Add an "identifier" property to the SMMUv3 device and use it when
building the ACPI IORT SMMUv3 node Identifier field.

This avoids relying on enumeration order and provides a stable
per-device identifier. This is useful when we add support for
Tegra241 CMDQV DSDT in subsequent patch.

No functional change intended.

Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
---
 hw/arm/smmuv3.c          | 1 +
 hw/arm/virt-acpi-build.c | 4 +++-
 hw/arm/virt.c            | 3 +++
 include/hw/arm/smmuv3.h  | 1 +
 4 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index 7858bf2c33..7f84c87a46 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -2114,6 +2114,7 @@ static const Property smmuv3_properties[] = {
      * Defaults to stage 1
      */
     DEFINE_PROP_STRING("stage", SMMUv3State, stage),
+    DEFINE_PROP_UINT8("identifier", SMMUv3State, identifier, 0),
     DEFINE_PROP_BOOL("accel", SMMUv3State, accel, false),
     /* GPA of MSI doorbell, for SMMUv3 accel use. */
     DEFINE_PROP_UINT64("msi-gpa", SMMUv3State, msi_gpa, 0),
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index ae3b4aac52..046e930ca5 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -342,6 +342,7 @@ static int iort_idmap_compare(gconstpointer a, gconstpointer b)
 typedef struct AcpiSMMUv3Dev {
     int irq;
     hwaddr base;
+    uint8_t id;
 
     /*
      * IORT-only fields.
@@ -407,6 +408,7 @@ static int iort_smmuv3_devices(Object *obj, void *opaque)
     bus = PCI_BUS(object_property_get_link(obj, "primary-bus", &error_abort));
     sdev.accel = object_property_get_bool(obj, "accel", &error_abort);
     sdev.ats = object_property_get_bool(obj, "ats", &error_abort);
+    sdev.id = object_property_get_uint(obj, "identifier", &error_abort);
     pbus = PLATFORM_BUS_DEVICE(vms->platform_bus_dev);
     sbdev = SYS_BUS_DEVICE(obj);
     sdev.base = platform_bus_get_mmio_addr(pbus, sbdev, 0);
@@ -642,7 +644,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
                      (ID_MAPPING_ENTRY_SIZE * smmu_mapping_count);
         build_append_int_noprefix(table_data, node_size, 2); /* Length */
         build_append_int_noprefix(table_data, 4, 1); /* Revision */
-        build_append_int_noprefix(table_data, id++, 4); /* Identifier */
+        build_append_int_noprefix(table_data, sdev->id, 4); /* Identifier */
         /* Number of ID mappings */
         build_append_int_noprefix(table_data, smmu_mapping_count, 4);
         /* Reference to ID Array */
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 390845c503..22ee5c4a41 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -3059,12 +3059,15 @@ static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
                        (vms->legacy_smmuv3_present) ?
                        "iommu=smmuv3" : "virtio-iommu");
         } else if (vms->iommu == VIRT_IOMMU_NONE) {
+            static uint8_t id;
+
             /* The new SMMUv3 device is specific to the PCI bus */
             object_property_set_bool(OBJECT(dev), "smmu_per_bus", true, NULL);
             object_property_set_link(OBJECT(dev), "memory",
                                      OBJECT(vms->sysmem), NULL);
             object_property_set_link(OBJECT(dev), "secure-memory",
                                      OBJECT(vms->secure_sysmem), NULL);
+            object_property_set_uint(OBJECT(dev), "identifier", id++, NULL);
         }
         if (object_property_get_bool(OBJECT(dev), "accel", &error_abort)) {
             hwaddr db_start = 0;
diff --git a/include/hw/arm/smmuv3.h b/include/hw/arm/smmuv3.h
index 87926f8cb3..39cb43506e 100644
--- a/include/hw/arm/smmuv3.h
+++ b/include/hw/arm/smmuv3.h
@@ -63,6 +63,7 @@ struct SMMUv3State {
     qemu_irq     irq[4];
     QemuMutex mutex;
     char *stage;
+    uint8_t identifier;
 
     /* SMMU has HW accelerator support for nested S1 + s2 */
     bool accel;
-- 
2.43.0