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,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 BCED6C10F14 for ; Tue, 16 Apr 2019 16:32:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 939402087C for ; Tue, 16 Apr 2019 16:32:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730032AbfDPQc1 (ORCPT ); Tue, 16 Apr 2019 12:32:27 -0400 Received: from foss.arm.com ([217.140.101.70]:59382 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726647AbfDPQc0 (ORCPT ); Tue, 16 Apr 2019 12:32:26 -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 C8CA380D; Tue, 16 Apr 2019 09:32:25 -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 2B2C43F59C; Tue, 16 Apr 2019 09:32:24 -0700 (PDT) Date: Tue, 16 Apr 2019 17:32:21 +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: [kvmtool PATCH v9 5/5] KVM: arm/arm64: Add a vcpu feature for pointer authentication Message-ID: <20190416163221.GY3567@e103592.cambridge.arm.com> References: <1555039236-10608-1-git-send-email-amit.kachhap@arm.com> <1555039236-10608-6-git-send-email-amit.kachhap@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1555039236-10608-6-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 Fri, Apr 12, 2019 at 08:50:36AM +0530, Amit Daniel Kachhap wrote: > This patch adds a runtime capabality for KVM tool to enable Arm64 8.3 > Pointer Authentication in guest kernel. Two vcpu features > KVM_ARM_VCPU_PTRAUTH_[ADDRESS/GENERIC] are supplied together to enable > Pointer Authentication in KVM guest after checking the capability. > > Command line options --enable-ptrauth and --disable-ptrauth are added > to use this feature. However, if those options are not provided then > also this feature is enabled if host supports this capability. > > The macros defined in the headers are not in sync and should be replaced > from the upstream. > > Signed-off-by: Amit Daniel Kachhap > --- > Changes since v8: > * Added option --enable-ptrauth and --disable-ptrauth to use ptrauth. Also > enable ptrauth if no option provided and Host supports ptrauth. [Dave Martin] > * The macro definition are not linear as the kvmtool is not synchronised with the > kernel changes present in kvmarm/next tree. > > arm/aarch32/include/kvm/kvm-cpu-arch.h | 1 + > arm/aarch64/include/asm/kvm.h | 2 ++ > arm/aarch64/include/kvm/kvm-config-arch.h | 6 +++++- > arm/aarch64/include/kvm/kvm-cpu-arch.h | 2 ++ > arm/include/arm-common/kvm-config-arch.h | 2 ++ > arm/kvm-cpu.c | 11 +++++++++++ > include/linux/kvm.h | 2 ++ > 7 files changed, 25 insertions(+), 1 deletion(-) > > diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h > index d28ea67..520ea76 100644 > --- a/arm/aarch32/include/kvm/kvm-cpu-arch.h > +++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h > @@ -13,4 +13,5 @@ > #define ARM_CPU_ID 0, 0, 0 > #define ARM_CPU_ID_MPIDR 5 > > +#define ARM_VCPU_PTRAUTH_FEATURE 0 > #endif /* KVM__KVM_CPU_ARCH_H */ > diff --git a/arm/aarch64/include/asm/kvm.h b/arm/aarch64/include/asm/kvm.h > index 97c3478..a2546e6 100644 > --- a/arm/aarch64/include/asm/kvm.h > +++ b/arm/aarch64/include/asm/kvm.h > @@ -102,6 +102,8 @@ struct kvm_regs { > #define KVM_ARM_VCPU_EL1_32BIT 1 /* CPU running a 32bit VM */ > #define KVM_ARM_VCPU_PSCI_0_2 2 /* CPU uses PSCI v0.2 */ > #define KVM_ARM_VCPU_PMU_V3 3 /* Support guest PMUv3 */ > +#define KVM_ARM_VCPU_PTRAUTH_ADDRESS 5 /* CPU uses address pointer authentication */ > +#define KVM_ARM_VCPU_PTRAUTH_GENERIC 6 /* CPU uses generic pointer authentication */ > > struct kvm_vcpu_init { > __u32 target; > diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h b/arm/aarch64/include/kvm/kvm-config-arch.h > index 04be43d..0279b13 100644 > --- a/arm/aarch64/include/kvm/kvm-config-arch.h > +++ b/arm/aarch64/include/kvm/kvm-config-arch.h > @@ -8,7 +8,11 @@ > "Create PMUv3 device"), \ > OPT_U64('\0', "kaslr-seed", &(cfg)->kaslr_seed, \ > "Specify random seed for Kernel Address Space " \ > - "Layout Randomization (KASLR)"), > + "Layout Randomization (KASLR)"), \ > + OPT_BOOLEAN('\0', "enable-ptrauth", &(cfg)->enable_ptrauth, \ > + "Enables pointer authentication"), \ > + OPT_BOOLEAN('\0', "disable-ptrauth", &(cfg)->disable_ptrauth, \ > + "Disables pointer authentication"), > > #include "arm-common/kvm-config-arch.h" > > diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h b/arm/aarch64/include/kvm/kvm-cpu-arch.h > index a9d8563..fcc2107 100644 > --- a/arm/aarch64/include/kvm/kvm-cpu-arch.h > +++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h > @@ -17,4 +17,6 @@ > #define ARM_CPU_CTRL 3, 0, 1, 0 > #define ARM_CPU_CTRL_SCTLR_EL1 0 > > +#define ARM_VCPU_PTRAUTH_FEATURE ((1UL << KVM_ARM_VCPU_PTRAUTH_ADDRESS) \ > + | (1UL << KVM_ARM_VCPU_PTRAUTH_GENERIC)) > #endif /* KVM__KVM_CPU_ARCH_H */ > diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h > index 5734c46..1b4287d 100644 > --- a/arm/include/arm-common/kvm-config-arch.h > +++ b/arm/include/arm-common/kvm-config-arch.h > @@ -10,6 +10,8 @@ struct kvm_config_arch { > bool aarch32_guest; > bool has_pmuv3; > u64 kaslr_seed; > + bool enable_ptrauth; > + bool disable_ptrauth; > enum irqchip_type irqchip; > u64 fw_addr; > }; > diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c > index 7780251..a45a649 100644 > --- a/arm/kvm-cpu.c > +++ b/arm/kvm-cpu.c > @@ -69,6 +69,17 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id) > } > > /* > + * Always enable Pointer Authentication if requested. If system supports > + * this extension then also enable it by default provided no disable > + * request present. > + */ > + if ((kvm->cfg.arch.enable_ptrauth) || Nit: redundant () > + (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) && Funny indentation? > + kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC) && > + !kvm->cfg.arch.disable_ptrauth)) > + vcpu_init.features[0] |= ARM_VCPU_PTRAUTH_FEATURE; > + Hmm, we have some weird behaviours here: --enable-ptrauth --disable-ptrauth will result in us trying to enable it, and --enable-ptrauth without the required caps will result in an unhelpful "Unable to initialise vcpu" error message. I'm not sure this is a whole lot worse than the way other options behave today, though. You could try to be more explicit about what happens in these cases, but I'm not sure it's worth it given the state of the existing code. [...] 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=-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=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 1D0E5C10F14 for ; Tue, 16 Apr 2019 16:32:31 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id CD75120821 for ; Tue, 16 Apr 2019 16:32:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD75120821 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 876344A51E; Tue, 16 Apr 2019 12:32:30 -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 0jqjMOSk-MrA; Tue, 16 Apr 2019 12:32:29 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 188C44A4F3; Tue, 16 Apr 2019 12:32:29 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D3B774A4DE for ; Tue, 16 Apr 2019 12:32:27 -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 nrAbPdkF-LiB for ; Tue, 16 Apr 2019 12:32:26 -0400 (EDT) Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 539314A4CC for ; Tue, 16 Apr 2019 12:32:26 -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 C8CA380D; Tue, 16 Apr 2019 09:32:25 -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 2B2C43F59C; Tue, 16 Apr 2019 09:32:24 -0700 (PDT) Date: Tue, 16 Apr 2019 17:32:21 +0100 From: Dave Martin To: Amit Daniel Kachhap Subject: Re: [kvmtool PATCH v9 5/5] KVM: arm/arm64: Add a vcpu feature for pointer authentication Message-ID: <20190416163221.GY3567@e103592.cambridge.arm.com> References: <1555039236-10608-1-git-send-email-amit.kachhap@arm.com> <1555039236-10608-6-git-send-email-amit.kachhap@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1555039236-10608-6-git-send-email-amit.kachhap@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) 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-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Message-ID: <20190416163221.VDqwChqz8uUA9RtqUNV6BNHo5QMge5GB3r27JRxrP50@z> On Fri, Apr 12, 2019 at 08:50:36AM +0530, Amit Daniel Kachhap wrote: > This patch adds a runtime capabality for KVM tool to enable Arm64 8.3 > Pointer Authentication in guest kernel. Two vcpu features > KVM_ARM_VCPU_PTRAUTH_[ADDRESS/GENERIC] are supplied together to enable > Pointer Authentication in KVM guest after checking the capability. > > Command line options --enable-ptrauth and --disable-ptrauth are added > to use this feature. However, if those options are not provided then > also this feature is enabled if host supports this capability. > > The macros defined in the headers are not in sync and should be replaced > from the upstream. > > Signed-off-by: Amit Daniel Kachhap > --- > Changes since v8: > * Added option --enable-ptrauth and --disable-ptrauth to use ptrauth. Also > enable ptrauth if no option provided and Host supports ptrauth. [Dave Martin] > * The macro definition are not linear as the kvmtool is not synchronised with the > kernel changes present in kvmarm/next tree. > > arm/aarch32/include/kvm/kvm-cpu-arch.h | 1 + > arm/aarch64/include/asm/kvm.h | 2 ++ > arm/aarch64/include/kvm/kvm-config-arch.h | 6 +++++- > arm/aarch64/include/kvm/kvm-cpu-arch.h | 2 ++ > arm/include/arm-common/kvm-config-arch.h | 2 ++ > arm/kvm-cpu.c | 11 +++++++++++ > include/linux/kvm.h | 2 ++ > 7 files changed, 25 insertions(+), 1 deletion(-) > > diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h > index d28ea67..520ea76 100644 > --- a/arm/aarch32/include/kvm/kvm-cpu-arch.h > +++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h > @@ -13,4 +13,5 @@ > #define ARM_CPU_ID 0, 0, 0 > #define ARM_CPU_ID_MPIDR 5 > > +#define ARM_VCPU_PTRAUTH_FEATURE 0 > #endif /* KVM__KVM_CPU_ARCH_H */ > diff --git a/arm/aarch64/include/asm/kvm.h b/arm/aarch64/include/asm/kvm.h > index 97c3478..a2546e6 100644 > --- a/arm/aarch64/include/asm/kvm.h > +++ b/arm/aarch64/include/asm/kvm.h > @@ -102,6 +102,8 @@ struct kvm_regs { > #define KVM_ARM_VCPU_EL1_32BIT 1 /* CPU running a 32bit VM */ > #define KVM_ARM_VCPU_PSCI_0_2 2 /* CPU uses PSCI v0.2 */ > #define KVM_ARM_VCPU_PMU_V3 3 /* Support guest PMUv3 */ > +#define KVM_ARM_VCPU_PTRAUTH_ADDRESS 5 /* CPU uses address pointer authentication */ > +#define KVM_ARM_VCPU_PTRAUTH_GENERIC 6 /* CPU uses generic pointer authentication */ > > struct kvm_vcpu_init { > __u32 target; > diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h b/arm/aarch64/include/kvm/kvm-config-arch.h > index 04be43d..0279b13 100644 > --- a/arm/aarch64/include/kvm/kvm-config-arch.h > +++ b/arm/aarch64/include/kvm/kvm-config-arch.h > @@ -8,7 +8,11 @@ > "Create PMUv3 device"), \ > OPT_U64('\0', "kaslr-seed", &(cfg)->kaslr_seed, \ > "Specify random seed for Kernel Address Space " \ > - "Layout Randomization (KASLR)"), > + "Layout Randomization (KASLR)"), \ > + OPT_BOOLEAN('\0', "enable-ptrauth", &(cfg)->enable_ptrauth, \ > + "Enables pointer authentication"), \ > + OPT_BOOLEAN('\0', "disable-ptrauth", &(cfg)->disable_ptrauth, \ > + "Disables pointer authentication"), > > #include "arm-common/kvm-config-arch.h" > > diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h b/arm/aarch64/include/kvm/kvm-cpu-arch.h > index a9d8563..fcc2107 100644 > --- a/arm/aarch64/include/kvm/kvm-cpu-arch.h > +++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h > @@ -17,4 +17,6 @@ > #define ARM_CPU_CTRL 3, 0, 1, 0 > #define ARM_CPU_CTRL_SCTLR_EL1 0 > > +#define ARM_VCPU_PTRAUTH_FEATURE ((1UL << KVM_ARM_VCPU_PTRAUTH_ADDRESS) \ > + | (1UL << KVM_ARM_VCPU_PTRAUTH_GENERIC)) > #endif /* KVM__KVM_CPU_ARCH_H */ > diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h > index 5734c46..1b4287d 100644 > --- a/arm/include/arm-common/kvm-config-arch.h > +++ b/arm/include/arm-common/kvm-config-arch.h > @@ -10,6 +10,8 @@ struct kvm_config_arch { > bool aarch32_guest; > bool has_pmuv3; > u64 kaslr_seed; > + bool enable_ptrauth; > + bool disable_ptrauth; > enum irqchip_type irqchip; > u64 fw_addr; > }; > diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c > index 7780251..a45a649 