x86_iommu: Move machine check to x86_iommu_realize()

Instead of having the same error checks in vtd_realize()
and amdvi_realize(), move that over to the generic
x86_iommu_realize().
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NMohammed Gamal <mgamal@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>

hw/i386/amd_iommu.c

@@ -1144,18 +1144,9 @@ static void amdvi_realize(DeviceState *dev, Error **err)
     AMDVIState *s = AMD_IOMMU_DEVICE(dev);
     X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(dev);
     MachineState *ms = MACHINE(qdev_get_machine());
-    MachineClass *mc = MACHINE_GET_CLASS(ms);
-    PCMachineState *pcms =
-        PC_MACHINE(object_dynamic_cast(OBJECT(ms), TYPE_PC_MACHINE));
-    PCIBus *bus;
-
-    if (!pcms) {
-        error_setg(err, "Machine-type '%s' not supported by amd-iommu",
-                   mc->name);
-        return;
-    }
+    PCMachineState *pcms = PC_MACHINE(ms);
+    PCIBus *bus = pcms->bus;
 
-    bus = pcms->bus;
     s->iotlb = g_hash_table_new_full(amdvi_uint64_hash,
                                      amdvi_uint64_equal, g_free, g_free);
 

hw/i386/intel_iommu.c

@@ -3052,20 +3052,11 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
 static void vtd_realize(DeviceState *dev, Error **errp)
 {
     MachineState *ms = MACHINE(qdev_get_machine());
-    MachineClass *mc = MACHINE_GET_CLASS(ms);
-    PCMachineState *pcms =
-        PC_MACHINE(object_dynamic_cast(OBJECT(ms), TYPE_PC_MACHINE));
-    PCIBus *bus;
+    PCMachineState *pcms = PC_MACHINE(ms);
+    PCIBus *bus = pcms->bus;
     IntelIOMMUState *s = INTEL_IOMMU_DEVICE(dev);
     X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(dev);
 
-    if (!pcms) {
-        error_setg(errp, "Machine-type '%s' not supported by intel-iommu",
-                   mc->name);
-        return;
-    }
-
-    bus = pcms->bus;
     x86_iommu->type = TYPE_INTEL;
 
     if (!vtd_decide_config(s, errp)) {

hw/i386/x86-iommu.c

@@ -21,6 +21,8 @@
 #include "hw/sysbus.h"
 #include "hw/boards.h"
 #include "hw/i386/x86-iommu.h"
+#include "hw/i386/pc.h"
+#include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "trace.h"
 
@@ -80,7 +82,18 @@ static void x86_iommu_realize(DeviceState *dev, Error **errp)
 {
     X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(dev);
     X86IOMMUClass *x86_class = X86_IOMMU_GET_CLASS(dev);
+    MachineState *ms = MACHINE(qdev_get_machine());
+    MachineClass *mc = MACHINE_GET_CLASS(ms);
+    PCMachineState *pcms =
+        PC_MACHINE(object_dynamic_cast(OBJECT(ms), TYPE_PC_MACHINE));
     QLIST_INIT(&x86_iommu->iec_notifiers);
+
+    if (!pcms) {
+        error_setg(errp, "Machine-type '%s' not supported by IOMMU",
+                   mc->name);
+        return;
+    }
+
     if (x86_class->realize) {
         x86_class->realize(dev, errp);
     }