Previously it was disabled only right before translation was enabled.
This way the disable logic is still executed even when translation is not be activated, e.g. with hw.iommu.dma=0 tunable set.
In order to do the disabling early a hw.dmar.pmr.disable tunable has to be set.
On some platforms we need to disable PMR in order for core dump to work.
At the same time it was observed that enabling translation has a significant impact on network performance.
With this patch PMR can be disabled, with IOMMU translation not being turned on by appending the following to the loader.conf: