From mboxrd@z Thu Jan 1 00:00:00 1970 From: Razvan Cojocaru Subject: Re: [PATCH] libxc: Add xc_domain_hvm_get_mtrr_type() call Date: Wed, 19 Dec 2012 17:43:09 +0200 Message-ID: <50D1E08D.6020208@gmail.com> References: <1355850255.14620.277.camel@zakaz.uk.xensource.com> <50D0A6B1.30702@gmail.com> <1355912063.14620.286.camel@zakaz.uk.xensource.com> <50D19A2B.2050006@gmail.com> <1355916539.14620.332.camel@zakaz.uk.xensource.com> <50D1A9D1.2020106@gmail.com> <50D1D5BD.8080001@gmail.com> <1355929247.14620.436.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1355929247.14620.436.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: "Tim (Xen.org)" , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org > TBH until someone figures out or explains what overlap actually is I > don't know if it even needs exporting or taking into account in > userspace. http://www.mjmwired.net/kernel/Documentation/mtrr.txt "Creating overlapping MTRRs: %echo "base=0xfb000000 size=0x1000000 type=write-combining" >/proc/mtrr %echo "base=0xfb000000 size=0x1000 type=uncachable" >/proc/mtrr And the results: cat /proc/mtrr reg00: base=0x00000000 ( 0MB), size= 64MB: write-back, count=1 reg01: base=0xfb000000 (4016MB), size= 16MB: write-combining, count=1 reg02: base=0xfb000000 (4016MB), size= 4kB: uncachable, count=1" Overlapped MTRRs are MTRRs with the same base, but different types of addresses at different offsets. At least to my understanding. Thanks, Razvan Cojocaru