gem5  v22.0.0.2
Classes | Public Member Functions | Public Attributes | Protected Types | Protected Member Functions | Protected Attributes | Private Member Functions | Private Attributes | List of all members
gem5::BaseKvmCPU Class Referenceabstract

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

#include <base.hh>

Inheritance diagram for gem5::BaseKvmCPU:
gem5::ArmKvmCPU gem5::BaseArmKvmCPU gem5::X86KvmCPU gem5::ArmV8KvmCPU

Classes

class  KVMCpuPort
 KVM memory port. More...
 
struct  StatGroup
 

Public Member Functions

 BaseKvmCPU (const BaseKvmCPUParams &params)
 
virtual ~BaseKvmCPU ()
 
void init () override
 
void startup () 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
 
PortgetDataPort () override
 
PortgetInstPort () 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
 
ThreadContextgetContext (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

SimpleThreadthread
 A cached copy of a thread's state in the form of a SimpleThread object. More...
 
ThreadContexttc
 ThreadContext object, provides an interface for external objects to modify this thread's state. More...
 
KvmVMvm
 
gem5::BaseKvmCPU::StatGroup stats
 
Counter ctrInsts
 Number of instructions executed by the CPU. More...
 

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 void stutterPC (PCStateBase &pc) const =0
 Modify a PCStatePtr's value so that its next PC is the current PC. 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
 
virtual void ioctlRun ()
 Execute the KVM_RUN ioctl. More...
 
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...
 
EventQueuedeviceEventQueue ()
 Get a pointer to the event queue owning devices. 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...
 
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 restartEqThread ()
 Thread-specific initialization. More...
 
bool tryDrain ()
 Try to drain the CPU if a drain is pending. 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...
 
EventFunctionWrapper tickEvent
 
std::unique_ptr< BaseKvmTimerrunTimer
 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...
 

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 87 of file base.hh.

Member Enumeration Documentation

◆ Status

enum gem5::BaseKvmCPU::Status
protected
dot_inline_dotgraph_1.png
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 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:
   <ul>
     <li>IO/MMIO (Atomic): RunningServiceCompletion
     <li>IO/MMIO (Timing): RunningMMIOPending
     <li>Halt: Idle
     <li>Others: Running
   </ul>
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 188 of file base.hh.

Constructor & Destructor Documentation

◆ BaseKvmCPU()

gem5::BaseKvmCPU::BaseKvmCPU ( const BaseKvmCPUParams &  params)

Definition at line 65 of file base.cc.

References tick().

◆ ~BaseKvmCPU()

gem5::BaseKvmCPU::~BaseKvmCPU ( )
virtual

Definition at line 101 of file base.cc.

References _kvmRun, vcpuFD, and vcpuMMapSize.

Member Function Documentation

◆ activateContext()

void gem5::BaseKvmCPU::activateContext ( ThreadID  thread_num)
override

◆ archIsDrained()

virtual bool gem5::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 gem5::X86KvmCPU.

Definition at line 541 of file base.hh.

Referenced by drain(), and tryDrain().

◆ deallocateContext()

void gem5::BaseKvmCPU::deallocateContext ( ThreadID  thread_num)

Definition at line 540 of file base.cc.

References suspendContext().

◆ deviceEventQueue()

EventQueue* gem5::BaseKvmCPU::deviceEventQueue ( )
inlineprotected

Get a pointer to the event queue owning devices.

Devices always live in a separate device event queue when running in multi-core mode. We need to temporarily migrate to this queue when accessing devices. By convention, devices and the VM use the same event queue.

Definition at line 447 of file base.hh.

References gem5::EventManager::eventQueue(), and vm.

Referenced by doMMIOAccess(), gem5::X86KvmCPU::handleKvmExitIO(), gem5::ArmV8KvmCPU::updateKvmState(), and gem5::ArmV8KvmCPU::updateThreadContext().

◆ discardPendingSignal()

bool gem5::BaseKvmCPU::discardPendingSignal ( int  signum) const
private

Discard a (potentially) pending signal.

Parameters
signumSignal to discard
Returns
true if the signal was pending, false otherwise.

Definition at line 1238 of file base.cc.

References panic.

