_Use_decl_annotations_ bool __stdcall VmmVmExitHandler(VmmInitialStack *stack) {
// Save guest's context and raise IRQL as quick as possible
const auto guest_irql = KeGetCurrentIrql();
const auto guest_cr8 = IsX64() ? __readcr8() : 0;
if (guest_irql < DISPATCH_LEVEL) {
KeRaiseIrqlToDpcLevel();
}
NT_ASSERT(stack->reserved == MAXULONG_PTR);
// Capture the current guest state
GuestContext guest_context = {stack,
UtilVmRead(VmcsField::kGuestRflags),
UtilVmRead(VmcsField::kGuestRip),
guest_cr8,
guest_irql,
true};
guest_context.gp_regs->sp = UtilVmRead(VmcsField::kGuestRsp);
// Dispatch the current VM-exit event
VmmpHandleVmExit(&guest_context);
// Restore guest's context
if (guest_context.irql < DISPATCH_LEVEL) {
KeLowerIrql(guest_context.irql);
}
// Apply possibly updated CR8 by the handler
if (IsX64()) {
__writecr8(guest_context.cr8);
}
return guest_context.vm_continue;
}
FORCEINLINE
KIRQL
ApicGetCurrentIrql(VOID)
{
#ifdef _M_AMD64
return (KIRQL)__readcr8();
#elif defined(APIC_LAZY_IRQL)
// HACK: some magic to Sync VBox's APIC registers
ApicRead(APIC_VER);
/* Return the field in the PCR */
return (KIRQL)__readfsbyte(FIELD_OFFSET(KPCR, Irql));
#else
// HACK: some magic to Sync VBox's APIC registers
ApicRead(APIC_VER);
/* Read the TPR and convert it to an IRQL */
return TprToIrql(ApicRead(APIC_TPR));
#endif
}
