From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967218AbdJRJfx (ORCPT ); Wed, 18 Oct 2017 05:35:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35342 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934218AbdJRJfg (ORCPT ); Wed, 18 Oct 2017 05:35:36 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com EA935A790 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=pbonzini@redhat.com Subject: Re: [PATCH RFC 00/10] Intel EPT-Based Sub-page Write Protection Support. To: Jim Mattson , kvm list , LKML , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Alex Williamson References: <250725286.12444082.1507929205754.JavaMail.zimbra@redhat.com> <20171016000841.GB66870@dazhang1-ssd.sh.intel.com> From: Paolo Bonzini Message-ID: <96efaece-306c-cde3-06d6-553505612136@redhat.com> Date: Wed, 18 Oct 2017 11:35:12 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20171016000841.GB66870@dazhang1-ssd.sh.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 18 Oct 2017 09:35:36 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/10/2017 02:08, Yi Zhang wrote: >> And the introspection facility by Mihai uses a completely >> different API for the introspector, based on sockets rather than ioctls. >> So I'm not sure this is the right API at all. > > Currently, We only block the write access, As far as I know an example, > we now using it in a security daemon: Understood. However, I think QEMU is the wrong place to set this up. If the kernel wants to protect _itself_, it should use a hypercall. If an introspector appliance wants to protect the guest kernel, it should use the socket that connects it to the hypervisor. Paolo > Consider It has a server which launching in the host user-space, and a > client launching in the guest kernel. Yes, they are communicate with > sockets. The guest kernel wanna protect a special area to prevent all > the process including the kernel itself modify this area. the client > could send the guest physical address via the security socket to server > side, and server would update these protection into KVM. Thus, all the > write access in a guest specific area will be blocked. > > Now the implementation only on the second half(maybe third ^_^) of this > example: 'How kvm set the write-protect into a specific GFN?' > > Maybe a user space tools which use ioctl let kvm mmu update the > write-protection is a better choice. >