In some situations, we need a property that tracks the bit but can't change it (for instance, guest features of virtio device).
Signed-off-by: Maxim Davydov <maxim.davy...@virtuozzo.com> --- hw/core/qdev-properties.c | 32 ++++++++++++++++++++++++++++++++ include/hw/qdev-properties.h | 5 +++++ 2 files changed, 37 insertions(+) diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c index 50f4094..d7b0436 100644 --- a/hw/core/qdev-properties.c +++ b/hw/core/qdev-properties.c @@ -231,6 +231,38 @@ const PropertyInfo qdev_prop_bit64 = { .set_default_value = set_default_value_bool, }; +/* Read-only Bit64 */ + +static void prop_set_read_only_bit64(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + return; +} + +static uint64_t qdev_get_prop_read_only_mask64(Property *prop) +{ + assert(prop->info == &qdev_prop_read_only_bit64); + return 0x1ull << prop->bitnr; +} + +static void prop_get_read_only_bit64(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + Property *prop = opaque; + uint64_t *p = object_field_prop_ptr(obj, prop); + bool value = (*p & qdev_get_prop_read_only_mask64(prop)) != 0; + + visit_type_bool(v, name, &value, errp); +} + +const PropertyInfo qdev_prop_read_only_bit64 = { + .name = "bool", + .description = "on/off", + .get = prop_get_read_only_bit64, + .set = prop_set_read_only_bit64, + .set_default_value = set_default_value_bool, +}; + /* --- bool --- */ static void get_bool(Object *obj, Visitor *v, const char *name, void *opaque, diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h index 0ef97d6..4c4bac7 100644 --- a/include/hw/qdev-properties.h +++ b/include/hw/qdev-properties.h @@ -46,6 +46,7 @@ struct PropertyInfo { extern const PropertyInfo qdev_prop_bit; extern const PropertyInfo qdev_prop_bit64; +extern const PropertyInfo qdev_prop_read_only_bit64; extern const PropertyInfo qdev_prop_bool; extern const PropertyInfo qdev_prop_enum; extern const PropertyInfo qdev_prop_uint8; @@ -102,6 +103,10 @@ extern const PropertyInfo qdev_prop_link; .set_default = true, \ .defval.u = (bool)_defval) +#define DEFINE_PROP_READ_ONLY_BIT64(_name, _state, _field, _bit) \ + DEFINE_PROP(_name, _state, _field, qdev_prop_read_only_bit64, uint64_t, \ + .bitnr = (_bit)) + #define PROP_ARRAY_LEN_PREFIX "len-" /** -- 1.8.3.1