KVM: make io_bus interface more robust
Today kvm_io_bus_regsiter_dev() returns void and will internally BUG_ON
if it fails. We want to create dynamic MMIO/PIO entries driven from
userspace later in the series, so we need to enhance the code to be more
robust with the following changes:
1) Add a return value to the registration function
2) Fix up all the callsites to check the return code, handle any
failures, and percolate the error up to the caller.
3) Add an unregister function that collapses holes in the array
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index e4bcbdd..daf4606 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -539,6 +539,8 @@
struct kvm_pic *kvm_create_pic(struct kvm *kvm)
{
struct kvm_pic *s;
+ int ret;
+
s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL);
if (!s)
return NULL;
@@ -555,6 +557,11 @@
* Initialize PIO device
*/
kvm_iodevice_init(&s->dev, &picdev_ops);
- kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev);
+ ret = kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev);
+ if (ret < 0) {
+ kfree(s);
+ return NULL;
+ }
+
return s;
}