[Qemu-arm] [PATCH 2/2] hw/arm/virt: no ITS on older machine types

[Andrew Jones]

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 <address@hidden>
---

As Eduardo pointed out long ago for a different reason, we should
probably replace VirtGuestInfo with direct use of VirtMachineClass,
like x86 has done to replace PcGuestInfo with direct use of
PCMachineClass. I'll work on that, but wanted to get this ITS
fixup in sooner than later, so I'm posting this patch now, which
requires 'no_its' to be duplicated.

Also, this patch will have a trivial conflict with Wei's PMU
property series.


 hw/arm/virt-acpi-build.c         |  2 +-
 hw/arm/virt.c                    | 15 +++++++++++----
 include/hw/arm/virt-acpi-build.h |  1 +
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index c31349561c95..48820f372830 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -556,7 +556,7 @@ 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 0f6305d3c7f6..e3734d47df81 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 {
@@ -552,7 +553,8 @@ 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;
@@ -616,9 +618,9 @@ 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);
     }
 }
@@ -1376,7 +1378,7 @@ 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);
 
@@ -1408,6 +1410,7 @@ 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);
 
@@ -1562,8 +1565,12 @@ 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)
 
diff --git a/include/hw/arm/virt-acpi-build.h b/include/hw/arm/virt-acpi-build.h
index e43330ad659b..f5ec749b8fea 100644
--- a/include/hw/arm/virt-acpi-build.h
+++ b/include/hw/arm/virt-acpi-build.h
@@ -33,6 +33,7 @@ typedef struct VirtGuestInfo {
     const int *irqmap;
     bool use_highmem;
     int gic_version;
+    bool no_its;
 } VirtGuestInfo;
 
 
-- 
2.7.4