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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 6A6F6C47404 for ; Fri, 11 Oct 2019 14:25:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F0A321D7E for ; Fri, 11 Oct 2019 14:25:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728731AbfJKOZB (ORCPT ); Fri, 11 Oct 2019 10:25:01 -0400 Received: from foss.arm.com ([217.140.110.172]:34020 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728394AbfJKOZA (ORCPT ); Fri, 11 Oct 2019 10:25:00 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 389AE142F; Fri, 11 Oct 2019 07:25:00 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 51BD43F68E; Fri, 11 Oct 2019 07:24:57 -0700 (PDT) Date: Fri, 11 Oct 2019 15:24:55 +0100 From: Mark Rutland To: Dave Martin Cc: linux-kernel@vger.kernel.org, Andrew Jones , Arnd Bergmann , Catalin Marinas , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Kees Cook , Kristina =?utf-8?Q?Mart=C5=A1enko?= , Mark Brown , Paul Elliott , Peter Zijlstra , Richard Henderson , Sudakshina Das , Szabolcs Nagy , Thomas Gleixner , Will Deacon , Yu-cheng Yu , Amit Kachhap , Vincenzo Frascino , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 12/12] KVM: arm64: BTI: Reset BTYPE when skipping emulated instructions Message-ID: <20191011142454.GD33537@lakrids.cambridge.arm.com> References: <1570733080-21015-1-git-send-email-Dave.Martin@arm.com> <1570733080-21015-13-git-send-email-Dave.Martin@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1570733080-21015-13-git-send-email-Dave.Martin@arm.com> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 10, 2019 at 07:44:40PM +0100, Dave Martin wrote: > Since normal execution of any non-branch instruction resets the > PSTATE BTYPE field to 0, so do the same thing when emulating a > trapped instruction. > > Branches don't trap directly, so we should never need to assign a > non-zero value to BTYPE here. > > Signed-off-by: Dave Martin > --- > arch/arm64/include/asm/kvm_emulate.h | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h > index d69c1ef..33957a12 100644 > --- a/arch/arm64/include/asm/kvm_emulate.h > +++ b/arch/arm64/include/asm/kvm_emulate.h > @@ -452,8 +452,10 @@ static inline void kvm_skip_instr(struct kvm_vcpu *vcpu, bool is_wide_instr) > { > if (vcpu_mode_is_32bit(vcpu)) > kvm_skip_instr32(vcpu, is_wide_instr); > - else > + else { > *vcpu_pc(vcpu) += 4; > + *vcpu_cpsr(vcpu) &= ~(u64)PSR_BTYPE_MASK; > + } Style nit: both sides of an if-else should match brace-wise. i.e. please add braces to the other side. As with the prior patch, the u64 cast can also go. Otherwise, this looks right to me. Thanks, Mark.