linux/arch/x86/include/asm/virtext.h
Eduardo Habkost 1e9931146c x86: asm/virtext.h: add cpu_vmxoff() inline function
Unfortunately we can't use exactly the same code from vmx
hardware_disable(), because the KVM function uses the
__kvm_handle_fault_on_reboot() tricks.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:52:29 +02:00

47 lines
1.1 KiB
C

/* CPU virtualization extensions handling
*
* This should carry the code for handling CPU virtualization extensions
* that needs to live in the kernel core.
*
* Author: Eduardo Habkost <ehabkost@redhat.com>
*
* Copyright (C) 2008, Red Hat Inc.
*
* Contains code from KVM, Copyright (C) 2006 Qumranet, Inc.
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*/
#ifndef _ASM_X86_VIRTEX_H
#define _ASM_X86_VIRTEX_H
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/vmx.h>
/*
* VMX functions:
*/
static inline int cpu_has_vmx(void)
{
unsigned long ecx = cpuid_ecx(1);
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 */