Re: kexec reboot fails with extra wbinvd introduced for AME SME

From: Dave Young
Date: Wed Jan 17 2018 - 22:31:46 EST


On 01/18/18 at 11:04am, Dave Young wrote:
> On 01/17/18 at 07:00pm, Linus Torvalds wrote:
> > On Wed, Jan 17, 2018 at 6:57 PM, Dave Young <dyoung@xxxxxxxxxx> wrote:
> > >
> > > Could you say more about how to check this? My .config disabled
> > > CONFIG_X86_MCE, should this be enabled?
> >
> > By all means, try it.
> >
> > Some pending machine check exception that we have *not* reacted to,
> > and that is pending around kexec boot could very possibly be relevant.
> >
> > I forget your exact symptoms. Was it that the _first_ kexec works, but
> > the second one hangs? Or was that the other unrelated issue? Or have I
> > confused this with some other report entirely?
>
> Yes, 1st kexec works, 2nd hangs.
>
> Rebuilding with MCE enabled now.

dmesg only shows "mce: CPU supports 7 MCE banks"
Nothing special happens with MCE enabled , anyway thank all for
the hints, I will continue to think about this and maybe try more experiments.

>
> Thanks
> Dave
> >
> > Linus