On 23/06/21 09:44, Vitaly Kuznetsov wrote:
- RFC: I'm not 100% sure my 'smart' idea to use currently-unused HSAVE area is that smart. Also, we don't even seem to check that L1 set it up upon nested VMRUN so hypervisors which don't do that may remain broken. A very much needed selftest is also missing.
It's certainly a bit weird, but I guess it counts as smart too. It needs a few more comments, but I think it's a good solution.
One could delay the backwards memcpy until vmexit time, but that would require a new flag so it's not worth it for what is a pretty rare and already expensive case.
Paolo
