Santosh Shukla <santosh.shu...@caviumnetworks.com> writes: > Introducing RTE_PCI_DRV_IOVA_AS_VA flag. Flag used when driver needs > to operate in iova=va mode. > > Why driver need iova=va mapping? > > On NPU style co-processors like Octeontx, the buffer recycling has been > done in HW, unlike SW model. Here is the data flow: > 1) On control path, Fill the HW mempool with buffers(iova as pa address) > 2) on rx_burst, HW gives you IOVA address(iova as pa address) > 3) As application expects VA to operate on it, rx_burst() needs to > convert to _va from _pa. Which is very expensive. > Instead of that if iova as va mapping, we can avoid the cost of > converting with help of IOMMU/SMMU. > > Signed-off-by: Santosh Shukla <santosh.shu...@caviumnetworks.com> > Signed-off-by: Jerin Jacob <jerin.ja...@caviumnetworks.com> > Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com> > ---
This should be folded into patch 5; there's no clear need for it until then.