 virtio: handle non-virtio-1-capable backend for ccw
If you run a qemu advertising VERSION_1 with an old kernel where
vhost did not yet support VERSION_1, you'll end up with a device
that is {modern pci|ccw revision 1} but does not advertise VERSION_1.
This is not a sensible configuration and is rejected by the Linux
guest drivers.

To fix this, add a ->post_plugged() callback invoked after features
have been queried that can handle the VERSION_1 bit being withdrawn
and change ccw to fall back to revision 0 if VERSION_1 is gone.

Note that pci is _not_ fixed; we'll need to rethink the approach
for the next release but at least for pci it's not a regression.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-12-02 19:34:11 +02:00

115 lines
4.2 KiB
C

/*
* 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/>.
*
*/
#ifndef VIRTIO_BUS_H
#define VIRTIO_BUS_H
#include "hw/qdev.h"
#include "sysemu/sysemu.h"
#include "hw/virtio/virtio.h"
#define TYPE_VIRTIO_BUS "virtio-bus"
#define VIRTIO_BUS_GET_CLASS(obj) \
OBJECT_GET_CLASS(VirtioBusClass, obj, TYPE_VIRTIO_BUS)
#define VIRTIO_BUS_CLASS(klass) \
OBJECT_CLASS_CHECK(VirtioBusClass, klass, TYPE_VIRTIO_BUS)
#define VIRTIO_BUS(obj) OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_BUS)
typedef struct VirtioBusState VirtioBusState;
typedef struct VirtioBusClass {
/* This is what a VirtioBus must implement */
BusClass parent;
void (*notify)(DeviceState *d, uint16_t vector);
void (*save_config)(DeviceState *d, QEMUFile *f);
void (*save_queue)(DeviceState *d, int n, QEMUFile *f);
void (*save_extra_state)(DeviceState *d, QEMUFile *f);
int (*load_config)(DeviceState *d, QEMUFile *f);
int (*load_queue)(DeviceState *d, int n, QEMUFile *f);
int (*load_done)(DeviceState *d, QEMUFile *f);
int (*load_extra_state)(DeviceState *d, QEMUFile *f);
bool (*has_extra_state)(DeviceState *d);
bool (*query_guest_notifiers)(DeviceState *d);
int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign);
int (*set_host_notifier)(DeviceState *d, int n, bool assigned);
void (*vmstate_change)(DeviceState *d, bool running);
/*
* transport independent init function.
* This is called by virtio-bus just after the device is plugged.
*/
void (*device_plugged)(DeviceState *d, Error **errp);
/*
* Re-evaluate setup after feature bits have been validated
* by the device backend.
*/
void (*post_plugged)(DeviceState *d, Error **errp);
/*
* transport independent exit function.
* This is called by virtio-bus just before the device is unplugged.
*/
void (*device_unplugged)(DeviceState *d);
int (*query_nvectors)(DeviceState *d);
/*
* Does the transport have variable vring alignment?
* (ie can it ever call virtio_queue_set_align()?)
* Note that changing this will break migration for this transport.
*/
bool has_variable_vring_alignment;
} VirtioBusClass;
struct VirtioBusState {
BusState parent_obj;
};
void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp);
void virtio_bus_reset(VirtioBusState *bus);
void virtio_bus_device_unplugged(VirtIODevice *bus);
/* Get the device id of the plugged device. */
uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus);
/* Get the config_len field of the plugged device. */
size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus);
/* Get the features of the plugged device. */
uint32_t virtio_bus_get_vdev_features(VirtioBusState *bus,
uint32_t requested_features);
/* Get bad features of the plugged device. */
uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus);
/* Get config of the plugged device. */
void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config);
/* Set config of the plugged device. */
void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config);
static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus)
{
BusState *qbus = &bus->parent_obj;
BusChild *kid = QTAILQ_FIRST(&qbus->children);
DeviceState *qdev = kid ? kid->child : NULL;
/* This is used on the data path, the cast is guaranteed
* to succeed by the qdev machinery.
*/
return (VirtIODevice *)qdev;
}
#endif /* VIRTIO_BUS_H */