Red Hat Bugzilla – Bug 494469
qemu-kvm fails to boot gPXE ROMs
Last modified: 2009-08-07 10:34:57 EDT
Description of problem:
Fedora QEMU Maintainer, AKA glommer, spent 3 whole days trying to make gpxe roms boot under kvm. They boot fine under qemu. They simply stall after gpxe menu.
After a lot of investigation, glommer discovered that the problem is the rom sits in a loop waiting for address 0x46c to change its value. This address is updated by the BIOS timer interrupt, which is not ticking.
Further investigation showed that receiving an interrupt seem to block further interrupts from happening correctly. It might be related to acking of interrupts of any kind. This seem to only happen in real mode.
It's not clear whether any interrupt will cause this behaviour.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Try to boot a gpxe option rom under kvm
3. There's no number 3.
glommer does not find the bug.
someone fixes it, and everyone gets happy.
For reference, the original gPXE request was bug #457979
New information on this: It seems to happen only on vmx boxes.
temporary solution is to buy from amd ;-)
Created attachment 338650 [details]
magic patch to fix this issue.
I just sent the attached patch upstream. It turns out to be a kernel problem.
We have to make sure this is included in F11 kernel, otherwise no one (but me! hehe) will be able to boot gpxe roms in intel machines.
Let us hope it goes smoothly and naturally during kernel rebases.
Glauber has posted a couple more revisions of this patch, the latest is here:
This package has changed ownership in the Fedora Package Database. Reassigning to the new owner of this component.
This bug appears to have been reported against 'rawhide' during the Fedora 11 development cycle.
Changing version to '11'.
More information and reason for this action is here:
Okay, bug #512358 tracks this issue better and has a backport of the fix to the F-11 kernel
*** This bug has been marked as a duplicate of bug 512358 ***