Base class for KVM based CPU models. More...

#include <base.hh>

Inheritance diagram for BaseKvmCPU:

Classes
class	KVMCpuPort
	KVM memory port. More...

struct	TickEvent

Public Member Functions
	BaseKvmCPU (BaseKvmCPUParams *params)

virtual	~BaseKvmCPU ()

void	init () override

void	startup () override

void	regStats () override

void	serializeThread (CheckpointOut &cp, ThreadID tid) const override

void	unserializeThread (CheckpointIn &cp, ThreadID tid) override

DrainState	drain () override

void	drainResume () override

void	notifyFork () override

void	switchOut () override

void	takeOverFrom (BaseCPU *cpu) override

void	verifyMemoryMode () const override

MasterPort &	getDataPort () override

MasterPort &	getInstPort () override

void	wakeup (ThreadID tid=0) override

void	activateContext (ThreadID thread_num) override

void	suspendContext (ThreadID thread_num) override

void	deallocateContext (ThreadID thread_num)

void	haltContext (ThreadID thread_num) override

long	getVCpuID () const

ThreadContext *	getContext (int tn) override

Counter	totalInsts () const override

Counter	totalOps () const override

void	finishMMIOPending ()
	Callback from KvmCPUPort to transition the CPU out of RunningMMIOPending when all timing requests have completed. More...

virtual void	dump () const
	Dump the internal state to the terminal. More...

void	kick () const
	Force an exit from KVM. More...

Public Attributes
SimpleThread *	thread
	A cached copy of a thread's state in the form of a SimpleThread object. More...

ThreadContext *	tc
	ThreadContext object, provides an interface for external objects to modify this thread's state. More...

KvmVM &	vm

Counter	ctrInsts
	Number of instructions executed by the CPU. More...


Stats::Scalar	numInsts

Stats::Scalar	numVMExits

Stats::Scalar	numVMHalfEntries

Stats::Scalar	numExitSignal

Stats::Scalar	numMMIO

Stats::Scalar	numCoalescedMMIO

Stats::Scalar	numIO

Stats::Scalar	numHalt

Stats::Scalar	numInterrupts

Stats::Scalar	numHypercalls

Protected Types
enum	Status { Idle, Running, RunningService, RunningMMIOPending, RunningServiceCompletion }

Protected Member Functions
void	tick ()
	Execute the CPU until the next event in the main event queue or until the guest needs service from gem5. More...

virtual uint64_t	getHostCycles () const
	Get the value of the hardware cycle counter in the guest. More...

virtual Tick	kvmRun (Tick ticks)
	Request KVM to run the guest for a given number of ticks. More...

virtual Tick	kvmRunDrain ()
	Request the CPU to run until draining completes. More...

struct kvm_run *	getKvmRunState ()
	Get a pointer to the kvm_run structure containing all the input and output parameters from kvmRun(). More...

uint8_t *	getGuestData (uint64_t offset) const
	Retrieve a pointer to guest data stored at the end of the kvm_run structure. More...

void	kvmNonMaskableInterrupt ()
	Send a non-maskable interrupt to the guest. More...

void	kvmInterrupt (const struct kvm_interrupt &interrupt)
	Send a normal interrupt to the guest. More...

std::string	getAndFormatOneReg (uint64_t id) const
	Get and format one register for printout. More...

virtual bool	archIsDrained () const
	Is the architecture specific code in a state that prevents draining? More...

Tick	doMMIOAccess (Addr paddr, void *data, int size, bool write)
	Inject a memory mapped IO request into gem5. More...

int	ioctl (int request, long p1) const
	vCPU ioctl interface. More...

int	ioctl (int request, void *p1) const

int	ioctl (int request) const


void	getRegisters (struct kvm_regs &regs) const
	Get/Set the register state of the guest vCPU. More...

void	setRegisters (const struct kvm_regs &regs)

void	getSpecialRegisters (struct kvm_sregs &regs) const

void	setSpecialRegisters (const struct kvm_sregs &regs)


void	getFPUState (struct kvm_fpu &state) const
	Get/Set the guest FPU/vector state. More...

void	setFPUState (const struct kvm_fpu &state)


void	setOneReg (uint64_t id, const void *addr)
	Get/Set single register using the KVM_(SET\|GET)_ONE_REG API. More...

void	setOneReg (uint64_t id, uint64_t value)

void	setOneReg (uint64_t id, uint32_t value)

void	getOneReg (uint64_t id, void *addr) const

uint64_t	getOneRegU64 (uint64_t id) const

uint32_t	getOneRegU32 (uint64_t id) const


virtual void	updateKvmState ()=0
	Update the KVM state from the current thread context. More...

virtual void	updateThreadContext ()=0
	Update the current thread context with the KVM state. More...

void	syncThreadContext ()
	Update a thread context if the KVM state is dirty with respect to the cached thread context. More...

void	syncKvmState ()
	Update the KVM if the thread context is dirty. More...


virtual Tick	handleKvmExit ()
	Main kvmRun exit handler, calls the relevant handleKvmExit* depending on exit type. More...

virtual Tick	handleKvmExitIO ()
	The guest performed a legacy IO request (out/inp on x86) More...

virtual Tick	handleKvmExitHypercall ()
	The guest requested a monitor service using a hypercall. More...

virtual Tick	handleKvmExitIRQWindowOpen ()
	The guest exited because an interrupt window was requested. More...

virtual Tick	handleKvmExitUnknown ()
	An unknown architecture dependent error occurred when starting the vCPU. More...

virtual Tick	handleKvmExitException ()
	An unhandled virtualization exception occured. More...

virtual Tick	handleKvmExitFailEntry ()
	KVM failed to start the virtualized CPU. More...


void	setSignalMask (const sigset_t *mask)
	Set the signal mask used in kvmRun() More...

Protected Attributes
Status	_status
	CPU run state. More...

KVMCpuPort	dataPort
	Port for data requests. More...

KVMCpuPort	instPort
	Unused dummy port for the instruction interface. More...

const bool	alwaysSyncTC
	Be conservative and always synchronize the thread context on KVM entry/exit. More...

bool	threadContextDirty
	Is the gem5 context dirty? Set to true to force an update of the KVM vCPU state upon the next call to kvmRun(). More...

bool	kvmStateDirty
	Is the KVM state dirty? Set to true to force an update of the KVM vCPU state upon the next call to kvmRun(). More...

const long	vcpuID
	KVM internal ID of the vCPU. More...

pthread_t	vcpuThread
	ID of the vCPU thread. More...

Private Member Functions
Tick	flushCoalescedMMIO ()
	Service MMIO requests in the mmioRing. More...

void	setupSignalHandler ()
	Setup a signal handler to catch the timer signal used to switch back to the monitor. More...

bool	discardPendingSignal (int signum) const
	Discard a (potentially) pending signal. More...

void	startupThread ()
	Thread-specific initialization. More...

bool	tryDrain ()
	Try to drain the CPU if a drain is pending. More...

void	ioctlRun ()
	Execute the KVM_RUN ioctl. More...

void	setupInstStop ()
	Setup an instruction break if there is one pending. More...

Private Attributes
int	vcpuFD
	KVM vCPU file descriptor. More...

int	vcpuMMapSize
	Size of MMAPed kvm_run area. More...

struct kvm_run *	_kvmRun
	Pointer to the kvm_run structure used to communicate parameters with KVM. More...

struct kvm_coalesced_mmio_ring *	mmioRing
	Coalesced MMIO ring buffer. More...

const long	pageSize
	Cached page size of the host. More...

TickEvent	tickEvent

std::unique_ptr< BaseKvmTimer >	runTimer
	Timer used to force execution into the monitor after a specified number of simulation tick equivalents have executed in the guest. More...

float	hostFactor
	Host factor as specified in the configuration. More...

uint64_t	activeInstPeriod
	Currently active instruction count breakpoint. More...

PerfKvmCounter	hwCycles
	Guest cycle counter. More...

PerfKvmCounter	hwInstructions
	Guest instruction counter. More...

bool	perfControlledByTimer
	Does the runTimer control the performance counters? More...

void	setupCounters ()
	Setup hardware performance counters. More...

void	setupInstCounter (uint64_t period=0)
	Setup the guest instruction counter. More...

Additional Inherited Members
Static Public Member Functions inherited from BaseCPU
static int	numSimulatedInsts ()

static int	numSimulatedOps ()

static void	wakeup (ThreadID tid)

Detailed Description

Base class for KVM based CPU models.

All architecture specific KVM implementation should inherit from this class. The most basic CPU models only need to override the updateKvmState() and updateThreadContext() methods to implement state synchronization between gem5 and KVM.

The architecture specific implementation is also responsible for delivering interrupts into the VM. This is typically done by overriding tick() and checking the thread context before entering into the VM. In order to deliver an interrupt, the implementation then calls KvmVM::setIRQLine() or BaseKvmCPU::kvmInterrupt() depending on the specifics of the underlying hardware/drivers.

Definition at line 78 of file base.hh.

Member Enumeration Documentation

enum BaseKvmCPU::Status

protected

Enumerator
Idle	Context not scheduled in KVM. The CPU generally enters this state when the guest execute an instruction that halts the CPU (e.g., WFI on ARM or HLT on X86) if KVM traps this instruction. Ticks are not scheduled in this state. See Also suspendContext()
Running	Running normally. This is the normal run state of the CPU. KVM will be entered next time tick() is called.
RunningService	Requiring service at the beginning of the next cycle. The virtual machine has exited and requires service, tick() will call handleKvmExit() on the next cycle. The next state after running service is determined in handleKvmExit() and depends on what kind of service the guest requested: IO/MMIO (Atomic): RunningServiceCompletion IO/MMIO (Timing): RunningMMIOPending Halt: Idle Others: Running
RunningMMIOPending	Timing MMIO request in flight or stalled. The VM has requested IO/MMIO and we are in timing mode. A timing request is either stalled (and will be retried with recvReqRetry()) or it is in flight. After the timing request is complete, the CPU will transition to the RunningServiceCompletion state.
RunningServiceCompletion	Service completion in progress. The VM has requested service that requires KVM to be entered once in order to get to a consistent state. This happens in handleKvmExit() or one of its friends after IO exits. After executing tick(), the CPU will transition into the Running or RunningService state.

Definition at line 180 of file base.hh.

Constructor & Destructor Documentation

BaseKvmCPU::BaseKvmCPU ( BaseKvmCPUParams * params )

Definition at line 65 of file base.cc.

References FullSystem, SimpleThread::getTC(), ThreadContext::Halted, pageSize, panic, SimpleThread::setStatus(), tc, and thread.

BaseKvmCPU::~BaseKvmCPU ( )

virtual

Definition at line 100 of file base.cc.

References _kvmRun, vcpuFD, and vcpuMMapSize.

