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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 3FC23C4320A for ; Thu, 12 Aug 2021 05:09:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E87960FED for ; Thu, 12 Aug 2021 05:09:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234264AbhHLFJz (ORCPT ); Thu, 12 Aug 2021 01:09:55 -0400 Received: from foss.arm.com ([217.140.110.172]:37672 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234268AbhHLFJx (ORCPT ); Thu, 12 Aug 2021 01:09:53 -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 2CF281042; Wed, 11 Aug 2021 22:09:29 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.68.17]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 89A413F40C; Wed, 11 Aug 2021 22:09:25 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org Cc: Anshuman Khandual , Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Subject: [PATCH V2 4/5] KVM: arm64: Drop check_kvm_target_cpu() based percpu probe Date: Thu, 12 Aug 2021 10:39:53 +0530 Message-Id: <1628744994-16623-5-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1628744994-16623-1-git-send-email-anshuman.khandual@arm.com> References: <1628744994-16623-1-git-send-email-anshuman.khandual@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kvm_target_cpu() never returns a negative error code, so check_kvm_target() would never have 'ret' filled with a negative error code. Hence the percpu probe via check_kvm_target_cpu() does not make sense as its never going to find an unsupported CPU, forcing kvm_arch_init() to exit early. Hence lets just drop this percpu probe (and also check_kvm_target_cpu()) altogether. While here, this also changes kvm_target_cpu() return type to a u32, making it explicit that an error code will not be returned from this function. Cc: Marc Zyngier Cc: James Morse Cc: Alexandru Elisei Cc: Suzuki K Poulose Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu Cc: linux-kernel@vger.kernel.org Acked-by: Will Deacon Signed-off-by: Anshuman Khandual --- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/kvm/arm.c | 16 +--------------- arch/arm64/kvm/guest.c | 4 ++-- 3 files changed, 4 insertions(+), 18 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 41911585ae0c..26bbd84a02de 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -66,7 +66,7 @@ DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use); extern unsigned int kvm_sve_max_vl; int kvm_arm_init_sve(void); -int __attribute_const__ kvm_target_cpu(void); +u32 __attribute_const__ kvm_target_cpu(void); int kvm_reset_vcpu(struct kvm_vcpu *vcpu); void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 19560e457c11..ee9b1166f330 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1035,7 +1035,7 @@ static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu, const struct kvm_vcpu_init *init) { unsigned int i, ret; - int phys_target = kvm_target_cpu(); + u32 phys_target = kvm_target_cpu(); if (init->target != phys_target) return -EINVAL; @@ -2010,11 +2010,6 @@ static int finalize_hyp_mode(void) return 0; } -static void check_kvm_target_cpu(void *ret) -{ - *(int *)ret = kvm_target_cpu(); -} - struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr) { struct kvm_vcpu *vcpu; @@ -2074,7 +2069,6 @@ void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons) int kvm_arch_init(void *opaque) { int err; - int ret, cpu; bool in_hyp_mode; if (!is_hyp_mode_available()) { @@ -2089,14 +2083,6 @@ int kvm_arch_init(void *opaque) kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \ "Only trusted guests should be used on this system.\n"); - for_each_online_cpu(cpu) { - smp_call_function_single(cpu, check_kvm_target_cpu, &ret, 1); - if (ret < 0) { - kvm_err("Error, CPU %d not supported!\n", cpu); - return -ENODEV; - } - } - err = kvm_set_ipa_limit(); if (err) return err; diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 1dfb83578277..8ce850fa7b49 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -842,7 +842,7 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, return 0; } -int __attribute_const__ kvm_target_cpu(void) +u32 __attribute_const__ kvm_target_cpu(void) { unsigned long implementor = read_cpuid_implementor(); unsigned long part_number = read_cpuid_part_number(); @@ -874,7 +874,7 @@ int __attribute_const__ kvm_target_cpu(void) int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init) { - int target = kvm_target_cpu(); + u32 target = kvm_target_cpu(); if (target < 0) return -ENODEV; -- 2.20.1