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Date:   Mon, 12 Jun 2023 14:48:43 +0300
From:   "kirill.shutemov@linux.intel.com" <kirill.shutemov@linux.intel.com>
To:     "Huang, Kai" <kai.huang@intel.com>
Cc:     "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "Hansen, Dave" <dave.hansen@intel.com>,
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        "ak@linux.intel.com" <ak@linux.intel.com>,
        "Wysocki, Rafael J" <rafael.j.wysocki@intel.com>,
        "Luck, Tony" <tony.luck@intel.com>,
        "Chatre, Reinette" <reinette.chatre@intel.com>,
        "Christopherson,, Sean" <seanjc@google.com>,
        "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "Yamahata, Isaku" <isaku.yamahata@intel.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
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        "imammedo@redhat.com" <imammedo@redhat.com>,
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        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        "Huang, Ying" <ying.huang@intel.com>,
        "Williams, Dan J" <dan.j.williams@intel.com>
Subject: Re: [PATCH v11 18/20] x86: Handle TDX erratum to reset TDX private
 memory during kexec() and reboot
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On Mon, Jun 12, 2023 at 10:27:44AM +0000, Huang, Kai wrote:
> Does it make sense?

I understand your logic. AFAICS, it is correct (smp_mb() instead of __mb()
would be better), but it is not justified from complexity PoV. This
lockless exercise gave me a pause to understand.

Lockless doesn't buy you anything here, only increases complexity.
Just take a lock.

Kernel is big. I'm sure you'll find a better opportunity to be clever
about serialization :P

-- 
  Kiryl Shutsemau / Kirill A. Shutemov