From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C519CC55182 for ; Mon, 3 Aug 2026 13:45:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=hVABvhZU9pQJ0M3jbStXxENxKZtZVzsuXpcGoSosLOY=; b=rJwFfQLyRtydlW9kn4AlPX2M4z 6NoKPc8X9jlnWUobineuQCZnbC2UqORW4XxQNCUXa1w8U3Gq5jtAPLzyuUtVnw/Pl7WKn5de4dQed S/cE+w3kU3P6uSW5V1P95KmYFCkR/3nm9lGH2N5cKuobv6aBrlkOrgm+xLm2F/wheMf670NRo/Xjm G8T98rOvo/5c126WloPZdyjTZ/dsb10VzTWusDtvaeO7hFdplGLoC8dWOxtley7Sir3ecICjuXFpJ EkoO1LGf5AcL9WtR/gdXPm3+rKbRGoEAXV24jldg1Le7Jl82DFx3mr6KF/TqRVZpdeLwMmTunIABe FyTzRRBg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wqsyj-0000000HCOr-0wRV; Mon, 03 Aug 2026 13:45:17 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wqsyg-0000000HCMC-2UDU for linux-arm-kernel@lists.infradead.org; Mon, 03 Aug 2026 13:45:16 +0000 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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260803_064514_687869_B5445508 X-CRM114-Status: GOOD ( 12.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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