Re: [PATCH RFC 00/19] IOMMUFD Dirty Tracking

Jason Gunthorpe
2022-05-05T13:55:38Z

On Thu, May 05, 2022 at 11:03:18AM +0000, Tian, Kevin wrote:

> iiuc the purpose of 'write-protection' here is to capture in-fly dirty pages
> in the said race window until unmap and iotlb is invalidated is completed.

No, the purpose is to perform "unmap" without destroying the dirty bit
in the process.

If an IOMMU architecture has a way to render the page unmaped and
flush back the dirty bit/not destroy then it doesn't require a write
protect pass.

Jason