Re: [EXTERNAL] Re: [PATCH v2 0/2] vhost-vdpa: Add support for NO-IOMMU mode

Christoph Hellwig
2024-10-18T05:24:06Z

On Thu, Oct 17, 2024 at 08:53:08AM +0000, Srujana Challa wrote:
> We observed better performance with "intel_iommu=on" in high-end x86 machines,
> indicating that the performance limitations are specific to low-end x86 hardware.

What does "low-end" vs "high-end" mean? Atom vs other cores?

> This presents a trade-off between performance and security. Since intel_iommu
> is enabled by default, users who prioritize security over performance do not need to
> disable this option.

Either way, just disabling essential protection because it is slow
is a no-go. We'll need to either fix your issues, or you need to use
more suitable hardware for your workload.