Message-ID: <64945196-f05f-478e-a2b5-f0bd58345136@amd.com>
Date: Tue, 25 Mar 2025 13:23:07 +0100
From: Christian König <christian.koenig@....com>
To: Bert Karwatzki <spasswolf@....de>
Cc: Balbir Singh <balbirs@...dia.com>, Ingo Molnar <mingo@...nel.org>,
 Kees Cook <kees@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
 Linus Torvalds <torvalds@...ux-foundation.org>,
 Peter Zijlstra <peterz@...radead.org>, Andy Lutomirski <luto@...nel.org>,
 Alex Deucher <alexander.deucher@....com>, linux-kernel@...r.kernel.org,
 amd-gfx@...ts.freedesktop.org
Subject: Re: commit 7ffb791423c7 breaks steam game

Am 25.03.25 um 11:14 schrieb Bert Karwatzki:
> My /proc/iomem  contans two memory areas of 8G size which are
> belonging to PCI 0000:03:00.0, one of the is the BAR reported by dmesg
> [ 0.312692] [ T1] pci 0000:03:00.0: BAR 0 [mem 0xfc00000000-0xfdffffffff 64bit pref]

> the other one is "afe00000000-affffffffff : 0000:03:00.0" (in the case without nokaslr) which shifts
> to "3ffe00000000-3fffffffffff : 0000:03:00.0" in the case with nokaslr.

You need to figure out where that stuff is coming from.

See below for another extremely odd thing.

>
> Here's /proc/iomem in the case without nokaslr:
> 00000000-00000fff : Reserved
> 00001000-0009ffff : System RAM
> 000a0000-000fffff : Reserved
>   000a0000-000dffff : PCI Bus 0000:00
>   000f0000-000fffff : System ROM
> 00100000-09bfefff : System RAM
> 09bff000-0a000fff : Reserved
> 0a001000-0a1fffff : System RAM
> 0a200000-0a20efff : ACPI Non-volatile Storage
> 0a20f000-e62edfff : System RAM
> e62ee000-e63e1fff : Reserved
> e63e2000-e87cafff : System RAM
> e87cb000-e87cbfff : Reserved
> e87cc000-e9e1ffff : System RAM
> e9e20000-eb33efff : Reserved
>   eb31e000-eb321fff : MSFT0101:00
>   eb322000-eb325fff : MSFT0101:00
> eb33f000-eb39efff : ACPI Tables
> eb39f000-eb556fff : ACPI Non-volatile Storage
> eb557000-ed1fefff : Reserved
> ed1ff000-edffffff : System RAM
> ee000000-efffffff : Reserved
> f0000000-fcffffff : PCI Bus 0000:00
>   f0000000-f7ffffff : PCI ECAM 0000 [bus 00-7f]
>     f0000000-f7ffffff : pnp 00:00
>   fc500000-fc9fffff : PCI Bus 0000:08
>     fc500000-fc5fffff : 0000:08:00.7
>       fc500000-fc5fffff : pcie_mp2_amd
>     fc600000-fc6fffff : 0000:08:00.4
>       fc600000-fc6fffff : xhci-hcd
>     fc700000-fc7fffff : 0000:08:00.3
>       fc700000-fc7fffff : xhci-hcd
>     fc800000-fc8fffff : 0000:08:00.2
>       fc800000-fc8fffff : ccp
>     fc900000-fc97ffff : 0000:08:00.0
>     fc980000-fc9bffff : 0000:08:00.5
>       fc980000-fc9bffff : AMD ACP3x audio
>         fc980000-fc990200 : acp_pdm_iomem
>     fc9c0000-fc9c7fff : 0000:08:00.6
>       fc9c0000-fc9c7fff : ICH HD audio
>     fc9c8000-fc9cbfff : 0000:08:00.1
>       fc9c8000-fc9cbfff : ICH HD audio
>     fc9cc000-fc9cdfff : 0000:08:00.7
>     fc9ce000-fc9cffff : 0000:08:00.2
>       fc9ce000-fc9cffff : ccp
>   fca00000-fccfffff : PCI Bus 0000:01
>     fca00000-fcbfffff : PCI Bus 0000:02
>       fca00000-fcbfffff : PCI Bus 0000:03
>         fca00000-fcafffff : 0000:03:00.0
>         fcb00000-fcb1ffff : 0000:03:00.0
>         fcb20000-fcb23fff : 0000:03:00.1
>           fcb20000-fcb23fff : ICH HD audio
>     fcc00000-fcc03fff : 0000:01:00.0
>   fcd00000-fcdfffff : PCI Bus 0000:07
>     fcd00000-fcd03fff : 0000:07:00.0
>       fcd00000-fcd03fff : nvme
>   fce00000-fcefffff : PCI Bus 0000:06
>     fce00000-fce03fff : 0000:06:00.0
>       fce00000-fce03fff : nvme
>   fcf00000-fcffffff : PCI Bus 0000:05
>     fcf00000-fcf03fff : 0000:05:00.0
>     fcf04000-fcf04fff : 0000:05:00.0
>       fcf04000-fcf04fff : r8169
> fd300000-fd37ffff : amd_iommu
> fec00000-fec003ff : IOAPIC 0
> fec01000-fec013ff : IOAPIC 1
> fec10000-fec10fff : Reserved
>   fec10000-fec10fff : pnp 00:04
> fed00000-fed00fff : Reserved
>   fed00000-fed003ff : HPET 0
>     fed00000-fed003ff : PNP0103:00
> fed40000-fed44fff : Reserved
> fed80000-fed8ffff : Reserved
>   fed81200-fed812ff : AMDI0030:00
>   fed81500-fed818ff : AMDI0030:00
>     fed81500-fed818ff : AMDI0030:00 AMDI0030:00
> fedc0000-fedc0fff : pnp 00:04
> fedc4000-fedc9fff : Reserved
>   fedc5000-fedc5fff : AMDI0010:03
>     fedc5000-fedc5fff : AMDI0010:03 AMDI0010:03
> fedcc000-fedcefff : Reserved
> fedd5000-fedd5fff : Reserved
> fee00000-fee00fff : pnp 00:04
> ff000000-ffffffff : pnp 00:04
> 100000000-fee2fffff : System RAM
>   825600000-8261fa1b1 : Kernel code
>   826200000-82663dfff : Kernel rodata
>   826800000-82692ef3f : Kernel data
>   826eaf000-826ffffff : Kernel bss

