Re: [PATCH] PCI: Fix crash during pci_dev hot-unplug on pseries KVM guest

Amit Machhiwal <[email protected]> Thu, 11 Jul 2024 19:51:06 +0530

Newsgroups	org.kernel.vger.kvm-ppc,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pci,org.ozlabs.lists.linuxppc-dev
Message-ID	<qcidmczsjdhaqz7hy3cqnpkjiaulxi7277ayzly3zyrrdbcr4w@5s4x5cgd3xk2>

Hi Rob,

On 2024/07/11 06:20 AM, Rob Herring wrote:
> On Wed, Jul 3, 2024 at 8:17 AM Amit Machhiwal <[email protected]> wrote:
> >
> > With CONFIG_PCI_DYNAMIC_OF_NODES [1], a hot-plug and hot-unplug sequence
> > of a PCI device attached to a PCI-bridge causes following kernel Oops on
> > a pseries KVM guest:
> 
> Can I ask why you have this option on in the first place? Do you have
> a use for it or it's just a case of distros turn on every kconfig
> option.

Yes, this option is turned on in Ubuntu's distro kernel config where the issue
was originally reported, while Fedora is keeping this turned off.

    root@ubuntu:~# cat /boot/config-6.8.0-38-generic | grep PCI_DYN
    CONFIG_PCI_DYNAMIC_OF_NODES=y

    root@fedora:~# cat /boot/config-6.9.7-200.fc40.ppc64le | grep PCI_DYN
    # CONFIG_PCI_DYNAMIC_OF_NODES is not set

Thanks,
Amit

> 
> Rob