Re: [RFC PATCH v3 26/59] KVM: x86: Introduce vm_teardown() hook in kvm_arch_vm_destroy()

Paolo Bonzini
2021-11-25T20:58:40Z

On 11/25/21 20:46, Thomas Gleixner wrote:
> On Wed, Nov 24 2021 at 16:20, isaku yamahata wrote:
>> Add a second kvm_x86_ops hook in kvm_arch_vm_destroy() to support TDX's
>> destruction path, which needs to first put the VM into a teardown state,
>> then free per-vCPU resource, and finally free per-VM resources.
>>
>> Note, this knowingly creates a discrepancy in nomenclature for SVM as
>> svm_vm_teardown() invokes avic_vm_destroy() and sev_vm_destroy().
>> Moving the now-misnamed functions or renaming them is left to a future
>> patch so as not to introduce a functional change for SVM.
> That's just the wrong way around. Fixup SVM first and then add the TDX
> muck on top. Stop this 'left to a future patch' nonsense. I know for
> sure that those future patches never materialize.

Or just keep vm_destroy for the "early" destruction, and give a new name
to the new hook. It is used to give back the TDCS memory, so perhaps
you can call it vm_free?

Paolo