linux-kernel - Re: [PATCH 10/13] x86/tdx: Convert shared memory back to private on kexec

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Message-ID: <20231009133500.su4ylwpbnaiyln4d@box.shutemov.name>
Date:   Mon, 9 Oct 2023 16:35:00 +0300
From:   "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To:     Baoquan He <bhe@...hat.com>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        Elena Reshetova <elena.reshetova@...el.com>,
        Jun Nakajima <jun.nakajima@...el.com>,
        Rick Edgecombe <rick.p.edgecombe@...el.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        kexec@...ts.infradead.org, linux-coco@...ts.linux.dev,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 10/13] x86/tdx: Convert shared memory back to private on
 kexec

On Sun, Oct 08, 2023 at 04:35:27PM +0800, Baoquan He wrote:
> On 10/05/23 at 04:13pm, Kirill A. Shutemov wrote:
> > TDX guests allocate shared buffers to perform I/O. It is done by
> > allocating pages normally from the buddy allocator and converting them
> > to shared with set_memory_decrypted().
> > 
> > The target kernel has no idea what memory is converted this way. It only
>       ~~~~~~~~~~~~~
> > sees E820_TYPE_RAM.
> 
> I finally realized it means the 2nd kernel of kexec rebooting. Maybe we
> can call it 2nd kernel always, it works for both kexec and kdump
> jumping. 

Okay. Will fix. I am new to kexec and I don't know proper terminology :)

-- 
  Kiryl Shutsemau / Kirill A. Shutemov