From patchwork Mon Jan 28 06:58:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Daniel Kachhap X-Patchwork-Id: 10783355 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6EFB51390 for ; Mon, 28 Jan 2019 07:00:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5A5DA2A40F for ; Mon, 28 Jan 2019 07:00:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4E7E42A411; Mon, 28 Jan 2019 07:00:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id ADA192A40F for ; Mon, 28 Jan 2019 07:00:30 +0000 (UTC) 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:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=5ngtO7wjlL0skZNOavShPRtCSARMIOktBrlHPHeZN6g=; b=gd3ml+PqtVsEaat27vErAofNOQ QKR1ykr/vtyoYmZel7CGq5qOFRxHYiQ5oOOvVyM/2zFYlc88Ja28Mw92gx6HIzdtTvxInAsWuXvgk vGBz4r/q2qtSIvcTydX6iyLkIJnNB87ZkuS2/xEW9NE73z/Xu42tA9SyhtEEaSZnFamE5Qmz7sM13 k+PhoFs4Tj5o1EHUnBNTKs2YSi8R9kdvEI1m0HmWxwF2RKsSkQwPhYuerfH8zUCwNA2p4jiaKd6kY ImB8Any7T8H48J7V8CDfniqjP5A45o3GYoIUf5saLewQ0Zc16ckyHC1D7gYvKgJUbUbxH8KGJTGJq gmPzaXSQ==; 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 1go0uB-0004wf-QH; Mon, 28 Jan 2019 07:00:27 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1go0tH-0002yE-Kw for linux-arm-kernel@lists.infradead.org; Mon, 28 Jan 2019 06:59:35 +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 A916AA78; Sun, 27 Jan 2019 22:59:30 -0800 (PST) Received: from a075553-lin.blr.arm.com (a075553-lin.blr.arm.com [10.162.0.39]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E8CA43F5AF; Sun, 27 Jan 2019 22:59:26 -0800 (PST) From: Amit Daniel Kachhap To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 4/5] arm64/kvm: add a userspace option to enable pointer authentication Date: Mon, 28 Jan 2019 12:28:45 +0530 Message-Id: <1548658727-14271-5-git-send-email-amit.kachhap@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1548658727-14271-1-git-send-email-amit.kachhap@arm.com> References: <1548658727-14271-1-git-send-email-amit.kachhap@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190127_225932_307798_1FE43A0C X-CRM114-Status: GOOD ( 17.86 ) 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: Mark Rutland , Andrew Jones , Marc Zyngier , Catalin Marinas , Will Deacon , Christoffer Dall , Kristina Martsenko , kvmarm@lists.cs.columbia.edu, Ramana Radhakrishnan , Amit Daniel Kachhap , Dave Martin , linux-kernel@vger.kernel.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This feature will allow the KVM guest to allow the handling of pointer authentication instructions or to treat them as undefined if not set. It uses the existing vcpu API KVM_ARM_VCPU_INIT to supply this parameter instead of creating a new API. A new register is not created to pass this parameter via SET/GET_ONE_REG interface as just a flag (KVM_ARM_VCPU_PTRAUTH) supplied is enough to enable this feature. Signed-off-by: Amit Daniel Kachhap Cc: Mark Rutland Cc: Marc Zyngier Cc: Christoffer Dall Cc: Kristina Martsenko Cc: kvmarm@lists.cs.columbia.edu Cc: Ramana Radhakrishnan Cc: Will Deacon --- Documentation/arm64/pointer-authentication.txt | 9 +++++---- Documentation/virtual/kvm/api.txt | 4 ++++ arch/arm/include/asm/kvm_host.h | 4 ++++ arch/arm64/include/asm/kvm_host.h | 7 ++++--- arch/arm64/include/uapi/asm/kvm.h | 1 + arch/arm64/kvm/handle_exit.c | 3 ++- arch/arm64/kvm/hyp/ptrauth-sr.c | 13 +++++++++++++ arch/arm64/kvm/reset.c | 3 +++ include/uapi/linux/kvm.h | 1 + 9 files changed, 37 insertions(+), 8 deletions(-) diff --git a/Documentation/arm64/pointer-authentication.txt b/Documentation/arm64/pointer-authentication.txt index a25cd21..0529a7d 100644 --- a/Documentation/arm64/pointer-authentication.txt +++ b/Documentation/arm64/pointer-authentication.txt @@ -82,7 +82,8 @@ pointers). Virtualization -------------- -Pointer authentication is not currently supported in KVM guests. KVM -will mask the feature bits from ID_AA64ISAR1_EL1, and attempted use of -the feature will result in an UNDEFINED exception being injected into -the guest. +Pointer authentication is enabled in KVM guest when virtual machine is +created by passing a flag (KVM_ARM_VCPU_PTRAUTH) requesting this feature +to be enabled. Without this flag, pointer authentication is not enabled +in KVM guests and attempted use of the feature will result in an UNDEFINED +exception being injected into the