Currently, the KVM x86 always reports KVM_MAX_VCPUS for all VMs but doesn't
allow to enable KVM_CAP_MAX_VCPUS to configure the number of maximum vcpus
maximum number of vcpus
on VM-basis.
Add "per-VM maximum vcpus" to KVM x86/TDX to accommodate TDX's needs.
The userspace-configured value then can be verified when KVM is actually
used
creating the TDX guest.
"
I think we still have two options regarding to how 'max_vcpus' is
handled in ioctl() to do TDH.MNG.INIT:
1) Just use the 'max_vcpus' done in KVM_ENABLE_CAP(KVM_CAP_MAX_VCPUS),
2) Still pass the 'max_vcpus' as input, but KVM verifies it against the
value that is saved in KVM_ENABLE_CAP(KVM_CAP_MAX_VCPUS).
2) seems unnecessary, so I don't have objection to use 1). But it seems
we could still mention it in the changelog in that patch?
