VMCLEAR

if not in_vmx:
    fault(UD)
if vmx_nonroot:
    vm_exit(19)                  # the hypervisor emulates it
if CPL > 0:
    fault(GP, 0)
p = src.read()                   # a physical address
basic = msr[IA32_VMX_BASIC]
w = maxphyaddr                   # the physical-address width, or
if basic >> 48 & 1:              # 32 bits where IA32_VMX_BASIC[48]
    w = 32                       # says so
if p & 0xFFF or p >> w:
    vm_fail(2)                   # not 4-KByte aligned, or past the
                                 # physical-address width
elif p == vmxon_ptr:
    vm_fail(3)
else:
    vmcs_clear(p)                # the processor's copy of the data
                                 # to the region; launch state clear,
                                 # the VMCS no longer active
    if p == current_vmcs:
        current_vmcs = NO_VMCS
    vm_succeed()