From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37210) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WJP9H-0007ym-NE for qemu-devel@nongnu.org; Fri, 28 Feb 2014 10:14:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WJP99-0002qd-HX for qemu-devel@nongnu.org; Fri, 28 Feb 2014 10:14:51 -0500 Received: from fldsmtpe04.verizon.com ([140.108.26.143]:5089) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WJP99-0002py-DO for qemu-devel@nongnu.org; Fri, 28 Feb 2014 10:14:43 -0500 From: Don Slutz Message-ID: <5310A7DD.4060003@terremark.com> Date: Fri, 28 Feb 2014 10:14:37 -0500 MIME-Version: 1.0 References: <1393531262-5884-1-git-send-email-dslutz@verizon.com> <1393594506.3364.65.camel@nilsson.home.kraxel.org> In-Reply-To: <1393594506.3364.65.camel@nilsson.home.kraxel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/1] pc & q35: fix handling of lowmem List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: "Michael S. Tsirkin" , qemu-devel@nongnu.org, Don Slutz , Anthony Liguori On 02/28/14 08:35, Gerd Hoffmann wrote: > On Do, 2014-02-27 at 15:01 -0500, Don Slutz wrote: >> Without this, asking for 3.25G on memory for pc-i440fx-2.0 does not >> adjust the pci hole to start at 3G. Asking for 3.75G does do this >> adjustment. > This is intentional. > > If we can fit all ram into low memory, because it is less than 3.5G, > we'll do that (pc machine type, q35 numbers are different but logic is > the same). This way 32bit (+non-PAE) guests can continue to have up to > 3.5G memory. > > If we can't fit all ram into low memory (thus the guest should be able > to access ram above 4G anyway), then we'll cut off at a gigabyte > boundary (3G for pc machine type). This way our ram is nicely > gigabyte-aligned and we can get best performance benefits from huge > pages. > > The size of the pci hole changing in the second case is only a side > effect, it's not the main reason for the change. > > cheers, > Gerd > > Ok, I will drop this patch. -Don Slutz