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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 7D7E8C433E0 for ; Mon, 25 Jan 2021 13:21:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27D7222B37 for ; Mon, 25 Jan 2021 13:21:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728760AbhAYNVM (ORCPT ); Mon, 25 Jan 2021 08:21:12 -0500 Received: from foss.arm.com ([217.140.110.172]:47250 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728721AbhAYNQm (ORCPT ); Mon, 25 Jan 2021 08:16:42 -0500 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 B11A311FB; Mon, 25 Jan 2021 05:15:56 -0800 (PST) Received: from [10.57.40.145] (unknown [10.57.40.145]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 427C83F66E; Mon, 25 Jan 2021 05:15:53 -0800 (PST) Subject: Re: [PATCH v5 13/21] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line To: Marc Zyngier , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Mark Rutland , David Brazdil , Alexandru Elisei , Ard Biesheuvel , Jing Zhang , Ajay Patil , Prasad Sodagudi , Srinivas Ramana , James Morse , Julien Thierry , kernel-team@android.com References: <20210125105019.2946057-1-maz@kernel.org> <20210125105019.2946057-14-maz@kernel.org> From: Suzuki K Poulose Message-ID: Date: Mon, 25 Jan 2021 13:15:47 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20210125105019.2946057-14-maz@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/25/21 10:50 AM, Marc Zyngier wrote: > As we want to be able to disable VHE at runtime, let's match > "id_aa64mmfr1.vh=" from the command line as an override. > This doesn't have much effect yet as our boot code doesn't look > at the cpufeature, but only at the HW registers. > > Signed-off-by: Marc Zyngier > Acked-by: David Brazdil > --- > arch/arm64/include/asm/cpufeature.h | 2 ++ > arch/arm64/kernel/cpufeature.c | 5 ++++- > arch/arm64/kernel/idreg-override.c | 11 +++++++++++ > 3 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h > index 4179cfc8ed57..b0ed37da4067 100644 > --- a/arch/arm64/include/asm/cpufeature.h > +++ b/arch/arm64/include/asm/cpufeature.h > @@ -818,6 +818,8 @@ static inline unsigned int get_vmid_bits(u64 mmfr1) > return 8; > } > > +extern struct arm64_ftr_override id_aa64mmfr1_override; > + > u32 get_kvm_ipa_limit(void); > void dump_cpu_features(void); > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 4b84a1e1dc51..c1d6712c4249 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -557,6 +557,8 @@ static const struct arm64_ftr_bits ftr_raz[] = { > > #define ARM64_FTR_REG(id, table) ARM64_FTR_REG_OVERRIDE(id, table, &no_override) > > +struct arm64_ftr_override id_aa64mmfr1_override; Does this need to be ro_after_init ? Otherwise, looks good to me: Acked-by: Suzuki K Poulose