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

Eduardo Habkost
2008-11-13T17:44:34Z

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>
---
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 */