FreeBSD 10-R 8 vCPU panics at boot under XenServer (on 8 'core' CPU)

[Karl Pielorz]

--On 17 February 2014 16:56:14 +0100 Roger Pau Monné 
<roger.pau at citrix.com> wrote:

> In order to provide more debug info, could you apply the following patch:
>
> http://xenbits.xen.org/people/royger/0001-xen-debug-Xen-PV-timer.patch
>
> It will expand the panic message a little bit. Also, after applying the
> patch you can manually edit sys/dev/xen/timer/timer.c and increase
> NUM_RETRIES to see if that solves the problem.

Ok, tried adjusting the NUM_RETRIES #define in that patch (I left the PCI 
passthroughs in place at the moment). I had no idea what to set it to - so 
I went for 600. With it set at 600 that same guest now boots Ok now every 
time I've tried.

But I did notice the whole 'SMP AP CPU #x Launched!' takes forever, and 
varies a lot (e.g. one boot it took nearly 2 minutes to launch all CPU's 
and continue).

I removed the PCI passthroughs on that guest, and it now flies through the 
AP launches. Unfortunately though I need the passthroughs :(

I've passed through the onboard LSI 2308 SAS controller (mps), and a dual 
port PCI-E Intel NIC (igb) - all the passthroughs work on FreeBSD once it's 
booted - but obviously, not without causing the slow AP CPU launches.

I also remembered I set 'hw.pci.enable_msi=1' and 'hw.pci.enable_msix=0' in 
/etc/sysctl.conf - someone else found that was necessary to use the LSI in 
passthrough mode.

Aside from the slow launches, do you think (as they work) it's going to 
cause issues leaving those passthroughs active?

Thanks,

-Karl