[Qemu-devel] [RFC v4 10/13] pci: device-number & function properties

[Eduardo Habkost]

The "addr" property on PCI devices has some magic for parsing it
as a single PCI device number (called "slot" internally), or a
"<slot>.<function>" string.  Add simple integer properties that
can represent the device address with no special parsing.

Cc: "Michael S. Tsirkin" <address@hidden>
Cc: Marcel Apfelbaum <address@hidden>
Signed-off-by: Eduardo Habkost <address@hidden>
---
 hw/pci/pci.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index ead9cbf..5753af3 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -41,6 +41,7 @@
 #include "hw/hotplug.h"
 #include "hw/boards.h"
 #include "qemu/cutils.h"
+#include "qapi-visit.h"
 
 //#define DEBUG_PCI
 #ifdef DEBUG_PCI
@@ -2504,6 +2505,55 @@ MemoryRegion *pci_address_space_io(PCIDevice *dev)
     return dev->bus->address_space_io;
 }
 
+static void pci_device_get_devnr(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    PCIDevice *dev = PCI_DEVICE(obj);
+    uint32_t devnr = PCI_SLOT(dev->devfn);
+
+    visit_type_uint32(v, "device-number", &devnr, errp);
+}
+
+static void pci_device_set_devnr(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    PCIDevice *dev = PCI_DEVICE(obj);
+    uint32_t devnr;
+    Error *local_err = NULL;
+
+    visit_type_uint32(v, "device-number", &devnr, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    dev->devfn = PCI_DEVFN(devnr, PCI_FUNC(dev->devfn));
+}
+
+static void pci_device_get_function(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    PCIDevice *dev = PCI_DEVICE(obj);
+    uint32_t function = PCI_FUNC(dev->devfn);
+
+    visit_type_uint32(v, "function", &function, errp);
+}
+
+static void pci_device_set_function(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    PCIDevice *dev = PCI_DEVICE(obj);
+    uint32_t function;
+    Error *local_err = NULL;
+
+    visit_type_uint32(v, "function", &function, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+    dev->devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), function);
+}
+
 static void pci_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
@@ -2514,6 +2564,19 @@ static void pci_device_class_init(ObjectClass *klass, 
void *data)
     k->bus_type = TYPE_PCI_BUS;
     k->props = pci_props;
     pc->realize = pci_default_realize;
+
+    /* Internally, bits 3:8 of devfn are called "slots", but:
+     * - they can be confused with physical slot numbers;
+     * - TYPE_PCIE_SLOT objects already have a "slot" property.
+     * So we use the terminology used in the PCI specifiction:
+     * "device number".
+     */
+    object_class_property_add(klass, "device-number", "uint32",
+                              pci_device_get_devnr, pci_device_set_devnr,
+                              NULL, NULL, &error_abort);
+    object_class_property_add(klass, "function", "uint32",
+                              pci_device_get_function, pci_device_set_function,
+                              NULL, NULL, &error_abort);
 }
 
 AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
-- 
2.9.4