SGX is weird. SGX memory is managed outside the core mm. It doesn't have a 'struct page' and get_user_pages() doesn't work on it. Its VMAs are marked with VM_IO. So, none of the existing methods for avoiding page faults work on SGX memory. This patch set essentially helps extend existing "normal RAM" kernel ABIs to work for avoiding faults for SGX too. SGX users want to enjoy all of the benefits of a delayed allocation policy (better resource use, overcommit, NUMA affinity) but without the cost of millions of faults. Jarkko Sakkinen (3): mm: Add f_op->populate() for populating memory outside of core mm x86/sgx: Export sgx_encl_page_alloc() x86/sgx: Implement EAUG population with MAP_POPULATE arch/x86/kernel/cpu/sgx/driver.c | 128 +++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/encl.c | 38 +++++++++ arch/x86/kernel/cpu/sgx/encl.h | 3 + arch/x86/kernel/cpu/sgx/ioctl.c | 38 --------- include/linux/fs.h | 1 + mm/gup.c | 11 ++- 6 files changed, 178 insertions(+), 41 deletions(-) -- 2.35.1