Member Function Documentation

void BaseKvmCPU::activateContext ( ThreadID thread_num )

override

Definition at line 528 of file base.cc.

References _status, DPRINTF, Idle, ThreadState::lastActivate, ThreadState::lastSuspend, Running, Event::scheduled(), thread, and tickEvent.

virtual bool BaseKvmCPU::archIsDrained ( ) const

inlineprotectedvirtual

Is the architecture specific code in a state that prevents draining?

This method should return false if there are any pending events in the guest vCPU that won't be carried over to the gem5 state and thus will prevent correct checkpointing or CPU handover. It might, for example, check for pending interrupts that have been passed to the vCPU but not acknowledged by the OS. Architecures implementing this method must override kvmRunDrain().

See Also: BaseKvmCPU::kvmRunDrain()

Returns: true if the vCPU is drained, false otherwise.

Reimplemented in X86KvmCPU.

Definition at line 513 of file base.hh.

Referenced by drain(), and tryDrain().

void BaseKvmCPU::deallocateContext ( ThreadID thread_num )

Definition at line 569 of file base.cc.

References suspendContext().

bool BaseKvmCPU::discardPendingSignal ( int signum ) const

private

Discard a (potentially) pending signal.

Parameters

signum Signal to discard

Returns: true if the signal was pending, false otherwise.

Definition at line 1254 of file base.cc.

References panic.

Referenced by kvmRun().

Tick BaseKvmCPU::doMMIOAccess	(	Addr	paddr,
		void *	data,
		int	size,
		bool	write
	)

protected

Inject a memory mapped IO request into gem5.

Parameters

paddr	Physical address
data	Pointer to the source/destination buffer
size	Memory access size
write	True if write, False if read

Returns: Number of ticks spent servicing the memory access

Definition at line 1109 of file base.cc.

References ThreadContext::contextId(), dataPort, Packet::dataStatic(), EventManager::eventQueue(), ThreadContext::getDTBPtr(), SimpleThread::getTC(), GenericISA::handleIprRead(), GenericISA::handleIprWrite(), Request::isMmappedIpr(), NoFault, BaseTLB::Read, MemCmd::ReadReq, Packet::req, Request::setContext(), BaseKvmCPU::KVMCpuPort::submitIO(), syncThreadContext(), tc, thread, threadContextDirty, Request::UNCACHEABLE, vm, warn, BaseTLB::Write, and MemCmd::WriteReq.

Referenced by flushCoalescedMMIO(), and handleKvmExit().

DrainState BaseKvmCPU::drain ( )

override

FALLTHROUGH

Definition at line 355 of file base.cc.

References _status, archIsDrained(), DPRINTF, Drained, Draining, Idle, panic, Running, RunningMMIOPending, RunningService, RunningServiceCompletion, Event::scheduled(), syncThreadContext(), and tickEvent.

void BaseKvmCPU::drainResume ( )

override

Definition at line 419 of file base.cc.

References _status, ThreadContext::Active, DPRINTF, Idle, Running, Event::scheduled(), ThreadContext::status(), tc, tickEvent, and verifyMemoryMode().

void BaseKvmCPU::dump ( ) const

virtual

Dump the internal state to the terminal.

Reimplemented in ArmV8KvmCPU, and X86KvmCPU.

Definition at line 605 of file base.cc.

References inform.

Referenced by handleKvmExit(), handleKvmExitException(), handleKvmExitFailEntry(), handleKvmExitUnknown(), and serializeThread().

void BaseKvmCPU::finishMMIOPending ( )

Callback from KvmCPUPort to transition the CPU out of RunningMMIOPending when all timing requests have completed.

Definition at line 233 of file base.cc.

References _status, RunningMMIOPending, RunningServiceCompletion, Event::scheduled(), and tickEvent.

Tick BaseKvmCPU::flushCoalescedMMIO ( )

private

Service MMIO requests in the mmioRing.

Returns: Number of ticks spent servicing the MMIO requests in the MMIO ring buffer

Definition at line 1183 of file base.cc.

References doMMIOAccess(), DPRINTF, mmioRing, and numCoalescedMMIO.

Referenced by kvmRun().

std::string BaseKvmCPU::getAndFormatOneReg ( uint64_t id ) const

protected

Get and format one register for printout.

This function call getOneReg() to retrieve the contents of one register and automatically formats it for printing.

Note: The presence of this call depends on Kvm::capOneReg().

Definition at line 914 of file base.cc.

References panic, and ArmISA::ss.

Referenced by ArmV8KvmCPU::dump(), ArmKvmCPU::dumpKvmStateCoProc(), ArmKvmCPU::dumpKvmStateMisc(), ArmKvmCPU::dumpKvmStateVFP(), ArmV8KvmCPU::updateKvmState(), and ArmV8KvmCPU::updateThreadContext().

ThreadContext * BaseKvmCPU::getContext ( int tn )

override

Definition at line 583 of file base.cc.

References syncThreadContext(), and tc.

Referenced by ArmKvmCPU::onKvmExitHypercall().

MasterPort& BaseKvmCPU::getDataPort ( )

inlineoverride

Definition at line 100 of file base.hh.

References dataPort.

void BaseKvmCPU::getFPUState ( struct kvm_fpu & state ) const

protected

Get/Set the guest FPU/vector state.

Definition at line 865 of file base.cc.

References ioctl(), and panic.

Referenced by X86KvmCPU::dumpFpuRegs(), and X86KvmCPU::updateThreadContext().

uint8_t* BaseKvmCPU::getGuestData ( uint64_t offset ) const

inlineprotected

Retrieve a pointer to guest data stored at the end of the kvm_run structure.

