On 2/9/2026 7:23 PM, Zhao Liu wrote:
> DEFINE_PROP_UINT64_CHECKMASK is designed to detect and check user's
> property setting:
> * checking: check property value against a bitmask.
> * detection: ask caller to provide an invalid value as the initial
> "sentinel" value, which is impossible to be set by users. However,
> this detection is not strict, since the property could be also
> set internally.
>
> The entire mechanism is not easy to use.
>
> Now there's USER_SET flag in place (and the current unique use case
> "lbr-fmt" has been converted to checking USER_SET way), manual setting
> of invalid initial values is no longer required.
>
> Thus, extend DEFINE_PROP_UINT64_CHECKMASK to support *valid* default
> value, and for "lbr-fmt" case, replace the invalid initialization value
> `~PERF_CAP_LBR_FMT` with a valid value `0`.
>
> In addition, considering DEFINE_PROP_UINT64_CHECKMASK itself actually
> doesn't identify whether the property is set by the user or not, remove
> "user-supplied" related description in its document.
>
> Signed-off-by: Zhao Liu <[email protected]>
> ---
Nice to see "cpu->lbr_fmt = ~PERF_CAP_LBR_FMT" is gone.
Reviewed-by: Zide Chen <[email protected]>
> hw/core/qdev-properties.c | 1 +
> include/hw/core/qdev-properties.h | 14 +++++++-------
> target/i386/cpu.c | 4 +---
> 3 files changed, 9 insertions(+), 10 deletions(-)
>
> diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> index 91c4010e7dc9..b84214e60f19 100644
> --- a/hw/core/qdev-properties.c
> +++ b/hw/core/qdev-properties.c
> @@ -507,6 +507,7 @@ const PropertyInfo qdev_prop_uint64_checkmask = {
> .type = "uint64",
> .get = get_uint64,
> .set = set_uint64_checkmask,
> + .set_default_value = qdev_propinfo_set_default_value_uint,
> };
>
> /* --- pointer-size integer --- */
> diff --git a/include/hw/core/qdev-properties.h
> b/include/hw/core/qdev-properties.h
> index c06de37b1e9d..2ac784bb5e9c 100644
> --- a/include/hw/core/qdev-properties.h
> +++ b/include/hw/core/qdev-properties.h
> @@ -128,14 +128,14 @@ extern const PropertyInfo qdev_prop_link;
> ##__VA_ARGS__)
>
> /**
> - * The DEFINE_PROP_UINT64_CHECKMASK macro checks a user-supplied value
> - * against corresponding bitmask, rejects the value if it violates.
> - * The default value is set in instance_init().
> + * The DEFINE_PROP_UINT64_CHECKMASK macro checks a value against
> corresponding
> + * bitmask, rejects the value if it violates.
> */
> -#define DEFINE_PROP_UINT64_CHECKMASK(_name, _state, _field, _bitmask) \
> - DEFINE_PROP(_name, _state, _field, qdev_prop_uint64_checkmask, uint64_t,
> \
> - .bitmask = (_bitmask), \
> - .set_default = false)
> +#define DEFINE_PROP_UINT64_CHECKMASK(_name, _state, _field, _bitmask,
> _defval) \
> + DEFINE_PROP(_name, _state, _field, qdev_prop_uint64_checkmask, uint64_t,
> \
> + .bitmask = (_bitmask),
> \
> + .set_default = true,
> \
> + .defval.u = (_defval))
>
> /**
> * DEFINE_PROP_ARRAY:
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index a6d943c53a3f..56735570d66c 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -10265,9 +10265,7 @@ static void x86_cpu_initfn(Object *obj)
> object_property_add_alias(obj, "pause_filter", obj, "pause-filter");
> object_property_add_alias(obj, "sse4_1", obj, "sse4.1");
> object_property_add_alias(obj, "sse4_2", obj, "sse4.2");
> -
> object_property_add_alias(obj, "hv-apicv", obj, "hv-avic");
> - cpu->lbr_fmt = ~PERF_CAP_LBR_FMT;
> object_property_add_alias(obj, "lbr_fmt", obj, "lbr-fmt");
>
> if (xcc->model) {
> @@ -10439,7 +10437,7 @@ static const Property x86_cpu_properties[] = {
> #endif
> DEFINE_PROP_INT32("node-id", X86CPU, node_id, CPU_UNSET_NUMA_NODE_ID),
> DEFINE_PROP_BOOL("pmu", X86CPU, enable_pmu, false),
> - DEFINE_PROP_UINT64_CHECKMASK("lbr-fmt", X86CPU, lbr_fmt,
> PERF_CAP_LBR_FMT),
> + DEFINE_PROP_UINT64_CHECKMASK("lbr-fmt", X86CPU, lbr_fmt,
> PERF_CAP_LBR_FMT, 0),
>
> DEFINE_PROP_UINT32("hv-spinlocks", X86CPU, hyperv_spinlock_attempts,
> HYPERV_SPINLOCK_NEVER_NOTIFY),
