freebsd-dev/sys/dev/xen/xenstore/xenstored_dev.c
Roger Pau Monné cfa0b7b82f xen: remove direct usage of HYPERVISOR_start_info
HYPERVISOR_start_info is only available to PV and PVHv1 guests, HVM
and PVHv2 guests get this data from HVM parameters that are fetched
using a hypercall.

Instead provide a set of helper functions that should be used to fetch
this data. The helper functions have different implementations
depending on whether FreeBSD is running as PVHv1 or HVM/PVHv2 guest
type.

This helps to cleanup generic Xen code by removing quite a lot of
xen_pv_domain and xen_hvm_domain macro usages.

Sponsored by:	Citrix Systems R&D
2018-07-19 07:54:45 +00:00

166 lines
4.4 KiB
C

/*
* Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/cdefs.h>
#include <sys/errno.h>
#include <sys/uio.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/conf.h>
#include <sys/module.h>
#include <xen/xen-os.h>
#include <xen/hypervisor.h>
#include <xen/xenstore/xenstorevar.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#define XSD_READ_SIZE 20
static int xsd_dev_read(struct cdev *dev, struct uio *uio, int ioflag);
static int xsd_dev_mmap(struct cdev *dev, vm_ooffset_t offset,
vm_paddr_t *paddr, int nprot, vm_memattr_t *memattr);
static struct cdevsw xsd_dev_cdevsw = {
.d_version = D_VERSION,
.d_read = xsd_dev_read,
.d_mmap = xsd_dev_mmap,
.d_name = "xsd_dev",
};
static int
xsd_dev_read(struct cdev *dev, struct uio *uio, int ioflag)
{
char evtchn[XSD_READ_SIZE];
int error, len;
len = snprintf(evtchn, sizeof(evtchn), "%u", xs_evtchn());
if (len < 0 || len > uio->uio_resid)
return (EINVAL);
error = uiomove(evtchn, len, uio);
if (error)
return (error);
return (0);
}
static int
xsd_dev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
int nprot, vm_memattr_t *memattr)
{
if (offset != 0)
return (EINVAL);
*paddr = xs_address();
return (0);
}
/*------------------ Private Device Attachment Functions --------------------*/
/**
* \brief Identify instances of this device type in the system.
*
* \param driver The driver performing this identify action.
* \param parent The NewBus parent device for any devices this method adds.
*/
static void
xsd_dev_identify(driver_t *driver __unused, device_t parent)
{
if (!xen_domain() || xs_initialized())
return;
/*
* Only attach if xenstore is not available, because we are the
* domain that's supposed to run it.
*/
BUS_ADD_CHILD(parent, 0, driver->name, 0);
}
/**
* \brief Probe for the existence of the Xenstored device
*
* \param dev NewBus device_t for this instance.
*
* \return Always returns 0 indicating success.
*/
static int
xsd_dev_probe(device_t dev)
{
device_set_desc(dev, "Xenstored user-space device");
return (BUS_PROBE_NOWILDCARD);
}
/**
* \brief Attach the Xenstored device.
*
* \param dev NewBus device_t for this instance.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*/
static int
xsd_dev_attach(device_t dev)
{
struct cdev *xsd_cdev;
xsd_cdev = make_dev(&xsd_dev_cdevsw, 0, UID_ROOT, GID_WHEEL, 0400,
"xen/xenstored");
if (xsd_cdev == NULL)
return (EINVAL);
return (0);
}
/*-------------------- Private Device Attachment Data -----------------------*/
static device_method_t xsd_dev_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, xsd_dev_identify),
DEVMETHOD(device_probe, xsd_dev_probe),
DEVMETHOD(device_attach, xsd_dev_attach),
DEVMETHOD_END
};
DEFINE_CLASS_0(xsd_dev, xsd_dev_driver, xsd_dev_methods, 0);
devclass_t xsd_dev_devclass;
DRIVER_MODULE(xsd_dev, xenpv, xsd_dev_driver, xsd_dev_devclass,
NULL, NULL);