Re: 5.0-rc1 KVM inspired "BUG: Bad page state in process" spew

Mike Galbraith
2019-01-09T15:03:16Z

On Wed, 2019-01-09 at 15:42 +0100, Adam Borowski wrote:
> On Wed, Jan 09, 2019 at 06:38:58AM +0100, Mike Galbraith wrote:
> > KVM seems to be busted in master ATM. All I have to do to have host
> > start screaming and maybe exploding (if the guest doesn't do so first)
> > is to try to install a (obese in this case) kernel over nfs mount of
> > the host in a guest.
> >
> > Kernel producing the spew below is 3bd6e94, config attached.
>
> I get same, except that the BUGs were preceded by a bunch of warnings,

Yeah, I was in too much of a rush...

> > homer: # grep BUG: /netconsole.log
> > [ 1531.909703] BUG: Bad page state in process X pfn:100491
> > [ 1531.958141] BUG: Bad page state in process systemd-journal pfn:100412
> > [ 1532.662359] BUG: Bad page state in process X pfn:10043f
> > [ 1532.664033] BUG: Bad page state in process X pfn:10044d
> > [ 1532.686433] BUG: Bad page state in process systemd-journal pfn:1027b0
>
> the first one being:
>
> Jan 9 00:41:22 umbar kernel: [74122.790461] WARNING: CPU: 2 PID: 26769 at arch/x86/kvm/mmu.c:830 mmu_spte_clear_track_bits+0x7e/0x100

...I also get oodles of those.

-Mike