From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756895AbbE2TDP (ORCPT ); Fri, 29 May 2015 15:03:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35090 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756432AbbE2TDJ (ORCPT ); Fri, 29 May 2015 15:03:09 -0400 Date: Fri, 29 May 2015 21:03:05 +0200 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, guangrong.xiao@linux.intel.com, bdas@redhat.com Subject: Re: [PATCH v2 00/13] SMM implementation for KVM Message-ID: <20150529190305.GB7856@potion.brq.redhat.com> References: <1432746314-50196-1-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1432746314-50196-1-git-send-email-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I found a corner case that doesn't fit any specific patch: We allow INIT while in SMM. This brings some security complications as we also don't reset hflags (another long standing bug?), but we don't really need to because INIT in SMM is against the spec anyway; APM May 2013 2:10.3.3 Exceptions and Interrupts, • INIT—The processor does not recognize INIT while in SMM. SDM April 2015: 34.5.1 Initial SMM Execution Environment, Maskable hardware interrupts, exceptions, NMI interrupts, SMI interrupts, A20M interrupts, single-step traps, breakpoint traps, and INIT operations are inhibited when the processor enters SMM. And there is no mention of an exception for INIT. (Some extra old experiments say that INIT could be enabled, but that is not applicable now, http://www.rcollins.org/ddj/Mar97/Mar97.html) I think that INIT received before RSM should be delivered after.