[PATCH 03/11] x86: asm/virtext.h: add cpu_vmxoff() inline function

[Eduardo Habkost]

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 at redhat.com>
---
 arch/x86/include/asm/virtext.h |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h
index 351fa23..475fb17 100644
--- a/arch/x86/include/asm/virtext.h
+++ b/arch/x86/include/asm/virtext.h
@@ -45,4 +45,17 @@ 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 */
-- 
1.5.5.GIT