From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philip Herron Subject: Re: [RFC] Extending MTRRs above 4G Date: Wed, 17 Sep 2008 20:47:49 +0100 Message-ID: <1221680869.6710.3.camel@Omicron-Lire> References: <1221673872.16470.27.camel@lappy> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: Alex Williamson , kvm Return-path: Received: from ug-out-1314.google.com ([66.249.92.172]:29861 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752554AbYIQTr6 (ORCPT ); Wed, 17 Sep 2008 15:47:58 -0400 Received: by ug-out-1314.google.com with SMTP id k3so527255ugf.37 for ; Wed, 17 Sep 2008 12:47:56 -0700 (PDT) In-Reply-To: <1221673872.16470.27.camel@lappy> Sender: kvm-owner@vger.kernel.org List-ID: I am not sure if this is relevant but i had the problem that the host system had to have the paravirtulised guest support (its in processor type and features in 2.6.26-3 kernel) compiled into the kernel before the guest virtual machine would see more than 3.5gb memory. Then recently i found that sometimes if you have a good few virtual machines running with lots of ram i sometimes get segmentation faults but i think this is because of the balloning becasue i was overloading all the ram i had. On Wed, 2008-09-17 at 11:51 -0600, Alex Williamson wrote: > t's true, we're only providing MTRRs for memory below 4G. In fact > rombios32 knows very little, if anything, about memory above 4G, as > seen > by memory reporting in the SMBIOS table. > > It looks like the Linux kernel MTRR code does have a bail-out point f