Re: [PATCH 0/3] KVM: x86: move nested-related kvm_x86_ops to a separate struct

[Peter Xu]

On Fri, Apr 17, 2020 at 12:44:10PM -0400, Paolo Bonzini wrote:
> While this reintroduces some pointer chasing that was removed in
> afaf0b2f9b80 ("KVM: x86: Copy kvm_x86_ops by value to eliminate layer
> of indirection", 2020-03-31), the cost is small compared to retpolines
> and anyway most of the callbacks are not even remotely on a fastpath.
> In fact, only check_nested_events should be called during normal VM
> runtime.  When static calls are merged into Linux my plan is to use them
> instead of callbacks, and that will finally make things fast again by
> removing the retpolines.

Paolo,

Just out of curiousity: is there an explicit reason to not copy the
whole kvm_x86_nested_ops but use pointers (since after all we just
reworked kvm_x86_ops)?

Thanks,

-- 
Peter Xu