diff mbox series

[v2,5/6] hw/acpi/viot: sort VIOT ACPI table entries by PCI host bridge min_bus

Message ID 20220522155008.21832-6-mark.cave-ayland@ilande.co.uk (mailing list archive)
State New, archived
Headers show
Series hw/acpi/viot: generate stable VIOT ACPI tables | expand

Commit Message

Mark Cave-Ayland May 22, 2022, 3:50 p.m. UTC 
This ensures that the VIOT ACPI table output is always stable for a given PCI
topology by ensuring that entries are ordered according to min_bus.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
---
 hw/acpi/viot.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
diff mbox series

Patch

diff --git a/hw/acpi/viot.c b/hw/acpi/viot.c
index 6ca041d18e..ff46703d87 100644
--- a/hw/acpi/viot.c
+++ b/hw/acpi/viot.c
@@ -64,6 +64,20 @@  static int enumerate_pci_host_bridges(Object *obj, void *opaque)
     return 0;
 }
 
+static gint pci_host_range_compare(gconstpointer a, gconstpointer b)
+{
+    struct viot_pci_host_range *range_a = (struct viot_pci_host_range *)a;
+    struct viot_pci_host_range *range_b = (struct viot_pci_host_range *)b;
+
+    if (range_a->min_bus < range_b->min_bus) {
+        return -1;
+    } else if (range_a->min_bus > range_b->min_bus) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
 /*
  * Generate a VIOT table with one PCI-based virtio-iommu that manages PCI
  * endpoints.
@@ -87,6 +101,9 @@  void build_viot(MachineState *ms, GArray *table_data, BIOSLinker *linker,
     object_child_foreach_recursive(OBJECT(ms), enumerate_pci_host_bridges,
                                    pci_host_ranges);
 
+    /* Sort the pci host ranges by min_bus */
+    g_array_sort(pci_host_ranges, pci_host_range_compare);
+
     /* ACPI table header */
     acpi_table_begin(&table, table_data);
     /* Node count */