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Date:   Tue, 21 Nov 2023 12:24:30 +0300
From:   "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To:     Tao Liu <ltao@redhat.com>
Cc:     Baoquan He <bhe@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        Elena Reshetova <elena.reshetova@intel.com>,
        Jun Nakajima <jun.nakajima@intel.com>,
        Rick Edgecombe <rick.p.edgecombe@intel.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        "Kalra, Ashish" <ashish.kalra@amd.com>,
        Sean Christopherson <seanjc@google.com>,
        "Huang, Kai" <kai.huang@intel.com>, kexec@lists.infradead.org,
        linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv3 00/14] x86/tdx: Add kexec support
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On Tue, Nov 21, 2023 at 05:10:01PM +0800, Tao Liu wrote:
> > > My colleague Tao helped to double check this, he got the same testing result.
> > > Plesae
> > > 1) what can we do to enable the multiple cpu support for kexec reboot?
> >
> > You would need a patched BIOS image. I've hacked one[1] for my testing.
> > But it only works if kernel runs in 4-level paging mode (specify no5lvl in
> > kernel command line).
> >
> > BIOS folks work on proper patch, but it is not ready yet.
> >
> > [1] https://gist.github.com/kiryl/e1dc1719e0c990b3ceee5d8de8dbf332
> >
> Thanks a lot for providing the BIOS patch. One more question, is the
> patched BIOS image for the host physical machine or for the tdx guest
> vm?

For the guest.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov