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Date:   Wed, 4 Jan 2023 08:50:32 -0600
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     "Liang, Kan" <kan.liang@linux.intel.com>
Cc:     bhelgaas@google.com, hdegoede@redhat.com, kernelorg@undead.fr,
        kjhambrick@gmail.com, 2lprbe78@duck.com,
        nicholas.johnson-opensource@outlook.com.au, benoitg@coeus.ca,
        mika.westerberg@linux.intel.com, wse@tuxedocomputers.com,
        mumblingdrunkard@protonmail.com, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org, david.e.box@intel.com,
        yunying.sun@intel.com
Subject: Re: Bug report: the extended PCI config space is missed with 6.2-rc2
Message-ID: <20230104145032.GA1069244@bhelgaas>
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On Wed, Jan 04, 2023 at 09:39:56AM -0500, Liang, Kan wrote:
> Hi Bjorn,
> 
> Happy new year!
> 
> We found some PCI issues with the latest 6.2-rc2.
> 
> - Using the lspci -xxxx, the extended PCI config space of all PCI
> devices are missed with the latest 6.2-rc2. The system we used had 932
> PCI devices, at least 800 which have extended space as seen when booted
> into a 5.15 kernel. But none of them appeared in 6.2-rc2.
> - The drivers which rely on the information in the extended PCI config
> space don't work anymore. We have confirmed that the perf uncore driver
> (uncore performance monitoring) and Intel VSEC driver (telemetry) don't
> work in 6.2-rc2. There could be more drivers which are impacted.
> 
> After a bisect, we found the regression is caused by the below commit
> 07eab0901ede ("efi/x86: Remove EfiMemoryMappedIO from E820 map").
> After reverting the commit, the issues are gone.
> 
> Could you please take a look at the issues?

Certainly.  Can you capture the complete dmesg log, please?

Bjorn