On Thursday, July 01, 2010 05:37:29 pm Zach Carter wrote: > Hi: > > Under certain 100% reproducible circumstances, when I try to run qemu-kvm, > it completely hangs without appearing to do anything > > I have tried this with qemu-kvm 0.12.4 and with the latest code from the > git repository. > > Here are some more interesting details. The 64 bit host, kernel, and kvm > kernel module are all vanilla CentOS 5.4. If I use the kmod- > kvm-83-105.el5_4.9 version of the kernel module, it works fine. Yum update > to anything past that and the hang occurs 100% of the time. Update all > the way to the very latest CentOS 5.5 packages, and I still get the hang. > Downgrade just the kvm kernel modules and it starts working again. That's pretty well known. Use a newer kernel with a newer qemu-kvm, or use the packages that come with CentOS. > > I'm sure I could use the qemu-kvm that ships from CentOS with the > corresponding kernel module, however that lacks certain essential features, > including support for scsi disk drive emulation. There's a reason Redhat disables scsi support in their kvm... it's not really suggested to use it. > > After messing around with gdb and some printf statements, it looks to me > like it just loops forever and ever in the "while (1)" loop on about line > 1710 of qemu-kvm.c. Killing it and grabbing a backtrace shows that it is > spending its time mostly sitting in the "select" system call on about line > 1288 in vt.c. Maybe its normal to sit in that loop and poll for events, > but something else should happen eventually. What is it waiting for? > > If I add the -no-kvm option to the command line, it works fine. > > Any ideas on how to further troubleshoot? > > thanks! > > -Zach > > My command line: > > /opt/qemu-git/bin/qemu-system-x86_64 -drive > file=my.vmdk,if=scsi,cache=writeback -cdrom my.iso -boot d -nographic -m > 1024 - no-kvm-irqchip -kernel my.vmlinuz -initrd my.initrd.img -append > 'initrd=initrd.img root=/dev/ram0 console=tty0 console=ttyS0,19200 quiet > action=install mode=silent ramdisk_size=147169 mkvm_cpu_lm > mkvm_device=/dev/sda mkvm' > -- > 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 -- 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
