svn commit: r305034 - in head: lib/libdevctl sys/kern sys/sys usr.sbin/devctl

[John Baldwin]

On Monday, August 29, 2016 10:48:36 PM John Baldwin wrote:
> Author: jhb
> Date: Mon Aug 29 22:48:36 2016
> New Revision: 305034
> URL: https://svnweb.freebsd.org/changeset/base/305034
> 
> Log:
>   Implement 'devctl clear driver' to undo a previous 'devctl set driver'.
>   
>   Add a new 'clear driver' command for devctl along with the accompanying
>   ioctl and devctl_clear_driver() library routine to reset a device to
>   use a wildcard devclass instead of a fixed devclass.  This can be used
>   to undo a previous 'set driver' command.  After the device's name has
>   been reset to permit wildcard names, it is reprobed so that it can
>   attach to newly-available (to it) device drivers.
>   
>   MFC after:	1 month
>   Sponsored by:	Chelsio Communications

In particular, you can now do 'devctl set driver pciX:Y:Z ppt' to flip
a device into pass through mode for bhyve and then use
'devctl clear driver pciX:Y:Z' to revert back to the host driver.

Though for bhyve/ppt(4) in particular you need some additional changes
currently under review so that the device ends up back in the proper
I/O MMU domain so it can do DMA in the host.

-- 
John Baldwin