From: Alistair Popple <alistair@popple•id.au>
To: Alexey Kardashevskiy <aik@ozlabs•ru>
Cc: Reza Arbab <arbab@linux•ibm.com>,
linuxppc-dev@lists•ozlabs.org,
David Gibson <david@gibson•dropbear.id.au>
Subject: Re: [PATCH kernel v2] powerpc/ioda/npu: Call skiboot's hot reset hook when disabling NPU2
Date: Tue, 16 Oct 2018 11:38:48 +1100 [thread overview]
Message-ID: <2435624.zC36bzMth8@new-mexico> (raw)
In-Reply-To: <ac59afe1-cc7b-41f2-e19d-a7809d27b15a@ozlabs.ru>
Hi Alexey,
Looking at the skiboot side I think we only fence the NVLink bricks as part of a
PCIe function level reset (FLR) rather than a PCI Hot or Fundamental reset which
I believe is what the code here does. So to fence the bricks you would need to
do either a FLR on the given link or alter Skiboot to fence a given link as part
of a hot reset.
- Alistair
On Monday, 15 October 2018 6:17:51 PM AEDT Alexey Kardashevskiy wrote:
> Ping?
>
>
> On 02/10/2018 13:20, Alexey Kardashevskiy wrote:
> > The skiboot firmware has a hot reset handler which fences the NVIDIA V100
> > GPU RAM on Witherspoons and makes accesses no-op instead of throwing HMIs:
> > https://github.com/open-power/skiboot/commit/fca2b2b839a67
> >
> > Now we are going to pass V100 via VFIO which most certainly involves
> > KVM guests which are often terminated without getting a chance to offline
> > GPU RAM so we end up with a running machine with misconfigured memory.
> > Accessing this memory produces hardware management interrupts (HMI)
> > which bring the host down.
> >
> > To suppress HMIs, this wires up this hot reset hook to vfio_pci_disable()
> > via pci_disable_device() which switches NPU2 to a safe mode and prevents
> > HMIs.
> >
> > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs•ru>
> > ---
> > Changes:
> > v2:
> > * updated the commit log
> > ---
> > arch/powerpc/platforms/powernv/pci-ioda.c | 10 ++++++++++
> > 1 file changed, 10 insertions(+)
> >
> > diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> > index cde7102..e37b9cc 100644
> > --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> > +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> > @@ -3688,6 +3688,15 @@ static void pnv_pci_release_device(struct pci_dev *pdev)
> > pnv_ioda_release_pe(pe);
> > }
> >
> > +static void pnv_npu_disable_device(struct pci_dev *pdev)
> > +{
> > + struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev);
> > + struct eeh_pe *eehpe = edev ? edev->pe : NULL;
> > +
> > + if (eehpe && eeh_ops && eeh_ops->reset)
> > + eeh_ops->reset(eehpe, EEH_RESET_HOT);
> > +}
> > +
> > static void pnv_pci_ioda_shutdown(struct pci_controller *hose)
> > {
> > struct pnv_phb *phb = hose->private_data;
> > @@ -3732,6 +3741,7 @@ static const struct pci_controller_ops pnv_npu_ioda_controller_ops = {
> > .reset_secondary_bus = pnv_pci_reset_secondary_bus,
> > .dma_set_mask = pnv_npu_dma_set_mask,
> > .shutdown = pnv_pci_ioda_shutdown,
> > + .disable_device = pnv_npu_disable_device,
> > };
> >
> > static const struct pci_controller_ops pnv_npu_ocapi_ioda_controller_ops = {
> >
>
>
next prev parent reply other threads:[~2018-10-16 0:40 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-02 3:20 [PATCH kernel v2] powerpc/ioda/npu: Call skiboot's hot reset hook when disabling NPU2 Alexey Kardashevskiy
2018-10-15 7:17 ` Alexey Kardashevskiy
2018-10-16 0:38 ` Alistair Popple [this message]
2018-10-16 1:37 ` Alexey Kardashevskiy
2018-10-16 1:44 ` Alistair Popple
2018-10-16 2:02 ` Alexey Kardashevskiy
2018-10-16 2:19 ` Alistair Popple
2018-10-16 2:22 ` Alexey Kardashevskiy
2018-10-16 7:32 ` Alistair Popple
2018-10-16 7:55 ` Alexey Kardashevskiy
2018-10-18 1:05 ` Alistair Popple
2018-10-19 1:20 ` Alexey Kardashevskiy
2018-10-19 1:47 ` Alistair Popple
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2435624.zC36bzMth8@new-mexico \
--to=alistair@popple$(echo .)id.au \
--cc=aik@ozlabs$(echo .)ru \
--cc=arbab@linux$(echo .)ibm.com \
--cc=david@gibson$(echo .)dropbear.id.au \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox