From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754717AbbCSPzT (ORCPT ); Thu, 19 Mar 2015 11:55:19 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:21065 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751202AbbCSPzP (ORCPT ); Thu, 19 Mar 2015 11:55:15 -0400 Message-ID: <550AF0FB.7000801@oracle.com> Date: Thu, 19 Mar 2015 11:53:31 -0400 From: Boris Ostrovsky User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Juergen Gross , linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, daniel.kiper@oracle.com Subject: Re: [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; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/19/2015 10:31 AM, 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 | 13 ++++++++++++- > drivers/xen/Kconfig | 13 +++++++++++++ > 2 files changed, 25 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c > index 9f93af5..30e84ae 100644 > --- 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) Will this work in Kconfig instead? range 0 64 if CONFIG_X86_32 -boris > +#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 > + > static DEFINE_SPINLOCK(p2m_update_lock); > > static unsigned long *p2m_mid_missing_mfn; > @@ -387,7 +398,7 @@ void __init xen_vmalloc_p2m_tree(void) > static struct vm_struct vm; > > vm.flags = VM_ALLOC; > - vm.size = ALIGN(sizeof(unsigned long) * xen_max_p2m_pfn, > + vm.size = ALIGN(sizeof(unsigned long) * 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..0a61ddf 100644 > --- a/drivers/xen/Kconfig > +++ b/drivers/xen/Kconfig > @@ -55,6 +55,19 @@ config XEN_BALLOON_MEMORY_HOTPLUG > > In that case step 3 should be omitted. > > +config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT > + int > + default 512 if X86_64 > + default 4 if X86_32 > + depends on XEN_HAVE_PVMMU > + depends on XEN_BALLOON_MEMORY_HOTPLUG > + help > + Upper limit in GBs a pv domain can be expanded to using memory > + hotplug. > + > + This value is used to allocate enough space in internal tables needed > + for physical memory administration. > + > config XEN_SCRUB_PAGES > bool "Scrub pages before returning them to system" > depends on XEN_BALLOON