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Date: Fri, 17 Feb 2017 10:07:35 +0100 From: Borislav Petkov <bp@...en8.de> To: xlpang@...hat.com Cc: x86@...nel.org, linux-kernel@...r.kernel.org, kexec@...ts.infradead.org, Tony Luck <tony.luck@...el.com>, Ingo Molnar <mingo@...hat.com>, Dave Young <dyoung@...hat.com>, Prarit Bhargava <prarit@...hat.com>, Junichi Nomura <j-nomura@...jp.nec.com>, Kiyoshi Ueda <k-ueda@...jp.nec.com>, Naoya Horiguchi <n-horiguchi@...jp.nec.com>, Peter Zijlstra <peterz@...radead.org>, Thomas Gleixner <tglx@...utronix.de> Subject: Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after system panic On Fri, Feb 17, 2017 at 09:53:21AM +0800, Xunlei Pang wrote: > It changes the value of cpu_online_mask/etc which will cause confusion to vmcore analysis. Then export the crashing_cpu variable, initialize it to something invalid in the first kernel, -1 for example, and test it in the #MC handlier like this: int cpu; ... cpu = smp_processor_id(); if (cpu_is_offline(cpu) || ((crashing_cpu != -1) && (crashing_cpu != cpu)) { u64 mcgstatus; mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS); if (mcgstatus & MCG_STATUS_RIPV) { mce_wrmsrl(MSR_IA32_MCG_STATUS, 0); return; } } > Moreover, for the code(see comment inlined) > > if (cpu_is_offline(smp_processor_id())) { > u64 mcgstatus; > > mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS); > if (mcgstatus & MCG_STATUS_RIPV) { // This condition may be not true, the mce triggered on kdump cpu > // doesn't need to have this bit set for the other cpus remain in 1st kernel. Is this on kvm or on a real hardware? Because for kvm I don't care. And don't say "theoretically". -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.
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