[Qemu-ppc] [RFC PATCH 05/15] spapr_pci: add PHB unrealize

[Michael Roth]

To support PHB hotplug we need to clean up lingering references,
memory, child properties, etc. prior to the PHB object being
finalized. Generally this will be called as a result of calling
object_unref() on the PHB object, which in turn would normally
be called as the result of an unplug() operation.

When the PHB is finalized, child objects will be unparented in
turn, and finalized if the PHB was the only reference holder. so
we don't bother to explicitly unparent child objects of the PHB
(spapr_iommu, spapr_drc, etc).

We do need to handle memory regions explicitly however, since
they also take a reference on the PHB, and won't allow it to
be finalized otherwise.

Signed-off-by: Michael Roth <address@hidden>
---
 hw/ppc/spapr_pci.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 2e7590c..25a738c 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -1108,6 +1108,37 @@ static void spapr_phb_hot_unplug_child(HotplugHandler 
*plug_handler,
     }
 }
 
+static void spapr_phb_unrealize(DeviceState *dev, Error **errp)
+{
+    SysBusDevice *s = SYS_BUS_DEVICE(dev);
+    PCIHostState *phb = PCI_HOST_BRIDGE(s);
+    sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(phb);
+    sPAPRTCETable *tcet;
+
+    pci_unregister_bus(phb->bus);
+
+    g_free(sphb->dtbusname);
+    sphb->dtbusname = NULL;
+
+    /* remove IO/MMIO subregions and aliases, rest should get cleaned
+     * via PHB's unrealize->object_finalize
+     */
+    memory_region_del_subregion(get_system_memory(), &sphb->iowindow);
+    object_unparent(OBJECT(&sphb->iowindow));
+    object_unparent(OBJECT(&sphb->iospace));
+
+    memory_region_del_subregion(get_system_memory(), &sphb->memwindow);
+    object_unparent(OBJECT(&sphb->memwindow));
+    object_unparent(OBJECT(&sphb->memspace));
+
+    tcet = spapr_tce_find_by_liobn(sphb->dma_liobn);
+    memory_region_del_subregion(&sphb->iommu_root, &sphb->msiwindow);
+    memory_region_del_subregion(&sphb->iommu_root, spapr_tce_get_iommu(tcet));
+    address_space_destroy(&sphb->iommu_as);
+
+    QLIST_REMOVE(sphb, list);
+}
+
 static void spapr_phb_realize(DeviceState *dev, Error **errp)
 {
     SysBusDevice *s = SYS_BUS_DEVICE(dev);
@@ -1442,6 +1473,7 @@ static void spapr_phb_class_init(ObjectClass *klass, void 
*data)
 
     hc->root_bus_path = spapr_phb_root_bus_path;
     dc->realize = spapr_phb_realize;
+    dc->unrealize = spapr_phb_unrealize;
     dc->props = spapr_phb_properties;
     dc->reset = spapr_phb_reset;
     dc->vmsd = &vmstate_spapr_pci;
-- 
1.9.1