hw/arm/virt: Introduce the iommu option

ARM virt machine now exposes a new "iommu" option.
The SMMUv3 IOMMU is instantiated using -machine virt,iommu=smmuv3.
Signed-off-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: NPrem Mallappa <prem.mallappa@broadcom.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1524665762-31355-15-git-send-email-eric.auger@redhat.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/arm/virt.c

@@ -1561,6 +1561,34 @@ static void virt_set_gic_version(Object *obj, const char *value, Error **errp)
     }
 }
 
+static char *virt_get_iommu(Object *obj, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(obj);
+
+    switch (vms->iommu) {
+    case VIRT_IOMMU_NONE:
+        return g_strdup("none");
+    case VIRT_IOMMU_SMMUV3:
+        return g_strdup("smmuv3");
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static void virt_set_iommu(Object *obj, const char *value, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(obj);
+
+    if (!strcmp(value, "smmuv3")) {
+        vms->iommu = VIRT_IOMMU_SMMUV3;
+    } else if (!strcmp(value, "none")) {
+        vms->iommu = VIRT_IOMMU_NONE;
+    } else {
+        error_setg(errp, "Invalid iommu value");
+        error_append_hint(errp, "Valid values are none, smmuv3.\n");
+    }
+}
+
 static CpuInstanceProperties
 virt_cpu_index_to_props(MachineState *ms, unsigned cpu_index)
 {
@@ -1693,6 +1721,14 @@ static void virt_2_12_instance_init(Object *obj)
                                         NULL);
     }
 
+    /* Default disallows iommu instantiation */
+    vms->iommu = VIRT_IOMMU_NONE;
+    object_property_add_str(obj, "iommu", virt_get_iommu, virt_set_iommu, NULL);
+    object_property_set_description(obj, "iommu",
+                                    "Set the IOMMU type. "
+                                    "Valid values are none and smmuv3",
+                                    NULL);
+
     vms->memmap = a15memmap;
     vms->irqmap = a15irqmap;
 }