We've used older versions of QEMU for several years as a virtual target for our OS. Many thanks to the community for providing this platform.
We've been working to get our OS running under QEMU 2.x and have identified a few bugs in QEMU, have made some enhancements, and are still tracking down some other curious behaviors. I'm looking for some guidance as to how, and whether, you'd like patches for the following. 1. There is a defect in ppce500_spin.c:spin_kick() that creates an incorrectly sized TLB entry. This was reported as bug https://bugs.launchpad.net/qemu/+bug/1587535 I can provide a patch if desired. 2. We have implemented the PPC "yield" instruction. I can provide a patch if desired. 3. We're working on support for openpic timers. We're not finished, but it would be helpful to know if a patch is desired or if we should expect to maintain the changes independently. 4. We're currently tracking down why in our e500 (both unicore and multi-core) PPC QEMU 2.5 guest (x86 host), that with interrupts disabled, after enabling the decrementer and issuing a "wait" instruction QEMU continues to "busy loop", consuming an entire host CPU doing apparently nothing. As expected, issuing a "wait" prior to enabling the decrementer leaves the host process idle. We found the bug in the PPC "wait" instruction implementation that was independently reported and resolved last week, but that did not fix the problem. We also have our OS running on the g3beige and using MSR.POW which causes the host to "sleep", but we are having no joy with e500 and "wait". Any pointers would be appreciated. When we find something we'll report back.
