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@xxxxxxxxx> Acked-by: Alistair Popple <alistair@xxxxxxxxxxxx> Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> --- 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 9ee7a30..29c6837 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -3676,6 +3676,15 @@ 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; @@ -3720,6 +3729,7 @@ 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 = { -- 2.17.1
