Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754961AbZDPWlS (ORCPT ); Thu, 16 Apr 2009 18:41:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754536AbZDPWlA (ORCPT ); Thu, 16 Apr 2009 18:41:00 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39044 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753967AbZDPWk7 (ORCPT ); Thu, 16 Apr 2009 18:40:59 -0400 Message-ID: <49E7B3EB.6060101@zytor.com> Date: Thu, 16 Apr 2009 15:40:43 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Avi Kivity CC: Glauber Costa , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] deal with interrupt shadow state for emulated instruction References: <1239653210-10422-1-git-send-email-glommer@redhat.com> <49E45894.7090700@redhat.com> <49E4B4D4.1020903@zytor.com> <49E4B654.6060101@redhat.com> <49E4B8E9.7050703@zytor.com> <49E6F7D6.8010107@redhat.com> In-Reply-To: <49E6F7D6.8010107@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 553 Lines: 17 Avi Kivity wrote: > > We don't emulate guest user mode. > > Well, if guest userspace can convince its kernel to give it access to > some memory mapped I/O register, I guess it can execute repeated 'mov > ss, mmio' and starve the guest kernel. > It doesn't need a MMIO register to do that, even. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/