From: Xunlei Pang <xpang@redhat.com> To: Borislav Petkov <bp@alien8.de>, xlpang@redhat.com Cc: Prarit Bhargava <prarit@redhat.com>, Kiyoshi Ueda <k-ueda@ct.jp.nec.com>, Tony Luck <tony.luck@intel.com>, Peter Zijlstra <peterz@infradead.org>, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>, Junichi Nomura <j-nomura@ce.jp.nec.com>, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>, Dave Young <dyoung@redhat.com>, Thomas Gleixner <tglx@linutronix.de> Subject: Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after system panic Date: Sat, 18 Feb 2017 00:21:42 +0800 [thread overview] Message-ID: <58A72316.20204@redhat.com> (raw) In-Reply-To: <20170217090735.ls5pmtsfwkf3q5h6@pd.tnic> On 02/17/2017 at 05:07 PM, Borislav Petkov wrote: > 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; > } > } Yes, it is doable, I will do some tests later. >> 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". > 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? Regards, Xunlei
WARNING: multiple messages have this Message-ID (diff)
From: Xunlei Pang <xpang@redhat.com> To: Borislav Petkov <bp@alien8.de>, xlpang@redhat.com Cc: Prarit Bhargava <prarit@redhat.com>, Kiyoshi Ueda <k-ueda@ct.jp.nec.com>, Tony Luck <tony.luck@intel.com>, Peter Zijlstra <peterz@infradead.org>, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>, Junichi Nomura <j-nomura@ce.jp.nec.com>, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>, Dave Young <dyoung@redhat.com>, Thomas Gleixner <tglx@linutronix.de> Subject: Re: [PATCH] x86/mce: Keep quiet in case of broadcasted mce after system panic Date: Sat, 18 Feb 2017 00:21:42 +0800 [thread overview] Message-ID: <58A72316.20204@redhat.com> (raw) In-Reply-To: <20170217090735.ls5pmtsfwkf3q5h6@pd.tnic> On 02/17/2017 at 05:07 PM, Borislav Petkov wrote: > 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; > } > } Yes, it is doable, I will do some tests later. >> 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". > 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? Regards, Xunlei _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2017-02-17 16:19 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-01-23 8:01 [PATCH] x86/mce: Keep quiet in case of broadcasted mce after system panic Xunlei Pang 2017-01-23 8:01 ` Xunlei Pang 2017-01-23 12:51 ` Borislav Petkov 2017-01-23 12:51 ` Borislav Petkov 2017-01-23 13:35 ` Xunlei Pang 2017-01-23 13:35 ` Xunlei Pang 2017-01-23 14:50 ` Borislav Petkov 2017-01-23 14:50 ` Borislav Petkov 2017-01-23 17:40 ` Luck, Tony 2017-01-23 17:40 ` Luck, Tony 2017-01-23 17:51 ` Borislav Petkov 2017-01-23 17:51 ` Borislav Petkov 2017-01-23 18:01 ` Luck, Tony 2017-01-23 18:01 ` Luck, Tony 2017-01-23 18:14 ` Borislav Petkov 2017-01-23 18:14 ` Borislav Petkov 2017-01-24 2:33 ` Xunlei Pang 2017-01-24 2:33 ` Xunlei Pang 2017-01-24 1:46 ` Xunlei Pang 2017-01-24 1:46 ` Xunlei Pang 2017-01-24 1:51 ` Xunlei Pang 2017-01-24 1:51 ` Xunlei Pang 2017-01-24 1:27 ` Xunlei Pang 2017-01-24 1:27 ` Xunlei Pang 2017-01-24 12:22 ` Borislav Petkov 2017-01-24 12:22 ` Borislav Petkov 2017-01-26 6:30 ` Xunlei Pang 2017-01-26 6:30 ` Xunlei Pang 2017-01-26 6:44 ` Borislav Petkov 2017-01-26 6:44 ` Borislav Petkov 2017-02-16 5:36 ` Xunlei Pang 2017-02-16 5:36 ` Xunlei Pang 2017-02-16 10:18 ` Borislav Petkov 2017-02-16 10:18 ` Borislav Petkov 2017-02-16 11:52 ` Xunlei Pang 2017-02-16 11:52 ` Xunlei Pang 2017-02-16 12:22 ` Borislav Petkov 2017-02-16 12:22 ` Borislav Petkov 2017-02-17 1:53 ` Xunlei Pang 2017-02-17 1:53 ` Xunlei Pang 2017-02-17 9:07 ` Borislav Petkov 2017-02-17 9:07 ` Borislav Petkov 2017-02-17 16:21 ` Xunlei Pang [this message] 2017-02-17 16:21 ` Xunlei Pang 2017-02-21 18:20 ` Luck, Tony 2017-02-21 18:20 ` Luck, Tony 2017-02-22 5:50 ` Xunlei Pang 2017-02-22 5:50 ` Xunlei Pang
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=58A72316.20204@redhat.com \ --to=xpang@redhat.com \ --cc=bp@alien8.de \ --cc=dyoung@redhat.com \ --cc=j-nomura@ce.jp.nec.com \ --cc=k-ueda@ct.jp.nec.com \ --cc=kexec@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=mingo@redhat.com \ --cc=n-horiguchi@ah.jp.nec.com \ --cc=peterz@infradead.org \ --cc=prarit@redhat.com \ --cc=tglx@linutronix.de \ --cc=tony.luck@intel.com \ --cc=x86@kernel.org \ --cc=xlpang@redhat.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.