From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754809Ab2DPRVB (ORCPT ); Mon, 16 Apr 2012 13:21:01 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:17764 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754595Ab2DPRUv (ORCPT ); Mon, 16 Apr 2012 13:20:51 -0400 From: Konrad Rzeszutek Wilk To: linux-kernel@vger.kernel.org, david.vrabel@citrix.com, JBeulich@suse.com Cc: xen-devel@lists.xensource.com, Konrad Rzeszutek Wilk Subject: [PATCH 6/8] xen/setup: Work properly with 'dom0_mem=X' or with not dom0_mem. Date: Mon, 16 Apr 2012 13:15:37 -0400 Message-Id: <1334596539-18172-7-git-send-email-konrad.wilk@oracle.com> X-Mailer: git-send-email 1.7.7.5 In-Reply-To: <1334596539-18172-1-git-send-email-konrad.wilk@oracle.com> References: <1334596539-18172-1-git-send-email-konrad.wilk@oracle.com> X-Source-IP: acsinet22.oracle.com [141.146.126.238] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090208.4F8C54EB.007B,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We ignored the X value and ended up populating up to max(MAX_DOMAIN_PAGES, last E820_RAM entry). This fixes it by figuring out how many RAM nr_pages the hypervisor wanted to provide to us and cap the populate hypercalls up to that. The end result is (on a 8GB box): dom0_mem=1G -Memory: 610884k/9435136k available (5817k kernel code, 1136060k absent, 7688192k reserved, 2899k data, 696k init) +Memory: 724184k/1053064k available (5817k kernel code, 4552k absent, 324328k reserved, 2899k data, 696k init) no dom0_mem -Memory: 7619036k/9435136k available (5817k kernel code, 1136060k absent, 680040k reserved, 2899k data, 696k init) +Memory: 7621460k/9208688k available (5817k kernel code, 1136060k absent, 451168k reserved, 2899k data, 696k init) [v1: Details added] Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/setup.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 7b0ab77..0e82bf1 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -185,11 +185,29 @@ static unsigned long __init xen_get_max_pages(void) * the current maximum rather than the static maximum. In this * case the e820 map provided to us will cover the static * maximum region. + * + * The dom0_mem=min:X,max:Y tweaks options differently depending + * on the version, but in general this is what we get: + * | XENMEM_maximum_reser | nr_pages + * --------------++-----------------------+------------------- + * no dom0_mem | INT_MAX | max_phys_pfn + * =3G | INT_MAX | 786432 + * =max:3G | 786432 | 786432 + * =min:1G,max:3G| INT_MAX | max_phys_fn + * =1G,max:3G | INT_MAX | 262144 + * =min:1G,max:3G,2G | INT_MAX | max_phys_fn + * + * The =3G is often used and it lead to us initially setting + * 786432 and allowing dom0 to balloon up to the max_physical_pfn. + * This is at odd with the classic XenOClassic so lets emulate + * the classic behavior. */ if (xen_initial_domain()) { ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid); if (ret > 0) max_pages = ret; + if (ret == -1UL) + max_pages = xen_start_info->nr_pages; } return min(max_pages, MAX_DOMAIN_PAGES); -- 1.7.7.5