[Week 9] Import the Xen grant-table bus_dma(9) handlers from OpenBSD

[Pratyush Yadav]

Hi,

During the last week, I finished updating the blkfront driver to use
the new Xen-specific bus_dma(9) implementation.

After that, I figured out how I can run it. There were some troubles
with getting networking to work in the Xen domU, but I finally figured
it out and built the new kernel and ran it.

The driver works fine for the most part. But there is an error message
printed every second or so which says a read or write failed. I
investigated further, and it turns out around 35% of the read or write
operations fail. I have not been able to figure out where the problem
originates from yet. I will continue debugging until I find out what's
going wrong.

You can check the code here [0].

I maintain a blog on Blogger where I publish my progress every few
days. Check it out if you want more details on what I'm doing [1].



[0] https://github.com/prati0100/freebsd/tree/busdma_xen_clean
[1] https://pratyushgsoc.blogspot.com/

-- 
Regards,
Pratyush Yadav