Re: [PATCH RFC] KVM: nSVM: Fix L1 state corruption upon return from SMM

[Paolo Bonzini]

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