On Sun, Dec 29, 2013 at 01:24:11AM -0800, Christoffer Dall wrote: > On Mon, Oct 14, 2013 at 06:23:26PM +0200, Andrew Jones wrote: > > Hi Drew, > > > This series introduces arm to kvm-unit-tests. First, it does some > > tidying up of the repo. Then, it adds support for virtio-testdev, > > which was just posted to qemu-devel[1]. Next, it adds the basic > > infrastructure for booting a test case (guest). Finally, it adds > > support for vectors. This is just an initial drop, I'm starting > > work on smp support now, and then will bring in support for > > arm64. At that point we should be able to start actually adding > > tests. To use this you need an arm platform or simulator capable > > of running kvmarm and a qemu with the mach-virt patches[2], as > > well as the previously mentioned virtio-testdev. > > > > [1] http://lists.nongnu.org/archive/html/qemu-devel/2013-10/msg01815.html > > [2] http://lists.nongnu.org/archive/html/qemu-devel/2013-09/msg02142.html > > > > This patches are also available from a git repo here > > https://github.com/rhdrjones/kvm-unit-tests/tree/arm-branch/master > > > > I'm playing around with this, thanks again for working on it. It's long > overdue that we're getting something real done in this area. > > I have run into some problems trying to run this thing on real hardware. > The biggest problem is the known cache coherency issue where we need to > flush the data cache to make things coherent when the guest runs with > the MMU disabled. It shows up quite frequently if you just try to run > the small flat binaries with KVM, and I suspec the only reason we are > not seeing this with real kernels is that they are large enough that we > end up writing the necessary data all the way to main memory. > > I'm working on a vmexit test to measure stuff, and I noticed that we: > - really need to find a way to let a guest read the cycle counter > - need a way to let a call a dummy HVC to KVM to measure round-trip > times > - ... > > This is probably something we should try to discuss on one of the next > kvm/arm sync-up calls. I remember something about you not being able to > make those, but we can arrange a different time for one of them some > time. > > For now, I can work around the cache issue by enabling the DC bits and > by adding a terrible hack for the cycle counter and dummy HVC. You can > follow my hackings here: > > Kernel: > https://git.linaro.org/people/christoffer.dall/linux-kvm-arm.git/shortlog/refs/heads/kvm-arm-next-measure > > unit-tests: > https://github.com/columbia/kvm-unit-tests/tree/arm-support > > -Christoffer Thanks Christoffer! I'll look at these branches tomorrow. I'm glad we're getting some momentum on kvm-unit-tests/arm! drew -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
