From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932229AbbCWMqj (ORCPT ); Mon, 23 Mar 2015 08:46:39 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:35971 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932196AbbCWMq2 (ORCPT ); Mon, 23 Mar 2015 08:46:28 -0400 X-IronPort-AV: E=Sophos;i="5.11,452,1422921600"; d="scan'208";a="247433627" Message-ID: <55100B21.6040605@citrix.com> Date: Mon, 23 Mar 2015 12:46:25 +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 V2 1/2] xen: prepare p2m list for memory hotplug References: <1426856139-3359-1-git-send-email-jgross@suse.com> <1426856139-3359-2-git-send-email-jgross@suse.com> In-Reply-To: <1426856139-3359-2-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 20/03/15 12:55, 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). > > Signed-off-by: Juergen Gross > --- > arch/x86/xen/p2m.c | 10 +++++++++- > drivers/xen/Kconfig | 14 ++++++++++++++ > 2 files changed, 23 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c > index 9f93af5..b47124d 100644 > --- a/arch/x86/xen/p2m.c > +++ b/arch/x86/xen/p2m.c > @@ -91,6 +91,12 @@ 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 > +#define P2M_LIMIT CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT > +#else > +#define P2M_LIMIT 0 > +#endif > + > static DEFINE_SPINLOCK(p2m_update_lock); > > static unsigned long *p2m_mid_missing_mfn; > @@ -385,9 +391,11 @@ static void __init xen_rebuild_p2m_list(unsigned long *p2m) > void __init xen_vmalloc_p2m_tree(void) > { > static struct vm_struct vm; > + unsigned long p2m_limit; > > + p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE; > vm.flags = VM_ALLOC; > - vm.size = ALIGN(sizeof(unsigned long) * xen_max_p2m_pfn, > + vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit), > PMD_SIZE * PMDS_PER_MID_PAGE); > vm_area_register_early(&vm, PMD_SIZE * PMDS_PER_MID_PAGE); > pr_notice("p2m virtual area at %p, size is %lx\n", vm.addr, vm.size); > diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig > index b812462..0f1b509 100644 > --- a/drivers/xen/Kconfig > +++ b/drivers/xen/Kconfig > @@ -55,6 +55,20 @@ config XEN_BALLOON_MEMORY_HOTPLUG > > In that case step 3 should be omitted. > > +config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT > + int Because you've not supplied a summary for this option, it is not user configurable. Is this intentional? David