Re: [PATCH Kernel v18 4/7] vfio iommu: Implementation of ioctl for dirty pages tracking.

[Kirti Wankhede <kwankhede@nvidia.com>]

On 5/6/2020 1:45 PM, Yan Zhao wrote:
> On Mon, May 04, 2020 at 11:58:56PM +0800, Kirti Wankhede wrote:

<snip>

>>   /*
>>    * Helper Functions for host iova-pfn list
>>    */
>> @@ -567,6 +654,18 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
>>   			vfio_unpin_page_external(dma, iova, do_accounting);
>>   			goto pin_unwind;
>>   		}
>> +
>> +		if (iommu->dirty_page_tracking) {
>> +			unsigned long pgshift =
>> +					 __ffs(vfio_pgsize_bitmap(iommu));
>> +
> hi Kirti,
> may I know if there's any vfio_pin_pages() happpening during NVidia's vGPU migration?
> the code would enter into deadlock as I reported in last version.
> 

Hm, you are right and same is the case in vfio_iommu_type1_dma_rw_chunk().

Instead of calling vfio_pgsize_bitmap() from lots of places, I'm 
thinking of saving pgsize_bitmap in struct vfio_iommu, which should be 
populated whenever domain_list is updated. Alex, will that be fine?

Thanks,
Kirti


> Thanks
> Yan
>