On Thu, Aug 24, 2017 at 03:43:55PM +0800, Wanpeng Li wrote: > 2017-08-23 20:22 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>: > > On 22/08/2017 00:32, Adam Borowski wrote: > >> On Mon, Aug 21, 2017 at 09:58:34PM +0200, Radim Krčmář wrote: > >>> 2017-08-21 21:12+0200, Adam Borowski: > >>>> Also, it doesn't reproduce for me on 4.12. > >>> > >>> Great info ... the most suspicious between v4.12 and v4.13-rc5 is the > >>> series with dcdca5fed5f6 ("x86: kvm: mmu: make spte mmio mask more > >>> explicit"), does reverting it help? > >>> > >>> `git revert ce00053b1cfca312c22e2a6465451f1862561eab~1..995f00a619584e65e53eff372d9b73b121a7bad5` > >> > >> Alas, doesn't seem to help. > >> > >> I've first installed a Debian stretch guest, the host survived both the > >> installation and subsequent fooling around. But then I started a win10 > >> guest which splatted as soon as the initial screen. > > > > Can you check if disabling THP on the host also fixes it for you? As in: ? echo never >/sys/kernel/mm/transparent_hugepage/enabled echo never >/sys/kernel/mm/transparent_hugepage/defrag Still reproduces, with or without reverting ce00053b1cfca312c22e2a6465451f1862561eab~1..995f00a619584e65e53eff372d9b73b121a7bad5 > > I would also try commit 1372324b328cd5dabaef5e345e37ad48c63df2a9 to > > identify whether it was caused by a KVM change in 4.13 or something > > else. I've ran different guests for a couple of hours, no explosions. Thus it looks like updating Cornelia's email address isn't the cause. Too bad, there's 15k commits between 1372324b and 7f680d7ec315. > For the OOM testcase, the splat will disappear if disabling THP. Meow! -- ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢰⠒⠀⣿⡁ Vat kind uf sufficiently advanced technology iz dis!? ⢿⡄⠘⠷⠚⠋⠀ -- Genghis Ht'rok'din ⠈⠳⣄⠀⠀⠀⠀