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 X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 030DEC10F11 for ; Wed, 24 Apr 2019 13:42:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3D5F218DA for ; Wed, 24 Apr 2019 13:42:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730558AbfDXNm1 (ORCPT ); Wed, 24 Apr 2019 09:42:27 -0400 Received: from foss.arm.com ([217.140.101.70]:43768 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727112AbfDXNm1 (ORCPT ); Wed, 24 Apr 2019 09:42:27 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7C28315A2; Wed, 24 Apr 2019 06:42:26 -0700 (PDT) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C10653F238; Wed, 24 Apr 2019 06:42:24 -0700 (PDT) Date: Wed, 24 Apr 2019 14:42:22 +0100 From: Dave Martin To: Amit Daniel Kachhap Cc: Marc Zyngier , Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, Kristina Martsenko , Ramana Radhakrishnan , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v10 1/5] KVM: arm64: Add a vcpu flag to control ptrauth for guest Message-ID: <20190424134221.GX3567@e103592.cambridge.arm.com> References: <1555994558-26349-1-git-send-email-amit.kachhap@arm.com> <1555994558-26349-2-git-send-email-amit.kachhap@arm.com> <20190423154419.GL3567@e103592.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 24, 2019 at 11:27:50AM +0530, Amit Daniel Kachhap wrote: > Hi, > > On 4/23/19 9:14 PM, Dave Martin wrote: > >On Tue, Apr 23, 2019 at 10:12:34AM +0530, Amit Daniel Kachhap wrote: > >>A per vcpu flag is added to check if pointer authentication is > >>enabled for the vcpu or not. This flag may be enabled according to > >>the necessary user policies and host capabilities. > >> > >>This patch also adds a helper to check the flag. > >> > >>Reviewed-by: Dave Martin > >>Signed-off-by: Amit Daniel Kachhap > >>Cc: Mark Rutland > >>Cc: Marc Zyngier > >>Cc: Christoffer Dall > >>Cc: kvmarm@lists.cs.columbia.edu > >>--- > >>Changes since v9: > >> > >>* Added ptrauth cpufeature static check in vcpu_has_ptrauth [Marc Zyngier]. > >> > >> arch/arm64/include/asm/kvm_host.h | 5 +++++ > >> 1 file changed, 5 insertions(+) > >> > >>diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > >>index 7a096fd..7ccac42 100644 > >>--- a/arch/arm64/include/asm/kvm_host.h > >>+++ b/arch/arm64/include/asm/kvm_host.h > >>@@ -355,10 +355,15 @@ struct kvm_vcpu_arch { > >> #define KVM_ARM64_HOST_SVE_ENABLED (1 << 4) /* SVE enabled for EL0 */ > >> #define KVM_ARM64_GUEST_HAS_SVE (1 << 5) /* SVE exposed to guest */ > >> #define KVM_ARM64_VCPU_SVE_FINALIZED (1 << 6) /* SVE config completed */ > >>+#define KVM_ARM64_GUEST_HAS_PTRAUTH (1 << 7) /* PTRAUTH exposed to guest */ > >> #define vcpu_has_sve(vcpu) (system_supports_sve() && \ > >> ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE)) > >>+#define vcpu_has_ptrauth(vcpu) ((system_supports_address_auth() || \ > >>+ system_supports_generic_auth()) && \ > > > >Come to think of it, should this be > >system_supports_address_auth() _&&_ system_supports_generic_auth()? > I thought about it and kept it this way so that the implementation > limitation is not introduced in this patch but only in a single place in the > 3rd patch where all the documentation and reasoning is present on doing this > way. OK, I think that's reasonable. Just wanted to check that I wasn't missing some subtle issue here. Cheers ---Dave