Re: [RFC][PATCH 05/13] xen/x86/p2m: introduce set_identity_p2m_entry

["Chen, Tiejun" <tiejun.chen@intel.com>]

On 2015/4/16 23:05, Tim Deegan wrote:
> Hi,
>
> At 17:21 +0800 on 10 Apr (1428686516), Tiejun Chen wrote:
>> @@ -862,6 +862,36 @@ int set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
>>       return set_typed_p2m_entry(d, gfn, mfn, p2m_mmio_direct, access);
>>   }
>>
>> +int set_identity_p2m_entry(struct domain *d, unsigned long gfn,
>> +                           p2m_access_t p2ma)
>> +{
>> +    p2m_type_t p2mt;
>> +    p2m_access_t a;
>> +    mfn_t mfn;
>> +    struct p2m_domain *p2m = p2m_get_hostp2m(d);
>> +    int ret = -EBUSY;
>> +
>> +    gfn_lock(p2m, gfn, 0);
>> +
>> +    mfn = p2m->get_entry(p2m, gfn, &p2mt, &a, 0, NULL);
>> +
>> +    if ( !mfn_valid(mfn) )
>
> I don't think this check is quite right -- for example, this p2m entry
> might be an MMIO mapping or a PoD entry.  "if ( p2mt == p2m_invalid )"
> would be better.

Okay.

>
>> +        ret = p2m_set_entry(p2m, gfn, _mfn(gfn), PAGE_ORDER_4K, p2m_mmio_direct,
>
> This line seems to be > 80 chars -- can you wrap it a bit earlier, please?
>

Thanks.

Tiejun