src/arch/arm/kvm/gic.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2015-2017, 2021 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 "arch/arm/kvm/gic.hh"

 #include <linux/kvm.h>

 #include "arch/arm/kvm/base_cpu.hh"
 #include "arch/arm/regs/misc.hh"
 #include "debug/GIC.hh"
 #include "debug/Interrupt.hh"
 #include "params/MuxingKvmGicV2.hh"

 namespace gem5
 {

 KvmKernelGic::KvmKernelGic(KvmVM &_vm, uint32_t dev, unsigned it_lines)
     : vm(_vm),
       kdev(vm.createDevice(dev))
 {
     // Tell the VM that we will emulate the GIC in the kernel. This
     // disables IRQ and FIQ handling in the KVM CPU model.
     vm.enableKernelIRQChip();

     kdev.setAttr<uint32_t>(KVM_DEV_ARM_VGIC_GRP_NR_IRQS, 0, it_lines);
 }

 KvmKernelGic::~KvmKernelGic()
 {
 }

 void
 KvmKernelGic::setSPI(unsigned spi)
 {
     setIntState(KVM_ARM_IRQ_TYPE_SPI, 0, spi, true);
 }

 void
 KvmKernelGic::clearSPI(unsigned spi)
 {
     setIntState(KVM_ARM_IRQ_TYPE_SPI, 0, spi, false);
 }

 void
 KvmKernelGic::setPPI(unsigned vcpu, unsigned ppi)
 {
     setIntState(KVM_ARM_IRQ_TYPE_PPI, vcpu, ppi, true);
 }

 void
 KvmKernelGic::clearPPI(unsigned vcpu, unsigned ppi)
 {
     setIntState(KVM_ARM_IRQ_TYPE_PPI, vcpu, ppi, false);
 }

 void
 KvmKernelGic::setIntState(unsigned type, unsigned vcpu, unsigned irq,
                           bool high)
 {
     const unsigned vcpu_index = vcpu & 0xff;
     const unsigned vcpu2_index = (vcpu >> 8) & 0xff;

     static const bool vcpu2_enabled = vm.kvm->capIRQLineLayout2();
     uint32_t kvm_vcpu = (vcpu_index << KVM_ARM_IRQ_VCPU_SHIFT);

 #if defined(KVM_ARM_IRQ_VCPU2_SHIFT)
     if (vcpu2_enabled)
         kvm_vcpu |= vcpu2_index << KVM_ARM_IRQ_VCPU2_SHIFT;
 #endif

     panic_if((!vcpu2_enabled && vcpu2_index) || kvm_vcpu > 0xffff,
               "VCPU out of range");

     assert(type <= KVM_ARM_IRQ_TYPE_MASK);
     assert(irq <= KVM_ARM_IRQ_NUM_MASK);
     const uint32_t line(
         kvm_vcpu |
         (type << KVM_ARM_IRQ_TYPE_SHIFT) |
         (irq << KVM_ARM_IRQ_NUM_SHIFT));

     vm.setIRQLine(line, high);
 }

 KvmKernelGicV2::KvmKernelGicV2(KvmVM &_vm,
                                const MuxingKvmGicV2Params &p)
     : KvmKernelGic(_vm, KVM_DEV_TYPE_ARM_VGIC_V2, p.it_lines),
       cpuRange(RangeSize(p.cpu_addr, KVM_VGIC_V2_CPU_SIZE)),
       distRange(RangeSize(p.dist_addr, KVM_VGIC_V2_DIST_SIZE))
 {
     kdev.setAttr<uint64_t>(
         KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V2_ADDR_TYPE_DIST, p.dist_addr);
     kdev.setAttr<uint64_t>(
         KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V2_ADDR_TYPE_CPU, p.cpu_addr);
 }

 uint32_t
 KvmKernelGicV2::getGicReg(unsigned group, unsigned vcpu, unsigned offset)
 {
     uint64_t reg;

     assert(vcpu <= KVM_ARM_IRQ_VCPU_MASK);
     const uint64_t attr(
         ((uint64_t)vcpu << KVM_DEV_ARM_VGIC_CPUID_SHIFT) |
         (offset << KVM_DEV_ARM_VGIC_OFFSET_SHIFT));

