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 8A273423A7F; Wed, 13 May 2026 13:19:27 +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=1778678368; cv=none; b=XSyh7zXFJNe9ANGDQY3qotYqn7HmoqZdXZ+rA20IHmYPQah8LrLm6w9JvUgWAeSZQNqwWqMp8zInKMhPobwklCElQC7hvCOSYJKgV1hxaG26MqDZB/u1K31cH676w5E+1KEw3Sp4lQEjGZtKfFrOtOUwfgrbcwsPLNqbtwLCaPU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778678368; c=relaxed/simple; bh=XyhHOqSryuZS8p1TER/JzRvnrY9cIgXtR2qy2matUio=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cIPvcYWjh7oIhZD0J+YSl/oXKFf7r9SF7/cQg2MegALfN9LiLm32ClyX/TBt7VuLH1Pd1g+f/U6EmdmzQszTsgtBf8av5OckR0bk5PE8x4Hxktru4XrU9LaCwPq6WCm9Lsoiy/IwGTwh4wMPh6uGx/wZZgukfohHVtv56QGBKbM= 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=NP1fuI5v; 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="NP1fuI5v" 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 AA9072008; Wed, 13 May 2026 06:19:21 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.68.187]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BA97D3F836; Wed, 13 May 2026 06:19:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778678366; bh=XyhHOqSryuZS8p1TER/JzRvnrY9cIgXtR2qy2matUio=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NP1fuI5vArSoY8tcBBNDkh7PDlUfZDKSAYtGqS9ElXwZRsxGGZKFrevkbRJOzuOzY Jz1XKitDZYGTOT4lJ1Gv/RVkuq+4+DA8X/Rdd08stL3mbtX1YL8zIs8WhW+5FEjA4A U+OwtRTt1WUopk+mIt5HTM3gpyEWR4/r3375Kauw= 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.Pieralisi2@arm.com Subject: [PATCH v14 12/44] arm64: RMI: Check for LPA2 support Date: Wed, 13 May 2026 14:17:20 +0100 Message-ID: <20260513131757.116630-13-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260513131757.116630-1-steven.price@arm.com> References: <20260513131757.116630-1-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 --- New patch for v13 --- arch/arm64/kvm/rmi.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c index 1acc972a4b92..6e28b669ded2 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -5,9 +5,25 @@ #include +#include #include #include +static bool rmi_has_feature(unsigned long feature) +{ + return !!u64_get_bits(rmm_feat_reg0, feature); +} + +static int rmm_check_features(void) +{ + if (kvm_lpa2_is_enabled() && !rmi_has_feature(RMI_FEATURE_REGISTER_0_LPA2)) { + kvm_err("RMM doesn't support LPA2"); + return -ENXIO; + } + + return 0; +} + void kvm_init_rmi(void) { /* @@ -20,5 +36,8 @@ void kvm_init_rmi(void) if (!rmi_is_available()) return; + if (rmm_check_features()) + return; + /* Future patch will enable static branch kvm_rmi_is_available */ } -- 2.43.0