Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932134AbZJGFMR (ORCPT ); Wed, 7 Oct 2009 01:12:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753064AbZJGFMQ (ORCPT ); Wed, 7 Oct 2009 01:12:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:18723 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752319AbZJGFMP (ORCPT ); Wed, 7 Oct 2009 01:12:15 -0400 Date: Wed, 7 Oct 2009 10:40:47 +0530 From: Amit Shah To: "Ira W. Snyder" Cc: Gregory Haskins , Avi Kivity , David Howells , Gregory Haskins , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, "alacrityvm-devel@lists.sourceforge.net" Subject: Re: [Alacrityvm-devel] [PATCH v2 2/4] KVM: introduce "xinterface" API for external interaction with guests Message-ID: <20091007051047.GA24176@amit-x200.redhat.com> References: <20091002201159.4014.33268.stgit@dev.haskins.net> <20091002201927.4014.29432.stgit@dev.haskins.net> <4AC8780D.1060800@redhat.com> <4ACA87D7.1080206@gmail.com> <4ACB0F3C.1000705@redhat.com> <4ACB46AD.8010405@gmail.com> <4ACB6E21.8010109@redhat.com> <4ACB771E.8050404@gmail.com> <20091006181859.GD6386@ovro.caltech.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091006181859.GD6386@ovro.caltech.edu> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1047 Lines: 21 On (Tue) Oct 06 2009 [11:18:59], Ira W. Snyder wrote: > > The limitation I have is that memory made available from the host system > (PCI card) as PCI BAR1 must not be migrated around in memory. I can only > change the address decoding to hit a specific physical address. AFAIK, > this means it cannot be userspace memory (since the underlying physical > page could change, or it could be in swap), and must be allocated with > something like __get_free_pages() or dma_alloc_coherent(). If the dma area is just one page in size, that page can be pinned by the host (via a hypercall by the guest). If it's more, there is a reserve-ram patch by Andrea. That'll reserve some RAM area for the guest that's 1-1 mapped in the host address space. There was a patch posted on the list sometime back. Amit -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/