libvirt/src/driver.h
Daniel P. Berrange 55ea7be7d9 Removing probing of secondary drivers
For stateless, client side drivers, it is never correct to
probe for secondary drivers. It is only ever appropriate to
use the secondary driver that is associated with the
hypervisor in question. As a result the ESX & HyperV drivers
have both been forced to do hacks where they register no-op
drivers for the ones they don't implement.

For stateful, server side drivers, we always just want to
use the same built-in shared driver. The exception is
virtualbox which is really a stateless driver and so wants
to use its own server side secondary drivers. To deal with
this virtualbox has to be built as 3 separate loadable
modules to allow registration to work in the right order.

This can all be simplified by introducing a new struct
recording the precise set of secondary drivers each
hypervisor driver wants

struct _virConnectDriver {
    virHypervisorDriverPtr hypervisorDriver;
    virInterfaceDriverPtr interfaceDriver;
    virNetworkDriverPtr networkDriver;
    virNodeDeviceDriverPtr nodeDeviceDriver;
    virNWFilterDriverPtr nwfilterDriver;
    virSecretDriverPtr secretDriver;
    virStorageDriverPtr storageDriver;
};

Instead of registering the hypervisor driver, we now
just register a virConnectDriver instead. This allows
us to remove all probing of secondary drivers. Once we
have chosen the primary driver, we immediately know the
correct secondary drivers to use.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-01-27 12:02:04 +00:00

105 lines
3.5 KiB
C

/*
* driver.h: description of the set of interfaces provided by a
* entry point to the virtualization engine
*
* Copyright (C) 2006-2014 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#ifndef __VIR_DRIVER_H__
# define __VIR_DRIVER_H__
# include <unistd.h>
# include "internal.h"
# include "libvirt_internal.h"
# include "viruri.h"
/* Status codes returned from driver open call. */
typedef enum {
/* Opened successfully. */
VIR_DRV_OPEN_SUCCESS = 0,
/* 'name' is not for us. */
VIR_DRV_OPEN_DECLINED = -1,
/* 'name' is for us, but there was some error. virConnectOpen will
* return an error rather than continue probing the other drivers.
*/
VIR_DRV_OPEN_ERROR = -2,
} virDrvOpenStatus;
/* Internal feature-detection macro. Don't call drv->supports_feature
* directly if you don't have to, because it may be NULL, use this macro
* instead.
*
* Note that this treats a possible error returned by drv->supports_feature
* the same as not supported. If you care about the error, call
* drv->supports_feature directly.
*
* Returns:
* != 0 Feature is supported.
* 0 Feature is not supported.
*/
# define VIR_DRV_SUPPORTS_FEATURE(drv, conn, feature) \
((drv)->connectSupportsFeature ? \
(drv)->connectSupportsFeature((conn), (feature)) > 0 : 0)
# define __VIR_DRIVER_H_INCLUDES___
# include "driver-hypervisor.h"
# include "driver-interface.h"
# include "driver-network.h"
# include "driver-nodedev.h"
# include "driver-nwfilter.h"
# include "driver-secret.h"
# include "driver-state.h"
# include "driver-stream.h"
# include "driver-storage.h"
# undef __VIR_DRIVER_H_INCLUDES___
typedef struct _virConnectDriver virConnectDriver;
typedef virConnectDriver *virConnectDriverPtr;
struct _virConnectDriver {
virHypervisorDriverPtr hypervisorDriver;
virInterfaceDriverPtr interfaceDriver;
virNetworkDriverPtr networkDriver;
virNodeDeviceDriverPtr nodeDeviceDriver;
virNWFilterDriverPtr nwfilterDriver;
virSecretDriverPtr secretDriver;
virStorageDriverPtr storageDriver;
};
int virRegisterConnectDriver(virConnectDriverPtr driver,
bool setSharedDrivers) ATTRIBUTE_RETURN_CHECK;
int virRegisterStateDriver(virStateDriverPtr driver) ATTRIBUTE_RETURN_CHECK;
int virSetSharedInterfaceDriver(virInterfaceDriverPtr driver) ATTRIBUTE_RETURN_CHECK;
int virSetSharedNetworkDriver(virNetworkDriverPtr driver) ATTRIBUTE_RETURN_CHECK;
int virSetSharedNodeDeviceDriver(virNodeDeviceDriverPtr driver) ATTRIBUTE_RETURN_CHECK;
int virSetSharedNWFilterDriver(virNWFilterDriverPtr driver) ATTRIBUTE_RETURN_CHECK;
int virSetSharedSecretDriver(virSecretDriverPtr driver) ATTRIBUTE_RETURN_CHECK;
int virSetSharedStorageDriver(virStorageDriverPtr driver) ATTRIBUTE_RETURN_CHECK;
void *virDriverLoadModule(const char *name);
#endif /* __VIR_DRIVER_H__ */