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 3E236C4450B for ; Wed, 15 Jul 2026 14:29:31 +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=i4sn1AfuSjVMSHI04BfVVQFL/PeDcnTuFpwOSB+LP+k=; b=Z/0CVO+9qQDrnOmPyJkkR55arG W+Mc1k2TYyXeJ0oiWTybTNM6ZT0tmERGCAXMhapggL/P6PGLbm57d3p8rgJBbMznajBSXSAMWHwh9 I7TGrjepzq6E++4bPYKpSHamN6qadBwMQ6ru4OH2yO5cdLT1BYWTkJ0kw8rrjHqdwhoXJ04m4CSKX sgovmGsBbYFJ36fkgJHHBk3jCVMW5kuSbbY66/GU/DeIbNB4iAk8dpg8nMVuhL3AgQ1tNl6q9mKAA 8dW8NMVSSQIQQ6/EZZXQOpJp9vvnfITMTilPeCVQGSDo43w9TeOYrjXs/jntDHM1xN98v2KezfCPr Q2HVXvhg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wk0c0-0000000F82n-37pi; Wed, 15 Jul 2026 14:29:24 +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 1wk0bu-0000000F7yb-3SET for linux-arm-kernel@lists.infradead.org; Wed, 15 Jul 2026 14:29:23 +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 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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260715_072918_909289_19B1701E X-CRM114-Status: GOOD ( 12.89 ) 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. 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