From 6b7982fefc1fdcaa31b712f5fbc2e993cc99ad23 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 12 Aug 2021 10:39:53 +0530 Subject: [PATCH] KVM: arm64: Drop check_kvm_target_cpu() based percpu probe 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 Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/1628744994-16623-5-git-send-email-anshuman.khandual@arm.com --- 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 4191158..26bbd84 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 19560e4..ee9b116 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 1dfb835..8ce850f 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; -- 2.7.4