From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nadav Amit Subject: Re: [PATCH 08/21] KVM: x86: Reset FPU state during reset Date: Thu, 6 Nov 2014 11:13:59 +0200 Message-ID: <47A17AC1-9FAC-467B-9DBC-76D530D8F131@gmail.com> References: <1414922101-17626-1-git-send-email-namit@cs.technion.ac.il> <1414922101-17626-9-git-send-email-namit@cs.technion.ac.il> <545A1264.5030002@redhat.com> <545A3A6C.3010302@redhat.com> <545B3843.8090501@redhat.com> Mime-Version: 1.0 (Mac OS X Mail 8.0 \(1990.1\)) Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Nadav Amit , kvm@vger.kernel.org To: Paolo Bonzini Return-path: Received: from mail-wi0-f169.google.com ([209.85.212.169]:40647 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750901AbaKFJOF convert rfc822-to-8bit (ORCPT ); Thu, 6 Nov 2014 04:14:05 -0500 Received: by mail-wi0-f169.google.com with SMTP id n3so782038wiv.4 for ; Thu, 06 Nov 2014 01:14:02 -0800 (PST) In-Reply-To: <545B3843.8090501@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: > On Nov 6, 2014, at 10:58, Paolo Bonzini wrote: >=20 > On 05/11/2014 21:31, Nadav Amit wrote: >> You are correct, it does not appear clearly in the SDM, but that is = what real hardware does. >> If you look at bochs - http://code.metager.de/source/xref/bochs/boch= s/cpu/init.cc - you=92ll see they call >> "BX_CPU_THIS_PTR xcr0.set32(0x1);=94 regardless to whether it is har= dware or software reset (the latter happens on INIT). >=20 > Fair enough. :) Thanks. It is turning harder to find references for the crazy x86 behav= iour. :) >=20 > Does the patch in > http://permalink.gmane.org/gmane.comp.emulators.kvm.devel/129060 look= good? Yes. However, re-reviewing the patches both my patch and yours actually= do something slightly different than the spec: they clear XMM8-15 and = YMM[128:=85] which should not happen on INIT according to the spec. =46ixing it might be a bit intrusive. What do you say? Nadav