KVM: x86: check against irqchip_mode in ioapic_in_kernel()

KVM_IRQCHIP_KERNEL implies a fully inititalized ioapic, while
kvm->arch.vioapic might temporarily be set but invalidated again if e.g.
setting of default routing fails when setting KVM_CREATE_IRQCHIP.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
index 1cc6e54..d88e4b9 100644 (file)
--- a/arch/x86/kvm/ioapic.h
+++ b/arch/x86/kvm/ioapic.h
@@ -112,10 +112,11 @@ static inline struct kvm_ioapic *ioapic_irqchip(struct kvm *kvm)
 
 static inline int ioapic_in_kernel(struct kvm *kvm)
 {
-       int ret;
+       int mode = kvm->arch.irqchip_mode;
 
-       ret = (ioapic_irqchip(kvm) != NULL);
-       return ret;
+       /* Matches smp_wmb() when setting irqchip_mode */
+       smp_rmb();
+       return mode == KVM_IRQCHIP_KERNEL;
 }
 
 void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu);