From 466d27e48d7cd2542710309817cff1e91cd2e10a Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 30 Nov 2022 23:09:00 +0000 Subject: [PATCH] KVM: arm64: Simplify the CPUHP logic For a number of historical reasons, the KVM/arm64 hotplug setup is pretty complicated, and we have two extra CPUHP notifiers for vGIC and timers. It looks pretty pointless, and gets in the way of further changes. So let's just expose some helpers that can be called from the core CPUHP callback, and get rid of everything else. This gives us the opportunity to drop a useless notifier entry, as well as tidy-up the timer enable/disable, which was a bit odd. Signed-off-by: Marc Zyngier Signed-off-by: Isaku Yamahata Signed-off-by: Sean Christopherson Message-Id: <20221130230934.1014142-17-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/arm64/kvm/arch_timer.c | 27 ++++++++++----------------- arch/arm64/kvm/arm.c | 13 +++++++++++++ arch/arm64/kvm/vgic/vgic-init.c | 19 ++----------------- include/kvm/arm_arch_timer.h | 4 ++++ include/kvm/arm_vgic.h | 4 ++++ include/linux/cpuhotplug.h | 3 --- 6 files changed, 33 insertions(+), 37 deletions(-) diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index bb24a76..33fca1a 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -811,10 +811,18 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) ptimer->host_timer_irq_flags = host_ptimer_irq_flags; } -static void kvm_timer_init_interrupt(void *info) +void kvm_timer_cpu_up(void) { enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags); - enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags); + if (host_ptimer_irq) + enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags); +} + +void kvm_timer_cpu_down(void) +{ + disable_percpu_irq(host_vtimer_irq); + if (host_ptimer_irq) + disable_percpu_irq(host_ptimer_irq); } int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) @@ -976,18 +984,6 @@ void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu, preempt_enable(); } -static int kvm_timer_starting_cpu(unsigned int cpu) -{ - kvm_timer_init_interrupt(NULL); - return 0; -} - -static int kvm_timer_dying_cpu(unsigned int cpu) -{ - disable_percpu_irq(host_vtimer_irq); - return 0; -} - static int timer_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu) { if (vcpu) @@ -1185,9 +1181,6 @@ int kvm_timer_hyp_init(bool has_gic) goto out_free_irq; } - cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING, - "kvm/arm/timer:starting", kvm_timer_starting_cpu, - kvm_timer_dying_cpu); return 0; out_free_irq: free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus()); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e6c21b8..b572c78 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1677,7 +1677,15 @@ static void _kvm_arch_hardware_enable(void *discard) int kvm_arch_hardware_enable(void) { + int was_enabled = __this_cpu_read(kvm_arm_hardware_enabled); + _kvm_arch_hardware_enable(NULL); + + if (!was_enabled) { + kvm_vgic_cpu_up(); + kvm_timer_cpu_up(); + } + return 0; } @@ -1691,6 +1699,11 @@ static void _kvm_arch_hardware_disable(void *discard) void kvm_arch_hardware_disable(void) { + if (__this_cpu_read(kvm_arm_hardware_enabled)) { + kvm_timer_cpu_down(); + kvm_vgic_cpu_down(); + } + if (!is_protected_kvm_enabled()) _kvm_arch_hardware_disable(NULL); } diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index f6d4f40..6c7f6ae 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -465,17 +465,15 @@ out: /* GENERIC PROBE */ -static int vgic_init_cpu_starting(unsigned int cpu) +void kvm_vgic_cpu_up(void) { enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0); - return 0; } -static int vgic_init_cpu_dying(unsigned int cpu) +void kvm_vgic_cpu_down(void) { disable_percpu_irq(kvm_vgic_global_state.maint_irq); - return 0; } static irqreturn_t vgic_maintenance_handler(int irq, void *data) @@ -584,19 +582,6 @@ int kvm_vgic_hyp_init(void) return ret; } - ret = cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING, - "kvm/arm/vgic:starting", - vgic_init_cpu_starting, vgic_init_cpu_dying); - if (ret) { - kvm_err("Cannot register vgic CPU notifier\n"); - goto out_free_irq; - } - kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq); return 0; - -out_free_irq: - free_percpu_irq(kvm_vgic_global_state.maint_irq, - kvm_get_running_vcpus()); - return ret; } diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index cd6d8f2..1638418 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -104,4 +104,8 @@ void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu, u32 timer_get_ctl(struct arch_timer_context *ctxt); u64 timer_get_cval(struct arch_timer_context *ctxt); +/* CPU HP callbacks */ +void kvm_timer_cpu_up(void); +void kvm_timer_cpu_down(void); + #endif diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 9270cd8..0629e35 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -432,4 +432,8 @@ int vgic_v4_load(struct kvm_vcpu *vcpu); void vgic_v4_commit(struct kvm_vcpu *vcpu); int vgic_v4_put(struct kvm_vcpu *vcpu, bool need_db); +/* CPU HP callbacks */ +void kvm_vgic_cpu_up(void); +void kvm_vgic_cpu_down(void); + #endif /* __KVM_ARM_VGIC_H */ diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 6c6859b..5cae6bd 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -188,9 +188,6 @@ enum cpuhp_state { CPUHP_AP_TI_GP_TIMER_STARTING, CPUHP_AP_HYPERV_TIMER_STARTING, CPUHP_AP_KVM_STARTING, - CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING, - CPUHP_AP_KVM_ARM_VGIC_STARTING, - CPUHP_AP_KVM_ARM_TIMER_STARTING, /* Must be the last timer callback */ CPUHP_AP_DUMMY_TIMER_STARTING, CPUHP_AP_ARM_XEN_STARTING, -- 2.7.4