100644 > --- a/arm/kvm-cpu.c > +++ b/arm/kvm-cpu.c > @@ -69,6 +69,17 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id) > } > > /* > + * Always enable Pointer Authentication if requested. If system supports > + * this extension then also enable it by default provided no disable > + * request present. > + */ > + if ((kvm->cfg.arch.enable_ptrauth) || Nit: redundant () > + (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) && Funny indentation? > + kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC) && > + !kvm->cfg.arch.disable_ptrauth)) > + vcpu_init.features[0] |= ARM_VCPU_PTRAUTH_FEATURE; > + Hmm, we have some weird behaviours here: --enable-ptrauth --disable-ptrauth will result in us trying to enable it, and --enable-ptrauth without the required caps will result in an unhelpful "Unable to initialise vcpu" error message. I'm not sure this is a whole lot worse than the way other options behave today, though. You could try to be more explicit about what happens in these cases, but I'm not sure it's worth it given the state of the existing code. [...] Cheers ---Dave _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 CB581C10F13 for ; Tue, 16 Apr 2019 16:32:40 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 9BB9020821 for ; Tue, 16 Apr 2019 16:32:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="vAGL4TLu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BB9020821 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=mAgLDmzijSeuL53N89o4+ENxvBZYDxdk0NBhp05m+fQ=; b=vAGL4TLukktXpm bPtqlSQ5WZhWpsbGXJjXiY03mnxCXrlHO0ClCbQRtHhJ83lUvDlEv25sQjzJUx96VgKcjjTwWWhHo 02z2Z+M9/5or+pr7ChlpG6OfPA7HoURLoNIDLCCEvbl/XdWh/6aqdWgxjxbDQMcAwaeaVHtoLd763 OhBDLhx2mJwsjxCXZmTbvnOZefMz/1ltLWySNI6VmCvMVEM1IdKt6PVcA1y9pk1S4HdiAdwIWHQPK kL7tHsHAPMleOZD+kUuyMGp1BMmJFG/h8ZA/8wHcM/ytjPL9kv7A0qcbJFpzUAWuFBGkzzuMptslz rZzWwVVtfcu2WXq8vszw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hGR0b-0004Y3-IH; Tue, 16 Apr 2019 16:32:33 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hGR0T-0004RP-UJ for linux-arm-kernel@lists.infradead.org; Tue, 16 Apr 2019 16:32:27 +0000 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 C8CA380D; Tue, 16 Apr 2019 09:32:25 -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 2B2C43F59C; Tue, 16 Apr 2019 09:32:24 -0700 (PDT) Date: Tue, 16 Apr 2019 17:32:21 +0100 From: Dave Martin To: Amit Daniel Kachhap Subject: Re: [kvmtool PATCH v9 5/5] KVM: arm/arm64: Add a vcpu feature for pointer authentication Message-ID: <20190416163221.GY3567@e103592.cambridge.arm.com> References: <1555039236-10608-1-git-send-email-amit.kachhap@arm.com> <1555039236-10608-6-git-send-email-amit.kachhap@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1555039236-10608-6-git-send-email-amit.kachhap@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190416_093226_109158_10405551 X-CRM114-Status: GOOD ( 23.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 12, 2019 at 08:50:36AM +0530, Amit Daniel Kachhap wrote: > This patch adds a runtime capabality for KVM tool to enable Arm64 8.3 > Pointer Authentication in guest kernel. Two vcpu features > KVM_ARM_VCPU_PTRAUTH_[ADDRESS/GENERIC] are supplied together to enable > Pointer Authentication in KVM guest after checking the capability. > > Command line options --enable-ptrauth and --disable-ptrauth are added > to use this feature. However, if those options are not provided then > also this feature is enabled if host supports this capability. > > The macros defined in the headers are not in sync and should be replaced > from the upstream. > > Signed-off-by: Amit Daniel Kachhap > --- > Changes since v8: > * Added option --enable-ptrauth and --disable-ptrauth to use ptrauth. Also > enable ptrauth if no option provided and Host supports ptrauth. [Dave Martin] > * The macro definition are not linear as the kvmtool is not synchronised with the > kernel changes present in kvmarm/next tree. > > arm/aarch32/include/kvm/kvm-cpu-arch.h | 1 + > arm/aarch64/include/asm/kvm.h | 2 ++ > arm/aarch64/include/kvm/kvm-config-arch.h | 6 +++++- > arm/aarch64/include/kvm/kvm-cpu-arch.h | 2 ++ > arm/include/arm-common/kvm-config-arch.h | 2 ++ > arm/kvm-cpu.c | 11 +++++++++++ > include/linux/kvm.h | 2 ++ > 7 files changed, 25 insertions(+), 1 deletion(-) > > diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h > index d28ea67..520ea76 100644 > --- a/arm/aarch32/include/kvm/kvm-cpu-arch.h > +++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h > @@ -13,4 +13,5 @@ > #define ARM_CPU_ID 0, 0, 0 > #define ARM_CPU_ID_MPIDR 5 > > +#define ARM_VCPU_PTRAUTH_FEATURE 0 > #endif /* KVM__KVM_CPU_ARCH_H */ > diff --git a/arm/aarch64/include/asm/kvm.h b/arm/aarch64/include/asm/kvm.h > index 97c3478..a2546e6 100644 > --- a/arm/aarch64/include/asm/kvm.h > +++ b/arm/aarch64/include/asm/kvm.h > @@ -102,6 +102,8 @@ struct kvm_regs { > #define KVM_ARM_VCPU_EL1_32BIT 1 /* CPU running a 32bit VM */ > #define KVM_ARM_VCPU_PSCI_0_2 2 /* CPU uses PSCI v0.2 */ > #define KVM_ARM_VCPU_PMU_V3 3 /* Support guest PMUv3 */ > +#define KVM_ARM_VCPU_PTRAUTH_ADDRESS 5 /* CPU uses address pointer authentication */ > +#define KVM_ARM_VCPU_PTRAUTH_GENERIC 6 /* CPU uses generic pointer authentication */ > > struct kvm_vcpu_init { > __u32 target; > diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h b/arm/aarch64/include/kvm/kvm-config-arch.h > index 04be43d..0279b13 100644 > --- a/arm/aarch64/include/kvm/kvm-config-arch.h > +++ b/arm/aarch64/include/kvm/kvm-config-arch.h > @@ -8,7 +8,11 @@ > "Create PMUv3 device"), \ > OPT_U64('\0', "kaslr-seed", &(cfg)->kaslr_seed, \ > "Specify random seed for Kernel Address Space " \ > - "Layout Randomization (KASLR)"), > + "Layout Randomization (KASLR)"), \ > + OPT_BOOLEAN('\0', "enable-ptrauth", &(cfg)->enable_ptrauth, \ > + "Enables pointer authentication"), \ > + OPT_BOOLEAN('\0', "disable-ptrauth", &(cfg)->disable_ptrauth, \ > + "Disables pointer authentication"), > > #include "arm-common/kvm-config-arch.h" > > diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h b/arm/aarch64/include/kvm/kvm-cpu-arch.h > index a9d8563..fcc2107 100644 > --- a/arm/aarch64/include/kvm/kvm-cpu-arch.h > +++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h > @@ -17,4 +17,6 @@ > #define ARM_CPU_CTRL 3, 0, 1, 0 > #define ARM_CPU_CTRL_SCTLR_EL1 0 > > +#define ARM_VCPU_PTRAUTH_FEATURE ((1UL << KVM_ARM_VCPU_PTRAUTH_ADDRESS) \ > + | (1UL << KVM_ARM_VCPU_PTRAUTH_GENERIC)) > #endif /* KVM__KVM_CPU_ARCH_H */ > diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h > index 5734c46..1b4287d 100644 > --- a/arm/include/arm-common/kvm-config-arch.h > +++ b/arm/include/arm-common/kvm-config-arch.h > @@ -10,6 +10,8 @@ struct kvm_config_arch { > bool aarch32_guest; > bool has_pmuv3; > u64 kaslr_seed; > + bool enable_ptrauth; > + bool disable_ptrauth; > enum irqchip_type irqchip; > u64 fw_addr; > }; > diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c > index 7780251..a45a649 100644 > --- a/arm/kvm-cpu.c > +++ b/arm/kvm-cpu.c > @@ -69,6 +69,17 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id) > } > > /* > + * Always enable Pointer Authentication if requested. If system supports > + * this extension then also enable it by default provided no disable > + * request present. > + */ > + if ((kvm->cfg.arch.enable_ptrauth) || Nit: redundant () > + (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) && Funny indentation? > + kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC) && > + !kvm->cfg.arch.disable_ptrauth)) > + vcpu_init.features[0] |= ARM_VCPU_PTRAUTH_FEATURE; > + Hmm, we have some weird behaviours here: --enable-ptrauth --disable-ptrauth will result in us trying to enable it, and --enable-ptrauth without the required caps will result in an unhelpful "Unable to initialise vcpu" error message. I'm not sure this is a whole lot worse than the way other options behave today, though. You could try to be more explicit about what happens in these cases, but I'm not sure it's worth it given the state of the existing code. [...] Cheers ---Dave _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel