KVM: convert bus to slots_lock

Use slots_lock to protect device list on the bus.  slots_lock is already
taken for read everywhere, so we only need to take it for write when
registering devices.  This is in preparation to removing in_range and
kvm->lock around it.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index bcd00c76d69..4082cdd468e 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -583,6 +583,7 @@ static const struct kvm_io_device_ops speaker_dev_ops = {
         .in_range = speaker_in_range,
 };
 
+/* Caller must have writers lock on slots_lock */
 struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags)
 {
         struct kvm_pit *pit;
@@ -621,11 +622,11 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags)
         kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
 
         kvm_iodevice_init(&pit->dev, &pit_dev_ops);
-        kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev);
+        __kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev);
 
         if (flags & KVM_PIT_SPEAKER_DUMMY) {
                 kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops);
-                kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev);
+                __kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev);
         }
 
         return pit;