From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755469AbbCSQVz (ORCPT ); Thu, 19 Mar 2015 12:21:55 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:42982 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752941AbbCSQVx (ORCPT ); Thu, 19 Mar 2015 12:21:53 -0400 Date: Thu, 19 Mar 2015 17:21:41 +0100 From: Daniel Kiper To: Juergen Gross Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, boris.ostrovsky@oracle.com Subject: Re: [PATCH 2/2] xen: before ballooning hotplugged memory, set frames to invalid Message-ID: <20150319162141.GG27971@olila.local.net-space.pl> References: <1426775462-981-1-git-send-email-jgross@suse.com> <1426775462-981-3-git-send-email-jgross@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1426775462-981-3-git-send-email-jgross@suse.com> User-Agent: Mutt/1.5.21 (2010-09-15) 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 Thu, Mar 19, 2015 at 03:31:02PM +0100, Juergen Gross wrote: > Commit 25b884a83d487fd62c3de7ac1ab5549979188482 ("x86/xen: set > regions above the end of RAM as 1:1") introduced a regression. > > To be able to add memory pages which were added via memory hotplug to > a pv domain, the pages must be "invalid" instead of "identity" in the > p2m list before they can be added. > > Suggested-by: David Vrabel > Signed-off-by: Juergen Gross > --- > drivers/xen/balloon.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c > index 0b52d92..52e331f 100644 > --- a/drivers/xen/balloon.c > +++ b/drivers/xen/balloon.c > @@ -221,15 +221,24 @@ static bool balloon_is_inflated(void) > > static enum bp_state reserve_additional_memory(long credit) > { > - int nid, rc; > + int nid, rc = 0; > u64 hotplug_start_paddr; > unsigned long balloon_hotplug = credit; > + unsigned long pfn; > > hotplug_start_paddr = PFN_PHYS(SECTION_ALIGN_UP(max_pfn)); > balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION); > nid = memory_add_physaddr_to_nid(hotplug_start_paddr); > > - rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT); > + for (pfn = PFN_DOWN(hotplug_start_paddr); > + !rc && pfn < PFN_DOWN(hotplug_start_paddr) + balloon_hotplug; > + pfn++) > + if (!set_phys_to_machine(pfn, INVALID_P2M_ENTRY)) rc = set_phys_to_machine(pfn, INVALID_P2M_ENTRY)? > + rc = 1; I do not think that this stuff is needed for HVM or PVH guests. > + if (!rc) > + rc = add_memory(nid, hotplug_start_paddr, > + balloon_hotplug << PAGE_SHIFT); > > if (rc) { > pr_warn("Cannot add additional memory (%i)\n", rc); It will be nice to know what part of infrastructure failed. Could you create separate pr_warn() message for set_phys_to_machine()? Daniel