You are correct that it is dependent upon whether your motherboard has IOMMU [1]. Nevertheless, given the following paragraph, then it seems to be the reverse:

You are correct that it is dependent upon whether your motherboard has IOMMU [1]. Nevertheless, given the following paragraph, then it seems to be the reverse: it is generally unwise to willy-nilly give out PCI pass-through, unless you have confirmed that your hardware has IOMMU. Xen documentation explicitly states how to determine whether you have IOMMU on your hardware.[2] The hardware listed here [3], while out of date, conspicuously notes, for example, that "Core i7...most "K" versions don't support VT-d", which, according to Intel [4], means that the i7-4770K, for example, does not support IOMMU (VT-d). This tells me that if you are concerned about this issue, then you must check your hardware, even if it is new hardware. [1] = https://en.wikipedia.org/wiki/IOMMU https://en.wikipedia.org/wiki/IOMMU [2] = http://wiki.xenproject.org/wiki/Xen_PCI_Passthrough#How_can_I_tell_if_I_have_IOMMU_.2F_VT-D_support.3F http://wiki.xenproject.org/wiki/Xen_PCI_Passthrough#How_can_... [3] = http://wiki.xenproject.org/wiki/VTdHowTo http://wiki.xenproject.org/wiki/VTdHowTo [4] the i7-4770K probably lacks IOMMU because it would negatively affect performance on a CPU that is sold as a near top-of-the-line CPU for gaming, which generally excludes most virtualization use cases. edit: formatting