https://bugzilla.kernel.org/show_bug.cgi?id=205313 Bug ID: 205313 Summary: Machine check exception 90000040000f0005 and kernel panic Product: Virtualization Version: unspecified Kernel Version: 4.15.0-generic and 5.3.7-arch1-1-ARCH Hardware: Intel OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: fintelia@xxxxxxxxx Regression: No When trying to run certain builds of the sv6 research OS as a guest kernel inside QEMU/KVM, the Linux *host* system reports some machine check exceptions and then kernel panics. The same behavior happens on both a Skylake Laptop running Arch (kernel 5.3.7-arch1-1-ARCH) and a Broadwell server running Ubuntu 18.04 (kernel 4.15.0-generic). # Steps to reproduce 1) Download kernel.elf from https://github.com/fintelia/sv6/releases/tag/mce-bug-2 2) Run `qemu-system-x86_64 -nographic -enable-kvm -cpu qemu64,+fsgsbase -kernel kernel.elf` 3) Once the guest boots, execute "ls" 5-10 times in rapid succession. 4) Observe that the entire system stops responding, perhaps printing some error messages about MCEs or kernel panics in the process. # Example output Running on a 4th Generation Lenovo X1 Carbon Laptop (with a i7-6600U) the following errors are recorded in the system log: Oct 24 10:42:14 jonathan-ThinkPad-X1-Carbon kernel: L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details. Oct 24 10:42:19 jonathan-ThinkPad-X1-Carbon rasdaemon[614]: rasdaemon: mce_record store: 0x56538e929050 Oct 24 10:42:19 jonathan-ThinkPad-X1-Carbon kernel: mce_notify_irq: 1 callbacks suppressed Oct 24 10:42:19 jonathan-ThinkPad-X1-Carbon kernel: mce: [Hardware Error]: Machine check events logged Oct 24 10:42:19 jonathan-ThinkPad-X1-Carbon kernel: mce: [Hardware Error]: CPU 1: Machine Check: 0 Bank 0: 90000040000f0005 Oct 24 10:42:19 jonathan-ThinkPad-X1-Carbon kernel: mce: [Hardware Error]: TSC a5db750d4d Oct 24 10:42:19 jonathan-ThinkPad-X1-Carbon kernel: mce: [Hardware Error]: PROCESSOR 0:406e3 TIME 1571928139 SOCKET 0 APIC 2 microcode cc Oct 24 10:42:19 jonathan-ThinkPad-X1-Carbon rasdaemon[614]: rasdaemon: register inserted at db Oct 24 10:42:19 jonathan-ThinkPad-X1-Carbon rasdaemon[614]: <...>-24 [001] 0.000023: mce_record: 2019-10-24 10:42:19 -0400 bank=0, status= 90000040000f0005, Internal parity error, mci=Corrected_error Error_enabled, mca=Internal parity error, cpu_type= Intel generic architectural MCA, cpu= 1, socketid= 0, mcgstatus=0, mcgcap= c08, apicid= 2 Oct 24 10:42:32 jonathan-ThinkPad-X1-Carbon kernel: mce: [Hardware Error]: Machine check events logged Oct 24 10:42:32 jonathan-ThinkPad-X1-Carbon kernel: mce: [Hardware Error]: CPU 1: Machine Check: 0 Bank 0: d0000040000f0005 Oct 24 10:42:32 jonathan-ThinkPad-X1-Carbon kernel: mce: [Hardware Error]: TSC ae60fc6c1a Oct 24 10:42:32 jonathan-ThinkPad-X1-Carbon kernel: mce: [Hardware Error]: PROCESSOR 0:406e3 TIME 1571928152 SOCKET 0 APIC 2 microcode cc And afterwards there is a kernel panic that is printed to the screen but doesn't seem to be recorded anywhere: Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler Shutting down cpus with NMI Kernel Offset: 0x2bc00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) Rebooting in 30 seconds... -- You are receiving this mail because: You are watching the assignee of the bug.
