hw/arm/virt: no ITS on older machine types

We should avoid exposing new hardware (through DT and ACPI) on older
machine types. This patch keeps 2.7 and older from changing, despite
the introduction of ITS support for 2.8.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 1476117341-32690-3-git-send-email-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 12 insertions, 5 deletions

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 779d83d836..fa0655a775 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -554,7 +554,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtGuestInfo *guest_info)
         gicr->base_address = cpu_to_le64(memmap[VIRT_GIC_REDIST].base);
         gicr->range_length = cpu_to_le32(memmap[VIRT_GIC_REDIST].size);
 
-        if (its_class_name()) {
+        if (its_class_name() && !guest_info->no_its) {
             gic_its = acpi_data_push(table_data, sizeof *gic_its);
             gic_its->type = ACPI_APIC_GENERIC_TRANSLATOR;
             gic_its->length = sizeof(*gic_its);
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 795740d9bf..895446f17c 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -84,6 +84,7 @@ typedef struct {
     MachineClass parent;
     VirtBoardInfo *daughterboard;
     bool disallow_affinity_adjustment;
+    bool no_its;
 } VirtMachineClass;
 
 typedef struct {
@@ -551,7 +552,8 @@ static void create_v2m(VirtBoardInfo *vbi, qemu_irq *pic)
     fdt_add_v2m_gic_node(vbi);
 }
 
-static void create_gic(VirtBoardInfo *vbi, qemu_irq *pic, int type, bool secure)
+static void create_gic(VirtBoardInfo *vbi, qemu_irq *pic, int type,
+                       bool secure, bool no_its)
 {
     /* We create a standalone GIC */
     DeviceState *gicdev;
@@ -615,9 +617,9 @@ static void create_gic(VirtBoardInfo *vbi, qemu_irq *pic, int type, bool secure)
 
     fdt_add_gic_node(vbi, type);
 
-    if (type == 3) {
+    if (type == 3 && !no_its) {
         create_its(vbi, gicdev);
-    } else {
+    } else if (type == 2) {
         create_v2m(vbi, pic);
     }
 }
@@ -1375,7 +1377,7 @@ static void machvirt_init(MachineState *machine)
 
     create_flash(vbi, sysmem, secure_sysmem ? secure_sysmem : sysmem);
 
-    create_gic(vbi, pic, gic_version, vms->secure);
+    create_gic(vbi, pic, gic_version, vms->secure, vmc->no_its);
 
     fdt_add_pmu_nodes(vbi, gic_version);
 
@@ -1407,6 +1409,7 @@ static void machvirt_init(MachineState *machine)
     guest_info->irqmap = vbi->irqmap;
     guest_info->use_highmem = vms->highmem;
     guest_info->gic_version = gic_version;
+    guest_info->no_its = vmc->no_its;
     guest_info_state->machine_done.notify = virt_guest_info_machine_done;
     qemu_add_machine_init_done_notifier(&guest_info_state->machine_done);
 
@@ -1561,8 +1564,12 @@ static void virt_2_7_instance_init(Object *obj)
 
 static void virt_machine_2_7_options(MachineClass *mc)
 {
+    VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc));
+
     virt_machine_2_8_options(mc);
     SET_MACHINE_COMPAT(mc, VIRT_COMPAT_2_7);
+    /* ITS was introduced with 2.8 */
+    vmc->no_its = true;
 }
 DEFINE_VIRT_MACHINE(2, 7)