Re: [PATCH v2 1/2] hw/misc: Supporting AST2600 HACE accumulative mode

[Cédric Le Goater]

> > -static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode)
> > +static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode,
> > +                              bool acc_mode)
> >   {
> >       struct iovec iov[ASPEED_HACE_MAX_SG];
> >       g_autofree uint8_t *digest_buf;
> > @@ -103,6 +106,7 @@ static void do_hash_operation(AspeedHACEState *s, int algo, 
> > bool sg_mode)
> >       if (sg_mode) {
> >           uint32_t len = 0;
> > +        uint32_t total_len = 0;
> >           for (i = 0; !(len & SG_LIST_LEN_LAST); i++) {
> >               uint32_t addr, src;
> > @@ -123,10 +127,26 @@ static void do_hash_operation(AspeedHACEState *s, int 
> > algo, bool sg_mode)
> >                                           MEMTXATTRS_UNSPECIFIED, NULL);
> >               addr &= SG_LIST_ADDR_MASK;
> > -            iov[i].iov_len = len & SG_LIST_LEN_MASK;
> > -            plen = iov[i].iov_len;
> > +            plen = len & SG_LIST_LEN_MASK;
> >               iov[i].iov_base = address_space_map(&s->dram_as, addr, &plen, 
> > false,
> >                                                   MEMTXATTRS_UNSPECIFIED);
> > +
> > +            if (acc_mode) {
> > +                total_len += plen;
> > +
> > +                if (len & SG_LIST_LEN_LAST) {
> > +                    /*
> > +                     * In the padding message, the last 64/128 bit represents
> > +                     * the total length of bitstream in big endian.
> > +                     * SHA-224, SHA-256 are 64 bit
> > +                     * SHA-384, SHA-512, SHA-512/224, SHA-512/256 are 128 bit
> > +                     * However, we would not process such a huge bit stream.
>
> If we do not support accumulative mode with SHA-384, SHA-512, SHA-512/224,
> SHA-512/256 algos, we should make sure that do_hash_operation() is not
> called and emit a warning.

I misunderstood the comment. I don't think it is very complex to
extract the total length field correctly. You only need the algo
type to pick the right size. May be add one more parameter to
do_hash_operation() and


> > +                     */
> > +                    plen -= total_len - (ldq_be_p(iov[i].iov_base + plen - 8) 
> > / 8);

change the offset in the above ?

Thanks,

C.