From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Can VMX provide real mode support? Date: Wed, 21 Mar 2012 15:48:43 +0200 Message-ID: <4F69DC3B.3050509@redhat.com> References: <4F69DA5E.6010505@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: GaoYi , "qemu-devel@nongnu.org" , kvm To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33478 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753199Ab2CUNsu (ORCPT ); Wed, 21 Mar 2012 09:48:50 -0400 In-Reply-To: <4F69DA5E.6010505@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: On 03/21/2012 03:40 PM, Jan Kiszka wrote: > On 2012-03-21 13:38, GaoYi wrote: > > Hi Jan, > > > > Since the newest Intel-VT supports the guest OS under the real mode, which was already supported in AMD-V, can the VMX in the latest KVM support that case? > > Yes, both with our without that "unrestricted guest" support (as Intel > called it), real mode will generally work. Without that CPU feature, I > think to recall that there were some limitations for big real mode, not > sure. > Yes, big real mode will not work without "unrestricted guest". There was some work to emulate it (module option emulate_invalid_guest_state), but it is not complete. -- error compiling committee.c: too many arguments to function