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From: Kai Huang <kai.huang@intel.com>
To: Sathyanarayanan Kuppuswamy 
	<sathyanarayanan.kuppuswamy@linux.intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, Hans de Goede <hdegoede@redhat.com>,
	Mark Gross <mgross@linux.intel.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
	Tony Luck <tony.luck@intel.com>, Andi Kleen <ak@linux.intel.com>,
	linux-kernel@vger.kernel.org,
	platform-driver-x86@vger.kernel.org
Subject: Re: [PATCH v3 2/4] x86/tdx: Add tdx_hcall_get_quote() API support
Date: Tue, 19 Apr 2022 19:21:41 +1200	[thread overview]
Message-ID: <386efdc4a7f9dabd84cd19823c094a468a8644c4.camel@intel.com> (raw)
In-Reply-To: <67eda184-6823-7b23-85d2-9ff22bc0d215@linux.intel.com>

On Mon, 2022-04-18 at 22:28 -0700, Sathyanarayanan Kuppuswamy wrote:
> 
> On 4/18/22 9:40 PM, Kai Huang wrote:
> > > Please check the latest 1.0 specification (updated on Feb 2022). It has
> > > details about R13 register.
> > Thanks.  So it seems GHCI 1.0 has also been updated and it is consistent with
> > GHCI 1.5 now.  In this case, why do we still assume 8K shared memory?  Are you
> > going to update the driver?
> > 
> 
> Since the GetQuote spec only requires memory in 4K alignment, we just
> went with 8k constant allocation. Since existing users does not
> require more than 8k, it works. But I agree that this needs to be
> changed.

Quote format can be vendor specific, so there's no guarantee 3rd party won't
have a Quote larger than 8k.

> 
> In next version, I will change the driver to choose the allocation size
> based on user space request. Since this change would require us to do
> the memory allocation in IOCTL routine (instead of init code), it will
> make it slower. But I think this is negligible compared to time it takes
> for Quote request. So it should be fine.
> 
> > 

Yes attestation request should never be something that is very frequent, thus
should never be in a performance critical path.

  reply	other threads:[~2022-04-19  7:21 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-15 22:01 [PATCH v3 0/4] Add TDX Guest Attestation support Kuppuswamy Sathyanarayanan
2022-04-15 22:01 ` [PATCH v3 1/4] x86/tdx: Add tdx_mcall_tdreport() API support Kuppuswamy Sathyanarayanan
2022-04-19  2:29   ` Kai Huang
2022-04-19  3:37     ` Sathyanarayanan Kuppuswamy
2022-04-19  3:51       ` Kai Huang
2022-04-19  3:53         ` Sathyanarayanan Kuppuswamy
2022-04-15 22:01 ` [PATCH v3 2/4] x86/tdx: Add tdx_hcall_get_quote() " Kuppuswamy Sathyanarayanan
2022-04-19  2:59   ` Kai Huang
2022-04-19  4:04     ` Sathyanarayanan Kuppuswamy
2022-04-19  4:40       ` Kai Huang
2022-04-19  5:28         ` Sathyanarayanan Kuppuswamy
2022-04-19  7:21           ` Kai Huang [this message]
2022-04-20  3:39   ` Aubrey Li
2022-04-20  7:16     ` Sathyanarayanan Kuppuswamy
2022-04-20  8:08       ` Aubrey Li
2022-04-22 17:24       ` Isaku Yamahata
2022-04-25  3:06         ` Aubrey Li
2022-04-15 22:01 ` [PATCH v3 3/4] x86/tdx: Add TDX Guest event notify interrupt support Kuppuswamy Sathyanarayanan
2022-04-15 22:01 ` [PATCH v3 4/4] platform/x86: intel_tdx_attest: Add TDX Guest attestation interface driver Kuppuswamy Sathyanarayanan
2022-04-19  7:47   ` Kai Huang
2022-04-19  8:13     ` Borislav Petkov
2022-04-19 12:48       ` Sathyanarayanan Kuppuswamy
2022-04-20 22:00         ` Borislav Petkov
2022-04-20 22:09           ` Sathyanarayanan Kuppuswamy
2022-04-21  9:10             ` Borislav Petkov
2022-04-21 14:54               ` Sathyanarayanan Kuppuswamy
2022-04-19  8:16     ` Kai Huang
2022-04-19 14:00       ` Sathyanarayanan Kuppuswamy
2022-04-19 22:38         ` Kai Huang
2022-04-19 14:13     ` Dave Hansen
2022-04-19 14:19       ` Sathyanarayanan Kuppuswamy
2022-04-19 14:24         ` Dave Hansen
2022-04-19 14:26           ` Sathyanarayanan Kuppuswamy
2022-04-19 22:21       ` Kai Huang
2022-04-19 22:49         ` Dave Hansen
2022-04-19 23:02           ` Kai Huang
2022-04-20  1:20   ` Isaku Yamahata
2022-04-20  1:26     ` Sathyanarayanan Kuppuswamy
2022-04-21  7:04       ` Isaku Yamahata
2022-04-21 14:44         ` Sathyanarayanan Kuppuswamy
2022-04-20 23:18   ` Kai Huang
2022-04-20 23:45     ` Sathyanarayanan Kuppuswamy
2022-04-21  0:11       ` Kai Huang
2022-04-21  2:42         ` Sathyanarayanan Kuppuswamy
2022-04-21  6:57           ` Isaku Yamahata
2022-04-21 10:33             ` Kai Huang
2022-04-21 14:53             ` Sathyanarayanan Kuppuswamy
2022-04-21 16:53               ` Isaku Yamahata

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