KVM: x86: handle wrap around 32-bit address space

KVM is not handling the case where EIP wraps around the 32-bit address
space (that is, outside long mode).  This is needed both in vmx.c
and in emulate.c.  SVM with NRIPS is okay, but it can still print
an error to dmesg due to integer overflow.

Reported-by: Nick Peterson <everdox@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index bddaba9c..de5476f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5798,6 +5798,8 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 	}
 
 	ctxt->eip = ctxt->_eip;
+	if (ctxt->mode != X86EMUL_MODE_PROT64)
+		ctxt->eip = (u32)ctxt->_eip;
 
 done:
 	if (rc == X86EMUL_PROPAGATE_FAULT) {