Gleb Natapov wrote: > 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. ...and kvm_run->ready_for_interrupt_injection is not updated either in that case, right? That makes be wonder if KVM_INTERRUPT shouldn't better return an error in case the queue is full already. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux -- 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
