From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [PATCH 1/2][VTD] pci mmconfig support to be used for ATS Date: Thu, 20 Nov 2008 08:56:26 +0000 Message-ID: <4925344A.76E4.0078.0@novell.com> References: <57C9024A16AD2D4C97DC78E552063EA35C4BC7A4@orsmsx505.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <57C9024A16AD2D4C97DC78E552063EA35C4BC7A4@orsmsx505.amr.corp.intel.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Allen M Kay Cc: "xen-devel@lists.xensource.com" , Weidong Han , Dexuan Cui List-Id: xen-devel@lists.xenproject.org >>> "Kay, Allen M" 20.11.08 02:42 >>> >ATS (Address Translation Service) is a PCI specification used for = synchronizing iotlb translations between chipset iommu such as vt-d with = iotlb on board a PCI device. > >This patch enables PCI mmconfig for Intel64 systems. Most of the code = were copied from Linux. This functionality is need for parsing ATS = capability in PCIe extended configuration space. If this is x86-64 only anyway, why do you need to use fixmap space for = this (and limit things arbitrarily to 4 segments) rather than using a = 256Mb block from one of the unused virtual address regions in hypervisor = space? Also, using obj-$(CONFIG_X86_64) in the Makefile changes would avoid = building dead code for x86-32... Jan