guest. diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 356156f..1e646fb 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2642,6 +2642,10 @@ Possible features: Depends on KVM_CAP_ARM_PSCI_0_2. - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU. Depends on KVM_CAP_ARM_PMU_V3. + - KVM_ARM_VCPU_PTRAUTH: Emulate Pointer authentication for the CPU. + Depends on KVM_CAP_ARM_PTRAUTH and only on arm64 architecture. If + set, then the KVM guest allows the execution of pointer authentication + instructions or treats them as undefined if not set. 4.83 KVM_ARM_PREFERRED_TARGET diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index b200c14..b6950df 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -346,6 +346,10 @@ static inline int kvm_arm_have_ssbd(void) static inline void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) {} static inline void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_vcpu_ptrauth_reset(struct kvm_vcpu *vcpu) {} +static inline bool kvm_arm_vcpu_ptrauth_allowed(struct kvm_vcpu *vcpu) +{ + return false; +} #define __KVM_HAVE_ARCH_VM_ALLOC struct kvm *kvm_arch_alloc_vm(void); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index c798d0c..4a6ec40 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -43,7 +43,7 @@ #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS -#define KVM_VCPU_MAX_FEATURES 4 +#define KVM_VCPU_MAX_FEATURES 5 #define KVM_REQ_SLEEP \ KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) @@ -453,14 +453,15 @@ static inline bool kvm_arch_requires_vhe(void) void kvm_arm_vcpu_ptrauth_enable(struct kvm_vcpu *vcpu); void kvm_arm_vcpu_ptrauth_disable(struct kvm_vcpu *vcpu); +bool kvm_arm_vcpu_ptrauth_allowed(struct kvm_vcpu *vcpu); static inline void kvm_arm_vcpu_ptrauth_reset(struct kvm_vcpu *vcpu) { /* Disable ptrauth and use it in a lazy context via traps */ - if (has_vhe() && kvm_supports_ptrauth()) + if (has_vhe() && kvm_supports_ptrauth() + && kvm_arm_vcpu_ptrauth_allowed(vcpu)) kvm_arm_vcpu_ptrauth_disable(vcpu); } - void kvm_arm_vcpu_ptrauth_trap(struct kvm_vcpu *vcpu); static inline void kvm_arch_hardware_unsetup(void) {} diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index 97c3478..5f82ca1 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -102,6 +102,7 @@ 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 4 /* VCPU uses address authentication */ struct kvm_vcpu_init { __u32 target; diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 5b980e7..c0e5dcd 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -179,7 +179,8 @@ static int handle_sve(struct kvm_vcpu *vcpu, struct kvm_run *run) */ void kvm_arm_vcpu_ptrauth_trap(struct kvm_vcpu *vcpu) { - if (has_vhe() && kvm_supports_ptrauth()) + if (has_vhe() && kvm_supports_ptrauth() + && kvm_arm_vcpu_ptrauth_allowed(vcpu)) kvm_arm_vcpu_ptrauth_enable(vcpu); else kvm_inject_undefined(vcpu); diff --git a/arch/arm64/kvm/hyp/ptrauth-sr.c b/arch/arm64/kvm/hyp/ptrauth-sr.c index 0576c01..369624f 100644 --- a/arch/arm64/kvm/hyp/ptrauth-sr.c +++ b/arch/arm64/kvm/hyp/ptrauth-sr.c @@ -42,3 +42,16 @@ void __no_ptrauth __hyp_text __ptrauth_switch_to_host(struct kvm_vcpu *vcpu, ptrauth_keys_store((struct ptrauth_keys *) &guest_ctxt->sys_regs[APIAKEYLO_EL1]); ptrauth_keys_switch((struct ptrauth_keys *) &host_ctxt->sys_regs[APIAKEYLO_EL1]); } + +/** + * kvm_arm_vcpu_ptrauth_allowed - checks if ptrauth feature is present in vcpu + * + * @vcpu: The VCPU pointer + * + * This function will be used to enable/disable ptrauth in guest as configured + * by the KVM userspace API. + */ +bool kvm_arm_vcpu_ptrauth_allowed(struct kvm_vcpu *vcpu) +{ + return test_bit(KVM_ARM_VCPU_PTRAUTH, vcpu->arch.features); +} diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index b72a3dd..987e0c3c 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -91,6 +91,9 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ARM_VM_IPA_SIZE: r = kvm_ipa_limit; break; + case KVM_CAP_ARM_PTRAUTH: + r = kvm_supports_ptrauth(); + break; default: r = 0; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 6d4ea4b..a553477 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -988,6 +988,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_ARM_VM_IPA_SIZE 165 #define KVM_CAP_MANUAL_DIRTY_LOG_PROTECT 166 #define KVM_CAP_HYPERV_CPUID 167 +#define KVM_CAP_ARM_PTRAUTH 168 #ifdef KVM_CAP_IRQ_ROUTING