From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A20AFC072B1 for ; Thu, 30 May 2019 05:55:31 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7CA9724C11 for ; Thu, 30 May 2019 05:55:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7CA9724C11 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ispras.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:55925 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hWE2E-0007Ok-Oc for qemu-devel@archiver.kernel.org; Thu, 30 May 2019 01:55:30 -0400 Received: from eggs.gnu.org ([209.51.188.92]:38014) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hWE1O-00077A-Ow for qemu-devel@nongnu.org; Thu, 30 May 2019 01:54:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hWE1N-0003CP-Tj for qemu-devel@nongnu.org; Thu, 30 May 2019 01:54:38 -0400 Received: from mail.ispras.ru ([83.149.199.45]:48834) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hWE1N-0003AT-MU for qemu-devel@nongnu.org; Thu, 30 May 2019 01:54:37 -0400 Received: from PASHAISP (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id B8328540081; Thu, 30 May 2019 08:54:34 +0300 (MSK) From: "Pavel Dovgalyuk" To: "'Peter Xu'" References: <003a01d51611$6251a2b0$26f4e810$@ru> <20190530005243.GA28587@xz-x1> In-Reply-To: <20190530005243.GA28587@xz-x1> Date: Thu, 30 May 2019 08:54:38 +0300 Message-ID: <000901d516ac$2b1a7d80$814f7880$@ru> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: AdUWggc4ukGM/8TIT7mPEKR3TuoRLAAKfQwQ Content-Language: ru X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 83.149.199.45 Subject: Re: [Qemu-devel] i386: EFER vs 32-bit CPU X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ehabkost@redhat.com, quintela@redhat.com, dgilbert@redhat.com, qemu-devel@nongnu.org, pbonzini@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" > From: Peter Xu [mailto:peterx@redhat.com] > On Wed, May 29, 2019 at 02:26:39PM +0300, Pavel Dovgalyuk wrote: > > Hello! > > > > > > > > I found this while debugging the inconsistent saved/restored state of the virtual machine. > > > > > > > > i386 (32 bit) emulation uses this register (in wrmsr and in MMU fault processing). > > Sorry if this question is elementary, but... why would a 32bit guest > use IA32_EFER? From SDM I only see 4 bits defined in this MSR (SCE, > LME, LMA, NXE) but is there any of them that should be set in a 32bit > guest? Ubuntu server 16.04 (32 bit) sets NXE while booting. NXE affects the MMU fault processing and exception generation. Pavel Dovgalyuk