From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The ordering in ACPI specification [1] has bus number in the lowest byte.
As ACPI tables are little endian this is the reverse of the ordering
used by PCI_BUILD_BDF().  As a minimal fix split the QEMU BDF up
into bus and devfn and write them as single bytes in the correct
order.

[1] ACPI Spec 6.3, Table 5.80

Fixes: 0a5b5acdf2d8 ("hw/acpi: Implement the SRAT GI affinity structure")
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20240916171017.1841767-2-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 16c687d84574a1139a6475c33e3b9191f7932ac0)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/acpi/acpi_generic_initiator.c b/hw/acpi/acpi_generic_initiator.c
index 17b9a052f5..3d2b567999 100644
--- a/hw/acpi/acpi_generic_initiator.c
+++ b/hw/acpi/acpi_generic_initiator.c
@@ -92,7 +92,8 @@ build_srat_generic_pci_initiator_affinity(GArray *table_data, int node,
 
     /* Device Handle - PCI */
     build_append_int_noprefix(table_data, handle->segment, 2);
-    build_append_int_noprefix(table_data, handle->bdf, 2);
+    build_append_int_noprefix(table_data, PCI_BUS_NUM(handle->bdf), 1);
+    build_append_int_noprefix(table_data, PCI_BDF_TO_DEVFN(handle->bdf), 1);
     for (index = 0; index < 12; index++) {
         build_append_int_noprefix(table_data, 0, 1);
     }
-- 
2.39.5