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,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 3D63AC10F11 for ; Wed, 24 Apr 2019 13:41:36 +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 0A47D21773 for ; Wed, 24 Apr 2019 13:41:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ljo2IO3t" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0A47D21773 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=/34/9itSu3nC6skgKjF4uKLm7hW091hEKX0U5NqP/Tg=; b=ljo2IO3tfcoMhg WIM6RUtV3JMQcOfUWFZ1taS5Rr/f2XuehllO076ftaURlAWjOimfYHtXTl3q4RvDw74iTuxaqBnFf TDvAhcIIxulX+Rmv/MwnMyk3pcXoRYVgtvctmRalgEiMvBhkECnuvQscMMNNhZm9/t+ldBFKQdZFB 4WZPfIMHu10BpYrQ5scxKUvu2dUja+1fH2d85iT/GNHMaepiPtKaKTaAVdoWu+b7xn+khDBKcEZvU S5somsiPz21SwYn/KKUyBHARtX0yVyj6Da3RqYBkX9TgdM/EIRZanjacu+HmSLj259VETAYwr5bXH n1r37PMuvrNmzNiOXd+A==; 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 1hJI9Q-0001zL-Rb; Wed, 24 Apr 2019 13:41:28 +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 1hJI9N-0001yo-KG for linux-arm-kernel@lists.infradead.org; Wed, 24 Apr 2019 13:41:27 +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 539E880D; Wed, 24 Apr 2019 06:41:25 -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 993723F238; Wed, 24 Apr 2019 06:41:23 -0700 (PDT) Date: Wed, 24 Apr 2019 14:41:21 +0100 From: Dave Martin To: Amit Daniel Kachhap Subject: Re: [kvmtool PATCH v10 5/5] KVM: arm/arm64: Add a vcpu feature for pointer authentication Message-ID: <20190424134120.GW3567@e103592.cambridge.arm.com> References: <1555994558-26349-1-git-send-email-amit.kachhap@arm.com> <1555994558-26349-6-git-send-email-amit.kachhap@arm.com> <20190423154625.GP3567@e103592.cambridge.arm.com> <3b7bafc9-5d6a-7845-ef1f-577ea59000e2@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3b7bafc9-5d6a-7845-ef1f-577ea59000e2@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-20190424_064125_679510_19B73334 X-CRM114-Status: GOOD ( 28.02 ) 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 Wed, Apr 24, 2019 at 12:32:22PM +0530, Amit Daniel Kachhap wrote: > Hi, > > On 4/23/19 9:16 PM, Dave Martin wrote: > >On Tue, Apr 23, 2019 at 10:12:38AM +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 v9: > >>* Added a error check for both enable-ptrauth and disable-ptrauth > >> option. > >>* Make the error explicit when enable-ptrauth is provided [Dave Martin]. > >> > >> 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 | 20 ++++++++++++++++++-- > >> include/linux/kvm.h | 2 ++ > >> 7 files changed, 32 insertions(+), 3 deletions(-) > >> > >>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..acd1d5f 100644 > >>--- a/arm/kvm-cpu.c > >>+++ b/arm/kvm-cpu.c > >>@@ -68,6 +68,18 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id) > >> vcpu_init.features[0] |= (1UL << KVM_ARM_VCPU_PSCI_0_2); > >> } > >>+ /* Check Pointer Authentication command line arguments. */ > >>+ if (kvm->cfg.arch.enable_ptrauth && kvm->cfg.arch.disable_ptrauth) > >>+ die("Both enable-ptrauth and disable-ptrauth option cannot be present"); > > > >Preferably, print the leading dashes, the same as the user would see > >on the command line (e.g., --enable-ptrauth, --disable-ptrauth). > > > >For brevity, we could write something like: > > > > die("--enable-ptrauth conflicts with --disable-ptrauth"); > > > >>+ /* > >>+ * Always enable Pointer Authentication if system supports > >>+ * this extension unless disable-ptrauth option is present. > >>+ */ > >>+ if (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) && > >>+ kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC) && > >>+ !kvm->cfg.arch.disable_ptrauth) > >>+ vcpu_init.features[0] |= ARM_VCPU_PTRAUTH_FEATURE; > >>+ > >> /* > >> * If the preferred target ioctl is successful then > >> * use preferred target else try each and every target type > >>@@ -106,8 +118,12 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id) > >> die("Unable to find matching target"); > >> } > >>- if (err || target->init(vcpu)) > >>- die("Unable to initialise vcpu"); > >>+ if (err || target->init(vcpu)) { > >>+ if (kvm->cfg.arch.enable_ptrauth) > >>+ die("Unable to initialise vcpu with pointer authentication feature"); > > > >We don't special-case this error message for any other feature yet: > >there are a variety of reasons why we might have failed, so suggesting > >that the failure is something to do with ptrauth may be misleading to > >the user. > > > >If we want to be more informative, we could do something like the > >following: > > > > bool supported; > > > > supported = kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) && > > kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC); > > > > if (kvm->cfg.arch.enable_ptrauth && !supported) > > die("--enable-ptrauth not supported on this host"); > > > > if (supported && !kvm->cfg.arch.disable_ptrauth) > > vcpu_init.features[0] |= ARM_VCPU_PTRAUTH_FEATURE; > > > > /* ... */ > > > > if (err || target->init(vcpu)) > > die("Unable to initialise vcpu"); > > > >We don't do this for any other feature today, but since it helps the > >user to understand what went wrong it's probably a good idea. > Yes this is more clear. As Mark has picked the core guest ptrauth patches. I > will post this changes as standalone. Sounds good. (I also need to do that separately for SVE...) Cheers ---Dave _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel