RE: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after system panic

From	"Luck, Tony" <tony.luck@intel.com>
Newsgroups	linux.kernel
Subject	RE: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after system panic
Date	2017-02-21 19:50 +0100
Message-ID	<tdnFD-6qe-5@gated-at.bofh.it> (permalink)
References	(7 earlier) <tbsT7-5Hw-5@gated-at.bofh.it> <tbtm9-66o-1@gated-at.bofh.it> <tbG01-66D-7@gated-at.bofh.it> <tbMI9-2kt-5@gated-at.bofh.it> <tbTqh-6zb-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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> It's from my understanding, I didn't get the explicit description from the intel SDM on this point.
> If a broadcast SRAO comes on real hardware, will MSR_IA32_MCG_STATUS of each cpu have MCG_STATUS_RIPV bit set?

MCG_STATUS is a per-thread MSR and will contain the status appropriate for that thread when #MC is delivered.
So the RIPV bit will be set if, and only if, the thread saved a valid return address for this exception. The net result
is that it is almost always set for "innocent bystander" CPUs that were dragged into the exception handler because
of a broadcast #MC. We make the test because if it isn't set, then the do_machine_check() had better not return
because we have no idea where it will return to - since there is not a valid return IP.

-Tony

Thread

Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic Xunlei Pang <xpang@redhat.com> - 2017-02-16 06:40 +0100
  Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic Borislav Petkov <bp@alien8.de> - 2017-02-16 11:20 +0100
    Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic Xunlei Pang <xpang@redhat.com> - 2017-02-16 13:00 +0100
      Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic Borislav Petkov <bp@alien8.de> - 2017-02-16 13:30 +0100
        Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic Xunlei Pang <xpang@redhat.com> - 2017-02-17 03:00 +0100
          Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic Borislav Petkov <bp@alien8.de> - 2017-02-17 10:10 +0100
            Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic Xunlei Pang <xpang@redhat.com> - 2017-02-17 17:20 +0100
              RE: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic "Luck, Tony" <tony.luck@intel.com> - 2017-02-21 19:50 +0100
                Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after  system panic Xunlei Pang <xpang@redhat.com> - 2017-02-22 06:50 +0100

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