[PATCH] KVM: MMU: Fix cmpxchg8b emulation

cmpxchg8b uses edx:eax as the compare operand, not edi:eax.

cmpxchg8b is used by 32-bit pae guests to set page table entries atomically,
and this is emulated touching shadowed guest page tables.

Also, implement it for 32-bit hosts.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 1bff3e925fda..be70795b4822 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -1323,7 +1323,7 @@ twobyte_special_insn:
                                                          ctxt)) != 0))
                                 goto done;
                         if ((old_lo != _regs[VCPU_REGS_RAX])
-                            || (old_hi != _regs[VCPU_REGS_RDI])) {
+                            || (old_hi != _regs[VCPU_REGS_RDX])) {
                                 _regs[VCPU_REGS_RAX] = old_lo;
                                 _regs[VCPU_REGS_RDX] = old_hi;
                                 _eflags &= ~EFLG_ZF;