From patchwork Fri Jan 27 11:29:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 13118423 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 164E3C38142 for ; Fri, 27 Jan 2023 11:33:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233775AbjA0LdX (ORCPT ); Fri, 27 Jan 2023 06:33:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233718AbjA0Lcy (ORCPT ); Fri, 27 Jan 2023 06:32:54 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B185478AC3; Fri, 27 Jan 2023 03:31:20 -0800 (PST) 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 D3FBD16A3; Fri, 27 Jan 2023 03:31:20 -0800 (PST) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.35.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A3DDA3F8D6; Fri, 27 Jan 2023 03:30:36 -0800 (PST) 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 Subject: [RFC PATCH 22/28] arm64: Don't expose stolen time for realm guests Date: Fri, 27 Jan 2023 11:29:26 +0000 Message-Id: <20230127112932.38045-23-steven.price@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230127112932.38045-1-steven.price@arm.com> References: <20230127112248.136810-1-suzuki.poulose@arm.com> <20230127112932.38045-1-steven.price@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org It doesn't make much sense and with the ABI as it is it's a footgun for the VMM which makes fatal granule protection faults easy to trigger. Signed-off-by: Steven Price --- arch/arm64/kvm/arm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 46c152a9a150..645df5968e1e 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -302,7 +302,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = system_supports_mte(); break; case KVM_CAP_STEAL_TIME: - r = kvm_arm_pvtime_supported(); + if (kvm && kvm_is_realm(kvm)) + r = 0; + else + r = kvm_arm_pvtime_supported(); break; case KVM_CAP_ARM_EL1_32BIT: r = cpus_have_const_cap(ARM64_HAS_32BIT_EL1);