On Mon, Jun 13, 2016 at 06:08:30PM -0500, alar...@ddci.com wrote: > 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.
Hi, Thanks for your interest. > 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. Always interested in bug fixes. The e500 support probably doesn't get a whole lot of attention these days, but you're proof that there are at least a few people who care. > 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. Absolutely. > 2. We have implemented the PPC "yield" instruction. I can provide a > patch if desired. Sounds good. > 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. I don't see a reason we wouldn't want it, unless it's horribly invasive. By all means post patches, and I'll review as best I can. > 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. Ok. So, patches for ppc related code should be sent to myself and Alex Graf <ag...@suse.de>, co-maintainers for the target-ppc and related code. You should CC both qemu-...@nongnu.org and qemu-devel@nongnu.org. I have a (frequently rebased) git tree where I stage ppc patches at: https://github.com/dgibson/qemu/tree/ppc-for-2.7 -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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