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Date:   Tue, 5 Oct 2021 16:22:09 -0700
From:   Josh Poimboeuf <jpoimboe@redhat.com>
To:     Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
        David Hildenbrand <david@redhat.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Juergen Gross <jgross@suse.com>, Deep Shah <sdeep@vmware.com>,
        VMware Inc <pv-drivers@vmware.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, Peter H Anvin <hpa@zytor.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v8 09/11] x86/tdx: Add MSR support for TDX guest
Message-ID: <20211005232209.ozugpocq2cvx22li@treble>
References: <20211005025205.1784480-1-sathyanarayanan.kuppuswamy@linux.intel.com>
 <20211005025205.1784480-10-sathyanarayanan.kuppuswamy@linux.intel.com>
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On Mon, Oct 04, 2021 at 07:52:03PM -0700, Kuppuswamy Sathyanarayanan wrote:
> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
> 
> Use hypercall to emulate MSR read/write for TDX platform.
> 
> TDVMCALL[Instruction.RDMSR] and TDVMCALL[Instruction.WRMSR] provide MSR
> oprations.
> 
> RDMSR and WRMSR specification details can be found in
> Guest-Host-Communication Interface (GHCI) for Intel Trust Domain
> Extensions (Intel TDX) specification, sec titled "TDG.VP.
> VMCALL<Instruction.RDMSR>" and "TDG.VP.VMCALL<Instruction.WRMSR>".
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reviewed-by: Andi Kleen <ak@linux.intel.com>
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> ---
> 
> Changes since v7:
>  * Removed tdx_is_context_switched_msr() support (since the list
>    is incomplete).

This fails to build:

arch/x86/kernel/tdx.c: In function ‘tdx_write_msr_safe’:
arch/x86/kernel/tdx.c:135:22: error: implicit declaration of function ‘tdx_is_context_switched_msr’ [-Werror=implicit-function-declaration]
  135 |         WARN_ON_ONCE(tdx_is_context_switched_msr(msr));
      |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/asm-generic/bug.h:104:32: note: in definition of macro ‘WARN_ON_ONCE’
  104 |         int __ret_warn_on = !!(condition);                      \
      |                                ^~~~~~~~~

-- 
Josh