Re: [PATCH 09/26] KVM: PPC: Add PV guest scratch registers

Alexander Graf
2010-06-27T09:41:49Z

Am 27.06.2010 um 10:22 schrieb Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>:

> On 06/26/2010 02:24 AM, Alexander Graf wrote:
>> While running in hooked code we need to store register contents out
>> because
>> we must not clobber any registers.
>>
>> So let's add some fields to the shared page we can just happily
>> write to.
>>
>>
>
> How are these protected during interrupts?

By the 'critical section' bit. When in a critical section (read: using
scratch registers), we don't issue interrupts.

Alex