;*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*
; Written and compiled with FASMW v1.67.3
; 2006-08-25 HyperVista
; Thanks to vid and locodelassembly for their help and guidance
;
; The purpose of this simple program is to determine
; if the box on which it is run supports Intel's VT-x
; virtualization.
;
; This program uses CPUID to determine if the CPU is Intel
; and if so, it determines if it supports Intel's VT-x
; extensions.  First, we use CPUID with 00H in EAX in order
; to retrieve the vendor identification string and then we
; test that string.  Next we use CPUID with 01H in EAX to
; retrieve the Extended Feature information returned in ECX.
; If Bit 5 in CL is set it indicates that the processor
; supports VT-x.
;
; While this program only prints a message indicating the
; processor does or doesn't support Intel's VT-x, this routine
; can be used to determine if VT-x is supported as a first
; step in a VMM or hypervisor installation program or as a
; portion of a survey tool.
;
;*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*

org 100h

jmp start

; Print Routine
print:
        mov ah,9h
        int 21h
        ret

print_wait:
        call print
        xor ax,ax   ; pause screen until user hits any key
        int 16h
        jmp exit

; Message Text
no_msg db 'Genuine Intel, but no VT-x support!  Press any key to continue....', 13, 10, '$'
yes_msg db 'Genuine Intel and VT-x IS supported!  Please press any key to continue....', 13, 10, '$'
not_intel db 'Non-Intel Processor.  VT-x in NOT supported.  Please press any key to continue....', 13, 10, '$'

start:
        ;  Check to see if the processor is Intel
        mov ax,00h
        CPUID
        cmp ebx,'Genu'    ; partial Intel signature placed in EBX
        jz Is_Intel       ; if not an Intel chip, we're done
        mov dx,not_intel
        call print_wait

        Is_Intel:
        ; Check to see if VT-x is supported
           mov ax,01h
           CPUID
           and cl,20h       ; ECX bit 5 bit mask test
           jnz VTX_Supported
           mov dx,no_msg
           call print_wait

       ; VTX supported - we only print message now
       ; This is where we will launch VMM or hypervisor later
       VTX_Supported:
            mov dx,yes_msg
            call print_wait

        ; Program End
        exit:
           mov ax,4C00h   ; hand back control to the OS
           int 21h    

Code:

        mov dl,20h   ; Bit 5 bit mask 
        and cl,dl    

and cl, 20h    

Code:

        cmp ebx,756e6547h ;this value is partial Intel signature 
    

        cmp ebx, 'Genu' ;this value is partial Intel signature    

Are you coming to Krakow at the end of Sept?
HyperVista

int start_vmx(void)
{
    struct vmcs_struct *vmcs;
    u32 ecx;
    u32 eax, edx;
    u64 phys_vmcs;      /* debugging */

    /*
     * Xen does not fill x86_capability words except 0.
     */
    ecx = cpuid_ecx(1);
    boot_cpu_data.x86_capability[4] = ecx;

    if (!(test_bit(X86_FEATURE_VMXE, &boot_cpu_data.x86_capability)))
        return 0;

    rdmsr(IA32_FEATURE_CONTROL_MSR, eax, edx);

    if (eax & IA32_FEATURE_CONTROL_MSR_LOCK) {
        if ((eax & IA32_FEATURE_CONTROL_MSR_ENABLE_VMXON) == 0x0) {
            printk("VMX disabled by Feature Control MSR.\n");
            return 0;
        }
    }
    else {
        wrmsr(IA32_FEATURE_CONTROL_MSR,
              IA32_FEATURE_CONTROL_MSR_LOCK |
              IA32_FEATURE_CONTROL_MSR_ENABLE_VMXON, 0);
    }

    if (!check_vmx_controls(MONITOR_PIN_BASED_EXEC_CONTROLS,
                            MSR_IA32_VMX_PINBASED_CTLS_MSR))
        return 0;
    if (!check_vmx_controls(MONITOR_CPU_BASED_EXEC_CONTROLS,
                            MSR_IA32_VMX_PROCBASED_CTLS_MSR))
        return 0;
    if (!check_vmx_controls(MONITOR_VM_EXIT_CONTROLS,
                            MSR_IA32_VMX_EXIT_CTLS_MSR))
        return 0;
    if (!check_vmx_controls(MONITOR_VM_ENTRY_CONTROLS,
                            MSR_IA32_VMX_ENTRY_CTLS_MSR))
        return 0;

    set_in_cr4(X86_CR4_VMXE);   /* Enable VMXE */

    if (!(vmcs = alloc_vmcs())) {
        printk("Failed to allocate VMCS\n");
        return 0;
    }

    phys_vmcs = (u64) virt_to_maddr(vmcs);

    if (!(__vmxon(phys_vmcs))) {
        printk("VMXON is done\n");
    }

    vmx_save_init_msrs();

    /* Setup HVM interfaces */
    hvm_funcs.disable = stop_vmx;

    hvm_funcs.initialize_guest_resources = vmx_initialize_guest_resources;
    hvm_funcs.relinquish_guest_resources = vmx_relinquish_guest_resources;

    hvm_funcs.store_cpu_guest_regs = vmx_store_cpu_guest_regs;
    hvm_funcs.load_cpu_guest_regs = vmx_load_cpu_guest_regs;

    hvm_funcs.realmode = vmx_realmode;
    hvm_funcs.paging_enabled = vmx_paging_enabled;
    hvm_funcs.instruction_length = vmx_instruction_length;
    hvm_funcs.get_guest_ctrl_reg = vmx_get_ctrl_reg;

    hvm_funcs.init_ap_context = vmx_init_ap_context;

    hvm_enabled = 1;

    return 1;
}