From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6009845D903; Mon, 21 Sep 2026 09:00:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789981227; cv=none; b=PeUdnfrUCxGn5mbeBqk5zm3HGpEBOArj5Om/8G5cUlN8i6iWUyQCe05YIWxsoHJdrYcDwd37h3bDOLyJEk9RQJgirv+gO01WVqU8hp+9DCzvRFZKZkgQCGfLmMgFGpQ1yvKFmASOqpogeSDU6d5eveliZ4jH9bLKjjFT22a2ojo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789981227; c=relaxed/simple; bh=7FAGCstgztp6bQyjfL+K1zBPkIxsy8V7zCgPNPDJtbQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=F4/uwjV0mEkJufe5VWYbfbENEiElhWqr8LY2x+Aem6VLuUtK1tbEFOpdCygBul1A1BqmNE2pmaF0BvWURbiPJW85L/gsc/7Q1PuGSIAvtOp28YgussKXlTMA+y1ARA1DdDjZDs8A1Seuuh2+rPUWCNR5HenfCPW4V3FErXxEDpw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=oSa5Booe; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="oSa5Booe" 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 39BAD1CE0; Mon, 21 Sep 2026 02:00:21 -0700 (PDT) Received: from [10.0.128.141] (unknown [10.0.128.141]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ECAE23F86C; Mon, 21 Sep 2026 02:00:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789981224; bh=7FAGCstgztp6bQyjfL+K1zBPkIxsy8V7zCgPNPDJtbQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=oSa5BooeCN2HgtM8aUls3mxHMY3MXyU2nS3pbxXQChhKBqdmgK734c/lj7eVm0YO9 ZSKEbPNyh17gcrccayHqVU+68ufFTY1lZApU7H+TSnRhywToCaqGZxCnn+xzsn72jW 7MGPpF9u5Wz+sBuB3BdBclgAlWKwK0iyJ/u15DDo= Message-ID: Date: Mon, 21 Sep 2026 10:00:20 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v18 2/7] firmware: arm_rmm: Check for RMI support at init Content-Language: en-GB To: Jonathan Cameron Cc: kvm@vger.kernel.org, kvmarm@lists.linux.dev, maz@kernel.org, will@kernel.org, catalin.marinas@arm.com, 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 References: <20260912083611.2513845-1-suzuki.poulose@arm.com> <20260912083611.2513845-3-suzuki.poulose@arm.com> <178978126541.2352296.3637463397103730192.b4-review@b4> From: Suzuki K Poulose In-Reply-To: <178978126541.2352296.3637463397103730192.b4-review@b4> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 19/09/2026 02:27, Jonathan Cameron wrote: >> Query the RMI version number and check if it is a compatible version. >> The first two feature registers are read and exposed for future code to >> use. >> >> We only support this for Little Endian kernels, the Big Endian kernel >> support is anyway marked BROKEN and is being removed. > > Can we have a small comment here on why the default is y > > It's a big thing to opt into by default. Feels like defconfig > material maybe but not in the Kconfig defaults unless I'm missing > something. We need this for KVM arm64. I could drop the default here and KVM selects this anyways. But, how far do we go on this ? Do we need to be able to disable this completely even for KVM ? As such it is a relatively smaller blob: $ size drivers/firmware/arm_rmm/rmi.o text data bss dec hex filename 7477 572 1 8050 1f72 drivers/firmware/arm_rmm/rmi.o Cheers Suzuki > > >> >> Signed-off-by: Steven Price >> Signed-off-by: Suzuki K Poulose > >> diff --git a/drivers/firmware/arm_rmm/Kconfig b/drivers/firmware/arm_rmm/Kconfig >> new file mode 100644 >> index 000000000000..82724ee23186 >> --- /dev/null >> +++ b/drivers/firmware/arm_rmm/Kconfig >> @@ -0,0 +1,26 @@ >> + >> +config ARCH_SUPPORTS_RMM >> + bool >> + >> +config ARM_RMM_RMI >> + bool "Realm Management Interface (RMI) Support" >> + depends on ARCH_SUPPORTS_RMM >> + default y > Really? Why? >