On Wed, 2018-09-19 at 12:33 +0100, Bruce Richardson wrote: > On Wed, Sep 19, 2018 at 07:44:36AM +0000, Tone Zhang (Arm Technology > China) wrote: > > Hello Bruce, Luca, Rami and Stephen, > > > > Could you please help to review the change? > > > > Any comments are welcome. > > > > Thanks a lot! > > > > Br, > > Tone > > > > -----Original Message----- > > From: dev <dev-boun...@dpdk.org> On Behalf Of tone.zhang > > Sent: Wednesday, September 5, 2018 1:18 PM > > To: dev@dpdk.org > > Cc: Gavin Hu (Arm Technology China) <gavin...@arm.com>; bruce.richa > > rd...@intel.com; bl...@debian.org; roszenr...@gmail.com; nd <nd@arm > > .com> > > Subject: [dpdk-dev] [PATCH v3] doc: Clarify IOMMU usage with > > "uio_pci_generic" kernel module > > > > If the devices used for DPDK are bound to the "uio_pci_generic" > > kernel module, the IOMMU should be disabled in order not to break > > the IO transmission because of the virtual / physical address > > mapping. > > > > The patch clarifies the IOMMU configurations on both x86_64 and > > arm64 systems. > > > > Signed-off-by: tone.zhang <tone.zh...@arm.com> > > --- > > doc/guides/linux_gsg/linux_drivers.rst | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/doc/guides/linux_gsg/linux_drivers.rst > > b/doc/guides/linux_gsg/linux_drivers.rst > > index 371a817..b46fc6a 100644 > > --- a/doc/guides/linux_gsg/linux_drivers.rst > > +++ b/doc/guides/linux_gsg/linux_drivers.rst > > @@ -48,6 +48,13 @@ be loaded as shown below: > > ``vfio-pci`` kernel module rather than ``igb_uio`` or > > ``uio_pci_generic``. > > For more details see :ref:`linux_gsg_binding_kernel` below. > > > > +.. note:: > > + > > + If the devices used for DPDK are bound to the > > ``uio_pci_generic`` kernel module, > > + please make sure that the IOMMU is disabled. One can add > > ``intel_iommu=off`` or > > + ``intel_iommu=pt`` or ``amd_iommu=off`` in GRUB command line on > > x86_64 systems, > > + or add ``iommu.passthrough=1`` on arm64 system. > > + > > I'm not really an expert in these IOMMU commands, but for the > passthrough > option on my systems, I've always used "intel_iommu=on iommu=pt", > rather > than "intel_iommu=pt". Can someone confirm that the latter works ok, > as > documented here? > > /Bruce
Whops you are right, just checked and we use iommu=pt -- Kind regards, Luca Boccassi
