From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793706463; b=Vw7Mzgp2jEhcM+4KK0xR3vhV/+zIj8xE84YbnaSlJAcHnRsMn5PuslEW1szg1fREkTVt 3/wDTF92leuVO4dcUDXHmIFqdgnXvthulHM73Iao4H3IMAmEUIN/vfC2EELFAtkRMlwch rpGQncEqVqFkbN6GmxJJG9Cmsscb8D1G/A7mmtbxt17lFsLWbRxC8kNahlCEDcDV9yYYO hOTBTpGnxNgyEOM9cRmiMrLfS5lzOWmBFaZ3KObq2QPWrcJM7YWO3tOs/NpJyVvRuPSWG sAo3wwWcTwT0ItG1Pnj3zwDHzQjx1SFhCnGVbbgJHiLCPfjGHYqIP3HPb36TeYmOChw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793706463; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:Content-Language:To:Cc:References: From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=YJMeRkCmn9gDBAVzQVXW/T4MGrrHZj9tyHFg1Pygn9A=; b=fxH3YbUcvuXMXoI/xHGo7p8Jzlxy4K0im5wCeKfyLBTYBu7Ojw1QGfGh3X10Q0VvDwMF c8A0bK774Ha2+njXN74gBREw0FyNOQ8tmEI8Ox31zThoHvD6ChcgbCPhzif2bMk6nh5pi IG6ZCjpSuSzM0EzRmFf7nkZHQl9SYv9LxnbeuB6i4L4esB/QpTncszKvsvny1FCwVjm6x xWO5UfyIMVlRyxcHu9gF0GIc/emzy2utcqZyIJL3EbnCZUg/VNd9hYS4pahNbGYzouxvk R8d7GGr1WH6H8glac7xJfEyBvry3h7/rkUEiYAQSp6LjhyLsvZRW+sjodd5hByghgPg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=VzHG9OPV; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 31EDD606D804; Tue, 3 Nov 2026 11:47:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 31EDD606D804 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, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=VzHG9OPV 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 12C581576; Tue, 3 Nov 2026 03:47:39 -0800 (PST) Received: from [10.57.66.79] (unknown [10.57.66.79]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2825D3F632; Tue, 3 Nov 2026 03:47:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793706462; bh=zSgYiWzcO24ysSZVXSXH948NdVzqg3BzhoQrCEIVTso=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=VzHG9OPVGljGbtk8/efCtKN+jXXjyAuI9shD1Hi8lG9XoKy/j+wZrORgQYX3SWvdH TbbrdwV0WQUSkvcAtUMG6jZasRllCf8il54W8y5TJkprOXoSJzMc9YGDLV6rX2V7Dt djZpfn3ciOcg5sMuhjPPTBIf3cbJgogUR7N4zkIU= Message-ID: Date: Tue, 3 Nov 2026 11:47:36 +0000 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 04/11] KVM: arm64: CCA: Check for LPA2 support and SHA-256 Content-Language: en-GB To: Steven Price , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve , WeiLin.Chang@arm.com, Lorenzo Pieralisi References: <20261102141304.126883-1-steven.price@arm.com> <20261102141304.126883-5-steven.price@arm.com> From: Suzuki K Poulose In-Reply-To: <20261102141304.126883-5-steven.price@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Steven On 02/11/2026 14:12, Steven Price wrote: > If KVM has enabled LPA2 support then check that the RMM also supports > it. If there is a mismatch then disable support for realm guests as the > VMM may attempt to create a guest which is incompatible with the RMM. > > Also check for SHA-256 support in the RMM as to begin with we only > support SHA-256 based measurements. This can be relaxed in the future. This could be merged with the patch 3. > > Reviewed-by: Suzuki K Poulose > Signed-off-by: Steven Price > --- > arch/arm64/kvm/rmi.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c > index 9d118768550d..5b07beff8bc9 100644 > --- a/arch/arm64/kvm/rmi.c > +++ b/arch/arm64/kvm/rmi.c > @@ -6,8 +6,30 @@ > #include > #include > > +#include > #include > > +static bool rmi_has_feature(int reg, unsigned long feature) > +{ > + return !!u64_get_bits(rmi_feat_reg(reg), feature); > +} > + minor nit: Do we see this useful for others (e.g., DA) ? May be we could move this to the include/linux/arm-rmi-cmds.h ? May be we could even make the above a macro, something like #define rmi_has_feature(reg, feat) u64_get_bits(rmi_feat_reg(reg), RMI_FEATURE_REGISTER_#reg _#feat) Cheers Suzuki > +static int rmm_check_features(void) > +{ > + if (kvm_lpa2_is_enabled() && > + !rmi_has_feature(0, RMI_FEATURE_REGISTER_0_LPA2)) { > + kvm_err("RMM doesn't support LPA2\n"); > + return -ENXIO; > + } > + > + if (!rmi_has_feature(1, RMI_FEATURE_REGISTER_1_HASH_SHA_256)) { > + kvm_err("RMM doesn't support SHA-256 measurements\n"); > + return -ENXIO; > + } > + > + return 0; > +} > + > void kvm_init_rmi(void) > { > if (kvm_get_mode() != KVM_MODE_RMM) > @@ -16,5 +38,8 @@ void kvm_init_rmi(void) > if (!is_rmi_available()) > return; > > + if (rmm_check_features()) > + return; > + > /* Future patch will enable static branch kvm_rmi_is_available */ > }