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From: Dave Hansen <dave.hansen@intel.com>
To: Andrew Cooper <amc96@cam.ac.uk>,
	"Luck, Tony" <tony.luck@intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	"Christopherson, Sean J" <sean.j.christopherson@intel.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Tom Lendacky <thomas.lendacky@amd.com>, Pu Wen <puwen@hygon.cn>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Sasha Levin <alexander.levin@microsoft.com>,
	Dirk Hohndel <dirkhh@vmware.com>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>,
	"H. Peter Anvin" <hpa@linux.intel.com>,
	"Mallick, Asit K" <asit.k.mallick@intel.com>,
	Gordon Tetlow <gordon@tetlows.org>,
	David Kaplan <David.Kaplan@amd.com>
Subject: Re: TDX #VE in SYSCALL gap (was: [RFD] x86: Curing the exception and syscall trainwreck in hardware)
Date: Tue, 25 Aug 2020 11:38:31 -0700	[thread overview]
Message-ID: <31ff691d-ac71-861d-07f4-113fe3c918aa@intel.com> (raw)
In-Reply-To: <44754766-c996-48a3-a20e-013fa627c0a1@cam.ac.uk>

On 8/25/20 10:59 AM, Andrew Cooper wrote:
> If I've read the TDX spec/whitepaper properly, the main hypervisor can
> write to all the encrypted pages.  This will destroy data, break the
> MAC, and yields #PF inside the SEAM hypervisor, or the TD when the cache
> line is next referenced.

I think you're talking about:

> Attempting to access a private KeyID by software outside the SEAM
> mode would cause a page-fault exception (#PF).

I don't think that ever results in a TD guest #PF.  "A MAC-verification
failure would be fatal to the TD and lead to its termination."  In this
context, I think that means that the TD stops running and can not be
reentered.

  reply	other threads:[~2020-08-25 18:39 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-24 12:24 [RFD] x86: Curing the exception and syscall trainwreck in hardware Thomas Gleixner
2020-08-24 13:52 ` Andrew Cooper
2020-08-25  4:39   ` TDX #VE in SYSCALL gap (was: [RFD] x86: Curing the exception and syscall trainwreck in hardware) Sean Christopherson
2020-08-25 15:25     ` Dave Hansen
2020-08-25 16:49     ` Andy Lutomirski
2020-08-25 17:19       ` Sean Christopherson
2020-08-25 17:28         ` Andy Lutomirski
2020-08-25 17:35           ` Luck, Tony
2020-08-25 17:41             ` Andy Lutomirski
2020-08-25 17:59             ` Andrew Cooper
2020-08-25 18:38               ` Dave Hansen [this message]
2020-08-25 19:49             ` Thomas Gleixner
2020-08-26 19:16           ` Sean Christopherson
2020-08-30 15:37             ` Andy Lutomirski
2020-08-30 18:37               ` Linus Torvalds

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