Running a simple thing on this AMD host would trigger a reset right away. Unselect KCSAN kconfig makes everything work fine (the host would also reset If only "echo off > /sys/kernel/debug/kcsan” before running qemu-kvm). /usr/libexec/qemu-kvm -name ubuntu-18.04-server-cloudimg -cpu host -smp 2 -m 2G -hda ubuntu-18.04-server-cloudimg.qcow2 -cdrom ubuntu-18.04-server-cloudimg.iso -nic user,hostfwd=tcp::2222-:22 -serial mon:stdio -nographic With this config on today’s linux-next, https://raw.githubusercontent.com/cailca/linux-mm/master/kcsan.config Cherry-picked a few commits from -rcu (in case if it ever matters) 48b1fc1 kcsan: Add option to allow watcher interruptions 2402d0e kcsan: Add option for verbose reporting 43f7646 x86/mm/pat: Mark an intentional data race === console output === Kernel 5.6.0-next-20200408+ on an x86_64 hp-dl385g10-05 login: <...host reset...> ======================= HPE ProLiant System BIOS A40 v1.20 (03/09/2018) (C) Copyright 1982-2018 Hewlett Packard Enterprise Development LP Early system initialization, please wait... iLO 5 IPv4: 10.73.196.44 iLO 5 IPv6: FE80::D6C9:EFFF:FECE:717E 2%: Early Processor Initialization 4%: Processor Root Ports Initialization 8%: SMBIOS Table Initialization 12%: HPE SmartMemory Initialization 17%: iLO Embedded Health Initialization 21%: ACPI Table Initialization 25%: System Security Initialization 30%: BIOS Configuration Initialization 39%: Early PCI Initialization - Start 47%: Early PCI Initialization - Complete 60%: Switching console output to Primary Video. Please wait… ======== # lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 32 On-line CPU(s) list: 0-31 Thread(s) per core: 2 Core(s) per socket: 8 Socket(s): 2 NUMA node(s): 8 Vendor ID: AuthenticAMD CPU family: 23 Model: 1 Model name: AMD EPYC 7251 8-Core Processor Stepping: 2 CPU MHz: 2830.383 CPU max MHz: 2100.0000 CPU min MHz: 1200.0000 BogoMIPS: 4191.58 Virtualization: AMD-V L1d cache: 32K L1i cache: 64K L2 cache: 512K L3 cache: 4096K NUMA node0 CPU(s): 0,1,16,17 NUMA node1 CPU(s): 2,3,18,19 NUMA node2 CPU(s): 4,5,20,21 NUMA node3 CPU(s): 6,7,22,23 NUMA node4 CPU(s): 8,9,24,25 NUMA node5 CPU(s): 10,11,26,27 NUMA node6 CPU(s): 12,13,28,29 NUMA node7 CPU(s): 14,15,30,31 Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid amd_dcm aperfmperf pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb hw_pstate ssbd ibpb vmmcall fsgsbase bmi1 avx2 smep bmi2 rdseed adx smap clflushopt sha_ni xsaveopt xsavec xgetbv1 xsaves clzero irperf xsaveerptr arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif overflow_recov succor smca # cat /sys/kernel/debug/kcsan enabled: 1 used_watchpoints: 0 setup_watchpoints: 13777602 data_races: 47 assert_failures: 0 no_capacity: 598865 report_races: 0 races_unknown_origin: 226 unencodable_accesses: 0 encoding_false_positives: 0
