Re: [PATCH v4 1/2] qdev-properties: Add a new macro with bitmask check for uint64_t property

[Yang Weijiang <weijiang.yang@intel.com>]

On Sun, Jun 20, 2021 at 10:42:36AM +0800, Yang, Weijiang wrote:

Hi, Paolo and Eduardo,

Legacy Arch LBR patches have been merged in 5.12 kernel tree, these patches
are corresponding change from QEMU side, without these patches,legacy Arch LBR
cannot work, could you review them at your convenience?

Thanks a lot!

> The DEFINE_PROP_UINT64_CHECKMASK maro applies certain mask check agaist
> user-supplied property value, reject the value if it violates the bitmask.
> 
> Co-developed-by: Like Xu <like.xu@linux.intel.com>
> Signed-off-by: Like Xu <like.xu@linux.intel.com>
> Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
> ---
>  hw/core/qdev-properties.c    | 19 +++++++++++++++++++
>  include/hw/qdev-properties.h | 12 ++++++++++++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> index 50f40949f5..343a200784 100644
> --- a/hw/core/qdev-properties.c
> +++ b/hw/core/qdev-properties.c
> @@ -428,6 +428,25 @@ const PropertyInfo qdev_prop_int64 = {
>      .set_default_value = qdev_propinfo_set_default_value_int,
>  };
>  
> +static void set_uint64_checkmask(Object *obj, Visitor *v, const char *name,
> +                      void *opaque, Error **errp)
> +{
> +    Property *prop = opaque;
> +    uint64_t *ptr = object_field_prop_ptr(obj, prop);
> +
> +    visit_type_uint64(v, name, ptr, errp);
> +    if (*ptr & ~prop->bitmask) {
> +        error_setg(errp, "Property value for '%s' violates bitmask '0x%lx'",
> +                   name, prop->bitmask);
> +    }
> +}
> +
> +const PropertyInfo qdev_prop_uint64_checkmask = {
> +    .name  = "uint64",
> +    .get   = get_uint64,
> +    .set   = set_uint64_checkmask,
> +};
> +
>  /* --- string --- */
>  
>  static void release_string(Object *obj, const char *name, void *opaque)
> diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
> index 0ef97d60ce..075882e8c1 100644
> --- a/include/hw/qdev-properties.h
> +++ b/include/hw/qdev-properties.h
> @@ -17,6 +17,7 @@ struct Property {
>      const PropertyInfo *info;
>      ptrdiff_t    offset;
>      uint8_t      bitnr;
> +    uint64_t     bitmask;
>      bool         set_default;
>      union {
>          int64_t i;
> @@ -53,6 +54,7 @@ extern const PropertyInfo qdev_prop_uint16;
>  extern const PropertyInfo qdev_prop_uint32;
>  extern const PropertyInfo qdev_prop_int32;
>  extern const PropertyInfo qdev_prop_uint64;
> +extern const PropertyInfo qdev_prop_uint64_checkmask;
>  extern const PropertyInfo qdev_prop_int64;
>  extern const PropertyInfo qdev_prop_size;
>  extern const PropertyInfo qdev_prop_string;
> @@ -102,6 +104,16 @@ extern const PropertyInfo qdev_prop_link;
>                  .set_default = true,                         \
>                  .defval.u    = (bool)_defval)
>  
> +/**
> + * 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().
> + */
> +#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 PROP_ARRAY_LEN_PREFIX "len-"
>  
>  /**
> -- 
> 2.21.1