KVM: Add proper lockdep assertion in I/O bus unregister

Convert a comment above kvm_io_bus_unregister_dev() into an actual
lockdep assertion, and opportunistically add curly braces to a multi-line
for-loop.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210412222050.876100-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f84b126..545a283 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4620,21 +4620,23 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
        return 0;
 }
 
-/* Caller must hold slots_lock. */
 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
                              struct kvm_io_device *dev)
 {
        int i, j;
        struct kvm_io_bus *new_bus, *bus;
 
+       lockdep_assert_held(&kvm->slots_lock);
+
        bus = kvm_get_bus(kvm, bus_idx);
        if (!bus)
                return 0;
 
-       for (i = 0; i < bus->dev_count; i++)
+       for (i = 0; i < bus->dev_count; i++) {
                if (bus->range[i].dev == dev) {
                        break;
                }
+       }
 
        if (i == bus->dev_count)
                return 0;