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 9175738AC9A; Wed, 15 Jul 2026 14:29:18 +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=1784125760; cv=none; b=ZsoIan5ksFfhYJu871syXUt4eLvbQ6EAFUFUzZDfWZVIJ/la7bKv3/XTHjwDD/7oCwHw6eJ0NRWYzoo6DR9KieJj/xKYx6VM1eSxFdYqkSpGR/N1kLr+IxJyJ4elbaVKEptmY6xcm45Me7hqESRTzLAzgkir9Aqe5bp2K8dHdHE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784125760; c=relaxed/simple; bh=nW7/u/8ytSl027az4/gQTrog0UWHJWQHxjfzk2ofIrk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jkg0uLryUOYkn1idw+ANnjdhoiH2pVZWwty4ILgy0lKIwTOr60+yUvVW4llkNbIWl0sUcR2xLDPfIcR+ewq1jRx/qcJK24eYJN0VNw2MLCOSjYUAYcFs2NUqi4xoGkfTg+RdZfr504GvhlXd9ahGlnDKkB8nJGjyQKUI7i4kwJ0= 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=o79Cj0Uh; 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="o79Cj0Uh" 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 9446B153B; Wed, 15 Jul 2026 07:29:13 -0700 (PDT) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.25.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DF4413F7B4; Wed, 15 Jul 2026 07:29:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784125757; bh=nW7/u/8ytSl027az4/gQTrog0UWHJWQHxjfzk2ofIrk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o79Cj0UhKUE0ZUJMcVo9NDGCbiXgRWZ+bShrkDmKFuklkECL2mOQMjgsW4Y4akVqT OA++hUC1Enfa80QB53kaSBps6rSWkGJ1KiWEf3HUdRCRaHawGpY25mf5JM950VaSOm XN2g7hgfkJUw5HN2Fkkr4AiXQdr+Pj2btk3V0sds= From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , 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 Subject: [PATCH v15 05/37] KVM: arm64: CCA: Check for LPA2 support Date: Wed, 15 Jul 2026 15:28:07 +0100 Message-ID: <20260715142841.80544-6-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260715142841.80544-1-steven.price@arm.com> References: <20260715142841.80544-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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. Signed-off-by: Steven Price --- v15: * Extend rmi_has_feature() to take the register number and check the presence of SHA-256 support which is default. v13: * New patch --- 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 384991d69f78..247c4f033945 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -5,9 +5,31 @@ #include +#include #include #include +static bool rmi_has_feature(int reg, unsigned long feature) +{ + return !!u64_get_bits(rmi_feat_reg(reg), feature); +} + +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) { /* @@ -20,5 +42,8 @@ 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 */ } -- 2.43.0