Hi Bjorn, This is regarding the blacklisting of one of the Marvell QLogic FC adapter (1077/2261) on VPD area access. The commit that did was this: --8<-- pruned commit message --8<-- | commit 0d5370d1d85251e5893ab7c90a429464de2e140b | Author: Ethan Zhao <ethan.zhao@xxxxxxxxxx> | Date: Mon Feb 27 17:08:44 2017 +0900 | | PCI: Prevent VPD access for QLogic ISP2722 | Call Trace: | <NMI> [<ffffffff817193de>] dump_stack+0x63/0x81 | [<ffffffff81714072>] panic+0xd0/0x20e | [<ffffffff8101c8b4>] do_nmi+0xf4/0x170 | <<EOE>> [<ffffffff815db4b3>] raw_pci_read+0x23/0x40 | [<ffffffff815db4fc>] pci_read+0x2c/0x30 | [<ffffffff8136f612>] pci_user_read_config_word+0x72/0x110 | [<ffffffff8136f746>] pci_vpd_pci22_wait+0x96/0x130 | [<ffffffff8136ff9b>] pci_vpd_pci22_read+0xdb/0x1a0 | [<ffffffff8136ea30>] pci_read_vpd+0x20/0x30 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0d5370d1d85251e5893ab7c90a429464de2e140b While investigating the original report of the issue, I found an interesting information that may explain why Ethan Zhao was hitting the NMI/crash. If you notice the stack referred in the commit, you could see that a bunch of old vpd access functions, pci_vpd_pci22*, were referred. When these functions were in use (these functions were renamed around 2016 Feb by f1cd93f9aabe), there was a critical VPD access bug missing; missing in fact most of the life of those functions. This one: 104daa71b396: PCI: Determine actual VPD size on first access Without this patch, a read of the vpd sysfs file can access area outside of VPD space, which is not allowed by the spec. My guess here is that, Ethan, when trying to access VPD of the QLogic 1077/2261 adapter, was using a kernel that had the bug present and it led up to the NMI/crash he was observing on his machine. We had an early firmware that returned CA on VPD access beyond bounds that is known to NMI some servers. The FW has since changed to not clear the VPD flag upon out-of-bound access. In light of the above, plus the fact that I did try the experiment on multiple setups and was not able to reproduce the issue, would you be willing to revert the above patch? If so, I could send a git revert (or equivalent) patch of the commit. This blacklisting is preventing multiple customers from accessing the VPD area of the said production adapter and making their life a bit difficult. Regards, -Arun Old discussion of the topic: https://lkml.org/lkml/2019/5/21/991
