KVM: don't free an unallocated irq source id

Set assigned_dev->irq_source_id to -1 so that we can avoid freeing
a source ID which we never allocated.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8dab7cedd50b..63fd88209439 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -210,7 +210,10 @@ static void kvm_free_assigned_device(struct kvm *kvm,
                 pci_disable_msi(assigned_dev->dev);
 
         kvm_unregister_irq_ack_notifier(&assigned_dev->ack_notifier);
-        kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
+
+        if (assigned_dev->irq_source_id != -1)
+                kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
+        assigned_dev->irq_source_id = -1;
 
         if (cancel_work_sync(&assigned_dev->interrupt_work))
                 /* We had pending work. That means we will have to take
@@ -466,7 +469,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
         match->host_busnr = assigned_dev->busnr;
         match->host_devfn = assigned_dev->devfn;
         match->dev = dev;
-
+        match->irq_source_id = -1;
         match->kvm = kvm;
 
         list_add(&match->list, &kvm->arch.assigned_dev_head);