Explicitly check for an in-kernel PIC when checking for a pending ExtINT
in the PIC. Effectively swapping the split vs. full irqchip logic will
allow guarding the in-kernel I/O APIC (and PIC) emulation with a Kconfig,
and also makes it more obvious that kvm_pic_read_irq() won't result in a
NULL pointer dereference.
Opportunistically add WARNs in the fallthrough path, mostly to document
that the userspace ExtINT logic is only relevant to split IRQ chips.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/irq.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 97d68d837929..b9b9df00ab77 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -41,6 +41,14 @@ static int pending_userspace_extint(struct kvm_vcpu *v)
return v->arch.pending_external_vector != -1;
}
+static int get_userspace_extint(struct kvm_vcpu *vcpu)
+{
+ int vector = vcpu->arch.pending_external_vector;
+
+ vcpu->arch.pending_external_vector = -1;
+ return vector;
+}
+
/*
* check if there is pending interrupt from
* non-APIC source without intack.
@@ -67,10 +75,11 @@ int kvm_cpu_has_extint(struct kvm_vcpu *v)
if (!kvm_apic_accept_pic_intr(v))
return 0;
- if (irqchip_split(v->kvm))
- return pending_userspace_extint(v);
- else
+ if (pic_in_kernel(v->kvm))
return v->kvm->arch.vpic->output;
+
+ WARN_ON_ONCE(!irqchip_split(v->kvm));
+ return pending_userspace_extint(v);
}
/*
@@ -126,13 +135,11 @@ int kvm_cpu_get_extint(struct kvm_vcpu *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
+ if (pic_in_kernel(v->kvm))
return kvm_pic_read_irq(v->kvm); /* PIC */
+
+ WARN_ON_ONCE(!irqchip_split(v->kvm));
+ return get_userspace_extint(v);
}
EXPORT_SYMBOL_GPL(kvm_cpu_get_extint);
--
2.49.0.1101.gccaa498523-goog
