From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755722AbbGPSIJ (ORCPT ); Thu, 16 Jul 2015 14:08:09 -0400 Received: from foss.arm.com ([217.140.101.70]:45336 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751705AbbGPSIG (ORCPT ); Thu, 16 Jul 2015 14:08:06 -0400 Date: Thu, 16 Jul 2015 19:08:03 +0100 From: Will Deacon To: Marc Zyngier Cc: Catalin Marinas , Christoffer Dall , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "kvmarm@lists.cs.columbia.edu" Subject: Re: [PATCH 01/13] arm/arm64: Add new is_kernel_in_hyp_mode predicate Message-ID: <20150716180802.GS26390@arm.com> References: <1436372356-30410-1-git-send-email-marc.zyngier@arm.com> <1436372356-30410-2-git-send-email-marc.zyngier@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1436372356-30410-2-git-send-email-marc.zyngier@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 08, 2015 at 05:19:04PM +0100, Marc Zyngier wrote: > With ARMv8.1 VHE extension, it will be possible to run the kernel > at EL2 (aka HYP mode). In order for the kernel to easily find out > where it is running, add a new predicate that returns whether or > not the kernel is in HYP mode. > > For completeness, the 32bit code also get such a predicate (always > returning false) so that code common to both architecture (timers, > KVM) can use it transparently. > > Signed-off-by: Marc Zyngier > --- > arch/arm/include/asm/virt.h | 5 +++++ > arch/arm64/include/asm/virt.h | 10 ++++++++++ > 2 files changed, 15 insertions(+) [...] > +static inline bool is_kernel_in_hyp_mode(void) > +{ > + u64 el; > + > + asm("mrs %0, CurrentEL" : "=r" (el)); > + return el == CurrentEL_EL2; Missing mask? Will