Re: [PATCH] hw/arm/smmuv3: Fix addr_mask for range-based invalidation

[Auger Eric]

Hi Zenghui,

On 1/28/21 9:25 AM, Auger Eric wrote:
> Hi Zenghui,
> 
> On 12/25/20 10:50 AM, Zenghui Yu wrote:
>> When performing range-based IOTLB invalidation, we should decode the TG
>> field into the corresponding translation granule size so that we can pass
>> the correct invalidation range to backend. Set @granule to (tg * 2 + 10) to
>> properly emulate the architecture.
>>
>> Fixes: d52915616c05 ("hw/arm/smmuv3: Get prepared for range invalidation")
>> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
> 
> Good catch! I tested with older guest kernels though. I wonder how I did
> not face the bug?
Please ignore this wrong comment as this corresponds to recent kernels
instead. Still puzzled anyway ;-)

Eric
> 
> 
>> ---
>>  hw/arm/smmuv3.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
>> index bbca0e9f20..65231c7d52 100644
>> --- a/hw/arm/smmuv3.c
>> +++ b/hw/arm/smmuv3.c
>> @@ -801,7 +801,7 @@ static void smmuv3_notify_iova(IOMMUMemoryRegion *mr,
>>  {
>>      SMMUDevice *sdev = container_of(mr, SMMUDevice, iommu);
>>      IOMMUTLBEvent event;
>> -    uint8_t granule = tg;
>> +    uint8_t granule;
>>  
>>      if (!tg) {
>>          SMMUEventInfo event = {.inval_ste_allowed = true};
>> @@ -821,6 +821,8 @@ static void smmuv3_notify_iova(IOMMUMemoryRegion *mr,
>>              return;
>>          }
>>          granule = tt->granule_sz;
>> +    } else {
>> +        guanule = tg * 2 + 10;
> maybe just init granule to this value above while fixing the typo.
> 
> Thanks
> 
> Eric
>>      }
>>  
>>      event.type = IOMMU_NOTIFIER_UNMAP;
>>