Referenced by kvmRun().

◆ doMMIOAccess()

Tick gem5::BaseKvmCPU::doMMIOAccess ( Addr  paddr,
void *  data,
int  size,
bool  write 
)
protected

◆ drain()

DrainState gem5::BaseKvmCPU::drain ( )
override

◆ drainResume()

void gem5::BaseKvmCPU::drainResume ( )
override

◆ dump()

void gem5::BaseKvmCPU::dump ( ) const
virtual

Dump the internal state to the terminal.

Reimplemented in gem5::ArmV8KvmCPU, and gem5::X86KvmCPU.

Definition at line 577 of file base.cc.

References inform.

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

◆ finishMMIOPending()

void gem5::BaseKvmCPU::finishMMIOPending ( )

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

Definition at line 223 of file base.cc.

References _status, RunningMMIOPending, RunningServiceCompletion, gem5::Event::scheduled(), and tickEvent.

◆ flushCoalescedMMIO()

Tick gem5::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 1167 of file base.cc.

References doMMIOAccess(), DPRINTF, mmioRing, gem5::BaseKvmCPU::StatGroup::numCoalescedMMIO, and stats.

Referenced by kvmRun().

◆ getAndFormatOneReg()

std::string gem5::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 889 of file base.cc.

References panic, and ss.

Referenced by gem5::ArmV8KvmCPU::dump(), gem5::ArmKvmCPU::dumpKvmStateCoProc(), gem5::ArmKvmCPU::dumpKvmStateMisc(), gem5::ArmKvmCPU::dumpKvmStateVFP(), gem5::ArmV8KvmCPU::updateKvmState(), and gem5::ArmV8KvmCPU::updateThreadContext().

◆ getContext()

ThreadContext * gem5::BaseKvmCPU::getContext ( int  tn)
override

Definition at line 555 of file base.cc.

References syncThreadContext(), and tc.

◆ getDataPort()

Port& gem5::BaseKvmCPU::getDataPort ( )
inlineoverride

Definition at line 108 of file base.hh.

References dataPort.

◆ getFPUState()

void gem5::BaseKvmCPU::getFPUState ( struct kvm_fpu &  state) const
protected

Get/Set the guest FPU/vector state.

Definition at line 840 of file base.cc.

References ioctl(), panic, and state.

Referenced by gem5::X86KvmCPU::dumpFpuRegs(), and gem5::X86KvmCPU::updateThreadContext().

◆ getGuestData()

uint8_t* gem5::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
offsetOffset as specified by the kvm_run structure
Returns
Pointer to guest data

Definition at line 327 of file base.hh.

References _kvmRun, and gem5::ArmISA::offset.

Referenced by gem5::X86KvmCPU::handleIOMiscReg32(), and gem5::X86KvmCPU::handleKvmExitIO().

◆ getHostCycles()

uint64_t gem5::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 gem5::X86KvmCPU.

Definition at line 693 of file base.cc.

References hwCycles, and gem5::PerfKvmCounter::read().

Referenced by kvmRun().

◆ getInstPort()

Port& gem5::BaseKvmCPU::getInstPort ( )
inlineoverride

Definition at line 109 of file base.hh.

References instPort.

◆ getKvmRunState()

struct kvm_run* gem5::BaseKvmCPU::getKvmRunState ( )
inlineprotected

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

Definition at line 317 of file base.hh.

References _kvmRun.

Referenced by gem5::X86KvmCPU::handleIOMiscReg32(), gem5::X86KvmCPU::handleKvmExitIO(), gem5::X86KvmCPU::ioctlRun(), gem5::BaseArmKvmCPU::kvmRun(), gem5::X86KvmCPU::kvmRun(), gem5::X86KvmCPU::kvmRunDrain(), and gem5::X86KvmCPU::updateThreadContextSRegs().

◆ getOneReg()

void gem5::BaseKvmCPU::getOneReg ( uint64_t  id,
void *  addr 
) const
protected

◆ getOneRegU32()

uint32_t gem5::BaseKvmCPU::getOneRegU32 ( uint64_t  id) const
inlineprotected

◆ getOneRegU64()

uint64_t gem5::BaseKvmCPU::getOneRegU64 ( uint64_t  id) const
inlineprotected

◆ getRegisters()

void gem5::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 812 of file base.cc.

