From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tang Chen Subject: Re: [PATCH 0/4] kvm, mem-hotplug: Do not pin ept identity pagetable and apic access page. Date: Thu, 3 Jul 2014 09:17:59 +0800 Message-ID: <53B4AF47.1080008@cn.fujitsu.com> References: <1404291637-15048-1-git-send-email-tangchen@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: Tang Chen , , , , , , To: Return-path: In-Reply-To: <1404291637-15048-1-git-send-email-tangchen@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Hi Gleb, On 07/02/2014 05:00 PM, Tang Chen wrote: > Hi Gleb, Marcelo, > > Please help to review this patch-set. > > NOTE: This patch-set doesn't work properly. > > > ept identity pagetable and apic access page in kvm are pinned in memory. > As a result, they cannot be migrated/hot-removed. > > But actually they don't need to be pinned in memory. > > This patch-set introduces two new vcpu requests: KVM_REQ_MIGRATE_EPT and KVM_REQ_MIGRATE_APIC. > These two requests are made when the two pages are migrated by the mmu_notifier > to reset the related variable to unusable value. And will also be made when > ept violation happens to reset new pages. > > > [Known problem] > After this patch-set applied, the two pages can be migrated/hot-removed. > But after migrating apic access page, the guest died. > > The host physical address of apic access page is stored in VMCS. I reset > it to 0 to stop guest from accessing it when it is unmapped by > kvm_mmu_notifier_invalidate_page(). And reset it to new page's host physical > address in tdp_page_fault(). But it seems that guest will access apic page > directly by the host physical address. Would you please to give some advice about this problem ? Thanks.