     kdev.getAttrPtr(group, attr, &reg);
     return (uint32_t) reg;
 }

 void
 KvmKernelGicV2::setGicReg(unsigned group, unsigned vcpu, unsigned offset,
                           unsigned value)
 {
     uint64_t reg = value;

     assert(vcpu <= KVM_ARM_IRQ_VCPU_MASK);
     const uint64_t attr(
         ((uint64_t)vcpu << KVM_DEV_ARM_VGIC_CPUID_SHIFT) |
         (offset << KVM_DEV_ARM_VGIC_OFFSET_SHIFT));

     kdev.setAttrPtr(group, attr, &reg);
 }

 uint32_t
 KvmKernelGicV2::readDistributor(ContextID ctx, Addr daddr)
 {
     auto vcpu = vm.contextIdToVCpuId(ctx);
     return getGicReg(KVM_DEV_ARM_VGIC_GRP_DIST_REGS, vcpu, daddr);
 }

 uint32_t
 KvmKernelGicV2::readCpu(ContextID ctx, Addr daddr)
 {
     auto vcpu = vm.contextIdToVCpuId(ctx);
     return getGicReg(KVM_DEV_ARM_VGIC_GRP_CPU_REGS, vcpu, daddr);
 }

 void
 KvmKernelGicV2::writeDistributor(ContextID ctx, Addr daddr, uint32_t data)
 {
     auto vcpu = vm.contextIdToVCpuId(ctx);
     setGicReg(KVM_DEV_ARM_VGIC_GRP_DIST_REGS, vcpu, daddr, data);
 }

 void
 KvmKernelGicV2::writeCpu(ContextID ctx, Addr daddr, uint32_t data)
 {
     auto vcpu = vm.contextIdToVCpuId(ctx);
     setGicReg(KVM_DEV_ARM_VGIC_GRP_CPU_REGS, vcpu, daddr, data);
 }

 #ifndef SZ_64K
 #define SZ_64K 0x00000040
 #endif

 KvmKernelGicV3::KvmKernelGicV3(KvmVM &_vm,
                                const MuxingKvmGicV3Params &p)
     : KvmKernelGic(_vm, KVM_DEV_TYPE_ARM_VGIC_V3, p.it_lines),
       redistRange(RangeSize(p.redist_addr, KVM_VGIC_V3_REDIST_SIZE)),
       distRange(RangeSize(p.dist_addr, KVM_VGIC_V3_DIST_SIZE))
 {
     kdev.setAttr<uint64_t>(
         KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V3_ADDR_TYPE_DIST, p.dist_addr);
     kdev.setAttr<uint64_t>(
         KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V3_ADDR_TYPE_REDIST, p.redist_addr);
 }

 void
 KvmKernelGicV3::init()
 {
     kdev.setAttr<uint64_t>(
         KVM_DEV_ARM_VGIC_GRP_CTRL, KVM_DEV_ARM_VGIC_CTRL_INIT, 0);
 }

 template <typename Ret>
 Ret
 KvmKernelGicV3::getGicReg(unsigned group, unsigned mpidr, unsigned offset)
 {
     Ret reg;

     assert(mpidr <= KVM_DEV_ARM_VGIC_V3_MPIDR_MASK);
     const uint64_t attr(
         ((uint64_t)mpidr << KVM_DEV_ARM_VGIC_V3_MPIDR_SHIFT) |
         (offset << KVM_DEV_ARM_VGIC_OFFSET_SHIFT));

     kdev.getAttrPtr(group, attr, &reg);
     return reg;
 }

 template <typename Arg>
 void
 KvmKernelGicV3::setGicReg(unsigned group, unsigned mpidr, unsigned offset,
                           Arg value)
 {
     Arg reg = value;

     assert(mpidr <= KVM_DEV_ARM_VGIC_V3_MPIDR_MASK);
     const uint64_t attr(
         ((uint64_t)mpidr << KVM_DEV_ARM_VGIC_V3_MPIDR_SHIFT) |
         (offset << KVM_DEV_ARM_VGIC_OFFSET_SHIFT));

     kdev.setAttrPtr(group, attr, &reg);
 }

 uint32_t
 KvmKernelGicV3::readDistributor(Addr daddr)
 {
     return getGicReg<uint32_t>(KVM_DEV_ARM_VGIC_GRP_DIST_REGS, 0, daddr);
 }

 uint32_t
 KvmKernelGicV3::readRedistributor(const ArmISA::Affinity &aff, Addr daddr)
 {
     return getGicReg<uint32_t>(KVM_DEV_ARM_VGIC_GRP_REDIST_REGS, aff, daddr);
 }

