From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH 3/3] arm, arm64: KVM: handle potential incoherency of readonly memslots Date: Fri, 21 Nov 2014 12:19:36 +0100 Message-ID: <20141121111936.GA1785@cbox> References: <1416236333-9378-1-git-send-email-ard.biesheuvel@linaro.org> <1416236333-9378-3-git-send-email-ard.biesheuvel@linaro.org> <546A146E.1020804@redhat.com> <546A1905.6080607@redhat.com> <546D288F.1040107@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Laszlo Ersek , Paolo Bonzini , Ard Biesheuvel , kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com, drjones@redhat.com, wei@redhat.com, kvm@vger.kernel.org To: Mario Smarduch Return-path: Received: from mail-lb0-f180.google.com ([209.85.217.180]:38102 "EHLO mail-lb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752478AbaKULTK (ORCPT ); Fri, 21 Nov 2014 06:19:10 -0500 Received: by mail-lb0-f180.google.com with SMTP id z11so3739039lbi.25 for ; Fri, 21 Nov 2014 03:19:08 -0800 (PST) Content-Disposition: inline In-Reply-To: <546D288F.1040107@samsung.com> Sender: kvm-owner@vger.kernel.org List-ID: Hi Mario, On Wed, Nov 19, 2014 at 03:32:31PM -0800, Mario Smarduch wrote: > Hi Laszlo, > > couple observations. > > I'm wondering if access from qemu and guest won't > result in mixed memory attributes and if that's acceptable > to the CPU. > > Also is if you update memory from qemu you may break > dirty page logging/migration. Unless there is some other way > you keep track. Of course it may not be applicable in your > case (i.e. flash unused after boot). > I'm not concerned about this particular case; dirty page logging exists so KVM can inform userspace when a page may have been dirtied. If userspace directly dirties (is that a verb?) a page, then it already knows that it needs to migrate that page and deal with it accordingly. Or did I miss some more subtle point here? -Christoffer