Re: Second KVM process hangs eating 80-100% CPU on host during startup

[Avi Kivity <avi@qumranet.com>]

Alex Davis wrote:
> Host software:
> Linux 2.6.24.4
> KVM 65 (I am using the kernel modules from this release).
> X11 7.2 from Xorg
> SDL 1.2.13
> GCC 4.1.1
> Glibc 2.4
>
> Host hardware:
> Asus P5B Deluxe (P965 chipset based) motherboard
> 4 GB RAM
> Intel E6700 CPU
>
> Guest software:
> Slackware 12.0 installed from CD-ROM.
>
> Command used to first KVM instance:
> /usr/local/bin/qemu-system-x86_64 -hda /spare/vdisk1.img -cdrom /dev/cdrom -boot c -m 384 -net
> nic,macaddr=DE:AD:BE:EF:11:29 -net tap,ifname=tap0,script=no &
>
> Command used to start second KVM instance:
> /usr/local/bin/qemu-system-x86_64 -hda /spare/vdisk2.img -cdrom /dev/cdrom -boot c -m 384 -net
> nic,macaddr=DE:AD:BE:EF:11:30 -net tap,ifname=tap1,script=no &
>
> tap0 and tap1 are bridged on the host. The guest OS was installed on /spare/vdisk1.img, 
> which was initially created by /usr/local/bin/qemu-img create -f qcow /spare/vdisk.img 10G
> After the guest installation completed, vdisk1 was copied to vdisk2.
>
> The second instance always stops after printing
> Checking if the processor honours the WP bit even in supervisor mode... Ok.
> It stays hung until I press the return key in the first instance; sometimes clicking in another X
> window will wake it up as well. 
>
> This is a test machine so I can test patches (almost) at will.
>
>   

Strange.  Does pinning each guest to a different cpu help (use 'taskset 
1 qemu ... vdisk1.img &  ', taskset 2 qemu ... vdisk2.img)


-- 
Any sufficiently difficult bug is indistinguishable from a feature.


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