The new AMD/HYGON topology parser evaluates the SMT information in CPUID leaf
0x8000001e unconditionally while the original code restricted it to CPUs with
family 0x17 and greater.
This breaks family 0x15 CPUs which advertise that leaf and have a non-zero
value in the SMT section. The machine boots, but the scheduler complains loudly
about the mismatch of the core IDs:
WARNING: CPU: 1 PID: 0 at kernel/sched/core.c:6482 sched_cpu_starting+0x183/0x250
WARNING: CPU: 0 PID: 1 at kernel/sched/topology.c:2408 build_sched_domains+0x76b/0x12b0
Add the condition back to cure it.
[ bp: Make it actually build because grandpa is not concerned with
trivial stuff. :-P ]
Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Closes: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/issues/56
Reported-by: Tim Teichmann <teichmanntim@outlook.de>
Reported-by: Christian Heusel <christian@heusel.eu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tim Teichmann <teichmanntim@outlook.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/7skhx6mwe4hxiul64v6azhlxnokheorksqsdbp7qw6g2jduf6c@7b5pvomauugk
- Rework the x86 CPU vendor/family/model code: introduce the 'VFM'
value that is an 8+8+8 bit concatenation of the vendor/family/model
value, and add macros that work on VFM values. This simplifies the
addition of new Intel models & families, and simplifies existing
enumeration & quirk code.
- Add support for the AMD 0x80000026 leaf, to better parse topology
information.
- Optimize the NUMA allocation layout of more per-CPU data structures
- Improve the workaround for AMD erratum 1386
- Clear TME from /proc/cpuinfo as well, when disabled by the firmware
- Improve x86 self-tests
- Extend the mce_record tracepoint with the ::ppin and ::microcode fields
- Implement recovery for MCE errors in TDX/SEAM non-root mode
- Misc cleanups and fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-cpu-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu updates from Ingo Molnar:
- Rework the x86 CPU vendor/family/model code: introduce the 'VFM'
value that is an 8+8+8 bit concatenation of the vendor/family/model
value, and add macros that work on VFM values. This simplifies the
addition of new Intel models & families, and simplifies existing
enumeration & quirk code.
- Add support for the AMD 0x80000026 leaf, to better parse topology
information
- Optimize the NUMA allocation layout of more per-CPU data structures
- Improve the workaround for AMD erratum 1386
- Clear TME from /proc/cpuinfo as well, when disabled by the firmware
- Improve x86 self-tests
- Extend the mce_record tracepoint with the ::ppin and ::microcode fields
- Implement recovery for MCE errors in TDX/SEAM non-root mode
- Misc cleanups and fixes
* tag 'x86-cpu-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
x86/mm: Switch to new Intel CPU model defines
x86/tsc_msr: Switch to new Intel CPU model defines
x86/tsc: Switch to new Intel CPU model defines
x86/cpu: Switch to new Intel CPU model defines
x86/resctrl: Switch to new Intel CPU model defines
x86/microcode/intel: Switch to new Intel CPU model defines
x86/mce: Switch to new Intel CPU model defines
x86/cpu: Switch to new Intel CPU model defines
x86/cpu/intel_epb: Switch to new Intel CPU model defines
x86/aperfmperf: Switch to new Intel CPU model defines
x86/apic: Switch to new Intel CPU model defines
perf/x86/msr: Switch to new Intel CPU model defines
perf/x86/intel/uncore: Switch to new Intel CPU model defines
perf/x86/intel/pt: Switch to new Intel CPU model defines
perf/x86/lbr: Switch to new Intel CPU model defines
perf/x86/intel/cstate: Switch to new Intel CPU model defines
x86/bugs: Switch to new Intel CPU model defines
x86/bugs: Switch to new Intel CPU model defines
x86/cpu/vfm: Update arch/x86/include/asm/intel-family.h
x86/cpu/vfm: Add new macros to work with (vendor/family/model) values
...
The original topology evaluation code initialized cpu_data::topo::llc_id
with the die ID initialy and then eventually overwrite it with information
gathered from a CPUID leaf.
The conversion analysis failed to spot that particular detail and omitted
this initial assignment under the assumption that each topology evaluation
path will set it up. That assumption is mostly correct, but turns out to be
wrong in case that the CPUID leaf 0x80000006 does not provide a LLC ID.
In that case, LLC ID is invalid and as a consequence the setup of the
scheduling domain CPU masks is incorrect which subsequently causes the
scheduler core to complain about it during CPU hotplug:
BUG: arch topology borken
the CLS domain not a subset of the MC domain
Cure it by reusing legacy_set_llc() and assigning the die ID if the LLC ID
is invalid after all possible parsers have been tried.
Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Reported-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Link: https://lore.kernel.org/r/PUZPR04MB63168AC442C12627E827368581292@PUZPR04MB6316.apcprd04.prod.outlook.com
There's a new conflict between this commit pending in x86/cpu:
63edbaa48a x86/cpu/topology: Add support for the AMD 0x80000026 leaf
And these fixes in x86/urgent:
c064b536a8 x86/cpu/amd: Make the NODEID_MSR union actually work
1b3108f689 x86/cpu/amd: Make the CPUID 0x80000008 parser correct
Resolve them.
Conflicts:
arch/x86/kernel/cpu/topology_amd.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The topology rework missed that early_init_amd() tries to re-enable the
Topology Extensions when the BIOS disabled them.
The new parser is invoked before early_init_amd() so the re-enable attempt
happens too late.
Move it into the AMD specific topology parser code where it belongs.
Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/878r1j260l.ffs@tglx
A system with NODEID_MSR was reported to crash during early boot without
any output.
The reason is that the union which is used for accessing the bitfields in
the MSR is written wrongly and the resulting executable code accesses the
wrong part of the MSR data.
As a consequence a later division by that value results in 0 and that
result is used for another division as divisor, which obviously does not
work well.
The magic world of C, unions and bitfields:
union {
u64 bita : 3,
bitb : 3;
u64 all;
} x;
x.all = foo();
a = x.bita;
b = x.bitb;
results in the effective executable code of:
a = b = x.bita;
because bita and bitb are treated as union members and therefore both end
up at bit offset 0.
Wrapping the bitfield into an anonymous struct:
union {
struct {
u64 bita : 3,
bitb : 3;
};
u64 all;
} x;
works like expected.
Rework the NODEID_MSR union in exactly that way to cure the problem.
Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reported-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Laura Nao <laura.nao@collabora.com>
Link: https://lore.kernel.org/r/20240410194311.596282919@linutronix.de
Closes: https://lore.kernel.org/all/20240322175210.124416-1-laura.nao@collabora.com/
CPUID 0x80000008 ECX.cpu_nthreads describes the number of threads in the
package. The parser uses this value to initialize the SMT domain level.
That's wrong because cpu_nthreads does not describe the number of threads
per physical core. So this needs to set the CORE domain level and let the
later parsers set the SMT shift if available.
Preset the SMT domain level with the assumption of one thread per core,
which is correct ifrt here are no other CPUID leafs to parse, and propagate
cpu_nthreads and the core level APIC bitwidth into the CORE domain.
Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reported-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Laura Nao <laura.nao@collabora.com>
Link: https://lore.kernel.org/r/20240410194311.535206450@linutronix.de
On AMD processors that support extended CPUID leaf 0x80000026, use the
extended leaf to parse the topology information. In case of a failure,
fall back to parsing the information from CPUID leaf 0xb.
CPUID leaf 0x80000026 exposes the "CCX" and "CCD (Die)" information on
AMD processors which have been mapped to TOPO_TILE_DOMAIN and
TOPO_DIE_DOMAIN respectively.
Since this information was previously not available via CPUID leaf 0xb
or 0x8000001e, the "die_id", "logical_die_id", "max_die_per_pkg",
"die_cpus", and "die_cpus_list" will differ with this addition on
AMD processors that support extended CPUID leaf 0x80000026 and contain
more than one "CCD (Die)" on the package.
For example, following are the changes in the values reported by
"/sys/kernel/debug/x86/topo/cpus/16" after applying this patch on a 4th
Generation AMD EPYC System (1 x 128C/256T):
(CPU16 is the first CPU of the second CCD on the package)
tip:x86/apic tip:x86/apic
+ this patch
online: 1 1
initial_apicid: 80 80
apicid: 80 80
pkg_id: 0 0
die_id: 0 4 *
cu_id: 255 255
core_id: 64 64
logical_pkg_id: 0 0
logical_die_id: 0 4 *
llc_id: 8 8
l2c_id: 65535 65535
amd_node_id: 0 0
amd_nodes_per_pkg: 1 1
num_threads: 256 256
num_cores: 128 128
max_dies_per_pkg: 1 8 *
max_threads_per_core:2 2
[ prateek: commit log, updated comment in topoext_amd.c, changed has_0xb
to has_topoext, rebased the changes on tip:x86/apic, tested the
changes on 4th Gen AMD EPYC system ]
[ mingo: tidy up the changelog a bit more ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240314050432.1710-1-kprateek.nayak@amd.com
AMD/HYGON uses various methods for topology evaluation:
- Leaf 0x80000008 and 0x8000001e based with an optional leaf 0xb,
which is the preferred variant for modern CPUs.
Leaf 0xb will be superseded by leaf 0x80000026 soon, which is just
another variant of the Intel 0x1f leaf for whatever reasons.
- Subleaf 0x80000008 and NODEID_MSR base
- Legacy fallback
That code is following the principle of random bits and pieces all over the
place which results in multiple evaluations and impenetrable code flows in
the same way as the Intel parsing did.
Provide a sane implementation by clearly separating the three variants and
bringing them in the proper preference order in one place.
This provides the parsing for both AMD and HYGON because there is no point
in having a separate HYGON parser which only differs by 3 lines of
code. Any further divergence between AMD and HYGON can be handled in
different functions, while still sharing the existing parsers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153625.020038641@linutronix.de
