From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH 4/4] KVM: x86: Add VCPU substate for NMI states Date: Thu, 15 Oct 2009 13:27:09 +0200 Message-ID: <4AD7070D.7070108@siemens.com> References: <20091013160647.27006.58598.stgit@mchn012c.ww002.siemens.net> <20091013160648.27006.29041.stgit@mchn012c.ww002.siemens.net> <4AD6D8B6.3050003@redhat.com> <4AD6E9E1.1040704@siemens.com> <4AD6EB63.9030306@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , "kvm@vger.kernel.org" To: Avi Kivity Return-path: Received: from goliath.siemens.de ([192.35.17.28]:16972 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932288AbZJOL17 (ORCPT ); Thu, 15 Oct 2009 07:27:59 -0400 In-Reply-To: <4AD6EB63.9030306@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 10/15/2009 06:22 PM, Jan Kiszka wrote: >>> Needs a KVM_CAP as well. >>> >> KVM_CAP_VCPU_STATE will imply KVM_CAP_NMI_STATE, so I skipped the latter >> (user space code would use the former anyway to avoid yet another #ifdef >> layer). >> > > OK. New bits will need the KVM_CAP, though. For sure. > > Perhaps it makes sense to query about individual states, including > existing ones? That will allow us to deprecate and then phase out > broken states. It's probably not worth it. You may do this already with the given design: Set up a VCPU, then issue KVM_GET_VCPU_STATE on the substate in question. You will either get an error code or 0 if the substate is supported. At least no additional kernel code required. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux