Mohammed Gamal wrote: > On Fri, Jul 11, 2008 at 12:22 AM, Jan Kiszka wrote: >> Mohammed Gamal wrote: >>> On Thu, Jul 10, 2008 at 11:02 PM, Anthony Liguori wrote: >>>> Mohammed Gamal wrote: >>>>> On Thu, Jul 10, 2008 at 7:31 PM, Anthony Liguori >>>>> wrote: >>>>> >>>>>> Mohammed Gamal wrote: >>>>>> >>>>>>> After updating my kvm-userspace tree to the latest git tree. I am no >>>>>>> more able to run FreeDOS. The VM freezes after choosing any of the >>>>>>> boot options. I am running both latest kvm.git and kvm-userspace.git > > > >>> After booting FreeDOS, there are a number of boot options with >>> different memory extenders, after selecting any option the system >>> freezes and I get [Stopped] in thr QEMU title bar. >> "Stopped" - interesting. Seems like something causes QEMU to stop the >> guest as if some breakpoint was injected. >> >> I just downloaded that image and gave it a try against vanilla kvm-70 >> and my own tree which is augment with guest debugging related patches. >> The former shows your observed behavior (Boot from CD, provide an empty >> HD image -> press '1' + ENTER -> press '1' -> "Stopped"). The latter kvm >> tree made QEMU leave with a #GP in the guest. That may point to a debug >> register related issue, and that patch you identified just happen to >> make it visible. However, will try to investigate. >> >> Jan > > I'm interested in seeing these patches. If your tree is hosted online, > could you please provide me with its location so that I can merge it > with mine. If not, where can I get them from? Find both attached. They are a rebase of the kernel side (subset) from my earlier posted debug rework series. They apply against latest kvm kernel git in this order: 1. kvm-new-guest-debug-interface-v2.patch 2. kvm-x86-virtualize-debug-registers-v2.patch The first one makes no difference, but the second one changes the behavior from reporting a breakpoint to userland to reporting an exception. I haven't found enough time to dig into this yet, but my gut feeling so far is that some x86 real mode emulation issue is biting us. Debug registers are not involved, I've cross-checked with enhanced QEMU supporting that feature - no invocation of related helper functions there. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux