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=1793891549; b=hXNzOCt+8r+bHeRxvg5bl1uvO6yBfCAPJrU6qJwwqPp1zE7Jo637zV57lnwD80t9F4tb OVgZHRjAsJ05x6rRhsY0McAfDqCoGITQkpYNSLMln0/nnVc+bor7xrajFpXSWcZt6P+CN 4rapDXNo3f23hrsJc/2bphn5X0ROqKHGLWZTb/Jt7r0KQv1ml1zfC/cYh1idsrFWllFUR KrxQXwnWWVlxRr9ZDVDWsRkJU3pZgf7WE0V8GicvT+E3wto/lgHmcKsBut585XzfsE2CZ 3Xf7OUUn5/sOlVqZTGsLZowDSOk/3kiTfF4gq82xNcKUnYRxuTxHSfKy4feMvmb7vBw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793891549; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:To:Cc:References:From: Content-Language:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=IWJD0iHItHJ0ZLICudpIGPh2lKAzMkhjEJ2bZxXwT1g=; b=wSxly+ykQuhoX8SBrgR0NY6BMzr8kLy4ScAgEfReCGbnuZ3xcVFvmgFtSyNeXl7M+03x ftybAtmvpI9mHxY/t2vuJxBZEFC8pUB78SgtAy9FgMlpKOHrWWcgbDISGmBt9ZkAWyJRN PEtl6nW7nh3PAwHhdwoCCbxzU8ebEz8F7P++sqvkzJ5L1MAaxZX7XeCpg2wkM/3oYNzLQ skDM8CMmAuK3ORHstP4vCynNfzR9zQ+WCNcukg2uGh2VYxbtk1V4M5IxOYjiNwRA7uawZ 72kXFeghd8HDwbpC/BiQKOWlQXHANEZ9yIrtEggfZCsfVdLKa4nDXWWGHOvQrNmZ+7w== 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=I9yJWYMO; 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 679AF606D823; Thu, 5 Nov 2026 15:12:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 679AF606D823 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=I9yJWYMO 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 9E02B16F2; Thu, 5 Nov 2026 07:12:24 -0800 (PST) Received: from [10.0.128.250] (e122027.cambridge.arm.com [10.0.128.250]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D24EC3F628; Thu, 5 Nov 2026 07:12:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793891547; bh=K05vKtM+fPDTzjogjywixfTKzhfzKJwvrbfn/flAQKU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=I9yJWYMOEfAXqlqdwyFVq2M5GIwutk5K6psqq9Cpc7QM5j08Mcw18ktYr7AnqST3/ GjFIAmD16GvgTjVNYKV0YLBzFCCAvPxZyKsBXJAoSEfd1Vp0+12u1UwKcGhCWb1cWp eDOuw2QPcrF8XLvPwDKHxwX3Bkyl6a8Ir0NoK4TQ= Message-ID: Date: Thu, 5 Nov 2026 15:12:23 +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 To: Suzuki K Poulose , 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: Steven Price Content-Language: en-GB In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 03/11/2026 11:47, Suzuki K Poulose wrote: > 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. Makes sense. > >> >> 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) > Sashiko pointed out that my use of u64_get_bits() is problematic. So I'll fix that up and more it to the header file. Thanks, Steve > > 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 */ >>   } >