This is mainly used for PIO operations (KVM_EXIT_IO).

Parameters

offset Offset as specified by the kvm_run structure

Returns: Pointer to guest data

Definition at line 309 of file base.hh.

References _kvmRun, and ArmISA::offset.

Referenced by X86KvmCPU::handleIOMiscReg32(), and X86KvmCPU::handleKvmExitIO().

uint64_t BaseKvmCPU::getHostCycles ( ) const

protectedvirtual

Get the value of the hardware cycle counter in the guest.

This method is supposed to return the total number of cycles executed in hardware mode relative to some arbitrary point in the past. It's mainly used when estimating the number of cycles actually executed by the CPU in kvmRun(). The default behavior of this method is to use the cycles performance counter, but some architectures may want to use internal registers instead.

Returns: Number of host cycles executed relative to an undefined point in the past.

Reimplemented in X86KvmCPU.

Definition at line 717 of file base.cc.

References hwCycles, and PerfKvmCounter::read().

Referenced by kvmRun().

MasterPort& BaseKvmCPU::getInstPort ( )

inlineoverride

Definition at line 101 of file base.hh.

References instPort.

struct kvm_run* BaseKvmCPU::getKvmRunState ( )

inlineprotected

Get a pointer to the kvm_run structure containing all the input and output parameters from kvmRun().

Definition at line 299 of file base.hh.

References _kvmRun.

Referenced by X86KvmCPU::handleIOMiscReg32(), X86KvmCPU::handleKvmExitIO(), X86KvmCPU::kvmRun(), X86KvmCPU::kvmRunDrain(), X86KvmCPU::kvmRunWrapper(), and X86KvmCPU::updateThreadContextSRegs().

void BaseKvmCPU::getOneReg	(	uint64_t	id,
		void *	addr
	)		const

protected

Definition at line 897 of file base.cc.

References SparcISA::id, ioctl(), and panic.

Referenced by getOneRegU32(), getOneRegU64(), and ArmV8KvmCPU::updateThreadContext().

uint32_t BaseKvmCPU::getOneRegU32 ( uint64_t id ) const

inlineprotected

Definition at line 377 of file base.hh.

References getOneReg().

Referenced by ArmKvmCPU::dumpKvmStateCoProc(), ArmKvmCPU::dumpKvmStateCore(), ArmKvmCPU::updateTCStateCoProc(), and ArmKvmCPU::updateTCStateCore().

uint64_t BaseKvmCPU::getOneRegU64 ( uint64_t id ) const

inlineprotected

Definition at line 372 of file base.hh.

References getOneReg().

Referenced by ArmKvmCPU::updateTCStateCoProc(), ArmKvmCPU::updateTCStateVFP(), and ArmV8KvmCPU::updateThreadContext().

void BaseKvmCPU::getRegisters ( struct kvm_regs & regs ) const

protected

Get/Set the register state of the guest vCPU.

KVM has two different interfaces for accessing the state of the guest CPU. One interface updates 'normal' registers and one updates 'special' registers. The distinction between special and normal registers isn't very clear and is architecture dependent.

Definition at line 837 of file base.cc.

References ioctl(), and panic.

Referenced by X86KvmCPU::dumpIntRegs(), and X86KvmCPU::updateThreadContext().

void BaseKvmCPU::getSpecialRegisters ( struct kvm_sregs & regs ) const

protected

Definition at line 851 of file base.cc.

References ioctl(), and panic.

Referenced by X86KvmCPU::dumpSpecRegs(), and X86KvmCPU::updateThreadContext().

long BaseKvmCPU::getVCpuID ( ) const

inline

Definition at line 109 of file base.hh.

References vcpuID.

void BaseKvmCPU::haltContext ( ThreadID thread_num )

override

Definition at line 576 of file base.cc.

References suspendContext().

Tick BaseKvmCPU::handleKvmExit ( )

protectedvirtual

Main kvmRun exit handler, calls the relevant handleKvmExit* depending on exit type.

Returns: Number of ticks spent servicing the exit request

Definition at line 985 of file base.cc.

References _kvmRun, _status, dataPort, doMMIOAccess(), DPRINTF, dump(), handleKvmExitException(), handleKvmExitFailEntry(), handleKvmExitHypercall(), handleKvmExitIO(), handleKvmExitIRQWindowOpen(), handleKvmExitUnknown(), Idle, BaseKvmCPU::KVMCpuPort::nextIOState(), numHalt, numHypercalls, numIO, numMMIO, panic, Running, RunningService, SimpleThread::suspend(), and thread.

Referenced by tick().

Tick BaseKvmCPU::handleKvmExitException ( )

protectedvirtual

An unhandled virtualization exception occured.

Some KVM virtualization drivers return unhandled exceptions to the user-space monitor. This interface is currently only used by the Intel VMX KVM driver.

Returns: Number of ticks delay the next CPU tick

Definition at line 1092 of file base.cc.

References _kvmRun, dump(), and panic.

Referenced by handleKvmExit().

Tick BaseKvmCPU::handleKvmExitFailEntry ( )

protectedvirtual

KVM failed to start the virtualized CPU.

The kvm_run data structure contains the hardware-specific error code.

Returns: Number of ticks delay the next CPU tick

Definition at line 1101 of file base.cc.

References _kvmRun, dump(), and panic.

Referenced by handleKvmExit().

Tick BaseKvmCPU::handleKvmExitHypercall ( )

protectedvirtual

The guest requested a monitor service using a hypercall.

