Re: [Qemu-devel] encrypt in threads

[Daniel P . Berrangé]

On Wed, Nov 21, 2018 at 05:30:53PM +0000, Vladimir Sementsov-Ogievskiy wrote:
> Hi Daniel!
> 
> After moving compression to threads in Qcow2 it's an obvious next step to
> "threadyfy" encryption in Qcow2 too.
> 
> But it turned out to be not as simple as I assumed. If I call 
> qcrypto_block_encrypt
> in parallel threads with the same first argument (block), it just produce 
> wrong
> things (pattern verification fails in iotests)..

Yes, this makes sense, because the underlying crypto impls all require
that their state is only used from a single thread at any time. What's
likely happening is that the IV is being scrambled so we're encrypting
with the wrong tweak.

Regards,
Daniel
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