Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754629Ab2EHSMX (ORCPT ); Tue, 8 May 2012 14:12:23 -0400 Received: from smtp.citrix.com ([66.165.176.89]:16486 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753035Ab2EHSMV (ORCPT ); Tue, 8 May 2012 14:12:21 -0400 X-IronPort-AV: E=Sophos;i="4.75,552,1330923600"; d="scan'208";a="24990131" Message-ID: <4FA96202.9010503@citrix.com> Date: Tue, 8 May 2012 19:12:18 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20120428 Icedove/3.0.11 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: David Vrabel , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , "JBeulich@suse.com" Subject: Re: [Xen-devel] [PATCH] auto balloon initial domain and fix dom0_mem=X inconsistencies (v5). 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> In-Reply-To: <20120507184808.GA7249@phenom.dumpdata.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2172 Lines: 58 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. 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 -- 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/