pci: allow cleanup/unregistration of PCI root buses

This adds cleanup counterparts to pci_register_root_bus(),
pci_root_bus_new(), and pci_bus_irqs().

These cleanup routines are needed in the case of hotpluggable
PCIHostBridge implementations. Currently we can rely on the
object_unparent()'ing of the PCIHostState recursively unparenting
and cleaning up it's child buses, but we need explicit calls
to also:

  1) remove the PCIHostState from pci_host_bridges global list.
     otherwise, we risk accessing freed memory when we access
     the list later
  2) clean up memory allocated in pci_bus_irqs()

Both are handled outside the context of any particular bus or
host bridge's init/realize functions, making it difficult to
avoid the need for explicit cleanup functions without remodeling
how PCIHostBridges are created. So keep it simple and just add
them for now.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index eb12fa112e..d87f5f93e9 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -405,8 +405,10 @@ PCIBus *pci_root_bus_new(DeviceState *parent, const char *name,
                          MemoryRegion *address_space_mem,
                          MemoryRegion *address_space_io,
                          uint8_t devfn_min, const char *typename);
+void pci_root_bus_cleanup(PCIBus *bus);
 void pci_bus_irqs(PCIBus *bus, pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,
                   void *irq_opaque, int nirq);
+void pci_bus_irqs_cleanup(PCIBus *bus);
 int pci_bus_get_irq_level(PCIBus *bus, int irq_num);
 /* 0 <= pin <= 3 0 = INTA, 1 = INTB, 2 = INTC, 3 = INTD */
 int pci_swizzle_map_irq_fn(PCIDevice *pci_dev, int pin);
@@ -417,6 +419,7 @@ PCIBus *pci_register_root_bus(DeviceState *parent, const char *name,
                               MemoryRegion *address_space_io,
                               uint8_t devfn_min, int nirq,
                               const char *typename);
+void pci_unregister_root_bus(PCIBus *bus);
 void pci_bus_set_route_irq_fn(PCIBus *, pci_route_irq_fn);
 PCIINTxRoute pci_device_route_intx_to_irq(PCIDevice *dev, int pin);
 bool pci_intx_route_changed(PCIINTxRoute *old, PCIINTxRoute *new);