 RegVal
 KvmKernelGicV3::readCpu(const ArmISA::Affinity &aff,
                         ArmISA::MiscRegIndex misc_reg)
 {
     auto sys_reg = ArmISA::encodeAArch64SysReg(misc_reg).packed();
     return getGicReg<RegVal>(KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS, aff, sys_reg);
 }

 void
 KvmKernelGicV3::writeDistributor(Addr daddr, uint32_t data)
 {
     setGicReg<uint32_t>(KVM_DEV_ARM_VGIC_GRP_DIST_REGS, 0, daddr, data);
 }

 void
 KvmKernelGicV3::writeRedistributor(const ArmISA::Affinity &aff, Addr daddr,
                                    uint32_t data)
 {
     setGicReg<uint32_t>(KVM_DEV_ARM_VGIC_GRP_REDIST_REGS, aff, daddr, data);
 }

 void
 KvmKernelGicV3::writeCpu(const ArmISA::Affinity &aff,
                          ArmISA::MiscRegIndex misc_reg,
                          RegVal data)
 {
     auto sys_reg = ArmISA::encodeAArch64SysReg(misc_reg).packed();
     setGicReg<RegVal>(KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS, aff, sys_reg, data);
 }

 template <class Types>
 MuxingKvmGic<Types>::MuxingKvmGic(const Params &p)
   : SimGic(p),
     system(*p.system),
     kernelGic(nullptr),
     usingKvm(false)
 {
     auto vm = system.getKvmVM();
     if (vm && !p.simulate_gic) {
         kernelGic = new KvmGic(*vm, p);
     }
 }

 template <class Types>
 void
 MuxingKvmGic<Types>::startup()
 {
     SimGic::startup();

     if (kernelGic) {
         kernelGic->init();

         KvmVM *vm = system.getKvmVM();
         if (vm && vm->validEnvironment()) {
             usingKvm = true;
             fromGicToKvm();
         }
     }
 }

 template <class Types>
 DrainState
 MuxingKvmGic<Types>::drain()
 {
     if (usingKvm)
         fromKvmToGic();
     return SimGic::drain();
 }

 template <class Types>
 void
 MuxingKvmGic<Types>::drainResume()
 {
     SimGic::drainResume();

     KvmVM *vm = system.getKvmVM();
     bool use_kvm = kernelGic && vm && vm->validEnvironment();
     if (use_kvm != usingKvm) {
         // Should only occur due to CPU switches
         if (use_kvm) // from simulation to KVM emulation
             fromGicToKvm();
         // otherwise, drain() already sync'd the state back to the GicV2

         usingKvm = use_kvm;
     }
 }

 template <class Types>
 Tick
 MuxingKvmGic<Types>::read(PacketPtr pkt)
 {
     if (!usingKvm)
         return SimGic::read(pkt);

     panic("MuxingKvmGic: PIO from gem5 is currently unsupported\n");
 }

 template <class Types>
 Tick
 MuxingKvmGic<Types>::write(PacketPtr pkt)
 {
     if (!usingKvm)
         return SimGic::write(pkt);

     panic("MuxingKvmGic: PIO from gem5 is currently unsupported\n");
 }

 template <class Types>
 void
 MuxingKvmGic<Types>::sendInt(uint32_t num)
 {
     if (!usingKvm)
         return SimGic::sendInt(num);

     DPRINTF(Interrupt, "Set SPI %d\n", num);
     kernelGic->setSPI(num);
 }

 template <class Types>
 void
 MuxingKvmGic<Types>::clearInt(uint32_t num)
 {
     if (!usingKvm)
         return SimGic::clearInt(num);

     DPRINTF(Interrupt, "Clear SPI %d\n", num);
     kernelGic->clearSPI(num);
 }

 template <class Types>
 void
 MuxingKvmGic<Types>::sendPPInt(uint32_t num, uint32_t cpu)
 {
     if (!usingKvm)
         return SimGic::sendPPInt(num, cpu);
     DPRINTF(Interrupt, "Set PPI %d:%d\n", cpu, num);
     kernelGic->setPPI(cpu, num);
 }

 template <class Types>
 void
 MuxingKvmGic<Types>::clearPPInt(uint32_t num, uint32_t cpu)
 {
     if (!usingKvm)
         return SimGic::clearPPInt(num, cpu);

     DPRINTF(Interrupt, "Clear PPI %d:%d\n", cpu, num);
     kernelGic->clearPPI(cpu, num);
 }

 template <class Types>
 bool
 MuxingKvmGic<Types>::blockIntUpdate() const
 {
     // During Kvm->Gic state transfer, writes to the Gic will call
     // updateIntState() which can post an interrupt.  Since we're only
     // using the Gic model for holding state in this circumstance, we
     // short-circuit this behavior, as the GicV2 is not actually active.
     return usingKvm;
 }

 template <class Types>
 void
 MuxingKvmGic<Types>::fromGicToKvm()
 {
     this->copyGicState(static_cast<SimGic*>(this),
                        static_cast<KvmGic*>(kernelGic));
 }

 template <class Types>
 void
 MuxingKvmGic<Types>::fromKvmToGic()
 {
     this->copyGicState(static_cast<KvmGic*>(kernelGic),
                        static_cast<SimGic*>(this));

     // the values read for the Interrupt Priority Mask Register (PMR)
     // have been shifted by three bits due to its having been emulated by
     // a VGIC with only 5 PMR bits in its VMCR register.  Presently the
     // Linux kernel does not repair this inaccuracy, so we correct it here.
     if constexpr(std::is_same<SimGic, GicV2>::value) {
         for (int cpu = 0; cpu < system.threads.size(); ++cpu) {
            this->cpuPriority[cpu] <<= 3;
            assert((this->cpuPriority[cpu] & ~0xff) == 0);
         }
     }
 }

 template class MuxingKvmGic<GicV2Types>;
 template class MuxingKvmGic<GicV3Types>;

 } // namespace gem5
	/*
	* Copyright (c) 2015-2017, 2021 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 "arch/arm/kvm/gic.hh"

	#include <linux/kvm.h>

	#include "arch/arm/kvm/base_cpu.hh"
	#include "arch/arm/regs/misc.hh"
	#include "debug/GIC.hh"
	#include "debug/Interrupt.hh"
	#include "params/MuxingKvmGicV2.hh"

	namespace gem5
	{

	KvmKernelGic::KvmKernelGic(KvmVM &_vm, uint32_t dev, unsigned it_lines)
	: vm(_vm),
	kdev(vm.createDevice(dev))
	{
	// Tell the VM that we will emulate the GIC in the kernel. This
	// disables IRQ and FIQ handling in the KVM CPU model.
	vm.enableKernelIRQChip();

	kdev.setAttr<uint32_t>(KVM_DEV_ARM_VGIC_GRP_NR_IRQS, 0, it_lines);
	}

	KvmKernelGic::~KvmKernelGic()
	{
	}

	void
	KvmKernelGic::setSPI(unsigned spi)
	{
	setIntState(KVM_ARM_IRQ_TYPE_SPI, 0, spi, true);
	}

	void
	KvmKernelGic::clearSPI(unsigned spi)
	{
	setIntState(KVM_ARM_IRQ_TYPE_SPI, 0, spi, false);
	}

	void
	KvmKernelGic::setPPI(unsigned vcpu, unsigned ppi)
	{
	setIntState(KVM_ARM_IRQ_TYPE_PPI, vcpu, ppi, true);
	}

	void
	KvmKernelGic::clearPPI(unsigned vcpu, unsigned ppi)
	{
	setIntState(KVM_ARM_IRQ_TYPE_PPI, vcpu, ppi, false);
	}

	void
	KvmKernelGic::setIntState(unsigned type, unsigned vcpu, unsigned irq,
	bool high)
	{
	const unsigned vcpu_index = vcpu & 0xff;
	const unsigned vcpu2_index = (vcpu >> 8) & 0xff;

	static const bool vcpu2_enabled = vm.kvm->capIRQLineLayout2();
	uint32_t kvm_vcpu = (vcpu_index << KVM_ARM_IRQ_VCPU_SHIFT);

