From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:34153) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SALuJ-0005iY-AG for qemu-devel@nongnu.org; Wed, 21 Mar 2012 09:48:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SALuD-0000dR-4Q for qemu-devel@nongnu.org; Wed, 21 Mar 2012 09:48:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35022) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SALuC-0000dM-TK for qemu-devel@nongnu.org; Wed, 21 Mar 2012 09:48:49 -0400 Message-ID: <4F69DC3B.3050509@redhat.com> Date: Wed, 21 Mar 2012 15:48:43 +0200 From: Avi Kivity MIME-Version: 1.0 References: <4F69DA5E.6010505@siemens.com> In-Reply-To: <4F69DA5E.6010505@siemens.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Can VMX provide real mode support? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: GaoYi , "qemu-devel@nongnu.org" , kvm 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