_Use_decl_annotations_ EXTERN_C static bool VminitpInitializeVMCS(
PER_PROCESSOR_DATA *ProcessorData) {
// Write a VMCS revision identifier
IA32_VMX_BASIC_MSR vmxBasicMsr = {__readmsr(IA32_VMX_BASIC)};
ProcessorData->VmcsRegion->RevisionIdentifier =
vmxBasicMsr.Fields.RevisionIdentifier;
auto vmcsRegionPA = MmGetPhysicalAddress(ProcessorData->VmcsRegion);
// It stores the value FFFFFFFF_FFFFFFFFH if there is no current VMCS
if (__vmx_vmclear(
reinterpret_cast<unsigned long long *>(&vmcsRegionPA.QuadPart))) {
return false;
}
// Software makes a VMCS current by executing VMPTRLD with the address
// of the VMCS; that address is loaded into the current-VMCS pointer.
if (__vmx_vmptrld(
reinterpret_cast<unsigned long long *>(&vmcsRegionPA.QuadPart))) {
return false;
}
// The launch state of current VMCS is "clear"
return true;
}
NTSTATUS ControlAreaInitializeProcessor(LONG ProcessorNumber)
{
//
// Allocate host stack region
// 16 pages available for use
//
SIZE_T stackSize = 16 * PAGE_SIZE;
PUCHAR stackBase = ExAllocatePoolWithTag(NonPagedPool, stackSize, 'KSTK');
if (!stackBase)
return STATUS_NO_MEMORY;
RtlSecureZeroMemory((PVOID)stackBase, stackSize);
//
// Set up CPU control structure
//
PVIRT_CPU cpu = (PVIRT_CPU)(stackBase + stackSize - 8 - sizeof(VIRT_CPU));
cpu->HostStackBase = stackBase;
cpu->Self = cpu;
CpuControlArea[ProcessorNumber] = cpu;
//
// Allocate all VMX regions
//
if (!NT_SUCCESS(AllocateVmxProcessorData(&cpu->VmxonVa, &cpu->VmxonPa, &cpu->VmxonSize)))
return STATUS_NO_MEMORY;
if (!NT_SUCCESS(AllocateVmxProcessorData(&cpu->VmcsVa, &cpu->VmcsPa, &cpu->VmcsSize)))
return STATUS_NO_MEMORY;
if (!NT_SUCCESS(AllocateVmxProcessorData(&cpu->MSRBitmapVa, &cpu->MSRBitmapPa, &cpu->MSRBitmapSize)))
return STATUS_NO_MEMORY;
// Bitmap needs to be zeroed
RtlSecureZeroMemory(cpu->MSRBitmapVa, cpu->MSRBitmapSize);
__try
{
if (__vmx_on(PA_PTR_INT64(cpu->VmxonPa)) > 0)
return STATUS_UNSUCCESSFUL;
if (__vmx_vmclear(PA_PTR_INT64(cpu->VmcsPa)) > 0)
return STATUS_UNSUCCESSFUL;
if (__vmx_vmptrld(PA_PTR_INT64(cpu->VmcsPa)) > 0)
return STATUS_UNSUCCESSFUL;
}
__except (EXCEPTION_EXECUTE_HANDLER)
{
// Rare case (or if physical address is invalid)
return GetExceptionCode();
}
return STATUS_SUCCESS;
}
static bool init_vmcs(struct vmcs *vmcs)
{
u64 vmx = __readmsr(MSR_IA32_VMX_BASIC);
vmcs->revision_id = (u32)vmx;
uintptr_t pa = __pa(vmcs);
if (__vmx_vmclear(&pa))
return false;
return __vmx_vmptrld(&pa) == 0;
}
// See: VMM SETUP & TEAR DOWN
_Use_decl_annotations_ static bool VmpInitializeVMCS(
ProcessorData *processor_data) {
// Write a VMCS revision identifier
const Ia32VmxBasicMsr vmx_basic_msr = {UtilReadMsr64(Msr::kIa32VmxBasic)};
processor_data->vmcs_region->revision_identifier =