Returns: Number of ticks spent servicing the hypercall

Definition at line 1070 of file base.cc.

References panic.

Referenced by handleKvmExit().

Tick BaseKvmCPU::handleKvmExitIO ( )

protectedvirtual

The guest performed a legacy IO request (out/inp on x86)

Returns: Number of ticks spent servicing the IO request

Reimplemented in X86KvmCPU.

Definition at line 1062 of file base.cc.

References _kvmRun, and panic.

Referenced by handleKvmExit().

Tick BaseKvmCPU::handleKvmExitIRQWindowOpen ( )

protectedvirtual

The guest exited because an interrupt window was requested.

The guest exited because an interrupt window was requested (request_interrupt_window in the kvm_run structure was set to 1 before calling kvmRun) and it is now ready to receive

Returns: Number of ticks spent servicing the IRQ

Reimplemented in X86KvmCPU.

Definition at line 1076 of file base.cc.

References warn.

Referenced by handleKvmExit().

Tick BaseKvmCPU::handleKvmExitUnknown ( )

protectedvirtual

An unknown architecture dependent error occurred when starting the vCPU.

The kvm_run data structure contains the hardware error code. The defaults behavior of this method just prints the HW error code and panics. Architecture dependent implementations may want to override this method to provide better, hardware-aware, error messages.

Returns: Number of ticks delay the next CPU tick

Definition at line 1084 of file base.cc.

References _kvmRun, dump(), and panic.

Referenced by handleKvmExit().

void BaseKvmCPU::init ( )

override

Definition at line 108 of file base.cc.

References ThreadContext::contextId(), fatal, FullSystem, Stats::init, AlphaISA::initCPU(), ThreadContext::initMemProxies(), and tc.

void BaseKvmCPU::ioctlRun ( )

private

Execute the KVM_RUN ioctl.

Definition at line 1335 of file base.cc.

References ioctl(), and panic.

Referenced by kvmRun().

void BaseKvmCPU::kick ( ) const

inline

Force an exit from KVM.

Send a signal to the thread owning this vCPU to get it to exit from KVM. Ignored if the vCPU is not executing.

Definition at line 130 of file base.hh.

References KVM_KICK_SIGNAL, and vcpuThread.

Referenced by kvmRun(), and wakeup().

Tick BaseKvmCPU::kvmRun ( Tick ticks )

protectedvirtual

Request KVM to run the guest for a given number of ticks.

The method returns the approximate number of ticks executed.

Note: The returned number of ticks can be both larger or smaller than the requested number of ticks. A smaller number can, for example, occur when the guest executes MMIO. A larger number is typically due to performance counter inaccuracies.; This method is virtual in order to allow implementations to check for architecture specific events (e.g., interrupts) before entering the VM.; It is the response of the caller (normally tick()) to make sure that the KVM state is synchronized and that the TC is invalidated after entering KVM.; This method does not normally cause any state transitions. However, if it may suspend the CPU by suspending the thread, which leads to a transition to the Idle state. In such a case, kvm must not be entered.

Parameters

ticks Number of ticks to execute, set to 0 to exit immediately after finishing pending operations.

Returns: Number of ticks executed (see note)

Reimplemented in ArmKvmCPU, X86KvmCPU, and BaseArmKvmCPU.

Definition at line 723 of file base.cc.

References ctrInsts, curEventQueue(), discardPendingSignal(), DPRINTF, fatal_if(), flushCoalescedMMIO(), getHostCycles(), hostFactor, hwCycles, hwInstructions, ioctlRun(), kick(), KVM_KICK_SIGNAL, numInsts, numVMExits, numVMHalfEntries, perfControlledByTimer, PerfKvmCounter::read(), runTimer, PerfKvmCounter::start(), PerfKvmCounter::stop(), ArmISA::system, and vcpuFD.

Referenced by BaseArmKvmCPU::kvmRun(), ArmKvmCPU::kvmRun(), kvmRunDrain(), X86KvmCPU::kvmRunWrapper(), and tick().

Tick BaseKvmCPU::kvmRunDrain ( )

protectedvirtual

Request the CPU to run until draining completes.

This function normally calls kvmRun(0) to make KVM finish pending MMIO operations. Architecures implementing archIsDrained() must override this method.

See Also: BaseKvmCPU::archIsDrained()

Returns: Number of ticks executed

Reimplemented in X86KvmCPU.

Definition at line 703 of file base.cc.

References _status, kvmRun(), RunningMMIOPending, and RunningServiceCompletion.

Referenced by tick().

void BaseKvmCPU::notifyFork ( )

override

Definition at line 442 of file base.cc.

References _kvmRun, _status, PerfKvmCounter::detach(), hwCycles, hwInstructions, Idle, Event::scheduled(), tickEvent, vcpuFD, vcpuMMapSize, and warn.

void BaseKvmCPU::regStats ( )

override

Definition at line 273 of file base.cc.

References Stats::DataWrap< Derived, InfoProxyType >::desc(), name(), Stats::DataWrap< Derived, InfoProxyType >::name(), numCoalescedMMIO, numExitSignal, numHalt, numHypercalls, numInsts, numInterrupts, numIO, numMMIO, numVMExits, and numVMHalfEntries.

void BaseKvmCPU::serializeThread	(	CheckpointOut &	cp,
		ThreadID	tid
	)		const

override

Definition at line 331 of file base.cc.

