Bugs item #2681442, was opened at 2009-03-11 06:08 Message generated for change (Comment added) made by bliitz You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2681442&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: 5 Private: No Submitted By: Julian Stecklina (bliitz) Assigned to: Nobody/Anonymous (nobody) Summary: Task Switch causes reboot Initial Comment: I have a small test "kernel" that measures some x86 task switching stuff. KVM reboots the virtual machine when my test kernel tries to do a hardware task switch by CALLing a TSS descriptor in the GDT. I have attached an ISO which boots my test kernel. I can provide the source of this, if it's helpful. Output using: kvm -serial stdio -cdrom losysbench.iso losysbench [lots of debugging output] Calling TASK0_2 directly... [VM reboots] Output using kvm -no-kvm -serial stdio -cdrom losysbench.iso: losysbench [lots of debugging output] Calling TASK0_2 directly... 90730 [more stuff, i.e. everything went fine] My system info: Gentoo Linux Intel Core Duo L2400 KVM 84 Vanilla Linux 2.6.29-rc7 i386 ---------------------------------------------------------------------- >Comment By: Julian Stecklina (bliitz) Date: 2009-03-16 21:29 Message: The patch from the mailing list does indeed fix this. The test case reports: julian@tabernacle kvm-userspace % ./user/kvmctl user/test/x86/bootstrap user/test/x86/taskswitch.flat GUEST: task switching GUEST: Calling task (ring0) GUEST: Calling task (ring0) via gate GUEST: Calling task (ring3) GUEST: Done ---------------------------------------------------------------------- Comment By: Jan Kiszka (kiszka) Date: 2009-03-16 08:56 Message: Nice, with complete test case! But at least I'm too la^busy to try: Could you check if Bernhard Kohl's patch changes the picture for you? See http://permalink.gmane.org/gmane.comp.emulators.kvm.devel/29288 ---------------------------------------------------------------------- Comment By: Julian Stecklina (bliitz) Date: 2009-03-16 02:08 Message: File Added: taskswitch-test.patch ---------------------------------------------------------------------- Comment By: Avi Kivity (avik) Date: 2009-03-15 13:58 Message: A minimal test case (that can be added to kvm-xx/users/test/...) would be very useful. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2681442&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
