From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Heads up: More user-unaccessible x86 states? Date: Mon, 05 Oct 2009 08:18:36 +0200 Message-ID: <4AC98FBC.3030509@redhat.com> References: <4AC86404.3090209@web.de> <4AC87299.4040508@redhat.com> <4AC87E08.5070908@web.de> <4AC88BF2.7080200@redhat.com> <4AC8F282.3090307@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:29697 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751071AbZJEGTE (ORCPT ); Mon, 5 Oct 2009 02:19:04 -0400 In-Reply-To: <4AC8F282.3090307@web.de> Sender: kvm-owner@vger.kernel.org List-ID: On 10/04/2009 09:07 PM, Jan Kiszka wrote: >> btw, instead of adding a new ioctl, perhaps it makes sense to define a >> new KVM_VCPU_STATE structure that holds all current and future state >> (with generous reserved space), instead of separating state over a dozen >> ioctls. >> >> > OK, makes sense. With our without lapic state? I'm in two minds. I'm leaning towards including lapic but would welcome arguments either way. Note we have to be careful with timers such as the tsc and lapic timer. Maybe have a bitmask at the front specifying which elements are active. > How much "future space"? > avx will change the sse registers from 16x16 to 16x32, with a hint of more to come. Nested vmx needs the vmptr and some more bits. MSRs are potentially endless. Lots of space. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.