From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kip Macy Subject: Re: Xen at scale Date: Wed, 24 Mar 2004 11:55:06 -0800 (PST) Sender: xen-devel-admin@lists.sourceforge.net Message-ID: <20040324114134.G2890@demos.bsdclusters.com> References: <0b4e01c41199$3c84a150$070414ac@pin> <20040324074648.B68293@demos.bsdclusters.com> <0be301c411c3$9cd0a1b0$070414ac@pin> <20040324103447.V2890@demos.bsdclusters.com> <0c3201c411d8$028204e0$070414ac@pin> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <0c3201c411d8$028204e0$070414ac@pin> Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Christian Limpach Cc: Keir Fraser , "MAGENHEIMER,DAN (HP-FtCollins, ex1)" , xen-devel@lists.sourceforge.net List-Id: xen-devel@lists.xenproject.org On Wed, 24 Mar 2004, Christian Limpach wrote: > > > and where does the builder put the PTD? and what's the physical memory > > > layout? > > > > For BSD both are irrelevant - the PTD is passed in as an argument via a > > register. Only Linux relies on physical contiguity for the PTOV trick. > > BSD does a table lookup in the mapped page tables - it has no physical > > contiguity requirements. > > The domain builder still has to put the PTD somewhere and your > drawing/explanation doesn't say where. Same goes for physical memory > layout, you have to pick one, I'd be interested to know which you picked... The PTD is an arbitrary physical address mapped in right after the pages uses by the elf-loader. BSD's VM system is sufficiently general that it doesn't care about physical layout. Nonetheless, the physical layout ends up looking something like: |ktext|KPTphys|IdlePTD|ptomptpa|tmpstk|startinfopa|ptompages| I hadn't intended to commit the domain builder until the ports had been committed to the BSDs CVS repositories - which is going to wait until I've had time to write the block and bi-directional console drivers. However, if it is still unclear I can post the domain builder source itself. -Kip ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click