From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754868Ab2G3OoJ (ORCPT ); Mon, 30 Jul 2012 10:44:09 -0400 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:28497 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754703Ab2G3OoF (ORCPT ); Mon, 30 Jul 2012 10:44:05 -0400 X-IronPort-AV: E=Sophos;i="4.77,679,1336348800"; d="scan'208";a="13764326" Date: Mon, 30 Jul 2012 15:43:48 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Konrad Rzeszutek Wilk CC: Stefano Stabellini , Konrad Rzeszutek Wilk , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" Subject: Re: [Xen-devel] [PATCH 2/4] xen/x86: Use memblock_reserve for sensitive areas. In-Reply-To: <20120727174534.GF17427@andromeda.dapyr.net> Message-ID: References: <1343334845-5340-1-git-send-email-konrad.wilk@oracle.com> <1343334845-5340-3-git-send-email-konrad.wilk@oracle.com> <20120727174534.GF17427@andromeda.dapyr.net> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 27 Jul 2012, Konrad Rzeszutek Wilk wrote: > On Fri, Jul 27, 2012 at 11:49:02AM +0100, Stefano Stabellini wrote: > > On Thu, 26 Jul 2012, Konrad Rzeszutek Wilk wrote: > > > instead of a big memblock_reserve. This way we can be more > > > selective in freeing regions (and it also makes it easier > > > to understand where is what). > > > > > > [v1: Move the auto_translate_physmap to proper line] > > > Signed-off-by: Konrad Rzeszutek Wilk > > > --- > > > arch/x86/xen/enlighten.c | 38 ++++++++++++++++++++++++++++++++++++++ > > > arch/x86/xen/p2m.c | 5 +++++ > > > arch/x86/xen/setup.c | 9 --------- > > > 3 files changed, 43 insertions(+), 9 deletions(-) > > > > > > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > > > index ff962d4..9b1afa4 100644 > > > --- a/arch/x86/xen/enlighten.c > > > +++ b/arch/x86/xen/enlighten.c > > > @@ -998,7 +998,44 @@ static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) > > > > > > return ret; > > > } > > > +static void __init xen_reserve_mfn(unsigned long mfn) > > > +{ > > > + unsigned long pfn; > > > + > > > + if (!mfn) > > > + return; > > > + pfn = mfn_to_pfn(mfn); > > > + if (phys_to_machine_mapping_valid(pfn)) > > > + memblock_reserve(PFN_PHYS(pfn), PAGE_SIZE); > > > +} > > > > If the mfn is not in the m2p xen_reserve_mfn won't do anything. It is > > worth writing it down in a comment. > > Meaning in a printk? I meant a comment in the code. > > > +static void __init xen_reserve_internals(void) > > > +{ > > > + unsigned long size; > > > + > > > + if (!xen_pv_domain()) > > > + return; > > > + > > > + memblock_reserve(__pa(xen_start_info), PAGE_SIZE); > > > > xen_start_info is not in the m2p, so you cannot use xen_reserve_mfn > > It seems to work for me. For both the toolstack created guests > and dom0. Let me double check thought. I was just thinking out loud: you are calling memblock_reserve rather than xen_reserve_mfn, because xen_reserve_mfn wouldn't work in this case as xen_start_info is not in the m2p.