From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: RE: VP problematic for backend drivers on IA64? Date: Mon, 23 Jan 2006 08:52:57 -0700 Message-ID: <1138031577.3543.24.camel@localhost> References: <516F50407E01324991DD6D07B0531AD59036D8@cacexc12.americas.cpqcorp.net> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <516F50407E01324991DD6D07B0531AD59036D8@cacexc12.americas.cpqcorp.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Magenheimer, Dan (HP Labs Fort Collins)" Cc: okrieg@us.ibm.com, Jon Mason , xen-ia64-devel@lists.xensource.com, xen-devel List-Id: xen-devel@lists.xenproject.org On Sun, 2006-01-22 at 14:45 -0800, Magenheimer, Dan (HP Labs Fort Collins) wrote: > > Yes, unless there are legacy drivers/devices that circumvent the > DMA interface. I don't know if this is the case on some/many/all > Linux/ia64 configurations... perhaps someone with more familiarity > with a broad range of Linux/ia64 configurations can comment? I > would be concerned with, for example, IDE, GART, VGA, console...? VGA and serial consoles don't typically do DMA-like operations AFAIK. They may live in legacy address spaces, but I think their programming model is entirely reads and writes. All IDE chips can operate in standard PCI mode these days, so they should be covered by the DMA-API. GARTs are similar to IOMMUs, they'll need to be modified to understand the translation. Alex -- Alex Williamson HP Linux & Open Source Lab