922a5bb1f3
From Brett: In short, busdma maps for received packets were not being unloaded in the interrupt handler before the packets were passed up the network stack. The fix was to add a busdma sync and unload for the two receive maps. This bug is significant for certain busdma providers, for example IOMMUs, where not unloading the maps means that 1) the IOMMU mappings that allow the NIC to DMA the received packets into host memory stay open indefinitely, potentially violating a desired security policy, and 2) resources such as device address space addresses and host memory for bookkeeping are never freed. Without an IOMMU or bounce buffering enabled for the ixl device, I don't think adding these calls will have any significant performance impact. With the IOMMU enabled, I have noticed a performance impact on the receive side, which is expected. Submitted by: Brett Gutstein <bgutstein@rice.edu> Reviewed by: erj@ MFC after: 1 week
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