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 43DE928F2; Fri, 27 Jan 2023 11:30:39 +0000 (UTC) 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> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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); -- 2.34.1 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 E2CBCC38142 for ; Fri, 27 Jan 2023 11:52:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gMfWhgk44jIDekQ7gSKP26+vNFdwiIHioHxPFOAiNAs=; b=1jVpY/9ACzgOTR QwscXdV4zOq8PFm2WL6Wd+XtTp+/S57kSjXU5Rog9dBmWwYuYi2ONyfUkry9EcbD30PLDj4t2EqMt sYL3xAQFq/NeJqWTxzk5orkL1LdVTBp3VRK44382vXsurb+1g0RFLqwWQaxE+pbKF466o0YQVlNnz rqlN8Qtv/iUHc8V2avjIYx70tuQ69nSXZfsbY/LEh6ydNxAfkOvM/VRVa/xxvuewpE8qzf05WLRD3 Vq047qoCgVFojRUilYI9cXhQ6leEzccG7p9Fjsn4NW48JR49bSv2FS4IAqNp2Dt6PAK5xBCaEmkLR rvp6OrB8b1xgb9Nnqdmw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pLNG7-00EHnR-HS; Fri, 27 Jan 2023 11:51:08 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pLMwK-00E8MM-3D for linux-arm-kernel@lists.infradead.org; Fri, 27 Jan 2023 11:30:41 +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 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230127_033040_262151_FA167C3D X-CRM114-Status: GOOD ( 10.86 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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); -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel