On Mon, Jan 18, 2021 at 04:28:07PM +1000, Nicholas Piggin wrote: > The slbmte instruction is legal in radix mode, including radix guest > mode. This means radix guests can load the SLB with arbitrary data. > > KVM host does not clear the SLB when exiting a guest if it was a > radix guest, which would allow a rogue radix guest to use the SLB as > a side channel to communicate with other guests. No, because the code currently clears the SLB when entering a radix guest, which you remove in the next patch. I'm OK with moving the SLB clearing from guest entry to guest exit, I guess, but I don't see that you are in fact fixing anything by doing so. Paul.
