On 1/12/24 21:37, Dave Hansen wrote:

On 1/12/24 12:28, Tom Lendacky wrote:

quoted

I thought there was also a desire to remove the direct map for any pages
assigned to a guest as private, not just the case that the comment says.
So updating the comment would probably the best action.

I'm not sure who desires that.

It's sloooooooow to remove things from the direct map.  There's almost
certainly a frequency cutoff where running the whole direct mapping as
4k is better than the cost of mapping/unmapping.

Actually, where _is_ the TLB flushing here?

Hm yeah it seems to be using the _noflush version? Maybe the RMP issues this
avoids are only triggered with actual page tables and a stray outdated TLB
hit doesn't trigger it? Needs documenting though if that's the case.