From: Thomas Gleixner <tglx@linutronix.de>
To: "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>,
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 21:49:07 +0200 [thread overview]
Message-ID: <87ft8ay098.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <dfce335fefe043868301bacf57120759@intel.com>
On Tue, Aug 25 2020 at 17:35, Tony Luck wrote:
>> > Or malicious hypervisor action, and that's a problem.
>> >
>> > Suppose the hypervisor remaps a GPA used in the SYSCALL gap (e.g. the
>> > actual SYSCALL text or the first memory it accesses -- I don't have a
>> > TDX spec so I don't know the details).
>
> Is it feasible to defend against a malicious (or buggy) hypervisor?
>
> Obviously, we can't leave holes that guests can exploit. But the hypervisor
> can crash the system no matter how clever TDX is.
If it crashes and burns reliably then fine, but is that guaranteed?
I have serious doubts about that given the history and fragility of all
of this and I really have zero interest in dealing with the fallout a
year from now.
Thanks,
tglx
next prev parent reply other threads:[~2020-08-25 19:49 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
2020-08-25 19:49 ` Thomas Gleixner [this message]
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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