Re: [PATCH v4 1/5] KVM: MMU: fix release noslot pfn

Xiao Guangrong
2012-10-12T09:49:30Z

On 10/11/2012 10:31 PM, Marcelo Tosatti wrote:
> On Thu, Oct 11, 2012 at 09:06:12PM +0800, Xiao Guangrong wrote:
>> On 10/10/2012 11:11 PM, Marcelo Tosatti wrote:
>>
>>>
>>> Why does is_error_pfn() return true for mmio spte? Its not an "error",
>>> after all.
>>>
>>> Please kill is_invalid_pfn and use
>>>
>>> -> is_error_pfn for checking for errors (mmio spte is not an error pfn,
>>> its a special pfn)
>>>
>>> -> add explicit is_noslot_pfn checks where necessary in the code
>>> (say to avoid interpreting a noslot_pfn's pfn "address" bits).
>>>
>>> (should have noticed this earlier, sorry).
>>
>> Never mind, your comments are always appreciated! ;)
>>
>> Marcelo, is it good to you?
>> (will post it after your check and full test)
>
> Yes, this works (please check the validity of each case in addition to
> testing, haven't done it).
>
> Also add a oneline comment on top of each
> is_error_pfn,is_noslot_pfn,is_error_noslot_pfn
>
> /* is_noslot_pfn: userspace translation valid but no memory slot */
> /* is_error_pfn: ... */
>
> etc.
>

Marcelo, i think this fix should be backport and your idea can be a
separate patchset. Yes?