From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36322) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UiI7q-0002R7-At for qemu-devel@nongnu.org; Fri, 31 May 2013 01:43:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UiI7p-0004vw-CA for qemu-devel@nongnu.org; Fri, 31 May 2013 01:43:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62900) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UiI7p-0004vl-3U for qemu-devel@nongnu.org; Fri, 31 May 2013 01:43:41 -0400 Message-ID: <51A83889.60609@redhat.com> Date: Fri, 31 May 2013 07:43:37 +0200 From: Gerd Hoffmann MIME-Version: 1.0 References: <1369911913-10934-1-git-send-email-mst@redhat.com> <1369911913-10934-3-git-send-email-mst@redhat.com> <51A7430D.7060102@redhat.com> <20130530121950.GA12791@redhat.com> <51A746C1.5050902@redhat.com> <20130530125503.GE12791@redhat.com> In-Reply-To: <20130530125503.GE12791@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 2/5] pci: store PCI hole ranges in guestinfo structure List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Anthony Liguori , qemu-devel@nongnu.org Hi, > I see. I'll figure out the details and add a comment to this end. > > But that's for the 32 bit window - I don't see it playing > with mtrrs for the 64 bit ranges. > So I'm guessing alignment isn't needed there, right? mtrr's are a 32bit thing anyway IIRC. I still would place the 64bit window aligned. Given that 36 physical address lines (-> 64G address space) used to be quite common until recently I think reserving 16G from 64G downwards would be a good pick. For guests with *lots* of memory we could move the hole to be just below 1T and maybe also make it larger. cheers, Gerd