device.hh revision 10859 
1/*
2 * Copyright (c) 2015 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andreas Sandberg
38 */
39
40#ifndef __CPU_KVM_DEVICE_HH__
41#define __CPU_KVM_DEVICE_HH__
42
43#include <cstdint>
44
45/**
46 * KVM device wrapper
47 *
48 * This is a wrapper around a device emulated by KVM. Such devices can
49 * be created using KvmVM::createDevice() API. They are typically used
50 * for in-kernel interrupt controllers and similar devices.
51 *
52 * Each device has a device-specific set of attributes which are
53 * mapped into groups. The available attributes are described in the
54 * device's documentation in the kernel source tree
55 * (Documentation/virtual/kvm/devices/). Each attribute can be
56 * accessed with the getAttr() and setAttr() access methods. The
57 * presence of an attribute can be queried using the hasAttr() method.
58 */
59class KvmDevice
60{
61  public:
62    KvmDevice(int fd);
63    virtual ~KvmDevice();
64
65  public:
66    /**
67     * Get the value of an attribute
68     *
69     * See KVM's documentation, and specifically the device-specific
70     * documentation, for available attributes and attribute groups.
71     *
72     * @param group Attribute group
73     * @param attr Attribute ID within group
74     * @return Attribute value
75     */
76    template<typename T>
77    T getAttr(uint32_t group, uint64_t attr) const {
78        T data;
79        getAttrPtr(group, attr, &data);
80        return data;
81    }
82
83    /**
84     * Get the value of an attribute
85     *
86     * See KVM's documentation, and specifically the device-specific
87     * documentation, for available attributes and attribute groups.
88     *
89     * @param group Attribute group
90     * @param attr Attribute ID within group
91     * @return Attribute value
92     */
93    template<typename T>
94    void setAttr(uint32_t group, uint64_t attr, const T &data) const {
95        setAttrPtr(group, attr, &data);
96    }
97
98    void getAttrPtr(uint32_t group, uint64_t attr, void *data) const;
99    void setAttrPtr(uint32_t group, uint64_t attr, const void *data) const;
100
101    /**
102     * Check if a device attribute is valid
103     *
104     * See KVM's documentation, and specifically the device-specific
105     * documentation, for available attributes and attribute groups.
106     *
107     * @param group Attribute group
108     * @param attr Attribute ID within group
109     * @return true if attribute is valid, false otherwise.
110     */
111    bool hasAttr(uint32_t group, uint64_t attr) const;
112
113  protected:
114    int ioctl(int request, long p1) const;
115    int ioctl(int request, void *p1) const {
116        return ioctl(request, (long)p1);
117    }
118    int ioctl(int request) const {
119        return ioctl(request, 0L);
120    }
121
122  private:
123    int fd;
124};
125
126#endif // __CPU_KVM_DEVICE_HH__
127