From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752577AbbCWO3Z (ORCPT ); Mon, 23 Mar 2015 10:29:25 -0400 Received: from cantor2.suse.de ([195.135.220.15]:44285 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752158AbbCWO3V (ORCPT ); Mon, 23 Mar 2015 10:29:21 -0400 Message-ID: <5510233C.4080004@suse.com> Date: Mon, 23 Mar 2015 15:29:16 +0100 From: Juergen Gross User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: David Vrabel , linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, daniel.kiper@oracle.com, pebolle@tiscali.nl 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> <55100B21.6040605@citrix.com> In-Reply-To: <55100B21.6040605@citrix.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/23/2015 01:46 PM, David Vrabel wrote: > 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? No. Sorry, I just tested it via editing .config, not using the menues. Can you add it when committing (e.g. "Upper limit in GBs a pv domain can be expanded to using memory hotplug")? Or should I send another patch? Juergen