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linux/arch/x86/kvm/irq.c
Sean Christopherson aa9477966a KVM: x86: Fold kvm_get_apic_interrupt() into kvm_cpu_get_interrupt()
Fold kvm_get_apic_interrupt() into kvm_cpu_get_interrupt() now that nVMX
essentially open codes kvm_get_apic_interrupt() in order to correctly
emulate nested posted interrupts.

Opportunistically stop exporting kvm_cpu_get_interrupt(), as the
aforementioned nVMX flow was the only user in vendor code.

Link: https://lore.kernel.org/r/20240906043413.1049633-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-09-09 20:15:01 -07:00

178 lines
3.9 KiB
C

// 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>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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;
}
/*
* 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.
*/
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;
#ifdef CONFIG_KVM_XEN
if (kvm_xen_has_interrupt(v))
return v->kvm->arch.xen.upcall_vector;
#endif
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 */
}
EXPORT_SYMBOL_GPL(kvm_cpu_get_extint);
/*
* 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 */
vector = kvm_apic_has_interrupt(v); /* APIC */
if (vector != -1)
kvm_apic_ack_interrupt(v, vector);
return vector;
}
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);
}
void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
{
__kvm_migrate_apic_timer(vcpu);
__kvm_migrate_pit_timer(vcpu);
kvm_x86_call(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);
}
bool kvm_arch_irqchip_in_kernel(struct kvm *kvm)
{
return irqchip_in_kernel(kvm);
}