KVM: x86: check against irqchip_mode in pic_in_kernel()

Let's avoid checking against kvm->arch.vpic. We have kvm->arch.irqchip_mode
for that now.

KVM_IRQCHIP_KERNEL implies a fully inititalized pic, while kvm->arch.vpic
might temporarily be set but invalidated again if e.g. kvm_ioapic_init()
fails when setting KVM_CREATE_IRQCHIP. Although current users seem to be
fine, this avoids future bugs.

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

diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 59e05febc8fb8ecb51d6c5c022bdb2751f500f1d..26d8dd4a4323f6dbd04ac1fa102b7f043051de2d 100644 (file)
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -85,10 +85,11 @@ static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
 
 static inline int pic_in_kernel(struct kvm *kvm)
 {
-       int ret;
+       int mode = kvm->arch.irqchip_mode;
 
-       ret = (pic_irqchip(kvm) != NULL);
-       return ret;
+       /* Matches smp_wmb() when setting irqchip_mode */
+       smp_rmb();
+       return mode == KVM_IRQCHIP_KERNEL;
 }
 
 static inline int irqchip_split(struct kvm *kvm)