Bugs item #1872255, was opened at 2008-01-15 19:24 Message generated for change (Comment added) made by avik You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=1872255&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: libkvm Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Olivier Paquet (euzeka) Assigned to: Nobody/Anonymous (nobody) Summary: cygwin not working inside 64-bit guest Initial Comment: I installed cygwin on Windows XP x64 inside kvm-59 and it crashes randomly. The easiest way to reproduce it is by simply starting and quitting a few bash shells: ------------------------------- C:\cygwin\bin>Cygwin.bat C:\cygwin\bin>bash bash-3.2$ bash bash-3.2$ bash bash-3.2$ exit exit 10551 [main] bash 1488 sig_send: wait for sig_complete event failed, signal -34, rc -1, Win32 error 6 Segmentation fault bash-3.2$ exit exit 87 [main] bash 1592 sig_send: wait for sig_complete event failed, signal -34, rc -1, Win32 error 6 Segmentation fault bash-3.2$ exit exit C:\cygwin\bin> ------------------------------- But it also happens with other programs so it seems to be something related to their weird fork implementation. With kvm disabled (with kvm-56 as it won't boot anymore with 59), cygwin works fine. Host is a Core 2 Duo with slackware 11 and kernel 2.6.21.1. Running with: qemu-system-x86_64 -hda wintest.img -smp 1 -localtime -net nic,model=rtl8139 -net tap,ifname=tap0,script=no -m 512 ---------------------------------------------------------------------- >Comment By: Avi Kivity (avik) Date: 2009-01-21 15:45 Message: Very strange. The process dies accessing its thread control block (@ gs:[0x30]). gs.base is zero rather than pointing at the TCB. It also appears that it is the guest that zeroes gs.base, not kvm. Wierd, wierd. ---------------------------------------------------------------------- Comment By: Olivier Paquet (euzeka) Date: 2009-01-15 06:27 Message: I have also tried nearly every single release in the past year and they all had the bug, right up to kvm-83. I just tried migrating my test VM to an AMD box and it does *not* have the bug. So it would appear to be something in the kvm-intel module or specific to using that module. ---------------------------------------------------------------------- Comment By: Jamie Kirkpatrick (gringostarr) Date: 2009-01-06 12:12 Message: I have found the same problem in every version of KVM I have used including the current KVM-81 release. I've found that this is a known bug in not only KVM, but also in Xen. I posted about it here: http://thread.gmane.org/gmane.comp.emulators.kvm.devel/27003. There are a couple of links of interest in that post that detail the issue further. There also seem to be two issues here: one which is noted above, and another which causes a segfault if you use Cygwin bash's builtin test call ( if [[ 1 ]] then ... fi ). Doing this causes a segfault every time. People who have investigated this bug further from Cygwin's side have found that doing a block-by-block copy of the guest OS to a physical box makes the problem go away and it was agreed that it was definitely down to Xen in the posts I've read. Clearly KVM suffers too. Host: Linux kvm-host 2.6.27-rc9-amd64 #1 SMP Fri Oct 10 11:07:08 UTC 2008 x86_64 GNU/Linux CPU: Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz Command: /usr/bin/kvm -name windows-dev -smp 4 -m 4096 -daemonize -vnc :1 -usb -usbdevice tablet -net nic,macaddr=00:16:3e:00:00:1,model=e1000 -net tap,ifname=tap1 -pidfile /var/run/kvm/windows-dev.pid -boot c -drive index=0,media=disk,if=ide,file=/dev/kvm-host/windows-dev -drive index=2,media=cdrom,if=ide,file=/home/jkp/NETKVM-20081229.iso -k en-us -monitor telnet:127.0.0.1:4001,server,nowait ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=1872255&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
