Re: [RFC 2/7] iommu/vt-d: Remove iova handling code from non-dma ops path

Lu Baolu
2019-05-05T01:22:47Z

Hi,

On 5/5/19 9:19 AM, Lu Baolu wrote:
> Hi,
>
> On 5/4/19 9:23 PM, Tom Murphy via iommu wrote:
>> @@ -4181,58 +4168,37 @@ static int intel_iommu_memory_notifier(struct
>> notifier_block *nb,
>>                          unsigned long val, void *v)
>>   {
>>       struct memory_notify *mhp = v;
>> -    unsigned long long start, end;
>> -    unsigned long start_vpfn, last_vpfn;
>> +    unsigned long start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
>> +    unsigned long last_vpfn = mm_to_dma_pfn(mhp->start_pfn +
>> +            mhp->nr_pages - 1);
>>       switch (val) {
>>       case MEM_GOING_ONLINE:
>> -        start = mhp->start_pfn << PAGE_SHIFT;
>> -        end = ((mhp->start_pfn + mhp->nr_pages) << PAGE_SHIFT) - 1;
>> -        if (iommu_domain_identity_map(si_domain, start, end)) {
>> -            pr_warn("Failed to build identity map for [%llx-%llx]\n",
>> -                start, end);
>> +        if (iommu_domain_identity_map(si_domain, start_vpfn,
>> +                    last_vpfn)) {
>> +            pr_warn("Failed to build identity map for [%lx-%lx]\n",
>> +                start_vpfn, last_vpfn);
>>               return NOTIFY_BAD;
>>           }
>>           break;
>
> Actually we don't need to update the si_domain if iommu hardware
> supports pass-through mode. This should be made in a separated patch
> anyway.

Oh! please ignore it.

This callback is only registered when hardware doesn't support pass
through mode.

if (si_domain && !hw_pass_through)
register_memory_notifier(&intel_iommu_memory_nb);

Best regards,
Lu Baolu