From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v5 4/7] kvm, mem-hotplug: Reload L1' apic access page on migration in vcpu_enter_guest(). Date: Thu, 11 Sep 2014 16:37:39 +0200 Message-ID: <5411B3B3.900@redhat.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> <20140911143123.GE26540@minantech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit 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 To: Gleb Natapov Return-path: In-Reply-To: <20140911143123.GE26540@minantech.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Il 11/09/2014 16:31, Gleb Natapov ha scritto: >> > 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. Sorry, I meant "the APIC access page prepared by L1" for L2's execution. You wrote: > 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. but in that case you have to redo nested_get_page, so "do nothing" doesn't work. Paolo