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

From: Zhao, Yakui
Date: Thu Apr 25 2019 - 21:49:24 EST

On 2019å04æ26æ 03:45, Ingo Molnar wrote:

* Zhao, Yakui <yakui.zhao@xxxxxxxxx> wrote:

+ 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


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