Hi Stefan, > > Subject: Re: [Qemu-devel] [PATCH v14 0/2] virtio-crypto: virtio crypto device > specification > > On Mon, Dec 26, 2016 at 02:38:29AM +0000, Gonglei (Arei) wrote: > > Both Alex and Stefan mentioned that the process of create/close a session > > makes we have a least one full round-trip cost from guest to host to guest > > to be able to send any data for symmetric algorithms. It gets ourself into > > synchronization troubles in some scenarios like a web server handling lots > > of small requests whose algorithms and keys are different. > > > > Because the virtio crypto specification has not been voted yet and v15 is on > the way. > > I'd like to make some changes in order to support those scenarios better. > That means > > we will support one-blob request (no sessions) as well for symmetric > > algorithms, including HASH, MAC services. The benefit is obvious for > > HASH service because it's usually a one-blob operation. > > > > The main changes will be: > > 1) using the flag property of struct virtio_crypto_op_header to identify > > the > > type of crypto request. Aka Is it a session-based or non-session > request? > > The flag is not used currently, so we can make use of it. > > > > 2) extending virtio_crypto_*_para structures, for example, add the content > of > > struct virtio_crypto_cipher_session_para into struct > virtio_crypto_cipher_para. > > It's true that will increase the size of each crypto request after this > change. > > > > Does it make sense? Thanks! > > That sounds good. Hopefully many crypto API users only use a single > operation and can therefore benefit from this optimization. > Thanks for your feedback. I'll start this work.
Regards, -Gonglei
