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?
My thinking is that it is better to use "kernel synthesized" value for the EPC size, because kernel controls the EPC.
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.
Would make sense.
Second, how is this going to be used?
SGX kselftest creates a heap, of which size is the same as the total size of the EPC reported by the kernel.
Third, is this going to be the ABI forever?
AFAIK, debugfs is not part of the ABI.
/Jarkko