On Fri, 2022-12-02 at 09:06 -0800, Dave Hansen wrote:
> On 12/2/22 03:11, Huang, Kai wrote:
> > And also to address you concern that not all 892 bytes are reserved, how about
> > below:
> >
> > union {
> > - struct cpuid_config cpuid_configs[0];
> > - u8 reserved5[892];
> > + DECLARE_FLEX_ARRAY(struct cpuid_config, cpuid_configs);
> > + u8 padding[892];
> > };
> > } __packed __aligned(TDSYSINFO_STRUCT_ALIGNMENT);
> >
> > The goal is to make the size of 'struct tdsysinfo_struct' to be 1024B so we can
> > use a static variable for it, and at the meantime, it can still have 1024B
> > (enough space) for the TDH.SYS.INFO to write to.
>
> I just don't like the open-coded sizes.
>
> For instance, wouldn't it be great if you didn't have to know the size
> of *ANYTHING* else to properly size the '892'?
>
> Maybe we just need some helpers to hide the gunk:
>
> #define DECLARE_PADDED_STRUCT(type, name, alignment) \
> struct type##_padded { \
> union { \
> struct type name; \
> u8 padding[alignment]; \
> } \
> } name##_padded;
>
> #define PADDED_STRUCT(name) (name##_padded.name)
>
> That can get used like this:
>
> DECLARE_PADDED_STRUCT(struct tdsysinfo_struct, tdsysinfo,
> TDSYSINFO_STRUCT_ALIGNMENT);
>
>
> struct tdsysinfo_struct sysinfo = PADDED_STRUCT(tdsysinfo)
Thanks. Will try out this way.
