Bugs item #2703537, was opened at 2009-03-22 18:07 Message generated for change (Comment added) made by glebn You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2703537&group_id=180599 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None Status: Open Resolution: None Priority: 7 Private: No Submitted By: Technologov (technologov) Assigned to: Nobody/Anonymous (nobody) Summary: CPU hotplug causes segfault Initial Comment: Host: kvm-84 on Intel or AMD. (RHEL 5/x64) When I use empty VM and add CPU hotplug several times I get a segfault. Empty VM is started with PXE networking. # qemu-kvm -boot n Now I connect to Qemu monitor and use: (qemu) cpu_set 1 online (qemu) cpu_set 2 online (qemu) cpu_set 3 online (qemu) cpu_set 4 online (qemu) cpu_set 5 online When I add several CPUs like this - Qemu/KVM userspace will crash. Very easy to reproduce. GDB: Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x43c2b940 (LWP 3667)] 0x0000000000459167 in cpu_get_apic_tpr (env=0x1cef87b0) at /root/Linstall/kvm-84rc1/qemu/hw/apic.c:316 316 { (gdb) c Continuing. [Thread 0x4322a940 (LWP 3666) exited] [Thread 0x43c2b940 (LWP 3667) exited] [Thread 0x41e28940 (LWP 3660) exited] [Thread 0x42829940 (LWP 3661) exited] Program terminated with signal SIGSEGV, Segmentation fault. The program no longer exists. Dmesg: There are no interesting messages in dmesg. -Alexey, 22.3.2009. ---------------------------------------------------------------------- Comment By: Gleb Natapov (glebn) Date: 2009-03-23 11:25 Message: It is a known problem (at least by me). There is a race when APIC is accessed before it is created. ---------------------------------------------------------------------- Comment By: Technologov (technologov) Date: 2009-03-23 11:16 Message: Full GDB output attached. -Alexey, 23.3.2009. File Added: gdb_of_cpu_hotplug_crash.txt ---------------------------------------------------------------------- Comment By: Glauber de Oliveira Costa (glommer) Date: 2009-03-22 18:34 Message: Can you get a backtrace for all threads in qemu in the moment of the crash? thanks ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2703537&group_id=180599 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
