[ kvm-Bugs-2681442 ] Task Switch causes reboot

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux