From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: Re: [patch 05/21] Xen-paravirt: paravirt_ops: allocate a fixmap slot Date: Wed, 14 Feb 2007 09:43:49 +0100 Message-ID: <45D2CBC5.90809@suse.de> References: <20070213221729.772002682@goop.org> <20070213221829.845132535@goop.org> <45D2649D.4080508@vmware.com> <45D26797.5090600@goop.org> <45D27534.1070608@vmware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <45D27534.1070608@vmware.com> Sender: linux-kernel-owner@vger.kernel.org To: Dan Hecht Cc: Jeremy Fitzhardinge , Andrew Morton , Andi Kleen , xen-devel@lists.xensource.com, Chris Wright , virtualization@lists.osdl.org, linux-kernel@vger.kernel.org List-Id: virtualization@lists.linuxfoundation.org Dan Hecht wrote: > Right. But that is only because Xen decides to allocate the page from > the (machine) physical space, rather than from the pseudo-physical > space. My question is: why doesn't Xen allocate shared_info from the > pseudo-physical space? Historical reasons ... > If it had, then this page wouldn't need to be > treated specially. I'm not sure, but I seem to remember on 64-bit > Xen/XenLinux allocated shared_info from pseudo-physical space already... Yep, the ia64 port which came later handles some things differently, specifically some "magic" pages are allocated more clever ;) Changing that for x86 would break existing guests though. cheers, Gerd -- Gerd Hoffmann