On Thu, 15 Dec 2016 19:29:54 +0200 edgar helmut <[email protected]> wrote:
> Stephen, this is not the case, it relies on using the transparent hugepages > which looks like 2M hugepages size. > Why should be a problem to back 1G pages of the guest to 2M pages at the > host? > the transparent hugepages makes the deployment much more flexible. The IOMMU has a cache (like TLB) which has a limited number of slots. If using 2M pages then the IOMMU cache misses will cause a performance drop just like CPU cache misses. I think Intel had some slides back at IDF 2012 that showed the impact.
