On a Xen PV guest the DMA addresses and physical addresses are not 1:1
(such as Xen PV guests) and the generic dma_get_required_mask() does
not return the correct mask (since it uses max_pfn).
Some device drivers (such as mptsas, mpt2sas) use
dma_get_required_mask() to set the device's DMA mask
On a Xen PV guest the DMA addresses and physical addresses are not 1:1
(such as Xen PV guests) and the generic dma_get_required_mask() does
not return the correct mask (since it uses max_pfn).
Some device drivers (such as mptsas, mpt2sas) use
dma_get_required_mask() to set the device's DMA mask