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From: Dave Hansen <dave.hansen@intel.com>
To: Andy Lutomirski <luto@kernel.org>,
	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>,
	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>,
	Andi Kleen <ak@linux.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
Subject: Re: [PATCH v2 5/6] platform/x86: intel_tdx_attest: Add TDX Guest attestation interface driver
Date: Thu, 8 Jul 2021 15:35:22 -0700	[thread overview]
Message-ID: <169451ef-e8f6-5a07-f47a-61eaa085b4ef@intel.com> (raw)
In-Reply-To: <06c85c19-e16c-3121-ed47-075cfa779b67@kernel.org>

On 7/8/21 3:21 PM, Andy Lutomirski wrote:
>> +		ret = set_memory_decrypted((unsigned long)file->private_data,
>> +					   1UL << get_order(QUOTE_SIZE));
>> +		if (ret)
>> +			break;
> Now private_data is decrypted.  (And this operation is *expensive*.  Why
> is it done at ioctl time?)

Expensive and permanently fractures the direct map.

I'm struggling to figure out why the direct map is even touched here.
Why not just use a vmalloc area mapping?  You really just need *a*
decrypted mapping to the page.  You don't need to make *every* mapping
to the page decrypted.

  reply	other threads:[~2021-07-08 22:35 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-07 20:42 [PATCH v2 0/6] Add TDX Guest Support (Attestation support) Kuppuswamy Sathyanarayanan
2021-07-07 20:42 ` [PATCH v2 1/6] x86/tdx: Add TDREPORT TDX Module call support Kuppuswamy Sathyanarayanan
2021-07-08  8:16   ` Xiaoyao Li
2021-07-08 14:07     ` Kuppuswamy, Sathyanarayanan
2021-07-08 14:20       ` Hans de Goede
2021-07-08 17:06         ` Kuppuswamy, Sathyanarayanan
2021-07-07 20:42 ` [PATCH v2 2/6] x86/tdx: Add GetQuote TDX hypercall support Kuppuswamy Sathyanarayanan
2021-07-07 20:42 ` [PATCH v2 3/6] x86/tdx: Add SetupEventNotifyInterrupt " Kuppuswamy Sathyanarayanan
2021-07-07 20:42 ` [PATCH v2 4/6] x86/tdx: Add TDX Guest event notify interrupt vector support Kuppuswamy Sathyanarayanan
2021-07-07 20:42 ` [PATCH v2 5/6] platform/x86: intel_tdx_attest: Add TDX Guest attestation interface driver Kuppuswamy Sathyanarayanan
2021-07-08 22:21   ` Andy Lutomirski
2021-07-08 22:35     ` Dave Hansen [this message]
2021-07-09  0:38       ` Andi Kleen
2021-07-13  0:33         ` Kuppuswamy, Sathyanarayanan
2021-07-13  0:44           ` Dave Hansen
2021-07-08 23:34     ` Kuppuswamy, Sathyanarayanan
2021-07-08 23:36   ` Dan Williams
2021-07-08 23:57     ` Kuppuswamy, Sathyanarayanan
2021-07-09  0:20       ` Dan Williams
2021-07-09  0:36         ` Andi Kleen
2021-07-09  1:37           ` Dan Williams
2021-07-09  1:44             ` Andi Kleen
2021-07-09  2:04               ` Dan Williams
2021-07-09  2:43                 ` Kuppuswamy, Sathyanarayanan
2021-07-07 20:42 ` [PATCH v2 6/6] tools/tdx: Add a sample attestation user app Kuppuswamy Sathyanarayanan
2021-07-15  8:36   ` Mian Yousaf Kaukab
2021-07-15 15:19     ` Kuppuswamy, Sathyanarayanan
2022-03-30 22:17 [PATCH v2 0/6] Add TDX Guest Attestation support Kuppuswamy Sathyanarayanan
2022-03-30 22:18 ` [PATCH v2 5/6] platform/x86: intel_tdx_attest: Add TDX Guest attestation interface driver Kuppuswamy Sathyanarayanan
2022-04-04 10:07   ` Hans de Goede
2022-04-04 19:56     ` Sathyanarayanan Kuppuswamy
2022-04-11 14:38       ` Hans de Goede
2022-04-04 10:09   ` Hans de Goede
2022-04-04 10:11     ` Hans de Goede

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