References ioctl(), and panic.

Referenced by gem5::X86KvmCPU::dumpIntRegs(), and gem5::X86KvmCPU::updateThreadContext().

◆ getSpecialRegisters()

void gem5::BaseKvmCPU::getSpecialRegisters ( struct kvm_sregs &  regs) const
protected

Definition at line 826 of file base.cc.

References ioctl(), and panic.

Referenced by gem5::X86KvmCPU::dumpSpecRegs(), and gem5::X86KvmCPU::updateThreadContext().

◆ getVCpuID()

long gem5::BaseKvmCPU::getVCpuID ( ) const
inline

Definition at line 117 of file base.hh.

References vcpuID.

◆ haltContext()

void gem5::BaseKvmCPU::haltContext ( ThreadID  thread_num)
override

Definition at line 547 of file base.cc.

References suspendContext().

◆ handleKvmExit()

Tick gem5::BaseKvmCPU::handleKvmExit ( )
protectedvirtual

◆ handleKvmExitException()

Tick gem5::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 1067 of file base.cc.

References _kvmRun, dump(), and panic.

Referenced by handleKvmExit().

◆ handleKvmExitFailEntry()

Tick gem5::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 1076 of file base.cc.

References _kvmRun, dump(), and panic.

Referenced by handleKvmExit().

◆ handleKvmExitHypercall()

Tick gem5::BaseKvmCPU::handleKvmExitHypercall ( )
protectedvirtual

The guest requested a monitor service using a hypercall.

Returns
Number of ticks spent servicing the hypercall

Definition at line 1045 of file base.cc.

References panic.

Referenced by handleKvmExit().

◆ handleKvmExitIO()

Tick gem5::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 gem5::X86KvmCPU.

Definition at line 1037 of file base.cc.

References _kvmRun, and panic.

Referenced by handleKvmExit().

◆ handleKvmExitIRQWindowOpen()

Tick gem5::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 gem5::X86KvmCPU.

Definition at line 1051 of file base.cc.

References warn.

Referenced by handleKvmExit().

◆ handleKvmExitUnknown()

Tick gem5::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 1059 of file base.cc.

References _kvmRun, dump(), and panic.

Referenced by handleKvmExit().

◆ init()

void gem5::BaseKvmCPU::init ( )
override

◆ ioctlRun()

void gem5::BaseKvmCPU::ioctlRun ( )
protectedvirtual

Execute the KVM_RUN ioctl.

Reimplemented in gem5::X86KvmCPU, and gem5::BaseArmKvmCPU.

Definition at line 1324 of file base.cc.

References ioctl(), and panic.

Referenced by gem5::BaseArmKvmCPU::ioctlRun(), gem5::X86KvmCPU::ioctlRun(), and kvmRun().

◆ kick()

void gem5::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 138 of file base.hh.

References KVM_KICK_SIGNAL, and vcpuThread.

Referenced by kvmRun(), and wakeup().

◆ kvmRun()

Tick gem5::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
ticksNumber of ticks to execute, set to 0 to exit immediately after finishing pending operations.
Returns
Number of ticks executed (see note)

Reimplemented in gem5::X86KvmCPU, gem5::BaseArmKvmCPU, and gem5::ArmKvmCPU.

Definition at line 699 of file base.cc.

References gem5::BaseKvmCPU::StatGroup::committedInsts, ctrInsts, gem5::curEventQueue(), discardPendingSignal(), DPRINTF, fatal_if, flushCoalescedMMIO(), getHostCycles(), hostFactor, hwCycles, hwInstructions, ioctlRun(), kick(), KVM_KICK_SIGNAL, gem5::BaseKvmCPU::StatGroup::numVMExits, gem5::BaseKvmCPU::StatGroup::numVMHalfEntries, perfControlledByTimer, gem5::PerfKvmCounter::read(), runTimer, gem5::PerfKvmCounter::start(), stats, gem5::PerfKvmCounter::stop(), and vcpuFD.

