| Message ID | 1402837982-24959-6-git-send-email-namit@cs.technion.ac.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index b354531..eb93eb4 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -4663,8 +4663,9 @@ special_insn: break; case 0x90 ... 0x97: /* nop / xchg reg, rax */ if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX)) - break; - rc = em_xchg(ctxt); + ctxt->dst.type = OP_NONE; + else + rc = em_xchg(ctxt); break; case 0x98: /* cbw/cwde/cdqe */ switch (ctxt->op_bytes) {
On long-mode the current NOP (0x90) emulation still writes back to RAX. As a result, EAX is zero-extended and the high 32-bits of RAX are cleared. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> --- arch/x86/kvm/emulate.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)