armv8_cpu.hh revision 11934:72977e8e15b8 
1/*
2 * Copyright (c) 2015, 2017 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 __ARCH_ARM_KVM_ARMV8_CPU_HH__
41#define __ARCH_ARM_KVM_ARMV8_CPU_HH__
42
43#include <vector>
44
45#include "arch/arm/intregs.hh"
46#include "arch/arm/kvm/base_cpu.hh"
47#include "arch/arm/miscregs.hh"
48
49struct ArmV8KvmCPUParams;
50
51/**
52 * This is an implementation of a KVM-based ARMv8-compatible CPU.
53 *
54 * Known limitations:
55 * <ul>
56 *
57 *   <li>The system-register-based generic timer can only be simulated
58 *       by the host kernel. Workaround: Use a memory mapped timer
59 *       instead to simulate the timer in gem5.
60 *
61 *   <li>Simulating devices (e.g., the generic timer) in the host
62 *       kernel requires that the host kernel also simulates the
63 *       GIC.
64 *
65 *   <li>ID registers in the host and in gem5 must match for switching
66 *       between simulated CPUs and KVM. This is particularly
67 *       important for ID registers describing memory system
68 *       capabilities (e.g., ASID size, physical address size).
69 *
70 *   <li>Switching between a virtualized CPU and a simulated CPU is
71 *       currently not supported if in-kernel device emulation is
72 *       used. This could be worked around by adding support for
73 *       switching to the gem5 (e.g., the KvmGic) side of the device
74 *       models. A simpler workaround is to avoid in-kernel device
75 *       models altogether.
76 *
77 * </ul>
78 *
79 */
80class ArmV8KvmCPU : public BaseArmKvmCPU
81{
82  public:
83    ArmV8KvmCPU(ArmV8KvmCPUParams *params);
84    virtual ~ArmV8KvmCPU();
85
86    void startup() override;
87
88    void dump() const override;
89
90  protected:
91    void updateKvmState() override;
92    void updateThreadContext() override;
93
94  protected:
95    /** Mapping between integer registers in gem5 and KVM */
96    struct IntRegInfo {
97        IntRegInfo(uint64_t _kvm, IntRegIndex _idx, const char *_name)
98            : kvm(_kvm), idx(_idx), name(_name) {}
99
100        /** Register index in KVM */
101        uint64_t kvm;
102        /** Register index in gem5 */
103        IntRegIndex idx;
104        /** Name to use in debug dumps */
105        const char *name;
106    };
107
108    /** Mapping between misc registers in gem5 and registers in KVM */
109    struct MiscRegInfo {
110        MiscRegInfo(uint64_t _kvm, MiscRegIndex _idx, const char *_name)
111            : kvm(_kvm), idx(_idx), name(_name) {}
112
113        /** Register index in KVM */
114        uint64_t kvm;
115        /** Register index in gem5 */
116        MiscRegIndex idx;
117        /** Name to use in debug dumps */
118        const char *name;
119    };
120
121    /**
122     * Get a map between system registers in kvm and gem5 registers
123     *
124     * This method returns a mapping between system registers in kvm
125     * and misc regs in gem5. The actual mapping is only created the
126     * first time the method is called and stored in a cache
127     * (ArmV8KvmCPU::sysRegMap).
128     *
129     * @return Vector of kvm<->misc reg mappings.
130     */
131    const std::vector<ArmV8KvmCPU::MiscRegInfo> &getSysRegMap() const;
132
133    /** Mapping between gem5 integer registers and integer registers in kvm */
134    static const std::vector<ArmV8KvmCPU::IntRegInfo> intRegMap;
135    /** Mapping between gem5 misc registers registers and registers in kvm */
136    static const std::vector<ArmV8KvmCPU::MiscRegInfo> miscRegMap;
137    /** Mapping between gem5 ID misc registers registers and registers in kvm */
138    static const std::vector<ArmV8KvmCPU::MiscRegInfo> miscRegIdMap;
139
140    /** Cached mapping between system registers in kvm and misc regs in gem5 */
141    mutable std::vector<ArmV8KvmCPU::MiscRegInfo> sysRegMap;
142};
143
144#endif // __ARCH_ARM_KVM_ARMV8_CPU_HH__
145