pci: Only unmap bus_master_enabled_region if was added previously

Normally pci_init_bus_master() would be called either via
bus->machine_done.notify or directly from do_pci_register_device().

However if a device's realize() failed, pci_init_bus_master() is not
called, and do_pci_unregister_device() fails on
memory_region_del_subregion() as it was not mapped.

This adds a check that subregion was mapped before unmapping it.

Fixes: c53598ed18 ("pci: Add missing drop of bus master AS reference")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: John Snow <jsnow@redhat.com>
This commit is contained in:
Alexey Kardashevskiy 2017-03-31 15:47:11 +11:00 committed by Michael S. Tsirkin
parent 87cc4c6102
commit 193982c6f9

View File

@ -869,8 +869,10 @@ static void do_pci_unregister_device(PCIDevice *pci_dev)
pci_dev->bus->devices[pci_dev->devfn] = NULL;
pci_config_free(pci_dev);
memory_region_del_subregion(&pci_dev->bus_master_container_region,
&pci_dev->bus_master_enable_region);
if (memory_region_is_mapped(&pci_dev->bus_master_enable_region)) {
memory_region_del_subregion(&pci_dev->bus_master_container_region,
&pci_dev->bus_master_enable_region);
}
address_space_destroy(&pci_dev->bus_master_as);
}