From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 079CCC04EB9 for ; Tue, 16 Oct 2018 00:40:42 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 34FC620866 for ; Tue, 16 Oct 2018 00:40:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34FC620866 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=popple.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 42YxLG6jzRzF3Tw for ; Tue, 16 Oct 2018 11:40:38 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=popple.id.au Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=popple.id.au (client-ip=150.101.137.143; helo=ipmail03.adl6.internode.on.net; envelope-from=alistair@popple.id.au; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=popple.id.au Received: from ipmail03.adl6.internode.on.net (ipmail03.adl6.internode.on.net [150.101.137.143]) by lists.ozlabs.org (Postfix) with ESMTP id 42YxJC2M0WzF3Fd for ; Tue, 16 Oct 2018 11:38:50 +1100 (AEDT) Received: from static-82-10.transact.net.au (HELO new-mexico.localnet) ([122.99.82.10]) by ipmail03.adl6.internode.on.net with ESMTP; 16 Oct 2018 11:08:52 +1030 From: Alistair Popple To: Alexey Kardashevskiy 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 Message-ID: <2435624.zC36bzMth8@new-mexico> User-Agent: KMail/5.2.3 (Linux/4.17.0-0.bpo.1-amd64; KDE/5.28.0; x86_64; ; ) In-Reply-To: References: <20181002032021.7126-1-aik@ozlabs.ru> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Reza Arbab , linuxppc-dev@lists.ozlabs.org, David Gibson Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 > > --- > > 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 = { > > > >