Re: Mentor of the Project "PCI frontend XEN PV driver"？

[Justin T. Gibbs]

On Apr 12, 2013, at 3:02 AM, Bei Guan <gbtju85 at gmail.com> wrote:

> Thank you for your reply. 
> 
> I think it's also a good project for me to write a SCSI or USB PV frontend for FreeBSD. I'm interest in Xen and have done some development about Xen PV and HVM, but I didn't do any development on FreeBSD. As to this project, where should I start? Is there any other similar FreeBSD project I can refer to?

Front-end drivers for network, block, and control already exist and should serve as a good starting point for the creation of another PV driver.

I've also updated the ideas page to include more information about our existing XEN implementation and what will be required for these projects.

> In order to write a SCSI or USB PV driver, do we need the Xen PV drivers in FreeBSD, such as event channel, hypercalls, xenbus, and so on?

Yes, FreeBSD already has support for all XenBus APIs needed to write these drivers.  See "sys/xen" and "sys/dev/xen" in the FreeBSD kernel source tree.

> You said the "drivers can be developed using an HVM guest", can you give me more information about it?

Typically, you install FreeBSD using standard install media as a full HVM guest on a system running Xen.  Then compile a custom kernel using the XENHVM config file in order to activate the existing PV drivers.

--
Justin