Re: [Qemu-devel] qemu with kqemu freezes when more than one qemu is running

[Bakul Shah <bakul+qemu@bitblocks.com>]

"Frank J. Beckmann" <frank@barda.agala.net> wrote:
>  
> qemu-0.8.1_1 with kqemu-kmod-1.3.0.p9 on FreeBSD 6.1-RELEASE i386 freezes 
> after less than one hour runtime when more than one qemu is running. If only 
> one qemu is running everything works fine. When more than one qemu runs none 
> of them can use kqemu without freezing after a short time. The frozen qemu 
> can get killed only by a kill -9. The same happened with kqemu-kmod-1.3.0.p7.
>  
>  
> The processor is an AMD Athlon 64, but I use the i386 release of FreeBSD. 

I ran two plan9 guests for over two hours now on my laptop
with no crash.  They are both doing a ping every 10 ms and
continuous floating pt additions.  kqemu is enabled but not
kernel-kqemu (as plan9performance under kernel-kqemu is
abysmal).  This is a Pentium M machine with 1GB of memory,
running FreeBSD-current.  plan9 is not very resource hungry
(RSS is about 70MB) so if this is a resource related problem
my test won't catch it.

A quick reading of kqemu-freebsd.c does not reveal any problems
for a uniprocessor machine (but I am not too sure of SMP).

Can people who are seeing crashes or hangs provide some more
information?

- symptom: (host crashes, guest crashes, guest hangs, guest loses its mind)
- freebsd version (also if UP or SMP version)
- processor
- command line used to invoke each qemu instance
- what guest oses are run when this happens
- if this is triggered more often by specific guest programs
- what happens if you run the same guests with less memory.
- output of sysctl kern.smp.cpus
- VSZ and RSS of these images (from ps axlw).
- whether -kernel-kqemu was used

I am hoping a pattern will emerge that will help us debug this.