In order for shared workqeues to work properly, desc->priv should be
set to 0 rather than 1. The need for this is described in commit
f5ccf55e1028 (dmaengine/idxd: Re-enable kernel workqueue under DMA
API), so we need to make IAA consistent with IOMMU settings, otherwise
we get:
[ 141.948389] IOMMU: dmar15: Page request in Privilege Mode
[ 141.948394] dmar15: Invalid page request: 2000026a100101 ffffb167
Dedicated workqueues ignore this field and are unaffected.
Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>