Re: Using IOAT PMD

[Lance Richardson <lance.richardson@broadcom.com>]

On Thu, Dec 16, 2021 at 11:20 AM Bruce Richardson
<bruce.richardson@intel.com> wrote:
>
> On Thu, Dec 16, 2021 at 11:04:54AM -0500, Lance Richardson wrote:
> > Hi Bruce,
> >
> > I've been looking into using the IOAT PMD, initially with dma_autotest
> > and the dpdk-dma example application. These seem to work fine on
> > SKX with the current main branch, but when I try the same procedure
> > on ICX (binding all 8 devices to vfio-pci in both cases), I get the following
> > output for each device when probed. Is something different needed when
> > using IOAT on ICX vs. SKX?
> >
> > Thanks,
> >      Lance
> >
> > EAL: Probe PCI driver: dmadev_ioat (8086:b00) device: 0000:80:01.0 (socket 2)
> > IOAT: ioat_dmadev_probe(): Init 0000:80:01.0 on NUMA node 2
> > IOAT: ioat_dmadev_create(): ioat_dmadev_create: Channel count == 255
> >
> > IOAT: ioat_dmadev_create(): ioat_dmadev_create: Channel appears locked
> >
> > IOAT: ioat_dmadev_create(): ioat_dmadev_create: cannot reset device.
> > CHANCMD=0xff, CHANSTS=0xffffffffffffffff, CHANERR=0xffffffff
> >
> > EAL: Releasing PCI mapped resource for 0000:80:01.0
> > EAL: Calling pci_unmap_resource for 0000:80:01.0 at 0x4102430000
> > EAL: Requested device 0000:80:01.0 cannot be used
>
> That is strange, the same PMD should work ok on both platforms. This is all
> on latest branch, right? Let me attempt to reproduce and get back to you.

Hi Bruce,

That's correct, I'm using the current tip of the main branch, which
seems to be identical to 21.11.0.
>
> /Bruce
>
> PS: Is this a 4-socket system you are running on, since I see "socket 2"
> being described as the socket number for device 80:01.0?
>
It is a two-socket system with sub-NUMA enabled, so it appears as four
NUMA nodes. I'm only binding the devices on the second socket.

Thanks,
    Lance