src/cpu/kvm/device.hh

   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
  38 #ifndef __CPU_KVM_DEVICE_HH__
  39 #define __CPU_KVM_DEVICE_HH__
  40
  41 #include <cstdint>
  42
  43 /**
  44  * KVM device wrapper
  45  *
  46  * This is a wrapper around a device emulated by KVM. Such devices can
  47  * be created using KvmVM::createDevice() API. They are typically used
  48  * for in-kernel interrupt controllers and similar devices.
  49  *
  50  * Each device has a device-specific set of attributes which are
  51  * mapped into groups. The available attributes are described in the
  52  * device's documentation in the kernel source tree
  53  * (Documentation/virtual/kvm/devices/). Each attribute can be
  54  * accessed with the getAttr() and setAttr() access methods. The
  55  * presence of an attribute can be queried using the hasAttr() method.
  56  */
  57 class KvmDevice
  58 {
  59   public:
  60     KvmDevice(int fd);
  61     virtual ~KvmDevice();
  62
  63   public:
  64     /**
  65      * Get the value of an attribute
  66      *
  67      * See KVM's documentation, and specifically the device-specific
  68      * documentation, for available attributes and attribute groups.
  69      *
  70      * @param group Attribute group
  71      * @param attr Attribute ID within group
  72      * @return Attribute value
  73      */
  74     template<typename T>
  75     T getAttr(uint32_t group, uint64_t attr) const {
  76         T data;
  77         getAttrPtr(group, attr, &data);
  78         return data;
  79     }
  80
  81     /**
  82      * Get the value of an attribute
  83      *
  84      * See KVM's documentation, and specifically the device-specific
  85      * documentation, for available attributes and attribute groups.
  86      *
  87      * @param group Attribute group
  88      * @param attr Attribute ID within group
  89      * @return Attribute value
  90      */
  91     template<typename T>
  92     void setAttr(uint32_t group, uint64_t attr, const T &data) const {
  93         setAttrPtr(group, attr, &data);
  94     }
  95
  96     void getAttrPtr(uint32_t group, uint64_t attr, void *data) const;
  97     void setAttrPtr(uint32_t group, uint64_t attr, const void *data) const;
  98
  99     /**
 100      * Check if a device attribute is valid
 101      *
 102      * See KVM's documentation, and specifically the device-specific
 103      * documentation, for available attributes and attribute groups.
 104      *
 105      * @param group Attribute group
 106      * @param attr Attribute ID within group
 107      * @return true if attribute is valid, false otherwise.
 108      */
 109     bool hasAttr(uint32_t group, uint64_t attr) const;
 110
 111   protected:
 112     int ioctl(int request, long p1) const;
 113     int ioctl(int request, void *p1) const {
 114         return ioctl(request, (long)p1);
 115     }
 116     int ioctl(int request) const {
 117         return ioctl(request, 0L);
 118     }
 119
 120   private:
 121     int fd;
 122 };
 123
 124 #endif // __CPU_KVM_DEVICE_HH__