References _status, DPRINTF, DTRACE, dump(), Idle, SimpleThread::serialize(), and thread.

void BaseKvmCPU::setFPUState ( const struct kvm_fpu & state )

protected

Definition at line 872 of file base.cc.

References ioctl(), and panic.

Referenced by X86KvmCPU::updateKvmStateFPULegacy().

void BaseKvmCPU::setOneReg	(	uint64_t	id,
		const void *	addr
	)

protected

Get/Set single register using the KVM_(SET|GET)_ONE_REG API.

Note: The presence of this call depends on Kvm::capOneReg().

Definition at line 880 of file base.cc.

References SparcISA::id, ioctl(), and panic.

Referenced by ArmKvmCPU::onKvmExitHypercall(), ArmV8KvmCPU::startup(), ArmV8KvmCPU::updateKvmState(), ArmKvmCPU::updateKvmStateCoProc(), ArmKvmCPU::updateKvmStateCore(), and ArmKvmCPU::updateKvmStateVFP().

void BaseKvmCPU::setOneReg	(	uint64_t	id,
		uint64_t	value
	)

inlineprotected

Definition at line 369 of file base.hh.

References setOneReg().

Referenced by setOneReg().

void BaseKvmCPU::setOneReg	(	uint64_t	id,
		uint32_t	value
	)

inlineprotected

Definition at line 370 of file base.hh.

References setOneReg().

Referenced by setOneReg().

void BaseKvmCPU::setRegisters ( const struct kvm_regs & regs )

protected

Definition at line 844 of file base.cc.

References ioctl(), and panic.

Referenced by X86KvmCPU::updateKvmStateRegs().

void BaseKvmCPU::setSignalMask ( const sigset_t * mask )

protected

Set the signal mask used in kvmRun()

This method allows the signal mask of the thread executing kvmRun() to be overridden inside the actual system call. This allows us to mask timer signals used to force KVM exits while in gem5.

The signal mask can be disabled by setting it to NULL.

Parameters

mask	Signals to mask

Definition at line 1153 of file base.cc.

References ioctl(), and panic.

Referenced by setupSignalHandler().

void BaseKvmCPU::setSpecialRegisters ( const struct kvm_sregs & regs )

protected

Definition at line 858 of file base.cc.

References ioctl(), and panic.

Referenced by X86KvmCPU::updateKvmStateSRegs().

void BaseKvmCPU::setupCounters ( )

private

Setup hardware performance counters.

Definition at line 1282 of file base.cc.

References PerfKvmCounter::attach(), PerfKvmCounterConfig::disabled(), DPRINTF, PerfKvmCounterConfig::exclude_host(), PerfKvmCounterConfig::exclude_hv(), hwCycles, perfControlledByTimer, PerfKvmCounterConfig::pinned(), PerfKvmCounterConfig::samplePeriod(), setupInstCounter(), and PerfKvmCounterConfig::wakeupEvents().

Referenced by startupThread().

void BaseKvmCPU::setupInstCounter ( uint64_t period = 0 )

private

Setup the guest instruction counter.

Setup the guest instruction counter and optionally request a signal every N instructions executed by the guest. This method will re-attach the counter if the counter has already been attached and its sampling settings have changed.

Parameters

period Signal period, set to 0 to disable signaling.

Definition at line 1358 of file base.cc.

References activeInstPeriod, PerfKvmCounter::attach(), PerfKvmCounter::attached(), PerfKvmCounter::detach(), PerfKvmCounter::enableSignals(), PerfKvmCounterConfig::exclude_host(), PerfKvmCounterConfig::exclude_hv(), hwCycles, hwInstructions, KVM_KICK_SIGNAL, PerfKvmCounterConfig::samplePeriod(), and PerfKvmCounterConfig::wakeupEvents().

Referenced by setupCounters(), and setupInstStop().

void BaseKvmCPU::setupInstStop ( )

private

Setup an instruction break if there is one pending.

Check if there are pending instruction breaks in the CPU's instruction event queue and schedule an instruction break using PerfEvent.

Note: This method doesn't currently handle the main system instruction event queue.

Definition at line 1345 of file base.cc.

References ctrInsts, and setupInstCounter().

Referenced by tick().

void BaseKvmCPU::setupSignalHandler ( )

private

Setup a signal handler to catch the timer signal used to switch back to the monitor.

Definition at line 1225 of file base.cc.

References KVM_KICK_SIGNAL, onKickSignal(), panic, and setSignalMask().

Referenced by startupThread().

void BaseKvmCPU::startup ( )

override

Definition at line 123 of file base.cc.

References _kvmRun, Kvm::capCoalescedMMIO(), KvmVM::cpuStartup(), KvmVM::createVCPU(), curTick(), Kvm::getVCPUMMapSize(), inform, KvmVM::kvm, mmioRing, MipsISA::p, pageSize, panic, SimpleThread::startup(), startupThread(), thread, vcpuFD, vcpuID, vcpuMMapSize, and vm.

Referenced by X86KvmCPU::startup(), BaseArmKvmCPU::startup(), and ArmKvmCPU::startup().

void BaseKvmCPU::startupThread ( )

private

Thread-specific initialization.

Some KVM-related initialization requires us to know the TID of the thread that is going to execute our event queue. For example, when setting up timers, we need to know the TID of the thread executing in KVM in order to deliver the timer signal to that thread. This method is called as the first event in this SimObject's event queue.

See Also: startup

Definition at line 243 of file base.cc.

References hwCycles, KVM_KICK_SIGNAL, MipsISA::p, runTimer, setupCounters(), setupSignalHandler(), and vcpuThread.

