From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sheng Yang Subject: Re: [PATCH][v2] Hybrid extension support in Xen Date: Tue, 2 Feb 2010 22:13:06 +0800 Message-ID: <201002022213.07173.sheng@linux.intel.com> References: Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: Ian Campbell , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On Tuesday 02 February 2010 22:01:43 Keir Fraser wrote: > On 02/02/2010 13:52, "Sheng Yang" wrote: > >> I didn't even find where these get used, except to reserve an area in > >> e820, and it wasn't clear why that reservation is necessary. > > > > It has been used in the last [6/6] patch of Linux kernel side, which > > would use the pages to map grant table. It works the same as the MMIO > > region in PVonHVM device. Reserve it in BIOS because we think it's more > > elegant than depends on QEmu to provide the reserved memory space. > > Hmm. Can't this be done in phases? It seems unnecessary to be making > changes solely to remove qemu dependencies in the intial patchset, when > the patchset does not actually achieve that aim. > > I think an HVM guest with no PCI space is a little way off, and perhaps we > can find a better way than hardcoding an address in two places. Sure. I would try stick to old QEmu provided MMIO first. (Maybe try Ian Campbell's advice to get some more flexible ones later). -- regards Yang, Sheng