vmx_basic_msr.fields.revision_identifier;
auto vmcs_region_pa = UtilPaFromVa(processor_data->vmcs_region);
if (__vmx_vmclear(&vmcs_region_pa)) {
return false;
}
if (__vmx_vmptrld(&vmcs_region_pa)) {
return false;
}
// The launch state of current VMCS is "clear"
return true;
}
/// <summary>
/// Switch CPU to root mode
/// </summary>
/// <param name="Vcpu">Virtual CPU data</param>
/// <returns>TRUE on success</returns>
BOOLEAN VmxEnterRoot( IN PVCPU Vcpu )
{
PKSPECIAL_REGISTERS Registers = &Vcpu->HostState.SpecialRegisters;
PIA32_VMX_BASIC_MSR pBasic = (PIA32_VMX_BASIC_MSR)&Vcpu->MsrData[VMX_MSR( MSR_IA32_VMX_BASIC )];
// Ensure the the VMCS can fit into a single page
if (pBasic->Fields.RegionSize > PAGE_SIZE)
{
DPRINT( "HyperBone: CPU %d: %s: VMCS region doesn't fit into one page\n", CPU_IDX, __FUNCTION__ );
return FALSE;
}
// Ensure that the VMCS is supported in writeback memory
if (pBasic->Fields.MemoryType != VMX_MEM_TYPE_WRITEBACK)
{
DPRINT( "HyperBone: CPU %d: %s: Unsupported memory type\n", CPU_IDX, __FUNCTION__ );
return FALSE;
}
// Ensure that true MSRs can be used for capabilities
if (pBasic->Fields.VmxCapabilityHint == 0)
{
DPRINT( "HyperBone: CPU %d: %s: No true MSR support\n", CPU_IDX, __FUNCTION__ );
return FALSE;
}
// Capture the revision ID for the VMXON and VMCS region
Vcpu->VMXON->RevisionId = pBasic->Fields.RevisionIdentifier;
Vcpu->VMCS->RevisionId = pBasic->Fields.RevisionIdentifier;
// Update CR0 with the must-be-zero and must-be-one requirements
Registers->Cr0 &= Vcpu->MsrData[VMX_MSR( MSR_IA32_VMX_CR0_FIXED1 )].LowPart;
Registers->Cr0 |= Vcpu->MsrData[VMX_MSR( MSR_IA32_VMX_CR0_FIXED0 )].LowPart;
// Do the same for CR4
Registers->Cr4 &= Vcpu->MsrData[VMX_MSR( MSR_IA32_VMX_CR4_FIXED1 )].LowPart;
Registers->Cr4 |= Vcpu->MsrData[VMX_MSR( MSR_IA32_VMX_CR4_FIXED0 )].LowPart;
// Update host CR0 and CR4 based on the requirements above
__writecr0( Registers->Cr0 );
__writecr4( Registers->Cr4 );
// Enable VMX Root Mode
PHYSICAL_ADDRESS phys = MmGetPhysicalAddress( Vcpu->VMXON );
int res = __vmx_on( (PULONG64)&phys );
if (res)
{
DPRINT( "HyperBone: CPU %d: %s: __vmx_on failed with status %d\n", CPU_IDX, __FUNCTION__, res );
return FALSE;
}
// Clear the state of the VMCS, setting it to Inactive
phys = MmGetPhysicalAddress( Vcpu->VMCS );
if (__vmx_vmclear( (PULONG64)&phys ))
{
DPRINT( "HyperBone: CPU %d: %s: __vmx_vmclear failed\n", CPU_IDX, __FUNCTION__ );
return FALSE;
}
// Load the VMCS, setting its state to Active
if (__vmx_vmptrld( (PULONG64)&phys ))
{
DPRINT( "HyperBone: CPU %d: %s: __vmx_vmptrld failed\n", CPU_IDX, __FUNCTION__ );
return FALSE;
}
// VMX Root Mode is enabled, with an active VMCS.
return TRUE;
}