> fee300000-100fffffff : Reserved

First it says that this range is reserved.

> 1010000000-ffffffffff : PCI Bus 0000:00

And this range here used for the PCI Bus.

>   fc00000000-fe0fffffff : PCI Bus 0000:01
>     fc00000000-fe0fffffff : PCI Bus 0000:02
>       fc00000000-fe0fffffff : PCI Bus 0000:03
>         fc00000000-fdffffffff : 0000:03:00.0 This is the usual BAR reported by dmesg (and lspci -vv)
>         fe00000000-fe0fffffff : 0000:03:00.0

And then it says that the PCIe devices are inside the reserved range.

>   fe20000000-fe301fffff : PCI Bus 0000:08
>     fe20000000-fe2fffffff : 0000:08:00.0
>     fe30000000-fe301fffff : 0000:08:00.0
>   fe30300000-fe304fffff : PCI Bus 0000:04
>     fe30300000-fe303fffff : 0000:04:00.0
>       fe30300000-fe303fffff : 0000:04:00.0
>     fe30400000-fe30403fff : 0000:04:00.0
>     fe30404000-fe30404fff : 0000:04:00.0

> afe00000000-affffffffff : 0000:03:00.0 This is the memory which shifts with nokaslr

To be honest that looks like a broken ACPI table to me, but it doesn't explain why this range here shifts when activating/deactivating nokaslr.

Do we have some option to enable printing when ranges are added to the iomem reservation? If yes than we should probably do that and take a look at the dmesg again.

Regards,
Christian.

>
> Bert Karwatzki

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