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Subject: Re: [PATCH v3 5/6] platform/x86: intel_tdx_attest: Add TDX Guest
 attestation interface driver
To:     Dave Hansen <dave.hansen@intel.com>,
        "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>,
        Hans de Goede <hdegoede@redhat.com>,
        Mark Gross <mgross@linux.intel.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>
Cc:     Peter H Anvin <hpa@zytor.com>, Tony Luck <tony.luck@intel.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
        x86@kernel.org, linux-kernel@vger.kernel.org,
        platform-driver-x86@vger.kernel.org, bpf@vger.kernel.org,
        netdev@vger.kernel.org
References: <20210720045552.2124688-1-sathyanarayanan.kuppuswamy@linux.intel.com>
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 <52caa0e2-d3da-eef0-da5f-e83cc54c133c@intel.com>
From:   Andi Kleen <ak@linux.intel.com>
Message-ID: <4f8dc9dd-0dbc-bff9-570b-0d20f673d3f0@linux.intel.com>
Date:   Tue, 20 Jul 2021 14:16:08 -0700
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On 7/20/2021 10:59 AM, Dave Hansen wrote:
> On 7/20/21 10:52 AM, Kuppuswamy, Sathyanarayanan wrote:
>>> Why does this need to use the page allocator directly?
> ^^ You didn't address this question.


The address needs to be naturally aligned, and I'm not sure all slab 
allocators guarantee 64 byte alignment. So using the page allocator 
seems to be safer. I guess a comment would be good.


-Andi