On Fri, May 29, 2009 at 04:52:41PM +0200, Jan Kiszka wrote: > Gleb Natapov wrote: > > On Fri, May 29, 2009 at 10:23:24AM +0200, Jan Kiszka wrote: > >> Hi Gleb, > >> > >> with latest kernel modules, namely beginning with 6bc0a1a235 (Remove > >> irq_pending bitmap), I'm loosing interrupts with upstream's KVM support. > >> After some bisecting, hair-pulling and a bit meditation I added a > >> WARN_ON(kvm_cpu_has_interrupt(vcpu)) to kvm_vcpu_ioctl_interrupt, and it > >> actually triggered right before the guest got stuck. > >> > >> This didn't trigger with qemu-kvm (and -no-kvm-irqchip) yet but, on the > >> other hand, I currently do not see a potential bug in upstream's > >> kvm_arch_pre_run. Could you have a look if you can reproduce, > >> specifically if this isn't a KVM kernel issue in the end? > >> > > In kvm_cpu_exec() after calling kvm_arch_pre_run() env->exit_request is > > tested and function can exit without calling kvm_vcpu_ioctl(KVM_RUN). > > Can you check if this what happens in your case? > > This path is executed quite frequently here. No obvious correlation with > the lost IRQ. > If kvm_arch_pre_run() injected interrupt kvm_vcpu_ioctl(KVM_RUN) have to be executed before injecting another interrupt, so if on the fist call of kvm_cpu_exec() kvm_arch_pre_run() injected interrupt, but kvm_vcpu_ioctl(KVM_RUN) was not executed because of env->exit_request and on the next kvm_cpu_exec() other interrupt is injected the previous one will be lost. -- Gleb. -- 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
