[Qemu-devel] [PATCH v3 07/10] hw/arm/virt: Introduce opt-in feature "fdt"

[Shameer Kolothum]

This is to disable/enable populating DT nodes in case
any conflict with acpi tables. The default is "off".

This will be used in subsequent patch where cold plug
device-memory support is added for DT boot.

If DT memory node support is added for cold-plugged device
memory, those memory will be visible to Guest kernel via
UEFI GetMemoryMap() and gets treated as early boot memory.
Hence memory becomes non hot-un-unpluggable even if Guest
is booted in ACPI mode.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com>
---
 hw/arm/virt.c         | 23 +++++++++++++++++++++++
 include/hw/arm/virt.h |  1 +
 2 files changed, 24 insertions(+)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 13db0e9..b602151 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1717,6 +1717,20 @@ static void virt_set_highmem(Object *obj, bool value, 
Error **errp)
     vms->highmem = value;
 }
 
+static bool virt_get_fdt(Object *obj, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(obj);
+
+    return vms->use_fdt;
+}
+
+static void virt_set_fdt(Object *obj, bool value, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(obj);
+
+    vms->use_fdt = value;
+}
+
 static bool virt_get_its(Object *obj, Error **errp)
 {
     VirtMachineState *vms = VIRT_MACHINE(obj);
@@ -2005,6 +2019,15 @@ static void virt_instance_init(Object *obj)
     object_property_set_description(obj, "gic-version",
                                     "Set GIC version. "
                                     "Valid values are 2, 3 and host", NULL);
+    /* fdt is disabled by default */
+    vms->use_fdt = false;
+    object_property_add_bool(obj, "fdt", virt_get_fdt,
+                             virt_set_fdt, NULL);
+    object_property_set_description(obj, "fdt",
+                                    "Set on/off to enable/disable device tree "
+                                    "nodes in case any conflict with ACPI"
+                                    "(eg: device memory node)",
+                                    NULL);
 
     vms->highmem_ecam = !vmc->no_highmem_ecam;
 
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index c5e4c96..14b2e0a 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -119,6 +119,7 @@ typedef struct {
     bool highmem_ecam;
     bool its;
     bool virt;
+    bool use_fdt;
     int32_t gic_version;
     VirtIOMMUType iommu;
     struct arm_boot_info bootinfo;
-- 
2.7.4