/**
* effects: Uninstall Vis Hypervisor
*/
static NTSTATUS NTAPI HvmLiberateCpu (
PVOID Param
)
{ //Finish
NTSTATUS Status;
ULONG64 Efer;
PCPU Cpu;
// called at DPC level
if (KeGetCurrentIrql () != DISPATCH_LEVEL)
return STATUS_UNSUCCESSFUL;
Efer = MsrRead (MSR_EFER);
Print(("Vis:HvmLiberateCpu(): Reading MSR_EFER on entry: 0x%X\n", Efer));
// cause VMM destruction
RegSetCr3(VIS_EXIT_FN);
Efer = MsrRead (MSR_EFER);
Print(("Vis:HvmLiberateCpu(): Reading MSR_EFER on exit: 0x%X\n", Efer));
return STATUS_SUCCESS;
}
/*
* effects: This service introduced in VMX Preemption
* Timer function to the VMCS.
* returns: If VMX-Preemption Timer is not supported on the current platform,
* returns HVSTATUS_UNSUPPORTED_FEATURE.
*/
HVSTATUS PtVmxSetTimerInterval(
PCPU Cpu,
ULONG32 Ticks, /* After how many ticks the VMX Timer will be expired, THIS VALUE IS FIXED TO BE 32 BITS LONG*/
BOOLEAN SaveTimerValueOnVMEXIT,
NBP_TRAP_CALLBACK TrapCallback /* If this is null, we won't register a callback function*/
)
{
ULONG32 Interceptions;
ULONG32 Ratio;
LARGE_INTEGER MsrValue,MsrValue1,MsrValue2;
PNBP_TRAP Trap;
NTSTATUS Status;
//Step 0. Check if the current platform supports VMX-Preemption Timer
if(!(Cpu->Vmx.FeaturesMSR.VmxPinBasedCTLs.HighPart & PIN_BASED_VMX_TIMER_MASK))
return HVSTATUS_UNSUPPORTED_FEATURE;
//Step 1. Activate VMX-Preemption Timer in PIN_BASED_VM_EXEC_CONTROL
Interceptions = VmxRead(PIN_BASED_VM_EXEC_CONTROL);
VmxWrite(PIN_BASED_VM_EXEC_CONTROL, Interceptions|PIN_BASED_VMX_TIMER_MASK);
// Activate VMX-preemption Timer
//Step 2. Get the Ratio of TSC-VMX Timer Tick in IA32_VMX_MISC MSR
MsrValue.QuadPart = MsrRead(MSR_IA32_VMX_MISC);
Ratio = MsrValue.LowPart & (~0xffffffe0);
//Step 3. Set the VMX-Preemption Timer Value
VmxWrite(VMCS_GUEST_VMX_PREEMPTION_TIMER_VALUE, Ticks>>Ratio);
//Step 4. Set whether saving VMX-Preemption Timer Value on VMEXIT
if(SaveTimerValueOnVMEXIT)
{
//Save the value
Interceptions = VmxRead(VM_EXIT_CONTROLS);
VmxWrite(VM_EXIT_CONTROLS, Interceptions|VM_EXIT_SAVE_TIMER_VALUE_ON_EXIT);
}
//Step 5. Register a callback function
if(TrapCallback)
{
Status = HvInitializeGeneralTrap(
Cpu,
EXIT_REASON_VMXTIMER_EXPIRED,
FALSE,
0, // length of the instruction, 0 means length need to be get from vmcs later.
TrapCallback,
&Trap,
LAB_TAG
);
if (!NT_SUCCESS (Status))
{
Print(("PtVmxSetTimerInterval(): Failed to register PtVmxSetTimerInterval Callback with status 0x%08hX\n", Status));
return Status;
}
MadDog_RegisterTrap (Cpu, Trap);
}
return HVSTATUS_SUCCESS;
}
static BOOLEAN NTAPI VmxDispatchMsrRead (
PCPU Cpu,
PGUEST_REGS GuestRegs,
PNBP_TRAP Trap,
BOOLEAN WillBeAlsoHandledByGuestHv,
...
)
{
LARGE_INTEGER MsrValue;
ULONG32 ecx;
ULONG inst_len;
if (!Cpu || !GuestRegs)
return TRUE;
inst_len = VmxRead (VM_EXIT_INSTRUCTION_LEN);
if (Trap->RipDelta == 0)
Trap->RipDelta = inst_len;
ecx = GuestRegs->ecx;
switch (ecx)
{
case MSR_IA32_SYSENTER_CS:
MsrValue.QuadPart = VmxRead (GUEST_SYSENTER_CS);
break;
case MSR_IA32_SYSENTER_ESP:
MsrValue.QuadPart = VmxRead (GUEST_SYSENTER_ESP);
break;
case MSR_IA32_SYSENTER_EIP:
MsrValue.QuadPart = VmxRead (GUEST_SYSENTER_EIP);
Print(("VmxDispatchMsrRead(): Guest EIP: 0x%x read MSR_IA32_SYSENTER_EIP value: 0x%x \n",
VmxRead(GUEST_RIP),
MsrValue.QuadPart));
break;
case MSR_GS_BASE:
MsrValue.QuadPart = VmxRead (GUEST_GS_BASE);
break;
case MSR_FS_BASE:
MsrValue.QuadPart = VmxRead (GUEST_FS_BASE);
break;
case MSR_EFER:
MsrValue.QuadPart = Cpu->Vmx.GuestEFER;
//_KdPrint(("Guestip 0x%llx MSR_EFER Read 0x%llx 0x%llx \n",VmxRead(GUEST_RIP),ecx,MsrValue.QuadPart));
break;
default:
if (ecx <= 0x1fff
|| (ecx >= 0xC0000000 && ecx <= 0xC0001fff))
{
MsrValue.QuadPart = MsrRead (ecx);
}
}
GuestRegs->eax = MsrValue.LowPart;
GuestRegs->edx = MsrValue.HighPart;
return TRUE;
}
/**
* This function is used to set value safely according to MSR register.
* make the <Ctl> values legal.
* e.g some Vmx Settings use MSR_IA32_VMX_PINBASED_CTLS & MSR_IA32_VMX_TRUE_PINBASED_CTLS.
*/
ULONG32 NTAPI PtVmxAdjustControls (
ULONG32 Ctl,
ULONG32 Msr
)
{
LARGE_INTEGER MsrValue;
MsrValue.QuadPart = MsrRead (Msr);
Ctl &= MsrValue.HighPart; /* bit == 0 in high word ==> must be zero */
Ctl |= MsrValue.LowPart; /* bit == 1 in low word ==> must be one */
return Ctl;
}
