* Tom Lendacky <thomas.lendacky@xxxxxxx> wrote: > This patch series provides support for AMD's new Secure Memory Encryption (SME) > feature. I'm wondering, what's the typical performance hit to DRAM access latency when SME is enabled? On that same note, if the performance hit is noticeable I'd expect SME to not be enabled in native kernels typically - but still it looks like a useful hardware feature. Since it's controlled at the page table level, have you considered allowing SME-activated vmas via mmap(), even on kernels that are otherwise not using encrypted DRAM? One would think that putting encryption keys into such encrypted RAM regions would generally improve robustness against various physical space attacks that want to extract keys but don't have full control of the CPU. Thanks, Ingo
