[Qemu-devel] [PATCH RFC 09/17] hw/pci: introduce TYPE_PCI_MAIN_HOST_BRIDGE interface

[Marcel Apfelbaum <marcel@redhat.com>]

From: Marcel Apfelbaum <marcel.a@redhat.com>

This is a marker interface used to differentiate the
"default" host bridge on a system with multiple host bridges.
This differentiation is required only for pc machines for now
by the ACPI subsystem.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
 hw/i386/acpi-build.c      | 9 ++++++---
 hw/pci-host/piix.c        | 5 +++++
 hw/pci-host/q35.c         | 4 ++++
 hw/pci/pci_host.c         | 6 ++++++
 include/hw/pci/pci_host.h | 7 +++++++
 5 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 8a91e96..d490a1e 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -250,7 +250,8 @@ static void acpi_get_pci_info(PcPciInfo *info)
     Object *pci_host;
     bool ambiguous;
 
-    pci_host = object_resolve_path_type("", TYPE_PCI_HOST_BRIDGE, &ambiguous);
+    pci_host = object_resolve_path_type("", TYPE_PCI_MAIN_HOST_BRIDGE,
+                                        &ambiguous);
     g_assert(!ambiguous);
     g_assert(pci_host);
 
@@ -1218,7 +1219,8 @@ build_ssdt(AcpiAml *table_aml, GArray *linker,
             PCIBus *bus = NULL;
             bool ambiguous;
 
-            pci_host = object_resolve_path_type("", TYPE_PCI_HOST_BRIDGE, &ambiguous);
+            pci_host = object_resolve_path_type("", TYPE_PCI_MAIN_HOST_BRIDGE,
+                                                &ambiguous);
             if (!ambiguous && pci_host) {
                 bus = PCI_HOST_BRIDGE(pci_host)->bus;
             }
@@ -1558,7 +1560,8 @@ static bool acpi_get_mcfg(AcpiMcfgInfo *mcfg)
     QObject *o;
     bool ambiguous;
 
-    pci_host = object_resolve_path_type("", TYPE_PCI_HOST_BRIDGE, &ambiguous);
+    pci_host = object_resolve_path_type("", TYPE_PCI_MAIN_HOST_BRIDGE,
+                                        &ambiguous);
     g_assert(!ambiguous);
     g_assert(pci_host);
 
diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
index f7cfbc8..970b9e9 100644
--- a/hw/pci-host/piix.c
+++ b/hw/pci-host/piix.c
@@ -767,6 +767,11 @@ static const TypeInfo i440fx_pcihost_info = {
     .instance_size = sizeof(I440FXState),
     .instance_init = i440fx_pcihost_initfn,
     .class_init    = i440fx_pcihost_class_init,
+    .interfaces    = (InterfaceInfo[]) {
+        { TYPE_PCI_MAIN_HOST_BRIDGE },
+        { }
+    }
+
 };
 
 static void i440fx_register_types(void)
diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index c36fefa..bd41465 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -193,6 +193,10 @@ static const TypeInfo q35_host_info = {
     .instance_size = sizeof(Q35PCIHost),
     .instance_init = q35_host_initfn,
     .class_init = q35_host_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_PCI_MAIN_HOST_BRIDGE },
+        { }
+    }
 };
 
 /****************************************************************************
diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
index 3e26f92..87180c8 100644
--- a/hw/pci/pci_host.c
+++ b/hw/pci/pci_host.c
@@ -175,6 +175,11 @@ const MemoryRegionOps pci_host_data_be_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
 };
 
+static const TypeInfo pci_main_host_interface_info = {
+    .name          = TYPE_PCI_MAIN_HOST_BRIDGE,
+    .parent        = TYPE_INTERFACE,
+};
+
 static const TypeInfo pci_host_type_info = {
     .name = TYPE_PCI_HOST_BRIDGE,
     .parent = TYPE_SYS_BUS_DEVICE,
@@ -185,6 +190,7 @@ static const TypeInfo pci_host_type_info = {
 
 static void pci_host_register_types(void)
 {
+    type_register_static(&pci_main_host_interface_info);
     type_register_static(&pci_host_type_info);
 }
 
diff --git a/include/hw/pci/pci_host.h b/include/hw/pci/pci_host.h
index ba31595..3c72e26 100644
--- a/include/hw/pci/pci_host.h
+++ b/include/hw/pci/pci_host.h
@@ -30,6 +30,13 @@
 
 #include "hw/sysbus.h"
 
+/**
+ * Marker interface for classes whose instances can
+ * be main host bridges. It is intended to be used
+ * when the QOM tree includes multiple host bridges.
+ */
+#define TYPE_PCI_MAIN_HOST_BRIDGE "pci-main-host-bridge"
+
 #define TYPE_PCI_HOST_BRIDGE "pci-host-bridge"
 #define PCI_HOST_BRIDGE(obj) \
     OBJECT_CHECK(PCIHostState, (obj), TYPE_PCI_HOST_BRIDGE)
-- 
2.1.0