2 files changed, 15 insertions, 1 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8091a4d90ddf..eafabd5c66b2 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -307,6 +307,7 @@ struct kvm_assigned_dev_kernel {
         int host_busnr;
         int host_devfn;
         int host_irq;
+        bool host_irq_disabled;
         int guest_irq;
         struct msi_msg guest_msi;
 #define KVM_ASSIGNED_DEV_GUEST_INTX     (1 << 0)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index eb70ca6c7145..fc6127cbea1f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -170,6 +170,7 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
                                 KVM_ASSIGNED_DEV_GUEST_MSI) {
                 assigned_device_msi_dispatch(assigned_dev);
                 enable_irq(assigned_dev->host_irq);
+                assigned_dev->host_irq_disabled = false;
         }
         mutex_unlock(&assigned_dev->kvm->lock);
         kvm_put_kvm(assigned_dev->kvm);
@@ -181,8 +182,12 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
                 (struct kvm_assigned_dev_kernel *) dev_id;
 
         kvm_get_kvm(assigned_dev->kvm);
+
         schedule_work(&assigned_dev->interrupt_work);
+
         disable_irq_nosync(irq);
+        assigned_dev->host_irq_disabled = true;
+
         return IRQ_HANDLED;
 }
 
@@ -196,8 +201,16 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
 
         dev = container_of(kian, struct kvm_assigned_dev_kernel,
                            ack_notifier);
+
         kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
-        enable_irq(dev->host_irq);
+
+        /* The guest irq may be shared so this ack may be
+         * from another device.
+         */
+        if (dev->host_irq_disabled) {
+                enable_irq(dev->host_irq);
+                dev->host_irq_disabled = false;
+        }
 }
 
 static void kvm_free_assigned_irq(struct kvm *kvm,