From: Thomas Gleixner <tglx@linutronix.de>
To: "Limonciello, Mario" <mario.limonciello@amd.com>,
LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Tom Lendacky <thomas.lendacky@amd.com>,
Tony Battersby <tonyb@cybernetics.com>,
Ashok Raj <ashok.raj@linux.intel.com>,
Tony Luck <tony.luck@intel.com>,
Arjan van de Veen <arjan@linux.intel.com>,
Eric Biederman <ebiederm@xmission.com>
Subject: Re: [patch v3 2/7] x86/smp: Dont access non-existing CPUID leaf
Date: Mon, 19 Jun 2023 19:15:01 +0200 [thread overview]
Message-ID: <87v8fjpe5m.ffs@tglx> (raw)
In-Reply-To: <220eb0c4-ace2-d67c-8680-fc9cd361f873@amd.com>
On Mon, Jun 19 2023 at 12:02, Limonciello, Mario wrote:
> On 6/15/2023 3:33 PM, Thomas Gleixner wrote:
>> From: Tony Battersby <tonyb@cybernetics.com>
>>
>> stop_this_cpu() tests CPUID leaf 0x8000001f::EAX unconditionally. CPUs
>> return the content of the highest supported leaf when a non-existing leaf
>> is read. So the result of the test is lottery except on AMD CPUs which
>> support that leaf.
>>
>> While harmless it's incorrect and causes the conditional wbinvd() to be
>> issued where not required.
>>
>> Check whether the leaf is supported before reading it.
>>
>> [ tglx: Adjusted changelog ]
>>
>> Fixes: 08f253ec3767 ("x86/cpu: Clear SME feature flag when not in use")
>
> Thanks for this fix.
> This particular patch should probably also CC to stable.
It's pretty much all stable material.
next prev parent reply other threads:[~2023-06-19 17:15 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-15 20:33 [patch v3 0/7] x86/smp: Cure stop_other_cpus() and kexec() troubles Thomas Gleixner
2023-06-15 20:33 ` [patch v3 1/7] x86/smp: Make stop_other_cpus() more robust Thomas Gleixner
2023-06-16 1:58 ` Ashok Raj
2023-06-16 7:53 ` Thomas Gleixner
2023-06-16 14:13 ` Ashok Raj
2023-06-16 18:01 ` Thomas Gleixner
2023-06-16 20:57 ` Ashok Raj
2023-06-19 17:51 ` Ashok Raj
2023-06-20 8:09 ` Borislav Petkov
2023-06-16 16:36 ` Tony Battersby
2023-06-15 20:33 ` [patch v3 2/7] x86/smp: Dont access non-existing CPUID leaf Thomas Gleixner
2023-06-19 17:02 ` Limonciello, Mario
2023-06-19 17:15 ` Thomas Gleixner [this message]
2023-06-20 8:20 ` Borislav Petkov
2023-06-15 20:33 ` [patch v3 3/7] x86/smp: Remove pointless wmb()s from native_stop_other_cpus() Thomas Gleixner
2023-06-20 8:47 ` Borislav Petkov
2023-06-20 13:00 ` [tip: x86/core] " tip-bot2 for Thomas Gleixner
2023-06-15 20:33 ` [patch v3 4/7] x86/smp: Use dedicated cache-line for mwait_play_dead() Thomas Gleixner
2023-06-20 9:01 ` Borislav Petkov
2023-06-20 13:00 ` [tip: x86/core] " tip-bot2 for Thomas Gleixner
2023-06-15 20:33 ` [patch v3 5/7] x86/smp: Cure kexec() vs. mwait_play_dead() breakage Thomas Gleixner
2023-06-20 9:23 ` Borislav Petkov
2023-06-20 12:25 ` Thomas Gleixner
2023-06-20 13:00 ` [tip: x86/core] " tip-bot2 for Thomas Gleixner
2023-06-15 20:33 ` [patch v3 6/7] x86/smp: Split sending INIT IPI out into a helper function Thomas Gleixner
2023-06-20 9:29 ` Borislav Petkov
2023-06-20 12:30 ` Thomas Gleixner
2023-06-20 13:00 ` [tip: x86/core] " tip-bot2 for Thomas Gleixner
2023-06-15 20:34 ` [patch v3 7/7] x86/smp: Put CPUs into INIT on shutdown if possible Thomas Gleixner
2023-06-20 10:27 ` Borislav Petkov
2023-06-20 13:00 ` [tip: x86/core] " tip-bot2 for Thomas Gleixner
2023-07-03 3:44 ` [BUG REPORT] Triggering a panic in an x86 virtual machine does not wait Baokun Li
2023-07-05 8:59 ` Thomas Gleixner
2023-07-06 6:44 ` Baokun Li
2023-07-07 10:18 ` Thomas Gleixner
2023-07-07 12:40 ` Baokun Li
2023-07-07 13:49 ` [tip: x86/core] x86/smp: Don't send INIT to boot CPU tip-bot2 for Thomas Gleixner
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