On Mon, Apr 20, 2009 at 02:56:12PM +0300, Avi Kivity wrote: > >Fedora 10 randomly hangs for me when run under KVM, whereas (unpatched) > >F9 works fine. When this happens, kvm_stat shows that the VM is seeing > >1000 IRQ exits per second, but nothing else seems to happen. The latest > >F9 update kernel seems to be bust as well. (I noticed that the KVM guest > >support status page says that "Alexey E." is seeing the same thing.) > > > >I tried about two dozen different kernel packages from koji, and it turns > >out that kernel-2.6.26-0.122.rc9.git4.fc10 is the last known good kernel, > >and kernel-2.6.26-0.124.rc9.git5.fc10 is the first kernel that's broken. > > > >The F10 instability appears since this commit (attached below as well): > > > > http://fedora.gitbits.net/?p=kernel;a=commit;h=a5991f36968f44d4d3c64fc5aaa285a21de1ba54 > > > >I built three new kernels from the latest 2.6.27-170.2.56.fc10 update > >in Fedora 10: > >1. One with PARAVIRT and all associated options disabled entirely. > >2. One with only KVM_GUEST disabled. > >3. One with only KVM_CLOCK disabled (and paravirt and KVM_GUEST enabled). > > > >Kernel (1) is stable. Kernel (2) is unstable like the unpatched F10 > >kernels are, in that it randomly locks up. Kernel (3) is stable as > >well, which suggests that KVM_CLOCK is what's causing the lockups. > > > >I tried booting the original F10 update kernel with no-kvmclock on > >the command line as well, and that makes things stable as well. > > > >I tried with the latest F10 updates-testing kernel (2.6.29.1-30.fc10), > >and that shows the same thing: with no-kvmclock it works fine, otherwise > >it hangs randomly. > > > >Running KVM 84 on x86_64 CentOS 5.3, with the kvm rpms from lfarkas.org. > >The host CPU is a Q6600 Core 2 Quad. > > > >Any ideas? > > This is a known issue. While kvm-84 fixed kvmclock, an issue remained > with cpu frequency scaling on older host kernels (including RHEL 5 / > CentOS 5). kvm-85 (to be released shortly) contains a fix (b395d156477a > in kvm-userspace.git). Seems to work fine, thanks! -- 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
