Re: [PATCH 9/11] Panic delay fix

Zachary Amsden
2007-02-08T09:08:18Z

Andi Kleen wrote:
> On Wed, Feb 07, 2007 at 02:31:57PM -0800, Zachary Amsden wrote:
>
>> Dmitry Torokhov wrote:
>>
>>> I am confused - does i8042 talk to a virtual or real hardware here? In
>>> any case I think you need to fix kernel/panic.c to have proper
>>> (m)delay, not mess with i8042.
>>>
>> I think I need to fix both of them actually. This is virtual hardware,
>> but when you grab focus on a VM, the virtual hardware gets reflected to
>> the actual physical keyboard. Driving physical hardware that fast is bad.
>>
>
> ???
>
> Surely the physical keyboard is always handled by the host kernel?
> I hope you're not saying it's trying to access the io ports directly?
>

No, not that. But the virtual keyboard I/O gets processed and converted
to physical keyboard I/O when a keyboard is attached to a VM. The
result is that the virtual keyboard spinning out of control causes the
physical keyboard to receive the same commands, far too rapidly.

So the keyboard blinks out of control and acts as if possessed by demons.

Zach