Re: Xen network domain performance for 10Gb NIC

[tosher 1 <akm2tosher@xxxxxxxxx>]

> Driver domains with passthrough devices need to perform IOMMU
operations in order to add/remove page table entries when doing grant
maps (ie: IOMMU TLB flushes), while dom0 doesn't need to because it
has the whole RAM identity mapped in the IOMMU tables. Depending on
how fast your IOMMU is and what capabilities it has doing such
operations can introduce a significant amount of overhead.

It makes sense to me. Do you know, in general, how to measure IOMMU 
performance, and what features/properties of IOMMU can contribute to getting a 
better network throughput? Please let me know. 

Thanks!