Re: [PATCH v2 1/3] KVM: x86: Allow CPU to force vendor-specific TDP level

From: Paolo Bonzini
Date: Tue Aug 10 2021 - 08:47:36 EST


On 10/08/21 13:00, Yu Zhang wrote:
I guess it's because, unlike EPT which are with either 4 or 5 levels, NPT's
level can range from 2 to 5, depending on the host paging mode...

Yes, on Linux that will be one of 3/4/5 based on host paging mode, and it will apply to all N_CR3...

But shadow EPT does not have such annoyance. Is above understanding correct?

... Right, because shadow EPT cannot have less than 4 levels, and it can always use 4 levels if that's what L1 uses.

Paolo