From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755407Ab2EHSaX (ORCPT ); Tue, 8 May 2012 14:30:23 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:45485 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755027Ab2EHSaV (ORCPT ); Tue, 8 May 2012 14:30:21 -0400 Date: Tue, 8 May 2012 14:24:19 -0400 From: Konrad Rzeszutek Wilk To: David Vrabel Cc: "xen-devel@lists.xensource.com" , "JBeulich@suse.com" , "linux-kernel@vger.kernel.org" Subject: Re: [Xen-devel] [PATCH] auto balloon initial domain and fix dom0_mem=X inconsistencies (v5). Message-ID: <20120508182419.GA9888@phenom.dumpdata.com> References: <1334596539-18172-1-git-send-email-konrad.wilk@oracle.com> <20120501163707.GA8741@phenom.dumpdata.com> <4FA27084.4030005@citrix.com> <4FA2A11E.1060907@cantab.net> <4FA2B1EF.8080900@citrix.com> <20120507184808.GA7249@phenom.dumpdata.com> <4FA96202.9010503@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4FA96202.9010503@citrix.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 08, 2012 at 07:12:18PM +0100, David Vrabel wrote: > On 07/05/12 19:48, Konrad Rzeszutek Wilk wrote: > > On Thu, May 03, 2012 at 05:27:27PM +0100, David Vrabel wrote: > >> On 03/05/12 16:15, David Vrabel wrote: > >>> > >>> xen: update VA mapping when releasing memory during setup > >>> > >>> In xen_memory_setup(), if a page that is being released has a VA > >>> mapping this must also be updated. Otherwise, the page will be not > >>> released completely -- it will still be referenced in Xen and won't be > >>> freed util the mapping is removed and this prevents it from being > >>> reallocated at a different PFN. > >>> > >>> This was already being done for the ISA memory region in > >>> xen_ident_map_ISA() but on many systems this was omitting a few pages > >>> as many systems marked a few pages below the ISA memory region as > >>> reserved in the e820 map. > >>> > >>> Signed-off-by: David Vrabel > >>> --- > >> [...] > >>> --- a/arch/x86/xen/mmu.c > >>> +++ b/arch/x86/xen/mmu.c > >>> @@ -1929,29 +1929,6 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) > >>> #endif > >>> } > >>> > >>> -void __init xen_ident_map_ISA(void) > >>> -{ > >>> - unsigned long pa; > >>> - > >>> - /* > >>> - * If we're dom0, then linear map the ISA machine addresses into > >>> - * the kernel's address space. > >>> - */ > >>> - if (!xen_initial_domain()) > >>> - return; > >> > >> It might look like this test has gone, however the new code which > >> updates the VA mapping uses the e820 map and for a domU its map will not > >> have a ISA region so there's no mapping to be updated. > > > > What if you use e820_hole=1 and the pci=xx in the guest? > > Are these xl configuration options? I'm not familiar with xl. Yeah. Just have this in your guest config: e820_hole=1 pci=["01:00.0"] (And do the PCI bind/unbind to the xen-pciback module) but looking at the source there is this comment: /* Weed out anything under 1MB */ so I think we are fine. > > The PCI memory hole should be above 3 GiB so this hole will be will > above the memory that will be initially mapped at boot. > > I've not managed to persuade my test box to passthrough a PCI device to > a guest (using xapi as the toolstack) to confirm, though. I'll have > another go tomorrow. > > David > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel