Re: [PATCH v33 11/21] x86/sgx: Linux Enclave Driver

Jarkko Sakkinen
2020-06-26T14:20:00Z

On Thu, Jun 25, 2020 at 11:34:48AM -0700, Sean Christopherson wrote:
> On Thu, Jun 25, 2020 at 07:23:19PM +0200, Borislav Petkov wrote:
> > Also, you had all patches until now split nice and logically doing one
> > thing only.
> >
> > But this one is huge. Why?
> >
> > Why can't you split out the facilities which the driver uses: encl.[ch]
> > into a patch, then ioctl.c into a separate one and then the driver into
> > a third one? Or do they all belong together inseparably?
> >
> > I guess I'll find out eventually but it would've been nice if they were
> > split out...
>
> Hmm, I think the most reasonable way to break up this beast would be to
> incrementally introduce functionality. E.g. four or so patches, one for
> each ioctl() of ENCLAVE_CREATE, ENCLAVE_ADD_PAGES, ENCLAVE_INIT and
> ENCLAVE_SET_ATTRIBUTE, in that order.
>
> Splitting up by file probably wouldn't work very well. The split is
> pretty arbitrary, e.g. encl.[ch] isn't simply a pure representation of an
> enclave, there is a lot of the driver details/dependencies in there, i.e.
> the functionality between encl/ioctl/driver is all pretty intertwined.
>
> But I think serially introducing each ioctl() would be fairly clean, and
> would help readers/reviewers better understand SGX as the patches would
> naturally document the process of building an enclave, e.g. CREATE the
> enclave, then ADD_PAGES, then INIT the enclave. SET_ATTRIBUTE is a bit
> of an outlier in that it would be chronologically out of order with
> respect to building the enclave, but I think that's ok.
>
> Jarkko, thoughts?

I proposed the same before I go this email so I guess we have a
consensus here.

/Jarkko