From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kip Macy Subject: Re: Xen at scale Date: Tue, 23 Mar 2004 22:54:36 -0800 (PST) Sender: xen-devel-admin@lists.sourceforge.net Message-ID: <20040323222107.A37635@demos.bsdclusters.com> References: <0a2101c4112d$db5be610$070414ac@pin> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <0a2101c4112d$db5be610$070414ac@pin> Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Christian Limpach Cc: "MAGENHEIMER,DAN (HP-FtCollins,ex1)" , xen-devel@lists.sourceforge.net List-Id: xen-devel@lists.xenproject.org > > Now it would seem easy to just not map the memory which will end up in > highmem but we need to have all the memory mapped initially so that we can > build the phys_to_machine_mapping array. I believe you can't build it only > from the machine_to_phys_mapping array provided by Xen since you don't know > which pages belong to the domain... The {DragonFly/Free}BSD domain builder sets the page tables up a little differently. It populates the phys_to_machine array before starting the domain - mapping it at a pre-determined address relative to KERNBASE. In addition it only maps the ktext and a stack page - the remainder of the pages are mapped at runtime by the same pmap_init used on native i386. > I think I would map the highmem pages starting at VA 0, the alternative > seems to be to pass an array with the page numbers to the domain. This is done for all pages with a pre-established P->M mapping. The domain builder passes in the number of pages used by the domain builder via a register. This is equivalent to the way native locore.s passes physfree (the address of the first free physical page) to init386. > Maybe there's a simpler solution? I don't think passing an array is more complicated. -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