3 ms·
Unwinding changes to the TLB on every mispredict would have a significant overhead and hurt overall performance. Removing valid data you just cached (speculativ
by jprx 4y ago
Unwinding changes to the TLB on every mispredict would have a significant overhead and hurt overall performance. Removing valid data you just cached (speculatively or otherwise) is generally a bad idea.
User mode software requires a TLB (unless you want to do a page walk for every single instruction!)
Even if you could remove the TLB entirely from the CPU somehow, the attacker could just use the cache or some other microarchitectural structure.
- aaron_m04 4y agoWell that's disappointing. Thanks for the explanation! I never have to worry about such low level details in my day-to-day work, so this is all new to me.