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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 07AC3C38A2A for ; Thu, 7 May 2020 14:22:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E288E2075E for ; Thu, 7 May 2020 14:22:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726627AbgEGOWl (ORCPT ); Thu, 7 May 2020 10:22:41 -0400 Received: from foss.arm.com ([217.140.110.172]:60562 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725914AbgEGOWk (ORCPT ); Thu, 7 May 2020 10:22:40 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id F3F41D6E; Thu, 7 May 2020 07:22:39 -0700 (PDT) Received: from [10.163.73.155] (unknown [10.163.73.155]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D8ED23F68F; Thu, 7 May 2020 07:22:36 -0700 (PDT) From: Anshuman Khandual Subject: Re: [PATCH] arm64/cpufeature: Verify KVM capabilities during CPU hotplug To: Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Mark Rutland , James Morse , Suzuki K Poulose , kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org References: <1588832387-8489-1-git-send-email-anshuman.khandual@arm.com> <20200507112028.4a5cc279@why> Message-ID: <5f75d3e5-df3a-0570-4cb1-37826b9099d8@arm.com> Date: Thu, 7 May 2020 19:52:06 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200507112028.4a5cc279@why> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/07/2020 03:50 PM, Marc Zyngier wrote: > On Thu, 7 May 2020 11:49:47 +0530 > Anshuman Khandual wrote: > > Hi Anshuman, Hi Marc, > >> This validates KVM capabilities like VMID width, IPA range for hotplug CPU >> against system finalized values. While here, it factors out get_vmid_bits() >> for general use and also defines ID_AA64MMFR0_PARANGE_MASK. > > nit: these are not KVM-specific capabilities, but general > virtualization features. Sure, will change as (s/kvm/hyp) instead and update the commit message here. > >> >> Cc: Catalin Marinas >> Cc: Will Deacon >> Cc: Marc Zyngier >> Cc: Mark Rutland >> Cc: James Morse >> Cc: Suzuki K Poulose >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: kvmarm@lists.cs.columbia.edu >> Cc: linux-kernel@vger.kernel.org >> >> Suggested-by: Suzuki Poulose >> Signed-off-by: Anshuman Khandual >> --- >> arch/arm64/include/asm/cpufeature.h | 22 +++++++++++++++++++ >> arch/arm64/include/asm/kvm_mmu.h | 2 +- >> arch/arm64/include/asm/sysreg.h | 1 + >> arch/arm64/kernel/cpufeature.c | 2 ++ >> arch/arm64/kvm/reset.c | 33 +++++++++++++++++++++++++++-- >> 5 files changed, 57 insertions(+), 3 deletions(-) >> >> diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h >> index afe08251ff95..6808a2091de4 100644 >> --- a/arch/arm64/include/asm/cpufeature.h >> +++ b/arch/arm64/include/asm/cpufeature.h >> @@ -745,6 +745,28 @@ static inline bool cpu_has_hw_af(void) >> extern bool cpu_has_amu_feat(int cpu); >> #endif >> >> +static inline unsigned int get_vmid_bits(u64 mmfr1) >> +{ >> + int vmid_bits; >> + >> + vmid_bits = cpuid_feature_extract_unsigned_field(mmfr1, >> + ID_AA64MMFR1_VMIDBITS_SHIFT); >> + if (vmid_bits == ID_AA64MMFR1_VMIDBITS_16) >> + return 16; >> + >> + /* >> + * Return the default here even if any reserved >> + * value is fetched from the system register. >> + */ >> + return 8; >> +} >> + >> +#ifdef CONFIG_KVM_ARM_HOST >> +void verify_kvm_capabilities(void); >> +#else >> +static inline void verify_kvm_capabilities(void) { } >> +#endif >> + >> #endif /* __ASSEMBLY__ */ >> >> #endif >> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h >> index 30b0e8d6b895..a7137e144b97 100644 >> --- a/arch/arm64/include/asm/kvm_mmu.h >> +++ b/arch/arm64/include/asm/kvm_mmu.h >> @@ -416,7 +416,7 @@ static inline unsigned int kvm_get_vmid_bits(void) >> { >> int reg = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); >> >> - return (cpuid_feature_extract_unsigned_field(reg, >> ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8; >> + return get_vmid_bits(reg); >> } >> >> /* >> diff --git a/arch/arm64/include/asm/sysreg.h >> b/arch/arm64/include/asm/sysreg.h index c4ac0ac25a00..3510a4668970 >> 100644 --- a/arch/arm64/include/asm/sysreg.h >> +++ b/arch/arm64/include/asm/sysreg.h >> @@ -705,6 +705,7 @@ >> #define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1 >> #define ID_AA64MMFR0_PARANGE_48 0x5 >> #define ID_AA64MMFR0_PARANGE_52 0x6 >> +#define ID_AA64MMFR0_PARANGE_MASK 0x7 >> >> #ifdef CONFIG_ARM64_PA_BITS_52 >> #define ID_AA64MMFR0_PARANGE_MAX ID_AA64MMFR0_PARANGE_52 >> diff --git a/arch/arm64/kernel/cpufeature.c >> b/arch/arm64/kernel/cpufeature.c index 9fac745aa7bb..041dd610b0f8 >> 100644 --- a/arch/arm64/kernel/cpufeature.c >> +++ b/arch/arm64/kernel/cpufeature.c >> @@ -2206,6 +2206,8 @@ static void verify_local_cpu_capabilities(void) >> >> if (system_supports_sve()) >> verify_sve_features(); >> + >> + verify_kvm_capabilities(); > > You should only check this if booted at EL2. Otherwise, it doesn't > really matter. Sure, will first check on is_hyp_mode_available() before calling into verify_kvm_capabilities(). > >> } >> >> void check_local_cpu_capabilities(void) >> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c >> index 30b7ea680f66..1eebcc2a8396 100644 >> --- a/arch/arm64/kvm/reset.c >> +++ b/arch/arm64/kvm/reset.c >> @@ -340,11 +340,39 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) >> return ret; >> } >> >> +void verify_kvm_capabilities(void) > > This is really in the wrong file. reset.c is supposed to contain things > that are meaningful to the guest reset state. This clearly isn't. I'd > suggest you add an accessor for the kvm_ipa_limit variable, and keep > the function next to the other verify_* functions in cpufeature.c. Sure, will do.