From: "H. Peter Anvin" <hpa@zytor.com>
To: Andy Lutomirski <luto@amacapital.net>, Theodore Ts'o <tytso@mit.edu>
Cc: Mathew John <mathewj@microsoft.com>,
kvm list <kvm@vger.kernel.org>, Gleb Natapov <gleb@kernel.org>,
Niels Ferguson <niels@microsoft.com>,
Linux Virtualization <virtualization@lists.linux-foundation.org>,
David Hepkin <davidhep@microsoft.com>,
Jake Oshins <jakeo@microsoft.com>,
Paolo Bonzini <pbonzini@redhat.com>,
John Starks <John.Starks@microsoft.com>
Subject: Re: Standardizing an MSR or other hypercall to get an RNG seed?
Date: Fri, 19 Sep 2014 16:29:53 -0700 [thread overview]
Message-ID: <541CBC71.9040709@zytor.com> (raw)
In-Reply-To: <CALCETrVbhvB3ExxxNQRB21NYbpvoXgKpX6XxzMKsd=b47rKCeA@mail.gmail.com>
On 09/19/2014 04:12 PM, Andy Lutomirski wrote:
>
> To force deterministic execution.
>
> I incorrectly thought that the kernel could switch RDRAND on and off.
> It turns out that a hypervisor can do this, but not the kernel. Also,
> determinism is lost anyway because of TSX, which *also* can't be
> turned on and off.
>
Actually, a much bigger reason is because it lets rogue guest *user
space*, even will a well-behaved guest OS, do something potentially
harmful to the host.
-hpa
next prev parent reply other threads:[~2014-09-19 23:29 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-18 2:50 Standardizing an MSR or other hypercall to get an RNG seed? Andy Lutomirski
2014-09-18 14:40 ` KY Srinivasan
2014-09-18 14:43 ` H. Peter Anvin
2014-09-18 15:38 ` Andy Lutomirski
2014-09-18 15:44 ` Andy Lutomirski
2014-09-18 15:58 ` Paolo Bonzini
2014-09-18 16:36 ` KY Srinivasan
2014-09-18 16:36 ` KY Srinivasan
2014-09-18 17:13 ` Nakajima, Jun
2014-09-18 17:17 ` Paolo Bonzini
2014-09-18 17:17 ` Paolo Bonzini
2014-09-18 17:20 ` Jake Oshins
2014-09-18 17:20 ` Jake Oshins
2014-09-18 17:20 ` KY Srinivasan
2014-09-18 17:20 ` KY Srinivasan
2014-09-18 17:42 ` Nakajima, Jun
2014-09-18 18:35 ` Andy Lutomirski
2014-09-18 18:39 ` H. Peter Anvin
2014-09-18 18:54 ` Niels Ferguson
2014-09-18 19:03 ` Andy Lutomirski
2014-09-18 21:54 ` David Hepkin
2014-09-18 21:54 ` David Hepkin
2014-09-19 6:04 ` Paolo Bonzini
2014-09-18 18:58 ` Paolo Bonzini
2014-09-18 19:07 ` Andy Lutomirski
2014-09-18 21:21 ` Nakajima, Jun
2014-09-18 21:35 ` Andy Lutomirski
2014-09-18 21:46 ` David Hepkin
2014-09-18 21:57 ` H. Peter Anvin
2014-09-18 22:07 ` Andy Lutomirski
2014-09-19 0:49 ` Nakajima, Jun
2014-09-19 1:03 ` Andy Lutomirski
2014-09-19 1:28 ` Andy Lutomirski
2014-09-19 16:14 ` Nakajima, Jun
2014-09-19 16:22 ` Paolo Bonzini
2014-09-19 16:40 ` H. Peter Anvin
2014-09-19 17:21 ` Andy Lutomirski
2014-09-19 17:36 ` H. Peter Anvin
2014-09-19 17:39 ` Andy Lutomirski
2014-09-19 22:05 ` Theodore Ts'o
2014-09-19 22:06 ` Andy Lutomirski
2014-09-19 22:57 ` Nakajima, Jun
2014-09-19 22:57 ` Theodore Ts'o
2014-09-19 23:12 ` Andy Lutomirski
2014-09-19 23:29 ` H. Peter Anvin [this message]
2014-09-19 23:29 ` H. Peter Anvin
2014-09-19 23:35 ` Theodore Ts'o
2014-09-19 23:41 ` Andy Lutomirski
2014-09-20 0:06 ` H. Peter Anvin
2014-09-19 1:28 ` Andy Lutomirski
2014-09-19 0:49 ` Nakajima, Jun
2014-09-18 22:00 ` Andy Lutomirski
2014-09-18 22:03 ` H. Peter Anvin
2014-09-19 16:37 ` Gleb Natapov
2014-09-19 16:40 ` H. Peter Anvin
2014-09-19 16:53 ` Gleb Natapov
2014-09-19 17:08 ` H. Peter Anvin
2014-09-19 17:15 ` Gleb Natapov
2014-09-19 17:18 ` H. Peter Anvin
2014-09-19 17:18 ` H. Peter Anvin
2014-09-19 17:49 ` Gleb Natapov
2014-09-19 18:02 ` Andy Lutomirski
2014-09-19 18:12 ` Gleb Natapov
2014-09-19 18:20 ` Andy Lutomirski
2014-09-19 20:53 ` Gleb Natapov
2014-09-22 4:11 ` Alok Kataria
2014-09-19 17:21 ` Andy Lutomirski
2014-09-19 17:59 ` Gleb Natapov
2014-09-19 17:59 ` Gleb Natapov
2014-09-18 21:46 ` David Hepkin
2014-09-18 18:56 ` Paolo Bonzini
2014-09-18 14:40 ` KY Srinivasan
2014-09-19 18:30 ` Christopher Covington
2014-09-19 18:42 ` Andy Lutomirski
2014-09-19 20:21 ` Nadav Amit
2014-09-19 20:46 ` Andy Lutomirski
2014-09-19 21:46 ` H. Peter Anvin
2014-09-22 13:31 ` Christopher Covington
2014-09-22 14:17 ` H. Peter Anvin
2014-09-22 14:18 ` H. Peter Anvin
2014-09-22 23:01 ` H. Peter Anvin
2014-09-21 12:39 ` Paolo Bonzini
2014-09-19 20:21 ` Nadav Amit
2014-09-22 13:33 ` Christopher Covington
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