On 18/10/12 14:51, Christoffer Dall wrote: > On Thu, Oct 18, 2012 at 7:00 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >> On 17/10/12 21:09, Christoffer Dall wrote: >>> On Wed, Oct 17, 2012 at 1:22 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >>>> On 17/10/12 17:53, Christoffer Dall wrote: >>>>> On Wed, Oct 17, 2012 at 12:09 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >>>>>> On 17/10/12 16:50, Christoffer Dall wrote: >>>>>>>>>> ARM: KVM: move MMIO handling to its own files >>>>>>>>> >>>>>>>>> this one I'll look at later today. >>>>>>>> >>>>>>>> OK. Let me know what you think. I have a couple of other patches on the >>>>>>>> same theme. >>>>>>>> >>>>>>> >>>>>>> I will. Since the mmio handling is controversial, it's good that we >>>>>>> split that up. >>>>>>> >>>>>>> Unless the other patches are *necessary* for an upstream merge, I >>>>>>> think we should announce a code freeze and target an upstream merge >>>>>>> asap for everyone's benefit. >>>>>> >>>>>> Depending what you can necessary. A number of patches I've queued are >>>>>> related to moving accesses to HSR and friends into inline functions, >>>>>> making the code more readable - again, this could help the reviewers. >>>>>> They are mostly one-liners. >>>>>> >>>>> >>>>> necessary as in bugfixes or API stabilization. >>>>> >>>>> My whole point is that we can keep improving forever, but the more >>>>> cosmetics we change the more changes need to be reviewed. >>>> >>>> I agree on the stabilization. But my point here is not to introduce new >>>> features. Just to make the core mode easily reviewed. One of the >>>> complains I've heard so far is that the code is hard to read. Which is >>>> not surprising given that there's a lot of it, and that the problems it >>>> tackles are not simple. >>>> >>>> I'll post these patches as an RFC, and you're free to take them or not. >>>> >>> >>> ok, thanks, I'll have a look. >> >> Incoming. >> >>>>>>> It seems to me that we have a bug on restart to fix and >>>>>> >>>>>> Care to elaborate on this one? >>>>>> >>>>> >>>>> just fire up a guest and execute "reboot" in there and see the guest >>>>> kernel crash when it comes back up. If you can't reproduce, we should >>>>> talk more :) >>>> >>>> Interesting. It looks like the guest is taking a timer interrupt before >>>> being ready to handle it... Probably because the timer has been disabled >>>> while something is still pending. Investigating. >>>> >>> >>> yeah, but a reset should mask interrupts, right? so I'm not sure, >>> anyway cool if you have cycles to look into it. >> >> Reset? Which reset? We do not have a mechanism to propagate QEMU's reset >> into the VM. I think that is part of the problem, but that would be >> papering over a real bug hiding somewhere. Either in the vgic code or in >> the timer. >> > > I actually assumed that a reboot would generate a virtual reset to the > cpu, but I haven't looked into this at all. What exactly happens in > the guest kernel side when you call reboot? You hit some special VE device that causes the VCPUs to be reset (Peter, can you be more specific than I am?), but we don't signal anything to the VM itself - hence the guest restarting with timers ticking and GIC in some arbitrary state (interrupts being queued into the list registers, for example...). M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
