Thanks, and yes I already saw that. That seems like a much better solution. I will give it a spin in my box with this problem.
On Thu, Jan 11, 2018 at 7:12 PM, Thomas Monjalon <tho...@monjalon.net> wrote: > 03/12/2017 01:23, Chas Williams: > > The particular machine in my case is a Dell Optiplex 790 which is fairly > > similar to another system that has basically the same problem. The IOMMU > > advertises that is can only handle 39 bits of addressing. The DMAR > address > > tables have a width of 36 bits, so all is well when using IOVA physical > > addresses. With IOVA virtual addresses, they sometimes go beyond the 39 > > bit boundary. I was under the impression that IOMMU widths are more > > typically 48 bits, but I appear to have some low end systems with a > simpler > > IOMMU. > > > > I could make it a runtime option. > > > > On Thu, Nov 30, 2017 at 4:17 AM, Thomas Monjalon <tho...@monjalon.net> > > wrote: > > > > > 30/11/2017 03:57, Chas Williams: > > > > From: Chas Williams <ch...@att.com> > > > > > > > > The IOMMU in some machines report that they can only support > > > > limited widths. IOVA virtual addresses may exceed this width > > > > making the use of IOVA virtual addresses difficult. The option > > > > CONFIG_RTE_LIBRTE_USE_PHYS_IOVA can used to force IOVA physical > > > > address usage. > > > > > > Which machines are you talking about? > > > A run-time option may be a better solution. > > Please check the patch from Maxime: > https://dpdk.org/dev/patchwork/patch/33192/ > > >
