I have built what may be my last Fedora 12 kernel (2.6.32.26-174.2.xendom0.fc12) as Fedora 12 EOLs today (this is the same Fedora patch level as the official 2.6.32.26-175.fc12 kernel which has just been released). It is available at http://koji.fedoraproject.org/koji/taskinfo?taskID=2637740 and the repository http://repos.fedorapeople.org/repos/myoung/dom0-kernel/ and includes a crash on exit fix. I haven't decided whether I am going to build any more 2.6.32.x kernels, I am going to continue building 2.6.37 kernels but these aren't ready for full dom0 use yet.
Moving forward and for the purposes of Fedora 15 development, can we get both patched 2.7.37/38 kernels that support DomU and raw upstream kernels? Or does xen/next-2.6.27 not have the requisite features yet anyway?
This kernel works as expected with one exception. The exception has been a nagging problem, but I have not reported it because 1) we are using a research OS in DomU and 2) we are not clear if the problem is in our code, Linux or Xen. But, here are the symptoms:
Occasionally (this seems to correlate to network activity between Dom0 and DomU), the system becomes unresponsive. I am running the Michael Young kernel at runlevel 3 within Dom0 (very little memory used by applications). Our OS runs in DomU and is constrained to 128MB of memory. When the system is unresponsive, typing a character into a Dom0 console take 2-5 seconds to appear on the screen. Likewise, other activity is extremely slow. As I mentioned, we have not been able to isolate where the problem is. Running, for example, an OpenWrt Linux build in DomU does not have this problem.
For those of you that are trying 2.6.37, I have built a vanilla 2.6.37-rc4 kernel (no additional xen patches) at http://koji.fedoraproject.org/koji/taskinfo?taskID=2635700
This kernel is the first from the 37/38 series that I have tested since I tested the initial upstream Xen accept. This seems to work within my expectations with two exceptions:
1. There are some warning related to nouveaufb. When I have time I will investigate a bit more, but 2.6.32 never really worked right for me with the nouveau drivers either.
2. On the positive side, it seems that the console back-end driver works. When I booted a DomU OS I received console messages. This surprised me. Soon after, Xen was unable to set up the networking for DomU, which is what I expected.
Dom0 continued to operate fine even though loading an OS in DomU failed.