From: Anthony Liguori Date: Thu, 3 Jul 2008 16:02:36 +0000 (+0300) Subject: x86: KVM guest: Add memory clobber to hypercalls X-Git-Tag: 2.1b_release~18262^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ca3739327b89bb4053a62ac41b67b106c1967ab0;p=platform%2Fkernel%2Fkernel-mfld-blackbay.git x86: KVM guest: Add memory clobber to hypercalls Hypercalls can modify arbitrary regions of memory. Make sure to indicate this in the clobber list. This fixes a hang when using KVM_GUEST kernel built with GCC 4.3.0. This was originally spotted and analyzed by Marcelo. Signed-off-by: Anthony Liguori Signed-off-by: Avi Kivity --- diff --git a/include/asm-x86/kvm_para.h b/include/asm-x86/kvm_para.h index bfd9900..76f3921 100644 --- a/include/asm-x86/kvm_para.h +++ b/include/asm-x86/kvm_para.h @@ -71,7 +71,8 @@ static inline long kvm_hypercall0(unsigned int nr) long ret; asm volatile(KVM_HYPERCALL : "=a"(ret) - : "a"(nr)); + : "a"(nr) + : "memory"); return ret; } @@ -80,7 +81,8 @@ static inline long kvm_hypercall1(unsigned int nr, unsigned long p1) long ret; asm volatile(KVM_HYPERCALL : "=a"(ret) - : "a"(nr), "b"(p1)); + : "a"(nr), "b"(p1) + : "memory"); return ret; } @@ -90,7 +92,8 @@ static inline long kvm_hypercall2(unsigned int nr, unsigned long p1, long ret; asm volatile(KVM_HYPERCALL : "=a"(ret) - : "a"(nr), "b"(p1), "c"(p2)); + : "a"(nr), "b"(p1), "c"(p2) + : "memory"); return ret; } @@ -100,7 +103,8 @@ static inline long kvm_hypercall3(unsigned int nr, unsigned long p1, long ret; asm volatile(KVM_HYPERCALL : "=a"(ret) - : "a"(nr), "b"(p1), "c"(p2), "d"(p3)); + : "a"(nr), "b"(p1), "c"(p2), "d"(p3) + : "memory"); return ret; } @@ -111,7 +115,8 @@ static inline long kvm_hypercall4(unsigned int nr, unsigned long p1, long ret; asm volatile(KVM_HYPERCALL : "=a"(ret) - : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)); + : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4) + : "memory"); return ret; }