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 9E5E535C6B7; Mon, 3 Aug 2026 13:45:14 +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=1785764716; cv=none; b=JeJkWZb4Z2esRit2Qe041fbQ5gDtluWKDOexa1B1Ld9P5at6plmGMr4vpRf0akijywrFqIEsimIcNtsnJRElwDarRXbsTmIy7cNV9DDo+83jz74z/1wFOvMF9/2ivu5p7j8BwRSxrCBWzA/m/GslrX7aWtFE9PKlBWAM9mmWzl0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785764716; c=relaxed/simple; bh=A5swwuKF1sO6Ks2eU21cOmS2+QgmSfc5adtL4WsCNVs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=A6Lz+luUOPeG9PSM+7bJfB/S7ypohGQQrOCK2mfTqtxg47ocWLsLNm7EXjEKLnsibZcr92/3TdhpJI/stevdgU5WlzmUnY3A+NLJtAymP4DdcTdB6CBsJOnolv8a+/iANkuGgU+FGPLsZI5X/5hvoXDEQ9MIoImFpswRv6X/jAY= 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=Cz+udvNR; 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="Cz+udvNR" 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 03344143D; Mon, 3 Aug 2026 06:45:10 -0700 (PDT) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.25.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B7D033F66F; Mon, 3 Aug 2026 06:45:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785764714; bh=A5swwuKF1sO6Ks2eU21cOmS2+QgmSfc5adtL4WsCNVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cz+udvNRcM1Tk4J/RUkbxEBfr01o+wyepwZMwkWNP6dPU53LYHVSaSaRSIAwEbG8P PD8KzhfmpLeMgjyAuA1bJBBn8kBae7e+GGTDKJMXmkyek873FlOBbB7jF/isgOtgW/ wiG9rwtlgwMcOX07xk3G1Ao0AERzyMQR9/Tpsx9U= 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 v16 12/45] KVM: arm64: CCA: Check for LPA2 support Date: Mon, 3 Aug 2026 14:43:28 +0100 Message-ID: <20260803134403.80630-13-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260803134403.80630-1-steven.price@arm.com> References: <20260803134403.80630-1-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. Reviewed-by: Suzuki K Poulose 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