From: Avi Kivity <avi@qumranet.com>

A "g" constraint may place a local variable in an %rsp-relative memory operand.
but if your assembly changes %rsp, the operand points to the wrong location.

An "r" constraint fixes that.

Thanks to Ingo Molnar for neatly bisecting the problem.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 drivers/kvm/vmx.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

diff -puN drivers/kvm/vmx.c~kvm-fix-asm-constraints-with-config_frame_pointer=n drivers/kvm/vmx.c
--- a/drivers/kvm/vmx.c~kvm-fix-asm-constraints-with-config_frame_pointer=n
+++ a/drivers/kvm/vmx.c
@@ -1825,7 +1825,7 @@ again:
 #endif
 		"setbe %0 \n\t"
 		"popf \n\t"
-	      : "=g" (fail)
+	      : "=r" (fail)
 	      : "r"(vcpu->launched), "d"((unsigned long)HOST_RSP),
 		"c"(vcpu),
 		[rax]"i"(offsetof(struct kvm_vcpu, regs[VCPU_REGS_RAX])),
_