From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756081AbaIKObw (ORCPT ); Thu, 11 Sep 2014 10:31:52 -0400 Received: from mail-we0-f181.google.com ([74.125.82.181]:34850 "EHLO mail-we0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752629AbaIKObc (ORCPT ); Thu, 11 Sep 2014 10:31:32 -0400 Date: Thu, 11 Sep 2014 17:31:24 +0300 From: Gleb Natapov To: Paolo Bonzini Cc: Tang Chen , mtosatti@redhat.com, nadav.amit@gmail.com, jan.kiszka@web.de, kvm@vger.kernel.org, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, guz.fnst@cn.fujitsu.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 4/7] kvm, mem-hotplug: Reload L1' apic access page on migration in vcpu_enter_guest(). Message-ID: <20140911143123.GE26540@minantech.com> References: <1410413886-32213-5-git-send-email-tangchen@cn.fujitsu.com> <541169AD.6060908@redhat.com> <20140911101200.GF25317@minantech.com> <54117DB4.307@redhat.com> <20140911113051.GG25317@minantech.com> <54119E01.9000908@redhat.com> <20140911135956.GC26540@minantech.com> <5411AC82.4080005@redhat.com> <20140911142121.GD26540@minantech.com> <5411B084.7030800@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5411B084.7030800@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 11, 2014 at 04:24:04PM +0200, Paolo Bonzini wrote: > Il 11/09/2014 16:21, Gleb Natapov ha scritto: > > As far as I can tell the if that is needed there is: > > > > if (!is_guest_mode() || !(vmcs12->secondary_vm_exec_control & ECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) > > write(PIC_ACCESS_ADDR) > > > > In other words if L2 shares L1 apic access page then reload, otherwise do nothing. > > What if the page being swapped out is L1's APIC access page? We don't > run prepare_vmcs12 in that case because it's an L2->L0->L2 entry, so we > need to "do something". We will do something on L2->L1 exit. We will call kvm_reload_apic_access_page(). That is what patch 5 of this series is doing. -- Gleb.