Bugs item #2019053, was opened at 2008-07-16 00:10 Message generated for change (Comment added) made by awwy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2019053&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: amd Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Alex Williamson (alex_williamson) Assigned to: Nobody/Anonymous (nobody) Summary: tbench fails on guest when AMD NPT enabled Initial Comment: Running on a dual-socket system with AMD 2356 quad-core processors (8 total cores), 32GB RAM, Ubuntu Hardy 2.6.24-19-generic (64bit) with kvm-71 userspace and kernel modules. With no module options, dmesg confirms: kvm: Nested Paging enabled Start guest with: /usr/local/kvm/bin/qemu-system-x86_64 -hda /dev/VM/Ubuntu64 -m 1024 -net nic,model=e1000,mac=de:ad:be:ef:00:01 -net tap,script=/root/bin/br0-ifup -smp 8 -vnc :0 Guest VM is also Ubuntu Hardy 64bit. On the guest run 'tbench 16 <tbench server>'. System running tbench_srv is a different system in my case. The tbench client will fail randomly, often quietly with "Child failed with status 1", but sometimes more harshly with a glibc double free error. If I unload the modules and reload w/o npt: modprobe -r kvm-amd modprobe -r kvm modprobe kvm-amd npt=0 dmesg confirms: kvm: Nested Paging disabled The tbench test now runs over and over successfully. The test also runs fine on an Intel E5450 (no EPT). ---------------------------------------------------------------------- Comment By: Alexander Graf (awwy) Date: 2008-07-24 05:45 Message: Logged In: YES user_id=376328 Originator: NO I'm seeing random segfaults when using NPT on a host kernel >= 2.6.23. So far I have not been able to reproduce my test case breakages with an openSUSE 10.3 kernel though, so could you please test that and verify if tbench works for you on openSUSE 10.3? It does break with 11.0. I have the feeling that we're seeing the same problem here. ---------------------------------------------------------------------- Comment By: Alex Williamson (alex_williamson) Date: 2008-07-16 15:18 Message: Logged In: YES user_id=333914 Originator: YES No, I added mlockall(MCL_CURRENT | MCL_FUTURE) to qemu/vl.c:main() and it makes no difference. I'm only starting a 1G guest on an otherwise idle 32G host, so host memory pressure is pretty light. ---------------------------------------------------------------------- Comment By: Avi Kivity (avik) Date: 2008-07-16 14:19 Message: Logged In: YES user_id=539971 Originator: NO Strange. If you add an mlockall() to qemu startup, does the test pass? ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2019053&group_id=180599 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
