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=-8.5 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_MUTT 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 41EDFC2BCA1 for ; Fri, 7 Jun 2019 14:42:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1545F2083D for ; Fri, 7 Jun 2019 14:42:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728729AbfFGOmg (ORCPT ); Fri, 7 Jun 2019 10:42:36 -0400 Received: from foss.arm.com ([217.140.110.172]:41370 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728252AbfFGOmg (ORCPT ); Fri, 7 Jun 2019 10:42:36 -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 0CE78337; Fri, 7 Jun 2019 07:42:35 -0700 (PDT) Received: from e103592.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 05C733F71A; Fri, 7 Jun 2019 07:42:33 -0700 (PDT) Date: Fri, 7 Jun 2019 15:42:31 +0100 From: Dave Martin To: Viresh Kumar Cc: Marc Zyngier , Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] KVM: arm64: Drop 'const' from argument of vq_present() Message-ID: <20190607144229.GF28398@e103592.cambridge.arm.com> References: <699121e5c938c6f4b7b14a7e2648fa15af590a4a.1559623368.git.viresh.kumar@linaro.org> <20190604095915.GW28398@e103592.cambridge.arm.com> <20190607060037.eaof3hllyombxlhc@vireshk-i7> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190607060037.eaof3hllyombxlhc@vireshk-i7> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 07, 2019 at 11:30:37AM +0530, Viresh Kumar wrote: > On 04-06-19, 10:59, Dave Martin wrote: > > On Tue, Jun 04, 2019 at 10:13:19AM +0530, Viresh Kumar wrote: > > > We currently get following compilation warning: > > > > > > arch/arm64/kvm/guest.c: In function 'set_sve_vls': > > > arch/arm64/kvm/guest.c:262:18: warning: passing argument 1 of 'vq_present' from incompatible pointer type > > > arch/arm64/kvm/guest.c:212:13: note: expected 'const u64 (* const)[8]' but argument is of type 'u64 (*)[8]' > > > > > > The argument can't be const, as it is copied at runtime using > > > copy_from_user(). Drop const from the prototype of vq_present(). > > > > > > Fixes: 9033bba4b535 ("KVM: arm64/sve: Add pseudo-register for the guest's vector lengths") > > > Signed-off-by: Viresh Kumar > > > --- > > > arch/arm64/kvm/guest.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c > > > index 3ae2f82fca46..78f5a4f45e0a 100644 > > > --- a/arch/arm64/kvm/guest.c > > > +++ b/arch/arm64/kvm/guest.c > > > @@ -209,7 +209,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > > > #define vq_mask(vq) ((u64)1 << ((vq) - SVE_VQ_MIN) % 64) > > > > > > static bool vq_present( > > > - const u64 (*const vqs)[KVM_ARM64_SVE_VLS_WORDS], > > > + u64 (*const vqs)[KVM_ARM64_SVE_VLS_WORDS], > > > unsigned int vq) > > > { > > > return (*vqs)[vq_word(vq)] & vq_mask(vq); > > > > Ack, but maybe this should just be converted to a macro? > > I will send a patch with that if that's what you want. I think this would solve the problem and simplify the code a bit at the same time. So go for it. Cheers ---Dave