hw/pci: Add a busnr property to pci_props and use for acpi/gi

Using a property allows us to hide the internal details of the PCI device
from the code to build a SRAT Generic Initiator Affinity Structure with
PCI Device Handle.

Suggested-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20240916171017.1841767-6-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 23 insertions, 5 deletions

diff --git a/hw/acpi/acpi_generic_initiator.c b/hw/acpi/acpi_generic_initiator.c
index 73bafaaaea..365feb527f 100644
--- a/hw/acpi/acpi_generic_initiator.c
+++ b/hw/acpi/acpi_generic_initiator.c
@@ -9,6 +9,7 @@
 #include "hw/boards.h"
 #include "hw/pci/pci_device.h"
 #include "qemu/error-report.h"
+#include "qapi/error.h"
 
 typedef struct AcpiGenericInitiatorClass {
     ObjectClass parent_class;
@@ -79,7 +80,8 @@ static int build_acpi_generic_initiator(Object *obj, void *opaque)
     MachineState *ms = MACHINE(qdev_get_machine());
     AcpiGenericInitiator *gi;
     GArray *table_data = opaque;
-    PCIDevice *pci_dev;
+    int32_t devfn;
+    uint8_t bus;
     Object *o;
 
     if (!object_dynamic_cast(obj, TYPE_ACPI_GENERIC_INITIATOR)) {
@@ -100,10 +102,12 @@ static int build_acpi_generic_initiator(Object *obj, void *opaque)
         exit(1);
     }
 
-    pci_dev = PCI_DEVICE(o);
-    build_srat_pci_generic_initiator(table_data, gi->node, 0,
-                                     pci_bus_num(pci_get_bus(pci_dev)),
-                                     pci_dev->devfn);
+    bus = object_property_get_uint(o, "busnr", &error_fatal);
+    devfn = object_property_get_int(o, "addr", &error_fatal);
+    /* devfn is constrained in PCI to be 8 bit but storage is an int32_t */
+    assert(devfn >= 0 && devfn < PCI_DEVFN_MAX);
+
+    build_srat_pci_generic_initiator(table_data, gi->node, 0, bus, devfn);
 
     return 0;
 }
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 87da35ca9b..0b6bdaa0d7 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -67,6 +67,19 @@ static char *pcibus_get_fw_dev_path(DeviceState *dev);
 static void pcibus_reset_hold(Object *obj, ResetType type);
 static bool pcie_has_upstream_port(PCIDevice *dev);
 
+static void prop_pci_busnr_get(Object *obj, Visitor *v, const char *name,
+                             void *opaque, Error **errp)
+{
+    uint8_t busnr = pci_dev_bus_num(PCI_DEVICE(obj));
+
+    visit_type_uint8(v, name, &busnr, errp);
+}
+
+static const PropertyInfo prop_pci_busnr = {
+    .name = "busnr",
+    .get = prop_pci_busnr_get,
+};
+
 static Property pci_props[] = {
     DEFINE_PROP_PCI_DEVFN("addr", PCIDevice, devfn, -1),
     DEFINE_PROP_STRING("romfile", PCIDevice, romfile),
@@ -87,6 +100,7 @@ static Property pci_props[] = {
                     QEMU_PCIE_ARI_NEXTFN_1_BITNR, false),
     DEFINE_PROP_SIZE32("x-max-bounce-buffer-size", PCIDevice,
                      max_bounce_buffer_size, DEFAULT_MAX_BOUNCE_BUFFER_SIZE),
+    { .name = "busnr", .info = &prop_pci_busnr },
     DEFINE_PROP_END_OF_LIST()
 };