Date:   Mon, 3 Jan 2022 18:15:16 +0300
From:   "Kirill A. Shutemov" <kirill@shutemov.name>
To:     Borislav Petkov <bp@alien8.de>
Cc:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Dave Hansen <dave.hansen@intel.com>, tglx@linutronix.de,
        mingo@redhat.com, luto@kernel.org, peterz@infradead.org,
        sathyanarayanan.kuppuswamy@linux.intel.com, aarcange@redhat.com,
        ak@linux.intel.com, dan.j.williams@intel.com, david@redhat.com,
        hpa@zytor.com, jgross@suse.com, jmattson@google.com,
        joro@8bytes.org, jpoimboe@redhat.com, knsathya@kernel.org,
        pbonzini@redhat.com, sdeep@vmware.com, seanjc@google.com,
        tony.luck@intel.com, vkuznets@redhat.com, wanpengli@tencent.com,
        x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 19/26] x86/tdx: Make pages shared in ioremap()
Message-ID: <20220103151516.pfcz2pap5l7r2rzv@box.shutemov.name>
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 <f61b591b-a06c-bc29-4b9b-a5d46111fe4e@intel.com>
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 <20211223205604.g44kez5d7iedatfo@box.shutemov.name>
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 <20211224110300.7zj3nc5nbbv7jobp@black.fi.intel.com>
 <33914dc1-37e8-f0bb-6468-71c3b5f4169d@amd.com>
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On Mon, Jan 03, 2022 at 03:29:44PM +0100, Borislav Petkov wrote:
> On Mon, Jan 03, 2022 at 05:17:05PM +0300, Kirill A. Shutemov wrote:
> > I'm not sure how to unwind this dependency hell. Any clues?
> 
> Forward-declaration maybe?
> 
> I.e., something like
> 
> struct task_struct;
> 
> at the top of arch/x86/include/asm/switch_to.h, for example...

Forward-declaration only works if you refer the struct/union by pointer,
not value.

And pgprot_t is not always a struct and when it is a struct it is
anonymous.

See "git grep 'typedef.*pgprot_t;'".

-- 
 Kirill A. Shutemov