A system with multiple VMGENID devices is undefined in the VMGENID spec by
omission.
Cc: "Michael S. Tsirkin" <m...@redhat.com>
Cc: Ben Warren <b...@skyportsystems.com>
Cc: Igor Mammedov <imamm...@redhat.com>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Signed-off-by: Laszlo Ersek <ler...@redhat.com>
---
Notes:
v2:
- use find_vmgenid_dev() rather than open-code
object_resolve_path_type() [Michael]
- add comments to both the definition of find_vmgenid_dev() and its call
site in vmgenid_realize() [Michael]
include/hw/acpi/vmgenid.h | 1 +
hw/acpi/vmgenid.c | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/include/hw/acpi/vmgenid.h b/include/hw/acpi/vmgenid.h
index 8578476baebe..7beb9592fb01 100644
--- a/include/hw/acpi/vmgenid.h
+++ b/include/hw/acpi/vmgenid.h
@@ -24,6 +24,7 @@ typedef struct VmGenIdState {
bool write_pointer_available;
} VmGenIdState;
+/* returns NULL unless there is exactly one device */
static inline Object *find_vmgenid_dev(void)
{
return object_resolve_path_type("", VMGENID_DEVICE, NULL);
diff --git a/hw/acpi/vmgenid.c b/hw/acpi/vmgenid.c
index c3ddcc8e7cb0..a32b847fe0df 100644
--- a/hw/acpi/vmgenid.c
+++ b/hw/acpi/vmgenid.c
@@ -221,6 +221,14 @@ static void vmgenid_realize(DeviceState *dev, Error **errp)
return;
}
+ /* Given that this function is executing, there is at least one VMGENID
+ * device. Check if there are several.
+ */
+ if (!find_vmgenid_dev()) {
+ error_setg(errp, "at most one %s device is permitted", VMGENID_DEVICE);
+ return;
+ }
+
qemu_register_reset(vmgenid_handle_reset, vms);
}
--
2.9.3
