From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amit Daniel Kachhap Subject: Re: [PATCH v10 1/5] KVM: arm64: Add a vcpu flag to control ptrauth for guest Date: Wed, 24 Apr 2019 11:27:50 +0530 Message-ID: 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=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190423154419.GL3567@e103592.cambridge.arm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dave Martin Cc: linux-arm-kernel@lists.infradead.org, Marc Zyngier , Catalin Marinas , Will Deacon , Kristina Martsenko , kvmarm@lists.cs.columbia.edu, Ramana Radhakrishnan , linux-kernel@vger.kernel.org List-Id: kvmarm@lists.cs.columbia.edu 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. > > It won't make a functional difference today though, since today > kvm_vcpu_enable_ptrauth() won't set KVM_ARM64_GUEST_HAS_PTRAUTH without > system_supports_address_auth() and system_supports_generic_auth() both > true. > > With || here, we won't have to change this if supporting the two auth > types independently in the future though. Yes right. > > Either way, my Reviewed-by stands. Thanks, Amit D > > Cheers > ---Dave > 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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 D7B95C282CE for ; Wed, 24 Apr 2019 05:58:01 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 73F942148D for ; Wed, 24 Apr 2019 05:58:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 73F942148D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D24824A4AA; Wed, 24 Apr 2019 01:58:00 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9y5Cbt36hwCh; Wed, 24 Apr 2019 01:57:58 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id A40934A480; Wed, 24 Apr 2019 01:57:58 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 81EFF4A477 for ; Wed, 24 Apr 2019 01:57:57 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Jod4KhWK1xYT for ; Wed, 24 Apr 2019 01:57:56 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 27F2C4A46F for ; Wed, 24 Apr 2019 01:57:56 -0400 (EDT) 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 44111A78; Tue, 23 Apr 2019 22:57:55 -0700 (PDT) Received: from [10.162.0.144] (a075553-lin.blr.arm.com [10.162.0.144]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B27573F5AF; Tue, 23 Apr 2019 22:57:52 -0700 (PDT) Subject: Re: [PATCH v10 1/5] KVM: arm64: Add a vcpu flag to control ptrauth for guest To: Dave Martin 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> From: Amit Daniel Kachhap Message-ID: Date: Wed, 24 Apr 2019 11:27:50 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190423154419.GL3567@e103592.cambridge.arm.com> Content-Language: en-US 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 X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="UTF-8"; format="flowed" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Message-ID: <20190424055750.PBFKHBjcC42MMGjFxXk2F4hXHUHtfQoXP3-wBAuSixg@z> 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. > > It won't make a functional difference today though, since today > kvm_vcpu_enable_ptrauth() won't set KVM_ARM64_GUEST_HAS_PTRAUTH without > system_supports_address_auth() and system_supports_generic_auth() both > true. > > With || here, we won't have to change this if supporting the two auth > types independently in the future though. Yes right. > > Either way, my Reviewed-by stands. Thanks, Amit D > > Cheers > ---Dave > _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm