Re: [PATCH v5 8/8] KVM: VMX: Resize PID-ponter table on demand for IPI virtualization

[Sean Christopherson]

On Wed, Jan 19, 2022, Zeng Guang wrote:
> It's self-adaptive , standalone function module in kvm, no any extra
> limitation introduced

I disagree.  Its failure mode on OOM is to degrade guest performance, _that_ is
a limitation.  OOM is absolutely something that should be immediately communicated
to userspace in a way that userspace can take action.

> and scalable even future extension on KVM_MAX_VCPU_IDS or new apic id
> implementation released.
>
> How do you think ? :)

Heh, I think I've made it quite clear that I think it's unnecesary complexity in
KVM.  It's not a hill I'll die on, e.g. if Paolo and others feel it's the right
approach then so be it, but I really, really dislike the idea of dynamically
changing the table, KVM has a long and sordid history of botching those types
of flows/features.