Function SvmVmexitHandler

Kernel-Bridge/API/Hypervisor.cpp:374–470

    }

    extern "C" VMM_STATUS SvmVmexitHandler(PRIVATE_VM_DATA* Private, GUEST_CONTEXT* Context)
    {
        // Load the host state:
        __svm_vmload(reinterpret_cast<size_t>(Private->VmmStack.Layout.InitialStack.HostVmcbPa));
        
        // Restore the guest's RAX that was overwritten by host's RAX on #VMEXIT:
        Context->Rax = Private->Guest.StateSaveArea.Rax;

        VMM_STATUS Status = VMM_STATUS::VMM_CONTINUE;
        switch (Private->Guest.ControlArea.ExitCode)
        {
        case VMEXIT_CPUID:
        {
            CPUID_REGS Regs = {};
            int Function = static_cast<int>(Context->Rax);
            int SubLeaf = static_cast<int>(Context->Rcx);
            __cpuidex(Regs.Raw, Function, SubLeaf);

            switch (Function) {
            case CPUID_VMM_SHUTDOWN:
            {
                // Shutdown was triggered:
                Status = VMM_STATUS::VMM_SHUTDOWN;
                break;
            }
            case CPUID::Generic::CPUID_MAXIMUM_FUNCTION_NUMBER_AND_VENDOR_ID:
            {
                // Vendor = 'Hyper-Bridge' as RBX + RDX + RCX:
                Context->Rax = Regs.Regs.Eax;
                GetHvCpuName(Context->Rbx, Context->Rcx, Context->Rdx);
                break;
            }
            default:
            {
                Context->Rax = Regs.Regs.Eax;
                Context->Rbx = Regs.Regs.Ebx;
                Context->Rcx = Regs.Regs.Ecx;
                Context->Rdx = Regs.Regs.Edx;
                break;
            }
            }
            break;
        }
        case VMEXIT_MSR:
        {
            if ((Context->Rcx & MAXUINT32) == static_cast<unsigned int>(AMD_MSR::MSR_EFER) && Private->Guest.ControlArea.ExitInfo1)
            {
                EFER Efer = {};
                Efer.Value = ((Context->Rdx & MAXUINT32) << 32) | (Context->Rax & MAXUINT32);
                if (!Efer.Bitmap.SecureVirtualMachineEnable)
                {
                    InjectEvent(&Private->Guest, 13, 3, 0); // #GP (Vector = 13, Type = Exception)
                    break;
                }
                Private->Guest.StateSaveArea.Efer = Efer.Value;
            }
            break;
        }