[PATCH] powerpc/kvm: Handle the boundary condition correctly

[Alexander Graf]

On 26.08.2013, at 05:28, Aneesh Kumar K.V wrote:

> Alexander Graf <agraf at suse.de> writes:
> 
>> On 23.08.2013, at 04:31, Aneesh Kumar K.V wrote:
>> 
>>> Alexander Graf <agraf at suse.de> writes:
>>> 
>>>> On 22.08.2013, at 12:37, Aneesh Kumar K.V wrote:
>>>> 
>>>>> From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>
>>>> 
>>>> Isn't this you?
>>> 
>>> Yes. The patches are generated using git format-patch and sent by
>>> git send-email. That's how it always created patches for me. I am not sure if
>>> there is a config I can change to avoid having From:
>>> 
>>>> 
>>>>> 
>>>>> We should be able to copy upto count bytes
>>>> 
>>>> Why?
>>>> 
>>> 
>>> Without this we end up doing
>>> 
>>> +    struct kvm_get_htab_buf {
>>> +        struct kvm_get_htab_header header;
>>> +        /*
>>> +         * Older kernel required one extra byte.
>>> +         */
>>> +        unsigned long hpte[3];
>>> +    } hpte_buf;
>>> 
>>> 
>>> even though we are only looking for one hpte entry.
>> 
>> Ok, please give me an example with real numbers and why it breaks.
>> 
>>> 
>>> http://mid.gmane.org/1376995766-16526-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com
>>> 
> 
> Didn't quiet get what you are looking for. As explained before, we now
> need to pass an array with array size 3 even though we know we need to
> read only 2 entries because kernel doesn't loop correctly.

But we need to do that regardless, because newer QEMU needs to be able to run on older kernels, no?


Alex