Re: [PATCH v2 0/4] Introduce bulk mode for crypto engine framework

From: Herbert Xu
Date: Mon Apr 18 2016 - 04:20:21 EST


On Mon, Apr 18, 2016 at 04:14:48PM +0800, Baolin Wang wrote:
> On 18 April 2016 at 16:04, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Mon, Apr 18, 2016 at 03:58:59PM +0800, Baolin Wang wrote:
> >>
> >> That depends on the hardware engine. Some cipher hardware engines
> >> (like xts(aes) engine) can handle the intermediate values (IV) by
> >> themselves in one bulk block, which means we can increase the size of
> >> the request by merging request rather than always 512 bytes and thus
> >> increase the hardware engine processing speed. But for some other
> >> hardware engines (like cbc(aes) engine), they can not support bulk
> >> block, must sector by sector. So the engine drivers can select the
> >> suitable mode to do encryption/decryption.
> >
> > So what is this supposed to handle, xts or cbc?
>
> As I know, now cbc engine also need to handle requests sector by
> sector, but for xts/ecb engine can support bulk block, which means can
> merge requests.

If it's just xts then why can't dm-crypt merge it and send a single
request?

Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt