svn commit: r306472 - in stable/10/sys/amd64/vmm: . io

[John Baldwin]

On Friday, September 30, 2016 01:42:29 AM John Baldwin wrote:
> Author: jhb
> Date: Fri Sep 30 01:42:29 2016
> New Revision: 306472
> URL: https://svnweb.freebsd.org/changeset/base/306472
> 
> Log:
>   MFC 304858,305485: Fix various issues with PCI pass through and VT-d.
>   
>   304858:
>   Enable I/O MMU when PCI pass through is first used.
>   
>   Rather than enabling the I/O MMU when the vmm module is loaded,
>   defer initialization until the first attempt to pass a PCI device
>   through to a guest.  If the I/O MMU fails to initialize or is not
>   present, than fail the attempt to pass a PCI device through to a
>   guest.
>   
>   The hw.vmm.force_iommu tunable has been removed since the I/O MMU is
>   no longer enabled during boot.  However, the I/O MMU support can be
>   disabled by setting the hw.vmm.iommu.enable tunable to 0 to prevent
>   use of the I/O MMU on any systems where it is buggy.
>   
>   305485:
>   Leave ppt devices in the host domain when they are not attached to a VM.
>   
>   This allows a pass through device to be reset to a normal device driver
>   on the host and reused on the host.  ppt devices are now always active in
>   some I/O MMU domain when the I/O MMU is active, either the host domain
>   or the domain of a VM they are attached to.

I did not MFC 305497 (update I/O MMU when adding/removing PCI devices) since
there was a conflict and neither SR-IOV nor PCI-e Hotplug are in 10 (though
Cardbus is in 10).  At this point I doubt I will get around to merging Hotplug
to 10, but if I do then 305497 could be merged.

-- 
John Baldwin