Re: [dpdk-dev] [PATCH v2 00/15] add OCTEONTX2 inline IPsec support

[Akhil Goyal <akhil.goyal@nxp.com>]

Hi Jerin,

> 
> On Mon, Jan 27, 2020 at 4:10 PM Akhil Goyal <akhil.goyal@nxp.com> wrote:
> >
> >
> > >
> > > On Wed, Jan 22, 2020 at 6:26 PM Akhil Goyal <akhil.goyal@nxp.com> wrote:
> > > >
> > > > > > >
> > > > > > > Hi Jerin,
> > > > > > >
> > > > > > > Will  do the suggested change (RX/rx-> Rx & TX/tx->Tx). Do you want
> me
> > > > > > > to trim the headline as well?
> > > > > > >
> > > > > >
> > > > > > Hi Anoob,
> > > > > >
> > > > > > > @Akhil, did you get a chance to review the series? Do you have any
> > > > > > > comments on the patches?
> > > > > > >
> > > > > >
> > > > > > You are adding inline ipsec support to ethernet device and not a crypto
> > > > > > device.
> > > > > > These patches should not be part of crypto PMD. There will be cyclic
> > > > > > dependency Between ethernet device and crypto device which can be
> > > easily
> > > > > > avoided.
> > > > >
> > > > > [Anoob] We have plans to use lookaside protocol to handle the "fallback"
> > > > > session. And that involves session sharing between inline and lookaside
> > > protocol
> > > > > offloads. Also, though the feature is exposed as a feature of ethdev, on
> our
> > > > > platform, it's the crypto block which primarily implements the feature.
> And
> > > so, if
> > > > > the code is moved to ethdev dir, there would be lot of code duplication.
> The
> > > > > idea is to have all security related code in one place.
> > > > >
> > > > > Also, the PMDs don't have any calls to each other. The communication
> > > between
> > > > > the two happens via common. The crypto dev PMD will register the
> required
> > > > > security ops to a common structure and ethdev would get it from there.
> So
> > > there
> > > > > won't be an issue of build dependency.
> > > > >
> > > >
> > > > - The code that need to be duplicated can be moved to drivers/common/
> > >
> > > I would like to keep the common code that is common to all the
> coprocessors.
> > >
> > > Moreover, there are logistic issues in that case where
> > > a) drivers/common/octeontx2/ going through master repo. So we will be
> > > creating unnecessary dependency with that 'master' tree.
> > > b) crypto and ethdev work is done by different teams so we would like
> > > to make responsibly clear wrt the review and ownership.
> >
> > I can agree upon that the code shall not be placed in the common/octeontx2,
> > But you can have a header file in crypto/octeontx2/ which has some inline
> functions
> > Which can be called from the ethernet as well as crypto device for inline proto
> > And lookaside cases respectively. I think with that the maintainability would
> not
> > be an issue.
> >
> > IMO, following approach can be looked upon and may be cleaner
> > - define security ctx and its ops in net/octeontx2.c or net/octeontx2_security.c
> > These are all control path and should not be any issue.
> >
> > - define crypto specific code (inline functions) in crypto/octeontx2_security.h
> > Which can be called for both inline protocol as well as lookaside proto case.
> 
> One problem with such an approach is we need to have fat inline functions.
> In some case, those inline functions to needs  accessing the
> array/driver specific symbols
> in another driver namespace then those array needs to be exported in
> map file and hence the
> build dependency comes.

How many such symbols are there. I don’t they will be many. Can they be
Passed as argument in the APIs to avoid build dependencies.

> 
> 
> >
> > - for data path you can have the processing as is. I hope all dependencies can
> > Be dealt with as the code will be there in crypto driver for all the mapping of
> > Event and crypto queues.
> >
> > - all APIs which are common for ethernet device and crypto device in
> > octeontx2_security.h should not prefix eth as is the case in current APIs.
> 
> If I understand it correctly, You have a concern in having the
> *rte_eth* symbols in driver/crypto/octeontx2?
> If so, we can check what can be done. Let us know the exact your
> concern in managing the code in this
> model?

Yes, rte_eth* symbols should not be there in crypto driver.
Because crypto driver is not leveraging any ethernet functionality,
It is the other way, ethernet device is using the crypto functionality/
Structs etc for supporting inline IPSEC.

Also, the security ctx should be part of ethdev  and its ops should be
Defined in ethernet device which may call some inline APIs placed in
Drivers/crypto/octeontx2/

> 
> >
> > I hope this will clear the ugliness of the code.
> 
> It is relative, I think, having fat inline functions and accessing
> both drivers is ugly.

Breaking the way an API need to be defined and used is even more uglier.
IMO, having fat inline functions will act as external library functions which
Are independent of the device which is calling it.
Something similar to drivers/common/dpaax/caamflib/.

My original suggestion was to put it in common, but I am ok, if you want that
In the crypto driver. I agree with the decision that all crypto/ipsec related stuff
Should be there under drivers/crypto if it is getting used from both the net and
Crypto driver. But atleast the API definitions should be there where it should be.


> 
> > >
> > > I would like to keep the security/crypto-related code to driver/crypto and
> > > hook to driver/net/octeontx2 with required functionalities over the
> > > driver/common
> > > using a few function pointers to remove the cyclic build dependency.
> > >
> > > Considering there is no cyclic build and shared library dependency
> > > now, Can we make forward progress
> > > with the existing scheme?
> > >
> > > > - You may not need to include rte_ethdev.h inside drivers/crypto
> > > > - otx2_sec_eth_ctx_create should be part of ethdev and you would need
> > > similar API
> > > > for crypto device as well when you would support the fallback session
> support.
> > > > So that would go in crypto. Session creation code may be common and can
> go
> > > > in drivers/common.
> > > > - You would have separate security_ctx for both eth device and crypto
> device
> > > and that should
> > > > In net device and crypto device separately. Similarly security->ops should
> be
> > > different in both of them.
> > > > However if they may have same session creation code and that can go in
> > > common.
> > > >
> >