Re: [dpdk-dev] [PATCH v8 1/3] vfio: revert changes for map contiguous areas in one go

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 05-Mar-21 7:50 AM, David Marchand wrote:
> On Fri, Jan 15, 2021 at 8:33 AM Nithin Dabilpuram
> <ndabilpuram@marvell.com> wrote:
>>
>> In order to save DMA entries limited by kernel both for externel
>> memory and hugepage memory, an attempt was made to map physically
>> contiguous memory in one go. This cannot be done as VFIO IOMMU type1
>> does not support partially unmapping a previously mapped memory
>> region while Heap can request for multi page mapping and
>> partial unmapping.
>> Hence for going back to old method of mapping/unmapping at
>> memseg granularity, this commit reverts
>> commit d1c7c0cdf7ba ("vfio: map contiguous areas in one go")
>>
>> Also add documentation on what module parameter needs to be used
>> to increase the per-container dma map limit for VFIO.
>>
>> Fixes: d1c7c0cdf7ba ("vfio: map contiguous areas in one go")
>> Cc: anatoly.burakov@intel.com
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
>> Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
>> Acked-by: David Christensen <drc@linux.vnet.ibm.com>
> 
> There is a regression reported in bz: https://bugs.dpdk.org/show_bug.cgi?id=649
> 
> I assigned it to Anatoly for now.
> Nithin, can you have a loo too?
> 
> Thanks.
> 
> 

I've responded on the bug tracker as well, but to repeat it here: this 
is not a regression, this is intended behavior. We cannot do anything 
about this.

-- 
Thanks,
Anatoly