Hi Eric,
Here's the output of /proc/iomem:
suse-laptop:~ # cat /proc/iomem 00000000-00000fff : Reserved 00001000-0009221f : System RAM 00092220-0009229f : System RAM 000922a0-0009828f : System RAM 00098290-0009829f : System RAM 000982a0-0009efff : System RAM 0009f000-0009ffff : Reserved 000e0000-000fffff : Reserved 000a0000-000effff : PCI Bus 0000:00 000f0000-000fffff : System ROM 00100000-09bfffff : System RAM 06200000-071fffff : Kernel code 07200000-07e6dfff : Kernel rodata 08000000-082e3eff : Kernel data 08ba8000-08ffffff : Kernel bss 09c00000-09d90fff : Reserved 09d91000-09efffff : System RAM 09f00000-09f0efff : ACPI Non-volatile Storage 09f0f000-bf5a2017 : System RAM ba000000-be7fffff : Crash kernel bf5a2018-bf5af857 : System RAM bf5af858-c3a60fff : System RAM c3a61000-c3b54fff : Reserved c3b55000-c443dfff : System RAM c443e000-c443efff : Reserved c443f000-c51adfff : System RAM c51ae000-c51aefff : Reserved c51af000-c747dfff : System RAM c747e000-cb67dfff : Reserved cb669000-cb66cfff : MSFT0101:00 cb669000-cb66cfff : MSFT0101:00 cb66d000-cb670fff : MSFT0101:00 cb66d000-cb670fff : MSFT0101:00 cb67e000-cd77dfff : ACPI Non-volatile Storage cd77e000-cd7fdfff : ACPI Tables cd7fe000-ce7fffff : System RAM ce800000-cfffffff : Reserved d0000000-f7ffffff : PCI Bus 0000:00 f8000000-fbffffff : PCI ECAM 0000 [bus 00-3f] f8000000-fbffffff : Reserved f8000000-fbffffff : pnp 00:00 fc000000-fdffffff : PCI Bus 0000:00 fd000000-fd0fffff : PCI Bus 0000:05 fd000000-fd0007ff : 0000:05:00.1 fd000000-fd0007ff : ahci fd001000-fd0017ff : 0000:05:00.0 fd001000-fd0017ff : ahci fd100000-fd4fffff : PCI Bus 0000:04 fd100000-fd1fffff : 0000:04:00.3 fd100000-fd1fffff : xhci-hcd fd200000-fd2fffff : 0000:04:00.4 fd200000-fd2fffff : xhci-hcd fd300000-fd3fffff : 0000:04:00.2 fd300000-fd3fffff : ccp fd400000-fd47ffff : 0000:04:00.0 fd480000-fd4bffff : 0000:04:00.5 fd4c0000-fd4c7fff : 0000:04:00.6 fd4c0000-fd4c7fff : ICH HD audio fd4c8000-fd4cbfff : 0000:04:00.1 fd4c8000-fd4cbfff : ICH HD audio fd4cc000-fd4cdfff : 0000:04:00.2 fd4cc000-fd4cdfff : ccp fd500000-fd5fffff : PCI Bus 0000:03 fd500000-fd503fff : 0000:03:00.0 fd500000-fd503fff : nvme fd600000-fd6fffff : PCI Bus 0000:02 fd600000-fd60ffff : 0000:02:00.0 fd600000-fd60ffff : rtw88_pci fd700000-fd7fffff : PCI Bus 0000:01 fd700000-fd703fff : 0000:01:00.0 fd704000-fd704fff : 0000:01:00.0 fd704000-fd704fff : r8169 fde10510-fde1053f : MSFT0101:00 fdf00000-fdf7ffff : amd_iommu feb00000-feb00007 : SB800 TCO fec00000-fec003ff : IOAPIC 0 fec01000-fec013ff : IOAPIC 1 fec10000-fec1001f : pnp 00:04 fed00000-fed003ff : HPET 2 fed00000-fed003ff : PNP0103:00 fed00000-fed003ff : pnp 00:04 fed61000-fed613ff : pnp 00:04 fed80000-fed80fff : Reserved fed80000-fed80fff : pnp 00:04 fed81200-fed812ff : AMDI0030:00 fed81500-fed818ff : AMDI0030:00 fed81500-fed818ff : AMDI0030:00 AMDI0030:00 fedc2000-fedc2fff : AMDI0010:00 fedc2000-fedc2fff : AMDI0010:00 AMDI0010:00 fedc3000-fedc3fff : AMDI0010:01 fedc3000-fedc3fff : AMDI0010:01 AMDI0010:01 fedc4000-fedc4fff : AMDI0010:02 fedc4000-fedc4fff : AMDI0010:02 AMDI0010:02 fee00000-fee00fff : pnp 00:00 ff000000-ffffffff : pnp 00:04 100000000-3af37ffff : System RAM 399000000-3ae4fffff : Crash kernel 3af380000-42fffffff : Reserved 430000000-ffffffffff : PCI Bus 0000:00 460000000-4701fffff : PCI Bus 0000:04 460000000-46fffffff : 0000:04:00.0 470000000-4701fffff : 0000:04:00.0 3fff80000000-3fffffffffff : 0000:04:00.0
Thanks for creating kexec btw, it's invaluable for systems with slow firmware and loader 🚀
Pavin.
On 3/31/24 09:25, Eric W. Biederman wrote:
Ingo Molnar mingo@kernel.org writes:
- Pavin Joseph me@pavinjoseph.com wrote:
On 3/29/24 13:45, Ingo Molnar wrote:
Just to clarify, we have the following 3 upstream (and soon to be upstream) versions:
v1: pre-d794734c9bbf kernels v2: d794734c9bbf x86/mm/ident_map: Use gbpages only where full GB page should be mapped. v3: c567f2948f57 Revert "x86/mm/ident_map: Use gbpages only where full GB page should be mapped."
Where v1 and v3 ought to be the same in behavior.
So how does the failure matrix look like on your systems? Is my understanding accurate:
Slight correction:
regular boot | regular kexec | nogbpages boot | nogbpages kexec boot-----------------|---------------|----------------|------------------ v1: OK | OK | OK | FAIL v2: OK | FAIL | OK | FAIL
Thanks!
So the question is now: does anyone have a theory about in what fashion the kexec nogbpages bootup differs from the regular nogbpages bootup to break on your system?
I'd have expected the described root cause of the firmware not properly enumerating all memory areas that need to be mapped to cause trouble on regular, non-kexec nogbpages bootups too. What makes the kexec bootup special to trigger this crash?
My blind hunch would be something in the first 1MiB being different. The first 1MiB is where all of the historical stuff is and where I have seen historical memory maps be less than perfectly accurate.
Changing what is mapped being the difference between success and failure sounds like some place that is dark and hard to debug a page fault is being triggered and that in turn becoming a triple fault.
Paving Joseph is there any chance you can provide your memory map? Perhaps just cat /proc/iomem?
If I have something to go one other than works/doesn't work I can probably say something intelligent.
Eric