From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47837) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WPWWq-0002xx-Rn for qemu-devel@nongnu.org; Mon, 17 Mar 2014 08:20:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WPWWk-0002ZV-4d for qemu-devel@nongnu.org; Mon, 17 Mar 2014 08:20:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54422) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WPWWj-0002ZO-Rf for qemu-devel@nongnu.org; Mon, 17 Mar 2014 08:20:22 -0400 Message-ID: <5326E870.5040802@redhat.com> Date: Mon, 17 Mar 2014 13:20:00 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <201403171154.s2HBsj6M009513@indigo.cs.bgu.ac.il> In-Reply-To: <201403171154.s2HBsj6M009513@indigo.cs.bgu.ac.il> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] different IDTs of the same VCPU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Binun Cc: yagel@cs.bgu.ac.il, kahilm@post.bgu.ac.il, Stefan Hajnoczi , qemu-devel@nongnu.org, boaz.menuhin@gmail.com, markbl@post.bgu.ac.il Il 17/03/2014 12:54, Alexander Binun ha scritto: > Dear friends, great thanks! > > To summarize: we are trying to monitor VCPU IDT changes that are done > by external parties (e.g. rootkits) and not by intra-KVM machinery. > Are there parameters that witness such changes ? There is no way to intercept changes to the interrupt descriptor table. You can: * look at the IDTR values on every vmexit, including before injecting an interrupt, but that won't protect from hijacking software interrupts such as int $0x80; * protect the IDT from writing using KVM's page table mechanisms, but that won't catch the case when the IDT is changed to a whole new page. Paolo