diff options
Diffstat (limited to 'arch/x86/kvm/irq.c')
| -rw-r--r-- | arch/x86/kvm/irq.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c new file mode 100644 index 000000000..f371f1292 --- /dev/null +++ b/arch/x86/kvm/irq.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * irq.c: API for in kernel interrupt controller + * Copyright (c) 2007, Intel Corporation. + * Copyright 2009 Red Hat, Inc. and/or its affiliates. + * + * Authors: + * Yaozu (Eddie) Dong <Eddie.dong@intel.com> + */ + +#include <linux/export.h> +#include <linux/kvm_host.h> + +#include "irq.h" +#include "i8254.h" +#include "x86.h" +#include "xen.h" + +/* + * check if there are pending timer events + * to be processed. + */ +int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) +{ + int r = 0; + + if (lapic_in_kernel(vcpu)) + r = apic_has_pending_timer(vcpu); + if (kvm_xen_timer_enabled(vcpu)) + r += kvm_xen_has_pending_timer(vcpu); + + return r; +} +EXPORT_SYMBOL(kvm_cpu_has_pending_timer); + +/* + * check if there is a pending userspace external interrupt + */ +static int pending_userspace_extint(struct kvm_vcpu *v) +{ + return v->arch.pending_external_vector != -1; +} + +/* + * check if there is pending interrupt from + * non-APIC source without intack. + */ +int kvm_cpu_has_extint(struct kvm_vcpu *v) +{ + /* + * FIXME: interrupt.injected represents an interrupt whose + * side-effects have already been applied (e.g. bit from IRR + * already moved to ISR). Therefore, it is incorrect to rely + * on interrupt.injected to know if there is a pending + * interrupt in the user-mode LAPIC. + * This leads to nVMX/nSVM not be able to distinguish + * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on + * pending interrupt or should re-inject an injected + * interrupt. + */ + if (!lapic_in_kernel(v)) + return v->arch.interrupt.injected; + + if (kvm_xen_has_interrupt(v)) + return 1; + + if (!kvm_apic_accept_pic_intr(v)) + return 0; + + if (irqchip_split(v->kvm)) + return pending_userspace_extint(v); + else + return v->kvm->arch.vpic->output; +} + +/* + * check if there is injectable interrupt: + * when virtual interrupt delivery enabled, + * interrupt from apic will handled by hardware, + * we don't need to check it here. + */ +int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) +{ + if (kvm_cpu_has_extint(v)) + return 1; + + if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v)) + return 0; + + return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ +} +EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr); + +/* + * check if there is pending interrupt without + * intack. + */ +int kvm_cpu_has_interrupt(struct kvm_vcpu *v) +{ + if (kvm_cpu_has_extint(v)) + return 1; + + return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ +} +EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); + +/* + * Read pending interrupt(from non-APIC source) + * vector and intack. + */ +static int kvm_cpu_get_extint(struct kvm_vcpu *v) +{ + if (!kvm_cpu_has_extint(v)) { + WARN_ON(!lapic_in_kernel(v)); + return -1; + } + + if (!lapic_in_kernel(v)) + return v->arch.interrupt.nr; + + if (kvm_xen_has_interrupt(v)) + return v->kvm->arch.xen.upcall_vector; + + if (irqchip_split(v->kvm)) { + int vector = v->arch.pending_external_vector; + + v->arch.pending_external_vector = -1; + return vector; + } else + return kvm_pic_read_irq(v->kvm); /* PIC */ +} + +/* + * Read pending interrupt vector and intack. + */ +int kvm_cpu_get_interrupt(struct kvm_vcpu *v) +{ + int vector = kvm_cpu_get_extint(v); + if (vector != -1) + return vector; /* PIC */ + + return kvm_get_apic_interrupt(v); /* APIC */ +} +EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt); + +void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu) +{ + if (lapic_in_kernel(vcpu)) + kvm_inject_apic_timer_irqs(vcpu); + if (kvm_xen_timer_enabled(vcpu)) + kvm_xen_inject_timer_irqs(vcpu); +} +EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs); + +void __kvm_migrate_timers(struct kvm_vcpu *vcpu) +{ + __kvm_migrate_apic_timer(vcpu); + __kvm_migrate_pit_timer(vcpu); + static_call_cond(kvm_x86_migrate_timers)(vcpu); +} + +bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) +{ + bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE; + + return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm); +} |