src/cpu/kvm/device.cc

/*
 * Copyright (c) 2015 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * 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;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
 * OWNER 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 "cpu/kvm/device.hh"

#include <linux/kvm.h>
#include <sys/ioctl.h>
#include <unistd.h>

#include <cassert>
#include <cerrno>

#include "base/logging.hh"

KvmDevice::KvmDevice(int _fd)
    : fd(_fd)
{
}

KvmDevice::~KvmDevice()
{
    close(fd);
}

void
KvmDevice::getAttrPtr(uint32_t group, uint64_t attr, void *data) const
{
#ifdef KVM_GET_DEVICE_ATTR
  struct kvm_device_attr dattr = {
        0, // Flags
        group,
        attr,
        reinterpret_cast<uint64_t>(data),
    };

    if (ioctl(KVM_GET_DEVICE_ATTR, &dattr) == -1) {
        panic("Failed to get attribute (group: %i, attr: %i, errno: %i)",
              group, attr, errno);
    }
#else
    panic("Kernel headers don't support KVM_GET_DEVICE_ATTR\n");
#endif
}

void
KvmDevice::setAttrPtr(uint32_t group, uint64_t attr, const void *data) const
{
#ifdef KVM_SET_DEVICE_ATTR
    struct kvm_device_attr dattr = {
        0, // Flags
        group,
        attr,
        reinterpret_cast<uint64_t>(data),
    };

    if (ioctl(KVM_SET_DEVICE_ATTR, &dattr) == -1) {
        panic("Failed to set attribute (group: %i, attr: %i, errno: %i)",
              group, attr, errno);
    }
#else
    panic("Kernel headers don't support KVM_GET_DEVICE_ATTR\n");
#endif
}

bool
KvmDevice::hasAttr(uint32_t group, uint64_t attr) const
{
#ifdef KVM_HAS_DEVICE_ATTR
    struct kvm_device_attr dattr = {
        0, // Flags
        group,
        attr,
        0, // Data address (ignored)
    };

    return ioctl(KVM_HAS_DEVICE_ATTR, &dattr) == 0;
#else
    panic("Kernel headers don't support KVM_HAS_DEVICE_ATTR\n");
#endif
}

int
KvmDevice::ioctl(int request, long p1) const
{
    assert(fd != -1);

    return ::ioctl(fd, request, p1);
}