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Date:   Wed, 14 Jun 2023 13:02:45 +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>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Hansen, Dave" <dave.hansen@intel.com>,
        "david@redhat.com" <david@redhat.com>,
        "bagasdotme@gmail.com" <bagasdotme@gmail.com>,
        "ak@linux.intel.com" <ak@linux.intel.com>,
        "Wysocki, Rafael J" <rafael.j.wysocki@intel.com>,
        "Chatre, Reinette" <reinette.chatre@intel.com>,
        "Christopherson,, Sean" <seanjc@google.com>,
        "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "Yamahata, Isaku" <isaku.yamahata@intel.com>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "Luck, Tony" <tony.luck@intel.com>,
        "peterz@infradead.org" <peterz@infradead.org>,
        "Shahar, Sagi" <sagis@google.com>,
        "imammedo@redhat.com" <imammedo@redhat.com>,
        "Gao, Chao" <chao.gao@intel.com>,
        "Brown, Len" <len.brown@intel.com>,
        "sathyanarayanan.kuppuswamy@linux.intel.com" 
        <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
Message-ID: <20230614100245.3vehux365zou3ze6@box>
References: <cover.1685887183.git.kai.huang@intel.com>
 <5aa7506d4fedbf625e3fe8ceeb88af3be1ce97ea.1685887183.git.kai.huang@intel.com>
 <d3df3a9fa3075066558dd3bc84ef76ab3747185b.camel@intel.com>
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On Wed, Jun 14, 2023 at 09:33:45AM +0000, Huang, Kai wrote:
> On Mon, 2023-06-05 at 02:27 +1200, Kai Huang wrote:
> > --- a/arch/x86/kernel/reboot.c
> > +++ b/arch/x86/kernel/reboot.c
> > @@ -720,6 +720,7 @@ void native_machine_shutdown(void)
> > ?
> > ?#ifdef CONFIG_X86_64
> > ?	x86_platform.iommu_shutdown();
> > +	x86_platform.memory_shutdown();
> > ?#endif
> > ?}
> 
> Hi Kirill/Dave,
> 
> I missed that this solution doesn't reset TDX private for emergency restart or
> when reboot_force is set, because machine_shutdown() isn't called for them.
> 
> Is it acceptable?  Or should we handle them too?

Force reboot is not used in kexec path, right? And the platform has to
handle erratum in BIOS to reset memory status on reboot anyway.

I think we should be fine. But it worth mentioning it in the commit
message.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov