From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 23 Jan 2007 03:10:00 +0000 (+1100)
Subject: [PATCH] vmx: Fix register constraint in launch code
X-Git-Tag: v2.6.20-rc6~48
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e00154891137e3b0659556b877d45a16cabd700c;p=linux-2.6

[PATCH] vmx: Fix register constraint in launch code

Both "=r" and "=g" breaks my build on i386:

  $ make
    CC [M]  drivers/kvm/vmx.o
  {standard input}: Assembler messages:
  {standard input}:3318: Error: bad register name `%sil'
  make[1]: *** [drivers/kvm/vmx.o] Error 1
  make: *** [_module_drivers/kvm] Error 2

The reason is that setbe requires an 8-bit register but "=r" does not
constrain the target register to be one that has an 8-bit version on
i386.

According to

	http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10153

the correct constraint is "=q".

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index ce219e3f55..0aa2659f6a 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1824,7 +1824,7 @@ again:
 #endif
 		"setbe %0 \n\t"
 		"popf \n\t"
-	      : "=g" (fail)
+	      : "=q" (fail)
 	      : "r"(vcpu->launched), "d"((unsigned long)HOST_RSP),
 		"c"(vcpu),
 		[rax]"i"(offsetof(struct kvm_vcpu, regs[VCPU_REGS_RAX])),