Lukasz <[email protected]> wrote: > From: Nadav Amit [mailto:[email protected]] > Sent: Tuesday, June 14, 2016 8:38 PM > >>> + pte_t pte = ptep_get_and_clear(mm, addr, ptep); >>> + >>> + if (boot_cpu_has_bug(X86_BUG_PTE_LEAK)) >>> + fix_pte_leak(mm, addr, ptep); >>> + return pte; >>> } >> >> I missed it on the previous iteration: ptep_get_and_clear already calls >> fix_pte_leak when needed. So do you need to call it again here? > > You're right, Nadav. Not needing this. Will be removed in next version of the > patch.
Be careful here. According to the SDM when invalidating a huge-page, each 4KB page needs to be invalidated separately. In practice, when Linux invalidates 2MB/1GB pages it performs a full TLB flush. The full flush may not be required on knights landing, and specifically for the workaround, but you should check. Regards, Nadav
