[ipxe-devel] eepro100 vs qemu

Alex Williamson alex.williamson at redhat.com
Tue Mar 15 01:42:01 UTC 2011

On Tue, 2011-03-15 at 01:25 +0000, Michael Brown wrote:
> On Monday 14 Mar 2011 19:57:35 Alex Williamson wrote:
> > Ok, sorry for the distraction, I think I can explain it now.  Last week
> > I was testing large (8G) guests.  Today I was trying to figure out how
> > the pcnet32 image ever worked because I couldn't make the old gpxe or
> > the new ipxe image work.  Eventually I discovered that it worked if I
> > used a smaller guest memory size (512M).  I then used that to test all
> > the images under qemu, followed by kvm.  Unfortunately nothing boots
> > under kvm with a 512M guest.  In fact, I can only boot these ROMs if the
> > guest has 3.6G or more (note that qemu/kvm currently has a 512MB I/O
> > hole, so this means there's memory bounding the hole on both sides).
> > 
> > This was introduced with the commit above, 132c3917.  So we've still got
> > a blocker for refreshing the current ROMs.  Thanks,
> Thanks for this.  I can reproduce a PMM failure using the current qemu git 
> tree with -enable-kvm.
> (On a related note, did the qemu invocation syntax change at some point?  I'm 
> sure I used to have to type "-no-kvm" to prevent KVM from being used; now KVM 
> seems to be disabled by default.)

Yes, it has been evolving.  This particular difference sounds like
qemu-kvm vs qemu though.  The qemu-kvm tree was the fork of qemu that
enabled kvm support, there kvm acceleration is the default.  Much of the
kvm acceleration has since been ported back into qemu, but afaik qemu
has never defaulted to kvm enabled.

> Will investigate.



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