Re: [PATCH 03/22] kvm: mmu: Init / Uninit the TDP MMU

[Paolo Bonzini]

On 30/09/20 18:57, Sean Christopherson wrote:
>> +
>> +static bool __read_mostly tdp_mmu_enabled = true;
>> +module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0644);
> This param should not exist until the TDP MMU is fully functional, e.g. running
> KVM against "kvm: mmu: Support zapping SPTEs in the TDP MMU" immediately hits a
> BUG() in the rmap code.  I haven't wrapped my head around the entire series to
> grok whether it make sense to incrementally enable the TDP MMU, but my gut says
> that's probably non-sensical.

No, it doesn't.  Whether to add the module parameter is kind of
secondary, but I agree it shouldn't be true---not even at the end of
this series, since fast page fault for example is not implemented yet.

Paolo