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 8186DC10F03 for ; Tue, 23 Apr 2019 15:45:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A5BA218CD for ; Tue, 23 Apr 2019 15:45:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728549AbfDWPpj (ORCPT ); Tue, 23 Apr 2019 11:45:39 -0400 Received: from foss.arm.com ([217.140.101.70]:58562 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728534AbfDWPpi (ORCPT ); Tue, 23 Apr 2019 11:45:38 -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 F11D180D; Tue, 23 Apr 2019 08:45:37 -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 426B23F5AF; Tue, 23 Apr 2019 08:45:36 -0700 (PDT) Date: Tue, 23 Apr 2019 16:45:33 +0100 From: Dave Martin To: Amit Daniel Kachhap 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 Subject: Re: [PATCH v10 4/5] KVM: arm64: Add capability to advertise ptrauth for guest Message-ID: <20190423154533.GO3567@e103592.cambridge.arm.com> References: <1555994558-26349-1-git-send-email-amit.kachhap@arm.com> <1555994558-26349-5-git-send-email-amit.kachhap@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1555994558-26349-5-git-send-email-amit.kachhap@arm.com> 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 Tue, Apr 23, 2019 at 10:12:37AM +0530, Amit Daniel Kachhap wrote: > This patch advertises the capability of two cpu feature called address > pointer authentication and generic pointer authentication. These > capabilities depend upon system support for pointer authentication and > VHE mode. > > The current arm64 KVM partially implements pointer authentication and > support of address/generic authentication are tied together. However, > separate ABI requirements for both of them is added so that any future > isolated implementation will not require any ABI changes. > > Signed-off-by: Amit Daniel Kachhap > Cc: Mark Rutland > Cc: Marc Zyngier > Cc: Christoffer Dall > Cc: kvmarm@lists.cs.columbia.edu > --- > Changes since v9: > * Fixed tab alignment issues [Dave Martin]. > * Clarify the api documentation [Dave Martin]. > > Documentation/virtual/kvm/api.txt | 14 ++++++++++---- > arch/arm64/kvm/reset.c | 5 +++++ > include/uapi/linux/kvm.h | 2 ++ > 3 files changed, 17 insertions(+), 4 deletions(-) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index 32afe7f..fac1887 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -2763,13 +2763,19 @@ Possible features: > > - KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication > for arm64 only. > - Both KVM_ARM_VCPU_PTRAUTH_ADDRESS and KVM_ARM_VCPU_PTRAUTH_GENERIC > - must be requested or neither must be requested. > + Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS. > + If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are > + both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and > + KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be > + requested. > > - KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication > for arm64 only. > - Both KVM_ARM_VCPU_PTRAUTH_ADDRESS and KVM_ARM_VCPU_PTRAUTH_GENERIC > - must be requested or neither must be requested. > + Depends on KVM_CAP_ARM_PTRAUTH_GENERIC. > + If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are > + both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and > + KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be > + requested. This looks clear now. The description is quite heavyweight, but should be hard for people to misunderstand. > - KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only). > Depends on KVM_CAP_ARM_SVE. > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > index 028d0c6..f0faf54 100644 > --- a/arch/arm64/kvm/reset.c > +++ b/arch/arm64/kvm/reset.c > @@ -101,6 +101,11 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext) > case KVM_CAP_ARM_SVE: > r = system_supports_sve(); > break; > + case KVM_CAP_ARM_PTRAUTH_ADDRESS: > + case KVM_CAP_ARM_PTRAUTH_GENERIC: > + r = has_vhe() && system_supports_address_auth() && > + system_supports_generic_auth(); > + break; > default: > r = 0; > } > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 1d56444..4dc34f8 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -989,6 +989,8 @@ struct kvm_ppc_resize_hpt { > #define KVM_CAP_MANUAL_DIRTY_LOG_PROTECT 166 > #define KVM_CAP_HYPERV_CPUID 167 > #define KVM_CAP_ARM_SVE 168 > +#define KVM_CAP_ARM_PTRAUTH_ADDRESS 169 > +#define KVM_CAP_ARM_PTRAUTH_GENERIC 170 [...] Reviewed-by: Dave Martin Cheers ---Dave