	#if defined(KVM_ARM_IRQ_VCPU2_SHIFT)
	if (vcpu2_enabled)
	kvm_vcpu \|= vcpu2_index << KVM_ARM_IRQ_VCPU2_SHIFT;
	#endif

	panic_if((!vcpu2_enabled && vcpu2_index) \|\| kvm_vcpu > 0xffff,
	"VCPU out of range");

	assert(type <= KVM_ARM_IRQ_TYPE_MASK);
	assert(irq <= KVM_ARM_IRQ_NUM_MASK);
	const uint32_t line(
	kvm_vcpu \|
	(type << KVM_ARM_IRQ_TYPE_SHIFT) \|
	(irq << KVM_ARM_IRQ_NUM_SHIFT));

	vm.setIRQLine(line, high);
	}

	KvmKernelGicV2::KvmKernelGicV2(KvmVM &_vm,
	const MuxingKvmGicV2Params &p)
	: KvmKernelGic(_vm, KVM_DEV_TYPE_ARM_VGIC_V2, p.it_lines),
	cpuRange(RangeSize(p.cpu_addr, KVM_VGIC_V2_CPU_SIZE)),
	distRange(RangeSize(p.dist_addr, KVM_VGIC_V2_DIST_SIZE))
	{
	kdev.setAttr<uint64_t>(
	KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V2_ADDR_TYPE_DIST, p.dist_addr);
	kdev.setAttr<uint64_t>(
	KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V2_ADDR_TYPE_CPU, p.cpu_addr);
	}

	uint32_t
	KvmKernelGicV2::getGicReg(unsigned group, unsigned vcpu, unsigned offset)
	{
	uint64_t reg;

	assert(vcpu <= KVM_ARM_IRQ_VCPU_MASK);
	const uint64_t attr(
	((uint64_t)vcpu << KVM_DEV_ARM_VGIC_CPUID_SHIFT) \|
	(offset << KVM_DEV_ARM_VGIC_OFFSET_SHIFT));

	kdev.getAttrPtr(group, attr, &reg);
	return (uint32_t) reg;
	}

	void
	KvmKernelGicV2::setGicReg(unsigned group, unsigned vcpu, unsigned offset,
	unsigned value)
	{
	uint64_t reg = value;

	assert(vcpu <= KVM_ARM_IRQ_VCPU_MASK);
	const uint64_t attr(
	((uint64_t)vcpu << KVM_DEV_ARM_VGIC_CPUID_SHIFT) \|
	(offset << KVM_DEV_ARM_VGIC_OFFSET_SHIFT));

	kdev.setAttrPtr(group, attr, &reg);
	}

	uint32_t
	KvmKernelGicV2::readDistributor(ContextID ctx, Addr daddr)
	{
	auto vcpu = vm.contextIdToVCpuId(ctx);
	return getGicReg(KVM_DEV_ARM_VGIC_GRP_DIST_REGS, vcpu, daddr);
	}

	uint32_t
	KvmKernelGicV2::readCpu(ContextID ctx, Addr daddr)
	{
	auto vcpu = vm.contextIdToVCpuId(ctx);
	return getGicReg(KVM_DEV_ARM_VGIC_GRP_CPU_REGS, vcpu, daddr);
	}

	void
	KvmKernelGicV2::writeDistributor(ContextID ctx, Addr daddr, uint32_t data)
	{
	auto vcpu = vm.contextIdToVCpuId(ctx);
	setGicReg(KVM_DEV_ARM_VGIC_GRP_DIST_REGS, vcpu, daddr, data);
	}

	void
	KvmKernelGicV2::writeCpu(ContextID ctx, Addr daddr, uint32_t data)
	{
	auto vcpu = vm.contextIdToVCpuId(ctx);
	setGicReg(KVM_DEV_ARM_VGIC_GRP_CPU_REGS, vcpu, daddr, data);
	}

	#ifndef SZ_64K
	#define SZ_64K 0x00000040
	#endif

	KvmKernelGicV3::KvmKernelGicV3(KvmVM &_vm,
	const MuxingKvmGicV3Params &p)
	: KvmKernelGic(_vm, KVM_DEV_TYPE_ARM_VGIC_V3, p.it_lines),
	redistRange(RangeSize(p.redist_addr, KVM_VGIC_V3_REDIST_SIZE)),
	distRange(RangeSize(p.dist_addr, KVM_VGIC_V3_DIST_SIZE))
	{
	kdev.setAttr<uint64_t>(
	KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V3_ADDR_TYPE_DIST, p.dist_addr);
	kdev.setAttr<uint64_t>(
	KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_VGIC_V3_ADDR_TYPE_REDIST, p.redist_addr);
	}

	void
	KvmKernelGicV3::init()
	{
	kdev.setAttr<uint64_t>(
	KVM_DEV_ARM_VGIC_GRP_CTRL, KVM_DEV_ARM_VGIC_CTRL_INIT, 0);
	}

	template <typename Ret>
	Ret
	KvmKernelGicV3::getGicReg(unsigned group, unsigned mpidr, unsigned offset)
	{
	Ret reg;

	assert(mpidr <= KVM_DEV_ARM_VGIC_V3_MPIDR_MASK);
	const uint64_t attr(
	((uint64_t)mpidr << KVM_DEV_ARM_VGIC_V3_MPIDR_SHIFT) \|
	(offset << KVM_DEV_ARM_VGIC_OFFSET_SHIFT));

	kdev.getAttrPtr(group, attr, &reg);
	return reg;
	}

	template <typename Arg>
	void
	KvmKernelGicV3::setGicReg(unsigned group, unsigned mpidr, unsigned offset,
	Arg value)
	{
	Arg reg = value;

	assert(mpidr <= KVM_DEV_ARM_VGIC_V3_MPIDR_MASK);
	const uint64_t attr(
	((uint64_t)mpidr << KVM_DEV_ARM_VGIC_V3_MPIDR_SHIFT) \|
	(offset << KVM_DEV_ARM_VGIC_OFFSET_SHIFT));

	kdev.setAttrPtr(group, attr, &reg);
	}

	uint32_t
	KvmKernelGicV3::readDistributor(Addr daddr)
	{
	return getGicReg<uint32_t>(KVM_DEV_ARM_VGIC_GRP_DIST_REGS, 0, daddr);
	}

	uint32_t
	KvmKernelGicV3::readRedistributor(const ArmISA::Affinity &aff, Addr daddr)
	{
	return getGicReg<uint32_t>(KVM_DEV_ARM_VGIC_GRP_REDIST_REGS, aff, daddr);
	}

	RegVal
	KvmKernelGicV3::readCpu(const ArmISA::Affinity &aff,
	ArmISA::MiscRegIndex misc_reg)
	{
	auto sys_reg = ArmISA::encodeAArch64SysReg(misc_reg).packed();
	return getGicReg<RegVal>(KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS, aff, sys_reg);
	}

	void
	KvmKernelGicV3::writeDistributor(Addr daddr, uint32_t data)
	{
	setGicReg<uint32_t>(KVM_DEV_ARM_VGIC_GRP_DIST_REGS, 0, daddr, data);
	}

	void
	KvmKernelGicV3::writeRedistributor(const ArmISA::Affinity &aff, Addr daddr,
	uint32_t data)
	{
	setGicReg<uint32_t>(KVM_DEV_ARM_VGIC_GRP_REDIST_REGS, aff, daddr, data);
	}

	void
	KvmKernelGicV3::writeCpu(const ArmISA::Affinity &aff,
	ArmISA::MiscRegIndex misc_reg,
	RegVal data)
	{
	auto sys_reg = ArmISA::encodeAArch64SysReg(misc_reg).packed();
	setGicReg<RegVal>(KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS, aff, sys_reg, data);
	}

	template <class Types>
	MuxingKvmGic<Types>::MuxingKvmGic(const Params &p)
	: SimGic(p),
	system(*p.system),
	kernelGic(nullptr),
	usingKvm(false)
	{
	auto vm = system.getKvmVM();
	if (vm && !p.simulate_gic) {
	kernelGic = new KvmGic(*vm, p);
	}
	}

	template <class Types>
	void
	MuxingKvmGic<Types>::startup()
	{
	SimGic::startup();

	if (kernelGic) {
	kernelGic->init();

	KvmVM *vm = system.getKvmVM();
	if (vm && vm->validEnvironment()) {
	usingKvm = true;
	fromGicToKvm();
	}
	}
	}

	template <class Types>
	DrainState
	MuxingKvmGic<Types>::drain()
	{
	if (usingKvm)
	fromKvmToGic();
	return SimGic::drain();
	}

	template <class Types>
	void
	MuxingKvmGic<Types>::drainResume()
	{
	SimGic::drainResume();

	KvmVM *vm = system.getKvmVM();
	bool use_kvm = kernelGic && vm && vm->validEnvironment();
	if (use_kvm != usingKvm) {
	// Should only occur due to CPU switches
	if (use_kvm) // from simulation to KVM emulation
	fromGicToKvm();
	// otherwise, drain() already sync'd the state back to the GicV2

	usingKvm = use_kvm;
	}
	}

	template <class Types>
	Tick
	MuxingKvmGic<Types>::read(PacketPtr pkt)
	{
	if (!usingKvm)
	return SimGic::read(pkt);

	panic("MuxingKvmGic: PIO from gem5 is currently unsupported\n");
	}

	template <class Types>
	Tick
	MuxingKvmGic<Types>::write(PacketPtr pkt)
	{
	if (!usingKvm)
	return SimGic::write(pkt);

	panic("MuxingKvmGic: PIO from gem5 is currently unsupported\n");
	}

	template <class Types>
	void
	MuxingKvmGic<Types>::sendInt(uint32_t num)
	{
	if (!usingKvm)
	return SimGic::sendInt(num);

	DPRINTF(Interrupt, "Set SPI %d\n", num);
	kernelGic->setSPI(num);
	}

	template <class Types>
	void
	MuxingKvmGic<Types>::clearInt(uint32_t num)
	{
	if (!usingKvm)
	return SimGic::clearInt(num);

	DPRINTF(Interrupt, "Clear SPI %d\n", num);
	kernelGic->clearSPI(num);
	}

	template <class Types>
	void
	MuxingKvmGic<Types>::sendPPInt(uint32_t num, uint32_t cpu)
	{
	if (!usingKvm)
	return SimGic::sendPPInt(num, cpu);
	DPRINTF(Interrupt, "Set PPI %d:%d\n", cpu, num);
	kernelGic->setPPI(cpu, num);
	}

	template <class Types>
	void
	MuxingKvmGic<Types>::clearPPInt(uint32_t num, uint32_t cpu)
	{
	if (!usingKvm)
	return SimGic::clearPPInt(num, cpu);

	DPRINTF(Interrupt, "Clear PPI %d:%d\n", cpu, num);
	kernelGic->clearPPI(cpu, num);
	}

	template <class Types>
	bool
	MuxingKvmGic<Types>::blockIntUpdate() const
	{
	// During Kvm->Gic state transfer, writes to the Gic will call
	// updateIntState() which can post an interrupt. Since we're only
	// using the Gic model for holding state in this circumstance, we
	// short-circuit this behavior, as the GicV2 is not actually active.
	return usingKvm;
	}

	template <class Types>
	void
	MuxingKvmGic<Types>::fromGicToKvm()
	{
	this->copyGicState(static_cast<SimGic*>(this),
	static_cast<KvmGic*>(kernelGic));
	}

	template <class Types>
	void
	MuxingKvmGic<Types>::fromKvmToGic()
	{
	this->copyGicState(static_cast<KvmGic*>(kernelGic),
	static_cast<SimGic*>(this));

	// the values read for the Interrupt Priority Mask Register (PMR)
	// have been shifted by three bits due to its having been emulated by
	// a VGIC with only 5 PMR bits in its VMCR register. Presently the
	// Linux kernel does not repair this inaccuracy, so we correct it here.
	if constexpr(std::is_same<SimGic, GicV2>::value) {
	for (int cpu = 0; cpu < system.threads.size(); ++cpu) {
	this->cpuPriority[cpu] <<= 3;
	assert((this->cpuPriority[cpu] & ~0xff) == 0);
	}
	}
	}

	template class MuxingKvmGic<GicV2Types>;
	template class MuxingKvmGic<GicV3Types>;

	} // namespace gem5