From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752642AbdLEMRh (ORCPT <rfc822;w@1wt.eu>);
        Tue, 5 Dec 2017 07:17:37 -0500
Received: from mx2.suse.de ([195.135.220.15]:55183 "EHLO mx2.suse.de"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1752035AbdLEMRf (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 5 Dec 2017 07:17:35 -0500
Subject: Re: [patch 01/60] x86/entry/64/paravirt: Use paravirt-safe macro to
 access eflags
To: Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Linus Torvalds <torvalds@linux-foundation.org>,
        Andy Lutomirsky <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Dave Hansen <dave.hansen@intel.com>, Borislav Petkov <bpetkov@suse.de>,
        Greg KH <gregkh@linuxfoundation.org>, keescook@google.com,
        hughd@google.com, Brian Gerst <brgerst@gmail.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Denys Vlasenko <dvlasenk@redhat.com>, Rik van Riel <riel@redhat.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        David Laight <David.Laight@aculab.com>,
        Eduardo Valentin <eduval@amazon.com>, aliguori@amazon.com,
        Will Deacon <will.deacon@arm.com>, daniel.gruss@iaik.tugraz.at,
        xen-devel@lists.xenproject.org
References: <20171204140706.296109558@linutronix.de>
 <20171204150604.899457242@linutronix.de>
From: Juergen Gross <jgross@suse.com>
Message-ID: <5cabf1be-7439-f3b6-5035-1ef575042d7d@suse.com>
Date: Tue, 5 Dec 2017 13:17:31 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.4.0
MIME-Version: 1.0
In-Reply-To: <20171204150604.899457242@linutronix.de>
Content-Type: text/plain; charset=iso-8859-15
Content-Language: de-DE
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 04/12/17 15:07, Thomas Gleixner wrote:
> From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> 
> Commit 1d3e53e8624a ("x86/entry/64: Refactor IRQ stacks and make them
> NMI-safe") added DEBUG_ENTRY_ASSERT_IRQS_OFF macro that acceses eflags
> using 'pushfq' instruction when testing for IF bit. On PV Xen guests
> looking at IF flag directly will always see it set, resulting in 'ud2'.
> 
> Introduce SAVE_FLAGS() macro that will use appropriate save_fl pv op when
> running paravirt.
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: jgross@suse.com
> Cc: xen-devel@lists.xenproject.org
> Cc: luto@kernel.org
> Link: https://lkml.kernel.org/r/1512159805-6314-1-git-send-email-boris.ostrovsky@oracle.com

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen