3 files changed, 17 insertions, 0 deletions

diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index faa264822cee..007bc654f928 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -172,3 +172,10 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
         __kvm_migrate_apic_timer(vcpu);
         __kvm_migrate_pit_timer(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);
+}
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index d5005cc26521..fd210cdd4983 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -114,6 +114,7 @@ static inline int irqchip_in_kernel(struct kvm *kvm)
         return mode != KVM_IRQCHIP_NONE;
 }
 
+bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu);
 void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu);
 void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 001aeda4c154..3972a9564c76 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -44,6 +44,12 @@
 
 static struct workqueue_struct *irqfd_cleanup_wq;
 
+bool __attribute__((weak))
+kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
+{
+        return true;
+}
+
 static void
 irqfd_inject(struct work_struct *work)
 {
@@ -297,6 +303,9 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
         if (!kvm_arch_intc_initialized(kvm))
                 return -EAGAIN;
 
+        if (!kvm_arch_irqfd_allowed(kvm, args))
+                return -EINVAL;
+
         irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL_ACCOUNT);
         if (!irqfd)
                 return -ENOMEM;