On Mon, Jul 30, 2012 at 07:39:31PM +0300, Avi Kivity wrote: > On 07/30/2012 05:07 PM, Chris Clayton wrote: > >> > >>>> With kernel 3.5.0 with b2da15ac26a0c00 reverted, I have just had 15 > >>>> clean invocations of vanilla qemu-kvm-1.1.1. So that commit would seem > >>>> to be the problem. > >>> > >>> Just to be sure, I've run some more tests today. No crashes occurred in > >>> 20 runs of vanilla qemu-kvm-1.1.1 on kernel 3.5.0 with b2da15ac26a0c00 > >>> reverted. > >> > >> Ok. I'm trying to reproduce it here on a nested-virt setup, since the > >> code looks correct. > >> > >> What's your preemption settings? > >> > >> > > [chris:~/kernel/linux-3.5.0]$ grep PREEMPT .config > > CONFIG_TREE_PREEMPT_RCU=y > > CONFIG_PREEMPT_RCU=y > > CONFIG_PREEMPT_NOTIFIERS=y > > # CONFIG_PREEMPT_NONE is not set > > # CONFIG_PREEMPT_VOLUNTARY is not set > > CONFIG_PREEMPT=y > > CONFIG_PREEMPT_COUNT=y > > Here's what I think that is happening > > vcpu_load > ... > vmx_save_host_state > vmx_vcpu_run > (ds.cpl, es.cpl cleared by hardware) > > interrupt > push ds, es # pushes bad ds, es > schedule > vmx_vcpu_put > vmx_load_host_state > reload ds, es > pop ds, es # of other thread's stack > iret > # other thread runs > interrupt > schedule # back in vcpu thread > interrupt return: pop ds, es # <-- problem > iret > > ... > vcpu_put > > # bad ds, es, but !vmx->host_state.loaded > > Marcelo, did I miss something here? Don't think so. > > Unfortunately, my reproducer has ceased to reproduce. But the fix is > easy if the analysis above is right. > > -- > error compiling committee.c: too many arguments to function > -- 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
