hw/arm/virt: Use stored SMMUv3 device list for IORT build

Introduce a GPtrArray in VirtMachineState to track all SMMUv3 devices
created on the virt machine, and use it when building the IORT table
instead of relying on object_child_foreach_recursive() walks of the
object tree.

This avoids recursive object traversal and provides a foundation for
subsequent patches that need direct access to SMMUv3 instances for
CMDQV-related handling.

No functional change. No bios-tables qtest failures observed.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20260609112552.378999-10-skolothumtho@nvidia.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/arm/virt-acpi-build.c

@@ -392,49 +392,41 @@ static int smmuv3_dev_idmap_compare(gconstpointer a, gconstpointer b)
     return map_a->input_base - map_b->input_base;
 }
 
-static int iort_smmuv3_devices(Object *obj, void *opaque)
-{
-    VirtMachineState *vms = VIRT_MACHINE(qdev_get_machine());
-    AcpiIortSMMUv3Dev sdev = {0};
-    GArray *sdev_blob = opaque;
-    AcpiIortIdMapping idmap;
-    PlatformBusDevice *pbus;
-    int min_bus, max_bus;
-    SysBusDevice *sbdev;
-    PCIBus *bus;
-
-    if (!object_dynamic_cast(obj, TYPE_ARM_SMMUV3)) {
-        return 0;
-    }
-
-    bus = PCI_BUS(object_property_get_link(obj, "primary-bus", &error_abort));
-    sdev.accel = object_property_get_bool(obj, "accel", &error_abort);
-    sdev.ats = smmuv3_ats_enabled(ARM_SMMUV3(obj));
-    pbus = PLATFORM_BUS_DEVICE(vms->platform_bus_dev);
-    sbdev = SYS_BUS_DEVICE(obj);
-    sdev.base = platform_bus_get_mmio_addr(pbus, sbdev, 0);
-    sdev.base += vms->memmap[VIRT_PLATFORM_BUS].base;
-    sdev.irq = platform_bus_get_irqn(pbus, sbdev, 0);
-    sdev.irq += vms->irqmap[VIRT_PLATFORM_BUS];
-    sdev.irq += ARM_SPI_BASE;
-
-    pci_bus_range(bus, &min_bus, &max_bus);
-    sdev.rc_smmu_idmaps = g_array_new(false, true, sizeof(AcpiIortIdMapping));
-    idmap.input_base = min_bus << 8,
-    idmap.id_count = (max_bus - min_bus + 1) << 8,
-    g_array_append_val(sdev.rc_smmu_idmaps, idmap);
-    g_array_append_val(sdev_blob, sdev);
-    return 0;
-}
-
 /*
  * Populate the struct AcpiIortSMMUv3Dev for all SMMUv3 devices and
  * return the total number of idmaps.
  */
-static int populate_smmuv3_dev(GArray *sdev_blob)
+static int populate_smmuv3_dev(VirtMachineState *vms, GArray *sdev_blob)
 {
-    object_child_foreach_recursive(object_get_root(),
-                                   iort_smmuv3_devices, sdev_blob);
+    for (int i = 0; i < vms->smmuv3_devices->len; i++) {
+        Object *obj = OBJECT(g_ptr_array_index(vms->smmuv3_devices, i));
+        AcpiIortSMMUv3Dev sdev = {0};
+        AcpiIortIdMapping idmap;
+        PlatformBusDevice *pbus;
+        int min_bus, max_bus;
+        SysBusDevice *sbdev;
+        PCIBus *bus;
+
+        bus = PCI_BUS(object_property_get_link(obj, "primary-bus",
+                                               &error_abort));
+        sdev.accel = object_property_get_bool(obj, "accel", &error_abort);
+        sdev.ats = smmuv3_ats_enabled(ARM_SMMUV3(obj));
+        pbus = PLATFORM_BUS_DEVICE(vms->platform_bus_dev);
+        sbdev = SYS_BUS_DEVICE(obj);
+        sdev.base = platform_bus_get_mmio_addr(pbus, sbdev, 0);
+        sdev.base += vms->memmap[VIRT_PLATFORM_BUS].base;
+        sdev.irq = platform_bus_get_irqn(pbus, sbdev, 0);
+        sdev.irq += vms->irqmap[VIRT_PLATFORM_BUS];
+        sdev.irq += ARM_SPI_BASE;
+
+        pci_bus_range(bus, &min_bus, &max_bus);
+        sdev.rc_smmu_idmaps = g_array_new(false, true,
+                                          sizeof(AcpiIortIdMapping));
+        idmap.input_base = min_bus << 8;
+        idmap.id_count = (max_bus - min_bus + 1) << 8;
+        g_array_append_val(sdev.rc_smmu_idmaps, idmap);
+        g_array_append_val(sdev_blob, sdev);
+    }
     /* Sort the smmuv3 devices(if any) by smmu idmap input_base */
     g_array_sort(sdev_blob, smmuv3_dev_idmap_compare);
     /*
@@ -568,7 +560,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     if (vms->legacy_smmuv3_present) {
         rc_smmu_idmaps_len = populate_smmuv3_legacy_dev(smmuv3_devs);
     } else {
-        rc_smmu_idmaps_len = populate_smmuv3_dev(smmuv3_devs);
+        rc_smmu_idmaps_len = populate_smmuv3_dev(vms, smmuv3_devs);
     }
 
     num_smmus = smmuv3_devs->len;

hw/arm/virt.c

@@ -3865,6 +3865,7 @@ static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
             }
 
             create_smmuv3_dev_dtb(vms, dev, bus, errp);
+            g_ptr_array_add(vms->smmuv3_devices, dev);
         }
     }
 
@@ -4319,6 +4320,8 @@ static void virt_instance_init(Object *obj)
     vms->oem_id = g_strndup(ACPI_BUILD_APPNAME6, 6);
     vms->oem_table_id = g_strndup(ACPI_BUILD_APPNAME8, 8);
     cxl_machine_init(obj, &vms->cxl_devices_state);
+
+    vms->smmuv3_devices = g_ptr_array_new_with_free_func(NULL);
 }
 
 static void virt_instance_finalize(Object *obj)

include/hw/arm/virt.h

@@ -207,6 +207,7 @@ struct VirtMachineState {
     MemoryRegion *sysmem;
     MemoryRegion *secure_sysmem;
     bool pci_preserve_config;
+    GPtrArray *smmuv3_devices;
 };
 
 #define VIRT_ECAM_ID(high) (high ? VIRT_HIGH_PCIE_ECAM : VIRT_PCIE_ECAM)