From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38567) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDoV5-0002Li-MV for qemu-devel@nongnu.org; Fri, 17 Jun 2016 03:47:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bDoV2-00082Q-HA for qemu-devel@nongnu.org; Fri, 17 Jun 2016 03:47:35 -0400 Received: from mail-wm0-x22d.google.com ([2a00:1450:400c:c09::22d]:35443) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDoV2-00082H-AO for qemu-devel@nongnu.org; Fri, 17 Jun 2016 03:47:32 -0400 Received: by mail-wm0-x22d.google.com with SMTP id v199so219230089wmv.0 for ; Fri, 17 Jun 2016 00:47:32 -0700 (PDT) Sender: Paolo Bonzini References: <1466097133-5489-1-git-send-email-dgilbert@redhat.com> <1466097133-5489-4-git-send-email-dgilbert@redhat.com> <20160616201408.GX18662@thinpad.lan.raisama.net> From: Paolo Bonzini Message-ID: Date: Fri, 17 Jun 2016 09:47:27 +0200 MIME-Version: 1.0 In-Reply-To: <20160616201408.GX18662@thinpad.lan.raisama.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 3/5] x86: fill high bits of mtrr mask List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost , "Dr. David Alan Gilbert (git)" Cc: aarcange@redhat.com, qemu-devel@nongnu.org On 16/06/2016 22:14, Eduardo Habkost wrote: > This is necessary only when phys_bits is higher on the > destination, right? > > Should we really default this to true? I would like to enable > this hack only when really necessary. Except when using host's > phys_bits (phys-bits=0), is there any valid reason to expect > higher phys-bits on the destination? It would need a property even if you did it only for phys-bits==0, and then it's simpler to just do it always. The bits are reserved anyway, so we can do whatever we want with them. In fact I think it's weird for the architecture to make them must-be-zero, it might even make more sense to make them must-be-one... It's a mask after all, and there's no way to access out-of-range physical addresses. Paolo