The patch dynamically enables Bus Master on P2P bridges only when requested by a device driver through PciIo.Attribute() to enable the Bus Master. Signed-off-by: Sean Brogan <sean.brogan@microsoft.com> Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com> Reviewed-by: Jiewen Yao <jiewen.yao@intel.com> Cc: Michael D Kinney <michael.d.kinney@intel.com>