From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Boccassi Subject: Re: [PATCH v3] doc: Clarify IOMMU usage with "uio_pci_generic" kernel module Date: Wed, 19 Sep 2018 12:54:28 +0100 Message-ID: <1537358068.10481.22.camel@debian.org> References: <1536122382-26525-1-git-send-email-tone.zhang@arm.com> <1536124655-27163-1-git-send-email-tone.zhang@arm.com> <20180919113342.GA16956@bricha3-MOBL.ger.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Cc: "dev@dpdk.org" , "Gavin Hu (Arm Technology China)" , "roszenrami@gmail.com" , Stephen Hemminger , nd To: Bruce Richardson , "Tone Zhang (Arm Technology China)" Return-path: Received: from mail-wm1-f68.google.com (mail-wm1-f68.google.com [209.85.128.68]) by dpdk.org (Postfix) with ESMTP id ED99D32A5 for ; Wed, 19 Sep 2018 13:54:30 +0200 (CEST) Received: by mail-wm1-f68.google.com with SMTP id y2-v6so5962523wma.1 for ; Wed, 19 Sep 2018 04:54:30 -0700 (PDT) In-Reply-To: <20180919113342.GA16956@bricha3-MOBL.ger.corp.intel.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 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, > >=20 > > Could you please help to review the change?=C2=A0 > >=20 > > Any comments are welcome. > >=20 > > Thanks a lot! > >=20 > > Br, > > Tone > >=20 > > -----Original Message----- > > From: dev On Behalf Of tone.zhang > > Sent: Wednesday, September 5, 2018 1:18 PM > > To: dev@dpdk.org > > Cc: Gavin Hu (Arm Technology China) ; bruce.richa > > rdson@intel.com; bluca@debian.org; roszenrami@gmail.com; nd > .com> > > Subject: [dpdk-dev] [PATCH v3] doc: Clarify IOMMU usage with > > "uio_pci_generic" kernel module > >=20 > > 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. > >=20 > > The patch clarifies the IOMMU configurations on both x86_64 and > > arm64 systems. > >=20 > > Signed-off-by: tone.zhang > > --- > > =C2=A0doc/guides/linux_gsg/linux_drivers.rst | 7 +++++++ > > =C2=A01 file changed, 7 insertions(+) > >=20 > > 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: > > =C2=A0=C2=A0=C2=A0=C2=A0``vfio-pci`` kernel module rather than ``igb_ui= o`` or > > ``uio_pci_generic``. > > =C2=A0=C2=A0=C2=A0=C2=A0For more details see :ref:`linux_gsg_binding_ke= rnel` below. > > =C2=A0 > > +.. note:: > > + > > +=C2=A0=C2=A0=C2=A0If the devices used for DPDK are bound to the > > ``uio_pci_generic`` kernel module, > > +=C2=A0=C2=A0=C2=A0please make sure that the IOMMU is disabled. One can= add > > ``intel_iommu=3Doff`` or > > +=C2=A0=C2=A0=C2=A0``intel_iommu=3Dpt`` or ``amd_iommu=3Doff`` in GRUB = command line on > > x86_64 systems, > > +=C2=A0=C2=A0=C2=A0or add ``iommu.passthrough=3D1`` on arm64 system. > > + >=20 > I'm not really an expert in these IOMMU commands, but for the > passthrough > option on my systems, I've always used "intel_iommu=3Don iommu=3Dpt", > rather > than "intel_iommu=3Dpt". Can someone confirm that the latter works ok, > as > documented here? >=20 > /Bruce Whops you are right, just checked and we use iommu=3Dpt --=20 Kind regards, Luca Boccassi