diff options
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/virtext.h | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h index 9aad0e0876fb..fda3e7747c22 100644 --- a/arch/x86/include/asm/virtext.h +++ b/arch/x86/include/asm/virtext.h @@ -30,15 +30,22 @@ static inline int cpu_has_vmx(void) } -/** Disable VMX on the current CPU +/** + * cpu_vmxoff() - 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. + * Disable VMX and clear CR4.VMXE (even if VMXOFF faults) + * + * Note, VMXOFF causes a #UD if the CPU is !post-VMXON, but it's impossible to + * atomically track post-VMXON state, e.g. this may be called in NMI context. + * Eat all faults as all other faults on VMXOFF faults are mode related, i.e. + * faults are guaranteed to be due to the !post-VMXON check unless the CPU is + * magically in RM, VM86, compat mode, or at CPL>0. */ static inline void cpu_vmxoff(void) { - asm volatile ("vmxoff"); + asm_volatile_goto("1: vmxoff\n\t" + _ASM_EXTABLE(1b, %l[fault]) :::: fault); +fault: cr4_clear_bits(X86_CR4_VMXE); } |