KVM: VMX: Add AX to list of registers clobbered by guest switch

KVM: VMX: Add AX to list of registers clobbered by guest switch

[Jan Kiszka]

By chance this caused no harm so far. We overwrite AX during switch
to/from guest context, so we must declare this.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/x86/kvm/vmx.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1a5ecfd..e315930 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4013,7 +4013,7 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
 #endif
 		[cr2]"i"(offsetof(struct vcpu_vmx, vcpu.arch.cr2))
 	      : "cc", "memory"
-		, R"bx", R"di", R"si"
+		, R"ax", R"bx", R"di", R"si"
 #ifdef CONFIG_X86_64
 		, "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15"
 #endif
-- 
1.7.1

Re: KVM: VMX: Add AX to list of registers clobbered by guest switch

[Avi Kivity]

  On 09/28/2010 04:37 PM, Jan Kiszka wrote:
> By chance this caused no harm so far. We overwrite AX during switch
> to/from guest context, so we must declare this.

Applied, thanks.

I think we can remove the use of ax, which should reduce the chance of a 
compile failure due to register pressure.  But that can come later.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.