RE: Intel QAT 8970 accel card on ARM Ampere Server

[Dharmik Jayesh Thakkar <DharmikJayesh.Thakkar@arm.com>]

> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Tuesday, October 10, 2023 2:26 AM
> To: Dharmik Jayesh Thakkar <DharmikJayesh.Thakkar@arm.com>
> Cc: Patrick Robb <probb@iol.unh.edu>; Ruifeng Wang
> <Ruifeng.Wang@arm.com>; Juraj Linkeš <juraj.linkes@pantheon.tech>;
> Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>; ci@dpdk.org; nd
> <nd@arm.com>; thomas@monjalon.net; Maxime Coquelin
> <maxime.coquelin@redhat.com>
> Subject: Re: Intel QAT 8970 accel card on ARM Ampere Server
>
> Hello,
>
> On Tue, Oct 10, 2023 at 5:56 AM Dharmik Jayesh Thakkar
> <DharmikJayesh.Thakkar@arm.com> wrote:
> >
> > Hi Patrick,
> >
> > Can you provide the grub settings? Is iommu.passthrough=1 included?
> >
> >
> >
> > Also, is qat_c62xvf loaded as well?
> >
> >
> >
> > Finally, a few guidelines on the vfio driver:
> >
> > At times, we need to configure the vfio driver.
> >
> > On kernel vers. 5.9+ we need to load the vfio-pci driver with the
> > additional parameter disable_denylist=1
>
> o_O
> I did not know this option, but it scares me a bit, reading its description.
> Could you please elaborate why this is needed?
>
>

Details for adding QAT to denylist provided in the below commit:
https://github.com/torvalds/linux/commit/50173329c8cc0c892eaa7a9d0f0692ac39cd7b04

> >
> > Unload the vfio-pci driver if it is already loaded so that we can reload it with
> the correct parameters :
> > sudo modprobe -r vfio_iommu_type1; sudo modprobe -r vfio_pci; sudo
> > modprobe -r vfio_virqfd; sudo modprobe -r vfio
> >
> > If you can't unload the vfio driver because it's been built into the kernel,
> you'll have to find another way to change VFIO parameters, or to rebuild your
> kernel with VFIO_PCI set as a module. Failing to do that, you might encounter
> issues later on when you try to bind the VFs to VFIO.
> >
> > Load the vfio-pci driver and bind it to QAT VFs device ids:
> > sudo modprobe vfio-pci disable_denylist=1 enable_sriov=1
> > vfio-pci.ids=8086:37c9
> >
> > Enable no-iommu-mode:
> > echo "1" | sudo tee
> > /sys/module/vfio/parameters/enable_unsafe_noiommu_mode
> >
> >  /sys/module/vfio/parameter is missing ?
> >
> > If /sys/module/vfio/parameters does not exist, you might be missing
> > the kernel module VFIO_NOIOMMU
> >
> >
> >
> > Automatically set VFIO params on boot
> >
> > It's possible to set these parameters automatically on boot by creating a
> /etc/modprobe.d/vfio-pci.conf file with the parameters :
> > cat /etc/modprobe.d/vfio-pci.conf
> > options vfio enable_unsafe_noiommu_mode=1 options vfio-pci
> > disable_denylist=1 enable_sriov=1 vfio-pci.ids=8086:37c9
> >
> >
> >
> > We haven’t encountered this issue in the past, so just making sure the
> configuration is correct. I don’t think having the driver static/loadable should
> make a difference, I will try with building statically on my setup.
>
>
> --
> David Marchand

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