Re: [kvm-devel] KVM console dying

[Anthony L. <an...@co...>]

Marcelo Tosatti wrote:
> From: Alan Pevec <ap...@re...>
>
>   
>> - add serial console, workaround for F9 livecd KVM guest dying with 
>> standard console only.
>>  VNC console will go blank but node will continue to boot
>>     
>
> With only console=tty qemu-kvm dies when, AFAICT from udevdebug output, start_udev is processing console rules.
>
> Here is backtrace:
>
> Program received signal SIGSEGV, Segmentation fault.
>
> [Switching to Thread -1208993168 (LWP 16163)]
>
> 0x0095337d in memmove () from /lib/libc.so.6
>
> Missing separate debuginfos, use: debuginfo-install SDL.i386 alsa-lib.i386 glibc.i686 gnutls.i386 libgcrypt.i386 libgpg-error.i386 zlib.i386
>   

The info that's needed is what the size of the vnc frame buffer is.  My 
suspicion is that we're racing.  A VCPU IO operation will trigger the 
bit blit which will cause this vnc_copy path to hit.  However, the VNC 
server is not thread safe so if the IO thread is running simultaneously, 
very bad things could happen.

Is this with standard KVM or your lock break-up patches?

Regards,

Anthony Liguori