Re: [PATCH] KVM: VMX: Enable memory mappedTPR shadow(FlexPriority)

Dong, Eddie
2007-10-31T14:26:08Z

>
> Hmm...
>
> The patched code needs to answer the question "what will
> happen if I EOI
> this vector now"? I think kvm can prepare the answer for that
> question, since it knows the irq is still asserted and that the mode
> is level-triggered.
>
> Basically the kvm lapic code has to calculate the IRR for a
> "speculative EOI" and post that in the shared memory block. If
> something changes (the IRQ line is de-asserted, for example) again it
> has to recalculate it.

But even it is not changed, we need to clear remote IRR, otherwise,
a new IRQ won't be set for that vector.

thx,eddie