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: 49270 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp786796wrn; Fri, 27 Jan 2023 03:42:31 -0800 (PST) X-Google-Smtp-Source: AMrXdXuJR3Y1Lk4fZvePrDpq71ljMdpmuOHYfTni/lIVdc1VOztfc+xCwOqTmmLGyBBlnH820r1P X-Received: by 2002:a17:902:c948:b0:194:6414:12e1 with SMTP id i8-20020a170902c94800b00194641412e1mr53148712pla.25.1674819750803; Fri, 27 Jan 2023 03:42:30 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674819750; cv=none; d=google.com; s=arc-20160816; b=Ub0X0ZaeiF29ctXP1Vt+ioQsHejnwWJE01ViNu1NuzvnRc+3Z8fvo1IoLFG8+C9oer LfbxwUV9oIObQKVHl70Pi+ktn8hDtsnEOaUoXJcDGk6+fnAcbBgvn/UXfJZnpvCzJn4A DuRabhMbLHQb3Vei4f6tBxvM6AVqiA6WVwbBqTEU5PWhwwP9nwCiKAUh1qmpKXdaRnes DOf6JOILbqiGysxNAvOoTNAKgl8pKfFuFHE5+JFquEaM08yRP4IsSvSdYwIsF8cylaMZ IDkyXZ6M99+mk5hcl//2A1D3ICdiGWbUXID0oxaH7R8VbiINHPJcSCfMnhvqJwv6aWNM ijXw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=q6aSkeHfa+QgDmcoSj2Xs/vTgTFVlKeTmNRgxwBzwS8=; b=ZmM9jNUzRbBuL4VFX34sib/Q6RbESlEIK3PowakySp+7NFSa5fRpAm6sW/xAtW5Eca FXAWA0UYGQWesbBFK/b2QUNGHPMvnHg+UstlxNtKroYVqNE9Mfzmxjm2hAd2i63RlCxf nOFCFPC23CfBS/NcremUpkDs6Nn6+Xv6ggm9zpd16fACF+o5ofVTI+pbVj3crBhnf2zj OpHHTZLPrB828R4IygGoJIDbKUoyT36HevYbokW/Rmlbv90e/eHFO1B65u7SFlAWHIJ0 aqD000reCsYu+e4Y928gi2ZqKjteXcA5staWk9y4/3grRNWHGzEmKWWYHu6m02cN9yyE SdSg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id c10-20020a170902d48a00b0019272f2ecc3si5035597plg.369.2023.01.27.03.42.17; Fri, 27 Jan 2023 03:42:30 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233716AbjA0Ld1 (ORCPT + 99 others); Fri, 27 Jan 2023 06:33:27 -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 X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756175794729747507?= X-GMAIL-MSGID: =?utf-8?q?1756175794729747507?= 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);