Re: [PATCH 1/4] x86/sgx: Add sgx_nr_all_pages to the debugfs

Greg KH
2021-07-06T15:39:20Z

On Tue, Jul 06, 2021 at 07:56:40AM -0700, Dave Hansen wrote:
> On 7/5/21 7:36 AM, Jarkko Sakkinen wrote:
> > Create /sys/kernel/debug/x86/sgx_nr_all_pages, which reports total
> > number of EPC pages available in the system.
> Could we flesh this out a bit, please?
>
> What's the value here when userspace could just re-enumerate the EPC
> size from CPUID?
>
> I'd really appreciate if we could draw parallels between these additions
> to the "SGX VM" and their analogs in the "core VM". In this case, I
> think the closest analog is probably "MemTotal" in /proc/meminfo.
>
> Second, how is this going to be used?
>
> Third, is this going to be the ABI forever?

debugfs is never a stable abi. If it is being used as such, then the
kernel code is wrong. This better just be debugging stuff only.

thanks,

greg k-h