We're interested in adopting the new migration v2 interface and the new dirty page logging for /dev/iommufd in an out-of-process device emulation protocol [1]. Although it's purely userspace, we do want to stay close to the new API(s) being proposed for many reasons, mainly to re-use the QEMU implementation. The migration-related changes are relatively straightforward, I'm more interested in the dirty page logging. I've started reading the relevant email threads and my impression so far is that the details are still being decided? I don't see any commits related to dirty page logging in Yi's repo (https://github.com/luxis1999/iommufd) (at least not in the commit messages). I see that Joao has done some work using the existing dirty bitmaps (https://github.com/jpemartins/linux/commits/iommufd). Is there a rough idea of how the new dirty page logging will look like? Is this already explained in the email threads an I missed it? [1] https://lore.kernel.org/all/a9b696ca38ee2329e371c28bcaa2921cac2a48a2.1641584316.git.john.g.johnson@xxxxxxxxxx/
