---
include/hw/pci/pci.h | 1 +
hw/pci/pci.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 34 insertions(+)
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index d5a40cd058..b6c9c44527 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -341,6 +341,7 @@ void pci_for_each_device_under_bus_reverse(PCIBus *bus,
void pci_for_each_bus_depth_first(PCIBus *bus, pci_bus_ret_fn begin,
pci_bus_fn end, void *parent_state);
PCIDevice *pci_get_function_0(PCIDevice *pci_dev);
+PCIDevice *pci_find_the_only_child(PCIBus *bus, int bus_num, Error **errp);
/* Use this wrapper when specific scan order is not required. */
static inline
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 208c16f450..34fd1fb5b8 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1771,6 +1771,39 @@ void pci_for_each_device(PCIBus *bus, int bus_num,
}
}
+typedef struct TheOnlyChild {
+ PCIDevice *dev;
+ int count;
+} TheOnlyChild;
+
+static void the_only_child_fn(PCIBus *bus, PCIDevice *dev, void *opaque)
+{
+ TheOnlyChild *s = opaque;
+
+ s->dev = dev;
+ s->count++;
+}
+
+PCIDevice *pci_find_the_only_child(PCIBus *bus, int bus_num, Error **errp)
+{
+ TheOnlyChild res = {0};
+
+ pci_for_each_device(bus, bus_num, the_only_child_fn, &res);
+
+ if (!res.dev) {
+ assert(res.count == 0);
+ error_setg(errp, "No child devices found");
+ return NULL;
+ }
+
+ if (res.count > 1) {
+ error_setg(errp, "Several child devices found");
+ return NULL;
+ }
+
+ return res.dev;
+}
+
const pci_class_desc *get_class_desc(int class)
{
const pci_class_desc *desc;