On Sun, Nov 26, 2017 at 07:33:56PM +0200, Jarkko Sakkinen wrote:
> > +struct sgx_encl_page {
> > +   unsigned long addr;
> > +   unsigned int flags;
> > +   void *epc_page;
> > +   struct sgx_va_page *va_page;
> > +   unsigned int va_offset;
> > +   struct list_head list;
> > +};
> 
> This can be without major streches hoops packed way more. There are 12
> bits free for use in the addr field. I can use low three bits for flags
> and upper nine bits for va_offset.
> 
> I think I can also quite easily union epc_page and va_page fields.
> 
> With these changes the struct would shrink to:
> 
> struct sgx_encl_page {
>       unsigned long addr;
>       union {
>               void *epc_page;
>               struct sgx_va_page *va_page;
>       };
>       struct list_head list;
> };

Once I started to thinking more about this I realized that this can be
shrunk even further. I can drop the list field and use a tag for loaded
pages in the radix tree where these are stored. The end result would be

struct sgx_encl_page {
        unsigned long addr;
        union {
                void *epc_page;
                struct sgx_va_page *va_page;
        };
};

/Jarkko

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