Re: [PATCH v22 16/24] x86/vdso: Add support for exception fixup in vDSO functions

[Jarkko Sakkinen]

On Sat, Oct 05, 2019 at 08:54:13AM -0700, Sean Christopherson wrote:
> On Fri, Oct 04, 2019 at 09:52:21PM +0300, Jarkko Sakkinen wrote:
> > On Thu, Oct 03, 2019 at 05:15:00PM -0700, Sean Christopherson wrote:
> > > I'll tackle this tomorrow.  I've been working on the feature control MSR
> > > series and will get that sent out tomorrow as well.  I should also be able
> > > to get you the multi-page EADD patch.
> > 
> > Great I'll compose the patch set during the weekend and take Monday off
> > so you have the full work day to get everything (probably send the patch
> > set on Sunday).
> 
> Didn't get to the actual SGX stuff yesterday as the feature control series
> took longer than expected to finish.  Working on the other items this
> morning.

I anyway decided to wait for your patches.

I said in earlier email that two ioctl's would be great but I think the
following would be the API that I would actually appreciate the most:

struct sgx_enclave_add_page_desc {
	__u64	addr;
	__u64	src;
	__u64	secinfo;
	__u16	mrmask;
	__u8	reserved[6];
};

struct sgx_enclave_add_page {
	__u64	nr_pages;
	__u64	pages;
};

This will keep the same amount of control and give the performance
benefit. And it is trivial to use in the single page case. Finally,
it follows the principle of minimal delta i.e. we move the least from
the existing API, which is somewhat proven, to fulfill the new
requirement.

Can you use this model for the API? For internals you can choose what
you see fits best.

/Jarkko