Re: [PATCH 1/5] mmu: mark spte present if the x bit is set

Wanpeng Li
2016-07-05T11:29:48Z

2016-07-05 18:50 GMT+08:00 Paolo Bonzini <pbonzini@redhat.com>:
>
>
> On 05/07/2016 05:06, Wanpeng Li wrote:
>> 2016-06-29 4:49 GMT+08:00 Paolo Bonzini <pbonzini@redhat.com>:
>> [...]
>>>
>>> I think another way to write it is "(pte & 0xFFFFFFFFull) &&
>>> !is_mmio_spte(pte)", since non-present/non-MMIO SPTEs never use bits
>>
>> I misunderstand it here, this will also treat -W- EPT SPTEs as present, right?
>
> -W- EPT SPTEs are present but invalid. They should never happen unless
> they are MMIO SPTEs (in which case !is_mmio_spte(pte) will return true
> and the function will return false).

Thanks for the explanation. :)

Regards,
Wanpeng Li