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Message-ID: <1547046196.31155.1.camel@gmx.de>
Subject: Re: 5.0-rc1 KVM inspired "BUG: Bad page state in process" spew
From:   Mike Galbraith <efault@gmx.de>
To:     Adam Borowski <kilobyte@angband.pl>
Cc:     kvm <kvm@vger.kernel.org>, lkml <linux-kernel@vger.kernel.org>
Date:   Wed, 09 Jan 2019 16:03:16 +0100
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         <20190109144257.erwh52326ucgc5tw@angband.pl>
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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