Re: [PATCH] x86/tboot: add an option to disable iommu force on

2017-04-26 Thread Joerg Roedel
On Tue, Apr 25, 2017 at 09:28:53AM -0700, Shaohua Li wrote: > IOMMU harms performance signficantly when we run very fast networking > workloads. It's 40GB networking doing XDP test. Software overhead is > almost unaware, but it's the IOTLB miss (based on our analysis) which > kills the performance.

[PATCH] x86/tboot: add an option to disable iommu force on

2017-04-25 Thread Shaohua Li
IOMMU harms performance signficantly when we run very fast networking workloads. It's 40GB networking doing XDP test. Software overhead is almost unaware, but it's the IOTLB miss (based on our analysis) which kills the performance. We observed the same performance issue even with software passthrou