Referenced by gem5::BaseArmKvmCPU::kvmRun(), gem5::X86KvmCPU::kvmRun(), gem5::ArmKvmCPU::kvmRun(), gem5::X86KvmCPU::kvmRunDrain(), kvmRunDrain(), and tick().

◆ kvmRunDrain()

Tick gem5::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 gem5::X86KvmCPU.

Definition at line 679 of file base.cc.

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

Referenced by tick().

◆ notifyFork()

void gem5::BaseKvmCPU::notifyFork ( )
override

◆ restartEqThread()

void gem5::BaseKvmCPU::restartEqThread ( )
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 and after drainResume to handle changes to event queue service threads.

See also
startup

Definition at line 233 of file base.cc.

References hwCycles, KVM_KICK_SIGNAL, gem5::VegaISA::p, runTimer, setupCounters(), setupSignalHandler(), and vcpuThread.

Referenced by drainResume(), and startup().

◆ serializeThread()

void gem5::BaseKvmCPU::serializeThread ( CheckpointOut cp,
ThreadID  tid 
) const
override

Definition at line 287 of file base.cc.

References _status, DPRINTF, dump(), Idle, gem5::SimpleThread::serialize(), and thread.

◆ setFPUState()

void gem5::BaseKvmCPU::setFPUState ( const struct kvm_fpu &  state)
protected

Definition at line 847 of file base.cc.

References ioctl(), panic, and state.

Referenced by gem5::X86KvmCPU::updateKvmStateFPULegacy().

◆ setOneReg() [1/3]

void gem5::BaseKvmCPU::setOneReg ( uint64_t  id,
const void *  addr 
)
protected

◆ setOneReg() [2/3]

void gem5::BaseKvmCPU::setOneReg ( uint64_t  id,
uint32_t  value 
)
inlineprotected

Definition at line 388 of file base.hh.

References setOneReg().

Referenced by setOneReg().

◆ setOneReg() [3/3]

void gem5::BaseKvmCPU::setOneReg ( uint64_t  id,
uint64_t  value 
)
inlineprotected

Definition at line 387 of file base.hh.

References setOneReg().

Referenced by setOneReg().

◆ setRegisters()

void gem5::BaseKvmCPU::setRegisters ( const struct kvm_regs &  regs)
protected

Definition at line 819 of file base.cc.

References ioctl(), and panic.

Referenced by gem5::X86KvmCPU::updateKvmStateRegs().

◆ setSignalMask()

void gem5::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
maskSignals to mask

Definition at line 1136 of file base.cc.

References ioctl(), gem5::mask(), gem5::VegaISA::p, and panic.

Referenced by setupSignalHandler().

◆ setSpecialRegisters()

void gem5::BaseKvmCPU::setSpecialRegisters ( const struct kvm_sregs &  regs)
protected

Definition at line 833 of file base.cc.

References ioctl(), and panic.

Referenced by gem5::X86KvmCPU::updateKvmStateSRegs().

◆ setupCounters()

void gem5::BaseKvmCPU::setupCounters ( )
private

◆ setupInstCounter()

void gem5::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
periodSignal period, set to 0 to disable signaling.

Definition at line 1346 of file base.cc.

References activeInstPeriod, gem5::PerfKvmCounter::attach(), gem5::PerfKvmCounter::attached(), gem5::PerfKvmCounter::detach(), gem5::PerfKvmCounter::enableSignals(), gem5::PerfKvmCounterConfig::exclude_host(), gem5::PerfKvmCounterConfig::exclude_hv(), hwCycles, hwInstructions, KVM_KICK_SIGNAL, gem5::PerfKvmCounterConfig::samplePeriod(), and gem5::PerfKvmCounterConfig::wakeupEvents().

Referenced by setupCounters(), and setupInstStop().

◆ setupInstStop()

void gem5::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 1334 of file base.cc.

References gem5::SimpleThread::comInstEventQueue, ctrInsts, gem5::EventQueue::empty(), gem5::EventQueue::nextTick(), setupInstCounter(), and thread.

Referenced by tick().

◆ setupSignalHandler()

void gem5::BaseKvmCPU::setupSignalHandler ( )
private

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

Definition at line 1209 of file base.cc.

