From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752783AbdK2HZ4 (ORCPT ); Wed, 29 Nov 2017 02:25:56 -0500 Received: from mx2.suse.de ([195.135.220.15]:34552 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751398AbdK2HZz (ORCPT ); Wed, 29 Nov 2017 02:25:55 -0500 Subject: Re: [PATCH v2] x86/entry/64/paravirt: Use paravirt-safe macro to access eflags To: Boris Ostrovsky , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, luto@kernel.org References: <1511882905-6326-1-git-send-email-boris.ostrovsky@oracle.com> From: Juergen Gross Message-ID: Date: Wed, 29 Nov 2017 08:25:53 +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: <1511882905-6326-1-git-send-email-boris.ostrovsky@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/11/17 16:28, Boris Ostrovsky wrote: > 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 Reviewed-by: Juergen Gross Juergen