SIGILL on VM

[nicolamori]

I compiled OpenBLAS 0.3.30 on a VM with AlmaLinux 9, and I am experiencing a SIGILL while loading the numpy python module (which uses libopenblas-r0.3.30.so).

The cpu supports x86_64-v3:

$ /usr/lib64/ld-linux-x86-64.so.2 --help
 . . .
Subdirectories of glibc-hwcaps directories, in priority order:
  x86-64-v4
  x86-64-v3 (supported, searched)
  x86-64-v2 (supported, searched)
 . . .

I compiled with spack for x86_64-v3 with these specs:

^openblas@0.3.30~bignuma~consistent_fpcsr+dynamic_dispatch+fortran~ilp64+locking+pic+shared build_system=makefile symbol_suffix=none threads=none platform=linux os=almalinux9 target=x86_64_v3 %c,cxx,fortran=gcc@11.5.0

as a dependence for py-numpy, but now when I do import numpy I get a SIGILL:

$ dmesg -T | tail -n 1
[Sun Jun  7 22:24:24 2026] traps: python3[2714035] trap invalid opcode ip:7f361685ba20 sp:7ffe39e391e8 error:0 in libopenblas-r0.3.30.so[7f3615fa8000+1e5c000]

This happens also for a version compiled with x86_64 target. But if I specify a value for OPENBLAS_CORETYPE then it works (tried with Nehalem and Zen).

I suspect that the reason could be a fault in detecting the CPU architecture, which is circumvented by explicitly specifying it at runtime. Actually lscpu reports:

$ lscpu
Architecture:                x86_64
  CPU op-mode(s):            32-bit, 64-bit
  Address sizes:             40 bits physical, 48 bits virtual
  Byte Order:                Little Endian
CPU(s):                      4
  On-line CPU(s) list:       0-3
Vendor ID:                   AuthenticAMD
  Model name:                QEMU Virtual CPU version 2.5+
    CPU family:              15
 . . .

so maybe the Model name: value is not correctly recognized?

[nicolamori]

This looks very similar:
#272

[nicolamori]

Here are some details about the CPU:

$ cat /proc/cpuinfo 
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 107
model name      : QEMU Virtual CPU version 2.5+
stepping        : 1
microcode       : 0x1000065
cpu MHz         : 2645.030
cache size      : 512 KB
physical id     : 0
siblings        : 4
core id         : 0
cpu cores       : 4
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx lm rep_good nopl cpuid extd_apicid tsc_known_freq pni ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c hypervisor lahf_lm cmp_legacy abm 3dnowprefetch vmmcall bmi1 avx2 bmi2
bugs            : fxsave_leak sysret_ss_attrs null_seg swapgs_fence amd_e400 spectre_v1 spectre_v2 spectre_v2_user
bogomips        : 5290.06
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

processor       : 1
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 107
model name      : QEMU Virtual CPU version 2.5+
stepping        : 1
microcode       : 0x1000065
cpu MHz         : 2645.030
cache size      : 512 KB
physical id     : 0
siblings        : 4
core id         : 1
cpu cores       : 4
apicid          : 1
initial apicid  : 1
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx lm rep_good nopl cpuid extd_apicid tsc_known_freq pni ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c hypervisor lahf_lm cmp_legacy abm 3dnowprefetch vmmcall bmi1 avx2 bmi2
bugs            : fxsave_leak sysret_ss_attrs null_seg swapgs_fence amd_e400 spectre_v1 spectre_v2 spectre_v2_user
bogomips        : 5290.06
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

processor       : 2
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 107
model name      : QEMU Virtual CPU version 2.5+
stepping        : 1
microcode       : 0x1000065
cpu MHz         : 2645.030
cache size      : 512 KB
physical id     : 0
siblings        : 4
core id         : 2
cpu cores       : 4
apicid          : 2
initial apicid  : 2
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx lm rep_good nopl cpuid extd_apicid tsc_known_freq pni ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c hypervisor lahf_lm cmp_legacy abm 3dnowprefetch vmmcall bmi1 avx2 bmi2
bugs            : fxsave_leak sysret_ss_attrs null_seg swapgs_fence amd_e400 spectre_v1 spectre_v2 spectre_v2_user
bogomips        : 5290.06
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

processor       : 3
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 107
model name      : QEMU Virtual CPU version 2.5+
stepping        : 1
microcode       : 0x1000065
cpu MHz         : 2645.030
cache size      : 512 KB
physical id     : 0
siblings        : 4
core id         : 3
cpu cores       : 4
apicid          : 3
initial apicid  : 3
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx lm rep_good nopl cpuid extd_apicid tsc_known_freq pni ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c hypervisor lahf_lm cmp_legacy abm 3dnowprefetch vmmcall bmi1 avx2 bmi2
bugs            : fxsave_leak sysret_ss_attrs null_seg swapgs_fence amd_e400 spectre_v1 spectre_v2 spectre_v2_user
bogomips        : 5290.06
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

If any more info is needed then please let me know.

[martin-frbg]

Hmm, which version of QEMU is this, and what cpu option are you using ? I cannot seem to get the AlmaLinux9 boot medium to start up without an immediate kernel panic unless I specify a cpu model like EPYC-Rome (at which point /proc/cpuinfo inside the vm shows a family 23 cpu and there is no SIGILL from OpenBLAS)