2009-04-23 07:57:18

by Chris Wright

[permalink] [raw]
Subject: [patch 089/100] KVM: is_long_mode() should check for EFER.LMA

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Amit Shah <[email protected]>

upstream commit: 41d6af119206e98764b4ae6d264d63acefcf851e

is_long_mode currently checks the LongModeEnable bit in
EFER instead of the LongModeActive bit. This is wrong, but
we survived this till now since it wasn't triggered. This
breaks guests that go from long mode to compatibility mode.

This is noticed on a solaris guest and fixes bug #1842160

Signed-off-by: Amit Shah <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
arch/x86/kvm/mmu.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -54,7 +54,7 @@ static inline int kvm_mmu_reload(struct
static inline int is_long_mode(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_X86_64
- return vcpu->arch.shadow_efer & EFER_LME;
+ return vcpu->arch.shadow_efer & EFER_LMA;
#else
return 0;
#endif