References KVM_KICK_SIGNAL, gem5::onKickSignal(), panic, gem5::ArmISA::sa, and setSignalMask().

Referenced by restartEqThread().

◆ startup()

void gem5::BaseKvmCPU::startup ( )
override

◆ stutterPC()

virtual void gem5::BaseKvmCPU::stutterPC ( PCStateBase pc) const
protectedpure virtual

Modify a PCStatePtr's value so that its next PC is the current PC.

This needs to be implemented in KVM base classes since modifying the next PC value is an ISA specific operation. This is only used in doMMIOAccess, for reasons explained in a comment there.

Implemented in gem5::X86KvmCPU, gem5::BaseArmKvmCPU, and gem5::ArmKvmCPU.

Referenced by doMMIOAccess().

◆ suspendContext()

void gem5::BaseKvmCPU::suspendContext ( ThreadID  thread_num)
override

◆ switchOut()

void gem5::BaseKvmCPU::switchOut ( )
override

Definition at line 435 of file base.cc.

References _status, DPRINTF, Idle, gem5::Event::scheduled(), and tickEvent.

◆ syncKvmState()

void gem5::BaseKvmCPU::syncKvmState ( )
protected

Update the KVM if the thread context is dirty.

Definition at line 948 of file base.cc.

References kvmStateDirty, threadContextDirty, and updateKvmState().

Referenced by tick().

◆ syncThreadContext()

void gem5::BaseKvmCPU::syncThreadContext ( )
protected

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

Definition at line 936 of file base.cc.

References kvmStateDirty, threadContextDirty, and updateThreadContext().

Referenced by gem5::X86KvmCPU::deliverInterrupts(), doMMIOAccess(), drain(), getContext(), gem5::X86KvmCPU::kvmRun(), and tick().

◆ takeOverFrom()

void gem5::BaseKvmCPU::takeOverFrom ( BaseCPU *  cpu)
override

◆ tick()

void gem5::BaseKvmCPU::tick ( )
protected

◆ totalInsts()

Counter gem5::BaseKvmCPU::totalInsts ( ) const
override

Definition at line 564 of file base.cc.

References ctrInsts.

◆ totalOps()

Counter gem5::BaseKvmCPU::totalOps ( ) const
override

Definition at line 570 of file base.cc.

References ctrInsts, and hack_once.

◆ tryDrain()

bool gem5::BaseKvmCPU::tryDrain ( )
private

Try to drain the CPU if a drain is pending.

Definition at line 1302 of file base.cc.

References _status, archIsDrained(), DPRINTF, gem5::Draining, Idle, and Running.

Referenced by tick().

◆ unserializeThread()

void gem5::BaseKvmCPU::unserializeThread ( CheckpointIn cp,
ThreadID  tid 
)
override

Definition at line 300 of file base.cc.

References _status, DPRINTF, Idle, thread, threadContextDirty, and gem5::SimpleThread::unserialize().

◆ updateKvmState()

virtual void gem5::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 gem5::X86KvmCPU, gem5::ArmV8KvmCPU, and gem5::ArmKvmCPU.

Referenced by syncKvmState(), and takeOverFrom().

◆ updateThreadContext()

virtual void gem5::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 gem5::X86KvmCPU, gem5::ArmV8KvmCPU, and gem5::ArmKvmCPU.

Referenced by syncThreadContext().

◆ verifyMemoryMode()

void gem5::BaseKvmCPU::verifyMemoryMode ( ) const
override

Definition at line 471 of file base.cc.

References fatal, and gem5::X86ISA::system.

Referenced by drainResume().

◆ wakeup()

void gem5::BaseKvmCPU::wakeup ( ThreadID  tid = 0)
override

Member Data Documentation

◆ _kvmRun

struct kvm_run* gem5::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 716 of file base.hh.

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

◆ _status

Status gem5::BaseKvmCPU::_status
protected

◆ activeInstPeriod

uint64_t gem5::BaseKvmCPU::activeInstPeriod
private

Currently active instruction count breakpoint.

Definition at line 756 of file base.hh.

Referenced by setupInstCounter().

◆ alwaysSyncTC

const bool gem5::BaseKvmCPU::alwaysSyncTC
protected

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

Definition at line 642 of file base.hh.

