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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5706AC98321 for ; Fri, 25 Sep 2026 15:24:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=0Mn9LHpATQYD60MMDJFhSmPSAE1hoAUrprtOqwvk3jQ=; b=rVPEhknGqug99MeQej7laxZM5r 0Yto66zzmekKiwIuPQ/LeDzhKDdc+O2r6LoHNBLNlsf4LBTZbupkz3h5jp/pWIU0VPITqyYqSmn8R wB0hUjmYjaHRmmIN7oVrRmcAsomxOwqJsqB3wFhaSXGWHAS9Lhxv3VpKenP0RwaQPKbZPsiarRk2C 5aIBCmMcLeiX+3wxETBEMQHM7ZadaZsrCth7NJ6oGH6TqUam/R2npE+zm281AXOdL1OrJT9fDwKQz NHr4m/OI/Rk3Wzs+7Jre/zmueI7FhsAO/9SevP9pk5f1OsF6NAzhIjFJ0/QeI6scjdPy4uU5KC4Bh lyFMA9JQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xA7mI-0000000Dm3c-0VAv; Fri, 25 Sep 2026 15:23:58 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xA7mF-0000000Dm3C-2mzV for linux-arm-kernel@lists.infradead.org; Fri, 25 Sep 2026 15:23:57 +0000 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 2E24B1688; Fri, 25 Sep 2026 08:23:51 -0700 (PDT) Received: from [10.57.10.17] (unknown [10.57.10.17]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 863F73F882; Fri, 25 Sep 2026 08:23:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790349834; bh=//y9dPhjHq/ujPCrO92ZhJvyqsgBfC/qyzgIoS31GyY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=hiPkvze6xWnuXgjf7isAW+6ZYs+8hiozwT76bIXaPIMZqQDQFSopSgQ6Ul8qjMvDN 1dn7ziLWqkMm5w1VMB5N5WKNtRd5RVjl7Wmcv+VRFKuQCVGYi7yYBkALg4o1GccVnq VNXBzkBnu5Ats955xS9i5iq3lPWyOYFAmdJTS9MI= Message-ID: Date: Fri, 25 Sep 2026 16:23:49 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v19 2/7] firmware: arm_rmm: Check for RMI support at init Content-Language: en-GB To: Catalin Marinas Cc: kvm@vger.kernel.org, kvmarm@lists.linux.dev, maz@kernel.org, will@kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, steven.price@arm.com, aneesh.kumar@kernel.org, oupton@kernel.org, gshan@redhat.com, joey.gouly@arm.com, tabba@google.com, yuzenghui@huawei.com, linux-coco@lists.linux.dev, gankulkarni@os.amperecomputing.com, sdonthineni@nvidia.com, alpergun@google.com, fj0570is@fujitsu.com, WeiLin.Chang@arm.com, lpieralisi@kernel.org, enju.kohei@fujitsu.com, sudeep.holla@arm.com, jonathan.cameron@oss.qualcomm.com References: <20260924135201.850038-1-suzuki.poulose@arm.com> <20260924135201.850038-3-suzuki.poulose@arm.com> From: Suzuki K Poulose In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260925_082356_146875_FFC5330B X-CRM114-Status: UNSURE ( 9.97 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 25/09/2026 11:42, Catalin Marinas wrote: > On Thu, Sep 24, 2026 at 02:51:56PM +0100, Suzuki K Poulose wrote: >> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c >> index 32102c3912fa7..e8b29983b0021 100644 >> --- a/arch/arm64/kernel/cpufeature.c >> +++ b/arch/arm64/kernel/cpufeature.c >> @@ -293,6 +293,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar3[] = { >> static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { >> ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV3_SHIFT, 4, 0), >> ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV2_SHIFT, 4, 0), >> + ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_RME_SHIFT, 4, 0), > > I think we end up exposing this to (any) guest unless we mask it out in > sanitise_id_aa64dfr0_el1(). Do the guests care about the RME version? I Valid point. I personally don't think this matters. The FEAT_RME alone is not useful or harmful. I could mask it in KVM as a safe bet. Cheers Suzuki > don't think they should, especially the non-realm ones. For nested it's > masked away already (limit_nv_id_reg()). >