From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753384AbbCSQSN (ORCPT ); Thu, 19 Mar 2015 12:18:13 -0400 Received: from smtp.citrix.com ([66.165.176.89]:42197 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751234AbbCSQSL (ORCPT ); Thu, 19 Mar 2015 12:18:11 -0400 X-IronPort-AV: E=Sophos;i="5.11,430,1422921600"; d="scan'208";a="245007929" Message-ID: <550AF6BA.7060209@citrix.com> Date: Thu, 19 Mar 2015 16:18:02 +0000 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 MIME-Version: 1.0 To: Juergen Gross , , , , , , Subject: Re: [Xen-devel] [PATCH 1/2] xen: prepare p2m list for memory hotplug References: <1426775462-981-1-git-send-email-jgross@suse.com> <1426775462-981-2-git-send-email-jgross@suse.com> In-Reply-To: <1426775462-981-2-git-send-email-jgross@suse.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/03/15 14:31, Juergen Gross wrote: > Commit 054954eb051f35e74b75a566a96fe756015352c8 ("xen: switch to linear > virtual mapped sparse p2m list") introduced a regression regarding to > memory hotplug for a pv-domain: as the virtual space for the p2m list > is allocated for the to be expected memory size of the domain only, > hotplugged memory above that size will not be usable by the domain. > > Correct this by using a configurable size for the p2m list in case of > memory hotplug enabled (default supported memory size is 512 GB for > 64 bit domains and 4 GB for 32 bit domains). [...] > --- a/arch/x86/xen/p2m.c > +++ b/arch/x86/xen/p2m.c > @@ -91,6 +91,17 @@ EXPORT_SYMBOL_GPL(xen_p2m_size); > unsigned long xen_max_p2m_pfn __read_mostly; > EXPORT_SYMBOL_GPL(xen_max_p2m_pfn); > > +#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT > +#ifdef CONFIG_X86_32 > +BUILD_BUG_ON_MSG(CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT > 64) > +#endif > +#define P2M_LIMIT max(xen_max_p2m_pfn, \ > + ((unsigned long)((u64)CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT * \ > + 1024 * 1024 * 1024 / PAGE_SIZE))) > +#else > +#define P2M_LIMIT xen_max_p2m_pfn > +#endif Can you arrange the #ifdef's to set xen_max_p2m_pfn to the right value instead of introducing P2M_LIMIT? David