diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h index 298b6a06110d..7dee5b59930e 100644 --- a/arch/x86/include/asm/virtext.h +++ b/arch/x86/include/asm/virtext.h @@ -18,6 +18,8 @@ #include #include +#include + /* * VMX functions: */ @@ -28,4 +30,17 @@ static inline int cpu_has_vmx(void) return test_bit(5, &ecx); /* CPUID.1:ECX.VMX[bit 5] -> VT */ } + +/** Disable VMX on the current CPU + * + * vmxoff causes a undefined-opcode exception if vmxon was not run + * on the CPU previously. Only call this function if you know VMX + * is enabled. + */ +static inline void cpu_vmxoff(void) +{ + asm volatile (ASM_VMX_VMXOFF : : : "cc"); + write_cr4(read_cr4() & ~X86_CR4_VMXE); +} + #endif /* _ASM_X86_VIRTEX_H */