From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH 3/4] kvm, memory-hotplug: Update ept identity pagetable when it is migrated. Date: Wed, 2 Jul 2014 19:34:20 +0300 Message-ID: <20140702163420.GC4399@minantech.com> References: <1404291637-15048-1-git-send-email-tangchen@cn.fujitsu.com> <1404291637-15048-4-git-send-email-tangchen@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: mtosatti@redhat.com, kvm@vger.kernel.org, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, guz.fnst@cn.fujitsu.com, linux-kernel@vger.kernel.org To: Tang Chen Return-path: Content-Disposition: inline In-Reply-To: <1404291637-15048-4-git-send-email-tangchen@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Jul 02, 2014 at 05:00:36PM +0800, Tang Chen wrote: > ept identity pagetable is pinned in memory, and as a result it cannot be > migrated/hot-removed. > > But actually it doesn't need to be pinned in memory. > > This patch introduces a new vcpu request: KVM_REQ_MIGRATE_EPT to reset ept > indetity pagetable related variable. This request will be made when > kvm_mmu_notifier_invalidate_page() is called when the page is unmapped > from the qemu user space to reset kvm->arch.ept_identity_pagetable to NULL. > And will also be made when ept violation happens to reset > kvm->arch.ept_identity_pagetable to the new page. kvm->arch.ept_identity_pagetable is never used as a page address, just boolean null/!null to see if identity pagetable is initialized. I do not see why would we want to track its address at all. Changing it to bool and assigning true during initialization should be enough. -- Gleb.