Since commit d8fb7d0969d5 ("vl: switch -M parsing to keyval"), machine
parameter definitions cannot use underscores, because keyval_dashify()
transforms them to dashes and the parser doesn't find the parameter.

This affects option default_bus_bypass_iommu which was introduced in the
same release:

$ qemu-system-aarch64 -M virt,default_bus_bypass_iommu=on
qemu-system-aarch64: Property 'virt-6.1-machine.default-bus-bypass-iommu' not found

Rename the parameter to "default-bus-bypass-iommu". Passing
"default_bus_bypass_iommu" is still valid since the underscore are
transformed automatically.

Fixes: 6d7a85483a06 ("hw/arm/virt: Add default_bus_bypass_iommu machine option")
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 hw/arm/virt.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 7170aaacd5..5fdd5aa888 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2687,10 +2687,10 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
                                           "Set the IOMMU type. "
                                           "Valid values are none and smmuv3");
 
-    object_class_property_add_bool(oc, "default_bus_bypass_iommu",
+    object_class_property_add_bool(oc, "default-bus-bypass-iommu",
                                    virt_get_default_bus_bypass_iommu,
                                    virt_set_default_bus_bypass_iommu);
-    object_class_property_set_description(oc, "default_bus_bypass_iommu",
+    object_class_property_set_description(oc, "default-bus-bypass-iommu",
                                           "Set on/off to enable/disable "
                                           "bypass_iommu for default root bus");
 
-- 
2.33.0