em problem in virtualbox since the weekend

John Baldwin jhb at freebsd.org
Wed Jul 20 15:15:01 UTC 2011


On Wednesday, July 20, 2011 8:33:07 am Bernhard Froehlich wrote:
> On Wed, 20 Jul 2011 07:41:26 -0400, John Baldwin wrote:
> > On Tuesday, July 19, 2011 10:35:42 pm Steve Wills wrote:
> >> Hi,
> >>
> >> While testing some other things, I found -CURRENT from yesterday doesn't
> >> work with the em0 in my VirtualBox 4.0.8 (a little out of date
> >> admittedly). It worked Friday or Saturday I think. Anyone else seen this
> >> or should I open a PR? Has the code changed or am I perhaps
> >> misremembering dates? The error reported is:
> >>
> >> em0: Unable to allocate bus resource: memory
> >> em0: Allocation of PCI resources failed
> > 
> > This is due to a bug in VirtualBox's BIOS implementation.  Someone
> > should file
> > a bug report with VirtualBox to ask them to fix their BIOS.  The problem is 
> > that they claim that the Host-PCI bridge in their system only decodes 
> > addresses 0xa0000-0xbffff (i.e. the VGA window) via the "Producer" resources 
> > in the _CRS method of the Host-PCI bridge device.  This tells the OS
> > that all
> > the existing PCI devices are using invalid memory address ranges but that 
> > there is also no available address space to allocate for PCI devices such as 
> > em0.
> > 
> > You can workaround this by setting "debug.acpi.disabled=hostres" until 
> > VirtualBox fixes their code.  I'm happy to provide further
> > clarification to an
> > existing VirtaulBox bug report if needed.
> 
> Thanks a lot for the analysis! I've talked to one of the virtualbox
> developers about that but they are not aware of such problems with Linux
> or Windows guests yet. So they are currently unsure if it's a VirtualBox
> or FreeBSD fault and if it's their fault why it works fine with other
> guests. I'm also unsure because I haven't heard of that problem before
> and now multiple people complain. That looks more like a FreeBSD related
> problem on current or stable.
> 
> I think it would be good if someone could try to reproduce that with
> emulators/virtualbox-ose-legacy which is 3.2.12 to get some vbox dev
> look into the problem again.

FreeBSD just started honoring this setting in the BIOS this week and ignored
it previously.  Can you get an acpidump from within VirtaulBox?  I might be
able to point to a bug in it directly if so.

-- 
John Baldwin


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