From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Wroblewski Subject: Re: GPU passthrough performance regression in >4GB vms due to XSA-60 changes Date: Thu, 15 May 2014 15:39:21 +0200 Message-ID: <5374C389.507@gmail.com> References: <537484A9.9000001@gmail.com> <5374CFF80200007800012A53@mail.emea.novell.com> <5374AEBD.7090403@gmail.com> <5374DBFD0200007800012AEE@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WkwpK-0005Vx-NV for xen-devel@lists.xenproject.org; Thu, 15 May 2014 14:40:06 +0000 Received: by mail-ee0-f45.google.com with SMTP id d49so735679eek.32 for ; Thu, 15 May 2014 07:40:05 -0700 (PDT) In-Reply-To: <5374DBFD0200007800012AEE@mail.emea.novell.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: Jan Beulich Cc: jinsong.liu@intel.com, xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org On 05/15/2014 03:23 PM, Jan Beulich wrote: >>>> On 15.05.14 at 14:10, wrote: >> Not really sure why it only affects 64bit vms but I've just noticed the >> pci BARs for the card are being relocated by hvmloader as per some logs: >> >> (XEN) HVM3: Relocating guest memory for lowmem MMIO space enabled >> (XEN) HVM3: Relocating 0xffff pages from 0e0001000 to 14dc00000 for >> lowmem MMIO hole >> (XEN) HVM3: Relocating 0x1 pages from 0e0000000 to 15dbff000 for lowmem >> MMIO hole >> >> So it might be also related to that. > Indeed it might - what are the (guest) MTRR types for those regions? It's writeback for both the 32bit and 64bit above ranges. > Jan >