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Subject: Re: [PATCH v3 1/1] x86/tdx: Handle MWAIT, MONITOR and WBINVD
To:     Andy Lutomirski <luto@amacapital.net>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Raj Ashok <ashok.raj@intel.com>,
        Sean Christopherson <seanjc@google.com>,
        linux-kernel@vger.kernel.org
References: <837afe840f5826bf7fcba07a5e483d7e2283db34.1617059703.git.sathyanarayanan.kuppuswamy@linux.intel.com>
 <377A7B0B-9959-4AFC-A575-7AC20FEE6077@amacapital.net>
From:   "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
Message-ID: <10834a17-cae4-d0e3-c82b-f69da7f9141a@linux.intel.com>
Date:   Mon, 29 Mar 2021 16:37:18 -0700
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On 3/29/21 4:23 PM, Andy Lutomirski wrote:
> 
>> On Mar 29, 2021, at 4:17 PM, Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> wrote:
>>
>> In non-root TDX guest mode, MWAIT, MONITOR and WBINVD instructions
>> are not supported. So handle #VE due to these instructions
>> appropriately.
> 
> Is there something I missed elsewhere in the code that checks CPL?
We don't check for CPL explicitly. But if we are reaching here, then we
executing these instructions with wrong CPL.
> 

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer