Re: [PATCH 2/2] kvm: rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDS

From: Eduardo Habkost
Date: Mon Sep 13 2021 - 12:57:05 EST


On Mon, Sep 13, 2021 at 12:24 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> On Mon, Sep 13, 2021, Juergen Gross wrote:
> > KVM_MAX_VCPU_ID is not specifying the highest allowed vcpu-id, but the
> > number of allowed vcpu-ids. This has already led to confusion, so
> > rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDS to make its semantics more
> > clear
>
> My hesitation with this rename is that the max _number_ of IDs is not the same
> thing as the max allowed ID. E.g. on x86, given a capability that enumerates the
> max number of IDs, I would expect to be able to create vCPUs with arbitrary 32-bit
> x2APIC IDs so long as the total number of IDs is below the max.
>

What name would you suggest instead? KVM_VCPU_ID_LIMIT, maybe?

I'm assuming we are not going to redefine KVM_MAX_VCPU_ID to be an
inclusive limit.

--
Eduardo