Referenced by startup().

void BaseKvmCPU::suspendContext ( ThreadID thread_num )

override

Definition at line 546 of file base.cc.

References _status, DPRINTF, Idle, Running, RunningServiceCompletion, Event::scheduled(), thread, and tickEvent.

Referenced by deallocateContext(), and haltContext().

void BaseKvmCPU::switchOut ( )

override

Definition at line 465 of file base.cc.

References _status, DPRINTF, Idle, Event::scheduled(), and tickEvent.

void BaseKvmCPU::syncKvmState ( )

protected

Update the KVM if the thread context is dirty.

Definition at line 973 of file base.cc.

References kvmStateDirty, threadContextDirty, and updateKvmState().

Referenced by tick().

void BaseKvmCPU::syncThreadContext ( )

protected

Update a thread context if the KVM state is dirty with respect to the cached thread context.

Definition at line 961 of file base.cc.

References kvmStateDirty, threadContextDirty, and updateThreadContext().

Referenced by X86KvmCPU::deliverInterrupts(), doMMIOAccess(), drain(), getContext(), X86KvmCPU::kvmRun(), and tick().

void BaseKvmCPU::takeOverFrom ( BaseCPU * cpu )

override

Definition at line 479 of file base.cc.

References _status, DPRINTF, Idle, Event::scheduled(), takeOverFrom(), threadContextDirty, tickEvent, and updateKvmState().

void BaseKvmCPU::tick ( )

protected

Execute the CPU until the next event in the main event queue or until the guest needs service from gem5.

Definition at line 611 of file base.cc.

References _kvmRun, _status, alwaysSyncTC, ctrInsts, curEventQueue(), curTick(), DPRINTF, Draining, handleKvmExit(), Idle, kvmRun(), kvmRunDrain(), kvmStateDirty, numExitSignal, panic, Running, RunningMMIOPending, RunningService, RunningServiceCompletion, setupInstStop(), syncKvmState(), syncThreadContext(), ArmISA::system, threadContextDirty, tickEvent, and tryDrain().

Counter BaseKvmCPU::totalInsts ( ) const

override

Definition at line 592 of file base.cc.

References ctrInsts.

Counter BaseKvmCPU::totalOps ( ) const

override

Definition at line 598 of file base.cc.

References ctrInsts, and hack_once.

bool BaseKvmCPU::tryDrain ( )

private

Try to drain the CPU if a drain is pending.

Definition at line 1313 of file base.cc.

References _status, archIsDrained(), DPRINTF, Draining, Idle, and Running.

Referenced by tick().

void BaseKvmCPU::unserializeThread	(	CheckpointIn &	cp,
		ThreadID	tid
	)

override

Definition at line 344 of file base.cc.

References _status, DPRINTF, Idle, thread, threadContextDirty, and SimpleThread::unserialize().

virtual void BaseKvmCPU::updateKvmState ( )

protectedpure virtual

Update the KVM state from the current thread context.

The base CPU calls this method before starting the guest CPU when the contextDirty flag is set. The architecture dependent CPU implementation is expected to update all guest state (registers, special registers, and FPU state).

Implemented in X86KvmCPU, ArmKvmCPU, and ArmV8KvmCPU.

Referenced by syncKvmState(), and takeOverFrom().

virtual void BaseKvmCPU::updateThreadContext ( )

protectedpure virtual

Update the current thread context with the KVM state.

The base CPU after the guest updates any of the KVM state. In practice, this happens after kvmRun is called. The architecture dependent code is expected to read the state of the guest CPU and update gem5's thread state.

Implemented in X86KvmCPU, ArmKvmCPU, and ArmV8KvmCPU.

Referenced by syncThreadContext().

void BaseKvmCPU::verifyMemoryMode ( ) const

override

Definition at line 501 of file base.cc.

References fatal, and ArmISA::system.

Referenced by drainResume().

void BaseKvmCPU::wakeup ( ThreadID tid = 0 )

override

Definition at line 510 of file base.cc.

References SimpleThread::activate(), DPRINTF, kick(), SimpleThread::status(), ThreadContext::Suspended, and thread.

Member Data Documentation

struct kvm_run* BaseKvmCPU::_kvmRun

private

Pointer to the kvm_run structure used to communicate parameters with KVM.

Note: This is the base pointer of the MMAPed KVM region. The first page contains the kvm_run structure. Subsequent pages may contain other data such as the MMIO ring buffer.

Definition at line 702 of file base.hh.

Referenced by getGuestData(), getKvmRunState(), handleKvmExit(), handleKvmExitException(), handleKvmExitFailEntry(), handleKvmExitIO(), handleKvmExitUnknown(), notifyFork(), startup(), tick(), and ~BaseKvmCPU().

Status BaseKvmCPU::_status

protected

CPU run state.

Definition at line 231 of file base.hh.

Referenced by activateContext(), drain(), drainResume(), finishMMIOPending(), handleKvmExit(), X86KvmCPU::kvmRun(), kvmRunDrain(), notifyFork(), serializeThread(), suspendContext(), switchOut(), takeOverFrom(), tick(), tryDrain(), and unserializeThread().

uint64_t BaseKvmCPU::activeInstPeriod

private

Currently active instruction count breakpoint.

Definition at line 742 of file base.hh.

Referenced by setupInstCounter().

const bool BaseKvmCPU::alwaysSyncTC

protected

Be conservative and always synchronize the thread context on KVM entry/exit.

Definition at line 612 of file base.hh.

