Networking issues with FreeBSD HVM + SMP

[Ben C.]

Hello all,

Thanks for taking time to read this post.  It's a fairly long winded
tale of confusion, but here goes:

* I originally installed FreeBSD 8.2-RELEASE fine working under 100%
HVM.  Using the GENERIC kernel with xen's qemu
* I trashed the box (kind of willingly, it's been a while since I've
had the pleasure of FreeBSD and think of it as my first pancake)
* Reinstalled.  Networking failed.  I had no idea why.  Several weeks
past, I finally got networking back working after about 20-30 install
attempts.
* Setup the box properly.
* Did some changes throughout the dom0/domu's - I had originally had
the vcpu's pinned to physical cpu's and all this mojo.  I found that
my load averages on the dom0 were significantly lower when the vcpu's
were bound to 'any physical' -- but that's beside the point.  The
point is, FreeBSD changed vcpu's from 1 to 2 - and networking stopped.
 * I honestly thought it surely was something else.  I triple-checked
and confirmed, when vcpu=1, networking worked as expected.  When vcpu
was >1, networking failed with a vauge .. em0 (or re0, see below) ..
watchdog timeout spewing all over.

If you take a look at my configuration below, I originally had
model=e1000 in the vif, which I *thought* was what made it work
originally.  I was apprently wrong.  vcpu pinning doesn't matter.
Essentially, if it has more than 1 (v)cpu's, networking fails.

The dom0 is running NetBSD -CURRENT [current there is just like
current here], on an Intel i7.  I could try the -current branch or
using the xenhvm kernel/drivers.  I'm fairly sure the latter may help
the situation, but honestly I'm just a bit bothered by the strangeness
of this "bug".   Does anyone else have any suggestions on what I
should try next?

Thanks for your time, Ben


name ="a5freebsd"
memory = 2048

kernel = "/usr/pkg/lib/xen/boot/hvmloader"
builder='hvm'
device_model = '/usr/pkg/libexec/qemu-dm'

disk = [
	'phy:/dev/mapper/rxenpool-a5freebsd_root,ioemu:hda,w',
	'file:/home/xen/iso/FreeBSD-8.2-RELEASE-amd64-disc1.iso,ioemu:hdc:cdrom,r'
]
boot = 'cd'

vcpus=2
#cpus=['2']


#vif=[ 'type=ioemu,bridge=bridge0,model=e1000,mac=00:16:3e:4f:bb:78' ]
vif=[ 'type=ioemu,bridge=bridge0,mac=00:16:3e:4f:bb:78' ]

vnc = 1
vncdisplay = 2
vnclisten = "1.2.3.4"
vncpasswd = "removed"

on_reboot   = 'restart'
on_crash    = 'restart'

usbdevice = 'tablet'