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,USER_AGENT_SANE_1 autolearn=unavailable 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 3B41FC433DB for ; Tue, 9 Mar 2021 14:53:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02CA665243 for ; Tue, 9 Mar 2021 14:53:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231712AbhCIOwg (ORCPT ); Tue, 9 Mar 2021 09:52:36 -0500 Received: from foss.arm.com ([217.140.110.172]:54794 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231625AbhCIOwG (ORCPT ); Tue, 9 Mar 2021 09:52:06 -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 3A04C1042; Tue, 9 Mar 2021 06:52:06 -0800 (PST) Received: from [192.168.0.130] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7EA983F71B; Tue, 9 Mar 2021 06:52:02 -0800 (PST) Subject: Re: [PATCH] arm64/mm: Fix __enable_mmu() for new TGRAN range values To: Will Deacon , Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org, James Morse , Catalin Marinas , Suzuki K Poulose , Ard Biesheuvel , Mark Rutland , kvmarm@lists.cs.columbia.edu, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org References: <1614954969-14338-1-git-send-email-anshuman.khandual@arm.com> <8735x5zozr.wl-maz@kernel.org> <20210309140527.GB28395@willie-the-truck> From: Anshuman Khandual Message-ID: <718f4b0c-20d9-8588-1268-e5b26690899d@arm.com> Date: Tue, 9 Mar 2021 20:22:38 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210309140527.GB28395@willie-the-truck> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On 3/9/21 7:35 PM, Will Deacon wrote: > On Mon, Mar 08, 2021 at 02:42:00PM +0000, Marc Zyngier wrote: >> On Fri, 05 Mar 2021 14:36:09 +0000, >> Anshuman Khandual wrote: >>> - switch (cpuid_feature_extract_unsigned_field(mmfr0, tgran_2)) { >>> - default: >>> - case 1: >>> + tgran_2 = cpuid_feature_extract_unsigned_field(mmfr0, tgran_2_shift); >>> + if (tgran_2 == ID_AA64MMFR0_TGRAN_2_SUPPORTED_NONE) { >>> kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n"); >>> return -EINVAL; >>> - case 0: >>> + } else if (tgran_2 == ID_AA64MMFR0_TGRAN_2_SUPPORTED_DEFAULT) { >>> kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n"); >>> - break; >>> - case 2: >>> + } else if (tgran_2 >= ID_AA64MMFR0_TGRAN_2_SUPPORTED_MIN && >>> + tgran_2 <= ID_AA64MMFR0_TGRAN_2_SUPPORTED_MAX) { >>> kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n"); >>> - break; >>> + } else { >>> + kvm_err("Unsupported value, giving up\n"); >>> + return -EINVAL; >> >> nit: this doesn't say *what* value is unsupported, and I really >> preferred the switch-case version, such as this: >> >> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c >> index 1f22b36a0eff..d267e4b1aec6 100644 >> --- a/arch/arm64/kvm/reset.c >> +++ b/arch/arm64/kvm/reset.c >> @@ -312,15 +312,18 @@ int kvm_set_ipa_limit(void) >> >> switch (cpuid_feature_extract_unsigned_field(mmfr0, tgran_2)) { >> default: >> - case 1: >> + case ID_AA64MMFR0_TGRAN_2_SUPPORTED_NONE: >> kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n"); >> return -EINVAL; >> - case 0: >> + case ID_AA64MMFR0_TGRAN_2_SUPPORTED_DEFAULT: >> kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n"); >> break; >> - case 2: >> + case ID_AA64MMFR0_TGRAN_2_SUPPORTED_MIN ... ID_AA64MMFR0_TGRAN_2_SUPPORTED_MAX: >> kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n"); >> break; >> + default: >> + kvm_err("Unsupported value for TGRAN_2, giving up\n"); >> + return -EINVAL; >> } >> >> kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange); >> >> >> Otherwise: >> >> Acked-by: Marc Zyngier > > Anshuman -- please can you spin a v2 with the switch syntax as suggested > above by Marc? Sure, will do.