Referenced by tick().

Counter BaseKvmCPU::ctrInsts

Number of instructions executed by the CPU.

Definition at line 803 of file base.hh.

Referenced by kvmRun(), setupInstStop(), tick(), totalInsts(), and totalOps().

KVMCpuPort BaseKvmCPU::dataPort

protected

Port for data requests.

Definition at line 603 of file base.hh.

Referenced by doMMIOAccess(), getDataPort(), handleKvmExit(), and X86KvmCPU::handleKvmExitIO().

float BaseKvmCPU::hostFactor

private

Host factor as specified in the configuration.

Definition at line 786 of file base.hh.

Referenced by kvmRun().

PerfKvmCounter BaseKvmCPU::hwCycles

private

Guest cycle counter.

This is the group leader of all performance counters measuring the guest system. It can be used in conjunction with the PerfKvmTimer (see perfControlledByTimer) to trigger exits from KVM.

Definition at line 752 of file base.hh.

Referenced by getHostCycles(), kvmRun(), notifyFork(), setupCounters(), setupInstCounter(), and startupThread().

PerfKvmCounter BaseKvmCPU::hwInstructions

private

Guest instruction counter.

This counter is typically only used to measure the number of instructions executed by the guest. However, it can also be used to trigger exits from KVM if the configuration script requests an exit after a certain number of instructions.

See Also: setupInstBreak; scheduleInstStop

Definition at line 765 of file base.hh.

Referenced by kvmRun(), notifyFork(), and setupInstCounter().

KVMCpuPort BaseKvmCPU::instPort

protected

Unused dummy port for the instruction interface.

Definition at line 606 of file base.hh.

Referenced by getInstPort().

bool BaseKvmCPU::kvmStateDirty

protected

Is the KVM state dirty? Set to true to force an update of the KVM vCPU state upon the next call to kvmRun().

Definition at line 624 of file base.hh.

Referenced by syncKvmState(), syncThreadContext(), and tick().

struct kvm_coalesced_mmio_ring* BaseKvmCPU::mmioRing

private

Coalesced MMIO ring buffer.

NULL if coalesced MMIO is not supported.

Definition at line 707 of file base.hh.

Referenced by flushCoalescedMMIO(), and startup().

Stats::Scalar BaseKvmCPU::numCoalescedMMIO

Definition at line 795 of file base.hh.

Referenced by flushCoalescedMMIO(), and regStats().

Stats::Scalar BaseKvmCPU::numExitSignal

Definition at line 793 of file base.hh.

Referenced by regStats(), and tick().

Stats::Scalar BaseKvmCPU::numHalt

Definition at line 797 of file base.hh.

Referenced by handleKvmExit(), and regStats().

Stats::Scalar BaseKvmCPU::numHypercalls

Definition at line 799 of file base.hh.

Referenced by handleKvmExit(), and regStats().

Stats::Scalar BaseKvmCPU::numInsts

Definition at line 790 of file base.hh.

Referenced by kvmRun(), and regStats().

Stats::Scalar BaseKvmCPU::numInterrupts

Definition at line 798 of file base.hh.

Referenced by kvmInterrupt(), kvmNonMaskableInterrupt(), and regStats().

Stats::Scalar BaseKvmCPU::numIO

Definition at line 796 of file base.hh.

Referenced by handleKvmExit(), and regStats().

Stats::Scalar BaseKvmCPU::numMMIO

Definition at line 794 of file base.hh.

Referenced by handleKvmExit(), and regStats().

Stats::Scalar BaseKvmCPU::numVMExits

Definition at line 791 of file base.hh.

Referenced by kvmRun(), and regStats().

Stats::Scalar BaseKvmCPU::numVMHalfEntries

Definition at line 792 of file base.hh.

Referenced by kvmRun(), and regStats().

const long BaseKvmCPU::pageSize

private

Cached page size of the host.

Definition at line 709 of file base.hh.

Referenced by BaseKvmCPU(), and startup().

bool BaseKvmCPU::perfControlledByTimer

private

Does the runTimer control the performance counters?

The run timer will automatically enable and disable performance counters if a PerfEvent-based timer is used to control KVM exits.

Definition at line 774 of file base.hh.

Referenced by kvmRun(), and setupCounters().

std::unique_ptr<BaseKvmTimer> BaseKvmCPU::runTimer

private

Timer used to force execution into the monitor after a specified number of simulation tick equivalents have executed in the guest.

This counter generates the signal specified by KVM_TIMER_SIGNAL.

Definition at line 783 of file base.hh.

Referenced by kvmRun(), and startupThread().

ThreadContext* BaseKvmCPU::tc

ThreadContext object, provides an interface for external objects to modify this thread's state.

Definition at line 150 of file base.hh.

SimpleThread* BaseKvmCPU::thread

A cached copy of a thread's state in the form of a SimpleThread object.

Normally the actual thread state is stored in the KVM vCPU. If KVM has been running this copy is will be out of date. If we recently handled some events within gem5 that required state to be updated this could be the most up-to-date copy. When getContext() or updateThreadContext() is called this copy gets updated. The method syncThreadContext can be used within a KVM CPU to update the thread context if the KVM state is dirty (i.e., the vCPU has been run since the last update).

Definition at line 145 of file base.hh.

Referenced by activateContext(), BaseKvmCPU(), X86KvmCPU::deliverInterrupts(), doMMIOAccess(), handleKvmExit(), serializeThread(), startup(), suspendContext(), unserializeThread(), and wakeup().