Re: [RFC PATCH v5 3/4] x86/acrn: Use HYPERVISOR_CALLBACK_VECTOR for ACRN guest upcall vector

[Zhao, Yakui]

On 2019å04æ26æ 03:45, Ingo Molnar wrote:
> * Zhao, Yakui <yakui.zhao@xxxxxxxxx> wrote:
>
> > > > +	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
> > > > +			acrn_hv_callback_vector);
> > >
> > > Why is this on two lines, not a single line?
> >
> > At first it used the long function name for acrn_hv_callback_vector.
> > As it exceeds 80 columns, it is split into two lines.
>
> No, it doesn't exceed 80 columns - the last character of that line is on
> column 71.

Thanks for the helps.
It will be fixed.
> > > Does the hypervisor model the APIC EOI command, i.e. does it require the
> > > APIC to be acked? I.e. would not acking the APIC create an IRQ storm?
> >
> > The hypervisor requires that the APIC EOI should be acked. If the EOI APIC
> > is not acked, the APIC ISR bit for the HYPERVISOR_CALLBACK_VECTOR will not
> > be cleared and then it will block the interrupt whose vector is lower than
> > HYPERVISOR_CALLBACK_VECTOR.
>
> Ok!

I will add some comments for calling entering_ack_irq in 
acrn_hv_callback_handler. Is this ok to you?

> Thanks,
>
> 	Ingo