Referenced by tick().

◆ ctrInsts

Counter gem5::BaseKvmCPU::ctrInsts

Number of instructions executed by the CPU.

Definition at line 821 of file base.hh.

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

◆ dataPort

KVMCpuPort gem5::BaseKvmCPU::dataPort
protected

Port for data requests.

Definition at line 633 of file base.hh.

Referenced by doMMIOAccess(), getDataPort(), handleKvmExit(), and gem5::X86KvmCPU::handleKvmExitIO().

◆ hostFactor

float gem5::BaseKvmCPU::hostFactor
private

Host factor as specified in the configuration.

Definition at line 800 of file base.hh.

Referenced by kvmRun().

◆ hwCycles

PerfKvmCounter gem5::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 766 of file base.hh.

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

◆ hwInstructions

PerfKvmCounter gem5::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 779 of file base.hh.

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

◆ instPort

KVMCpuPort gem5::BaseKvmCPU::instPort
protected

Unused dummy port for the instruction interface.

Definition at line 636 of file base.hh.

Referenced by getInstPort().

◆ kvmStateDirty

bool gem5::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 654 of file base.hh.

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

◆ mmioRing

struct kvm_coalesced_mmio_ring* gem5::BaseKvmCPU::mmioRing
private

Coalesced MMIO ring buffer.

NULL if coalesced MMIO is not supported.

Definition at line 721 of file base.hh.

Referenced by flushCoalescedMMIO(), and startup().

◆ pageSize

const long gem5::BaseKvmCPU::pageSize
private

Cached page size of the host.

Definition at line 723 of file base.hh.

Referenced by startup().

◆ perfControlledByTimer

bool gem5::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 788 of file base.hh.

Referenced by kvmRun(), and setupCounters().

◆ runTimer

std::unique_ptr<BaseKvmTimer> gem5::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 797 of file base.hh.

Referenced by kvmRun(), restartEqThread(), and tick().

◆ stats

gem5::BaseKvmCPU::StatGroup gem5::BaseKvmCPU::stats

◆ tc

ThreadContext* gem5::BaseKvmCPU::tc

◆ thread

SimpleThread* gem5::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 153 of file base.hh.

Referenced by activateContext(), gem5::X86KvmCPU::deliverInterrupts(), doMMIOAccess(), handleKvmExit(), serializeThread(), setupInstStop(), suspendContext(), tick(), unserializeThread(), and wakeup().

◆ threadContextDirty

bool gem5::BaseKvmCPU::threadContextDirty
protected

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

Definition at line 648 of file base.hh.

Referenced by gem5::X86KvmCPU::deliverInterrupts(), doMMIOAccess(), syncKvmState(), syncThreadContext(), takeOverFrom(), tick(), and unserializeThread().

◆ tickEvent

EventFunctionWrapper gem5::BaseKvmCPU::tickEvent
private

◆ vcpuFD

int gem5::BaseKvmCPU::vcpuFD
private

KVM vCPU file descriptor.

Definition at line 705 of file base.hh.

Referenced by ioctl(), kvmRun(), notifyFork(), startup(), and ~BaseKvmCPU().

◆ vcpuID

long gem5::BaseKvmCPU::vcpuID
protected

KVM internal ID of the vCPU.

Definition at line 657 of file base.hh.

Referenced by getVCpuID(), init(), gem5::BaseArmKvmCPU::kvmRun(), gem5::ArmKvmCPU::kvmRun(), and startup().

◆ vcpuMMapSize

int gem5::BaseKvmCPU::vcpuMMapSize
private

Size of MMAPed kvm_run area.

Definition at line 707 of file base.hh.

Referenced by notifyFork(), startup(), and ~BaseKvmCPU().

◆ vcpuThread

pthread_t gem5::BaseKvmCPU::vcpuThread
protected

ID of the vCPU thread.

Definition at line 660 of file base.hh.

Referenced by kick(), and restartEqThread().

◆ vm

KvmVM* gem5::BaseKvmCPU::vm

The documentation for this class was generated from the following files:

Generated on Thu Jul 28 2022 13:32:58 for gem5 by doxygen 1.8.17