From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: [patch 06/26] Xen-paravirt_ops: paravirt_ops: allocate a fixmap slot Date: Tue, 27 Feb 2007 10:55:17 -0800 Message-ID: <45E47E95.2060803@goop.org> References: <20070227081337.434798469@goop.org> <20070227081631.122933982@goop.org> <20070227101143.GC10827@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20070227101143.GC10827@elte.hu> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ingo Molnar Cc: Zachary Amsden , xen-devel@lists.xensource.com, virtualization@lists.osdl.org, Rusty Russell , linux-kernel@vger.kernel.org, Chris Wright , Andi Kleen , Andrew Morton List-Id: virtualization@lists.linuxfoundation.org Ingo Molnar wrote: > * Jeremy Fitzhardinge wrote: > > >> Allocate a fixmap slot for use by a paravirt_ops implementation. Xen >> uses this to map the hypervisor's shared info page, which doesn't have >> a pseudo-physical page number, and therefore can't be mapped >> ordinarily. >> > > why not vmalloc it on the guest side? fixmaps are bad for this purpose > for a general paravirt implementation, it limits the size of the shared > info page, etc. Yes. vmalloc would have the annoying side-effect of actually allocating some pages which would be shadowed by the remapping, but I guess get_vm_area would do the job. I'll give it a go. J