From: Theodore Ts'o <tytso@mit.edu>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathew John <mathewj@microsoft.com>,
kvm list <kvm@vger.kernel.org>, Gleb Natapov <gleb@kernel.org>,
Niels Ferguson <niels@microsoft.com>,
Andy Lutomirski <luto@amacapital.net>,
David Hepkin <davidhep@microsoft.com>,
Jake Oshins <jakeo@microsoft.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Linux Virtualization <virtualization@lists.linux-foundation.org>,
John Starks <John.Starks@microsoft.com>
Subject: Re: Standardizing an MSR or other hypercall to get an RNG seed?
Date: Fri, 19 Sep 2014 18:05:37 -0400 [thread overview]
Message-ID: <20140919220537.GR26995@thunk.org> (raw)
In-Reply-To: <541C5C8A.6030304@zytor.com>
On Fri, Sep 19, 2014 at 09:40:42AM -0700, H. Peter Anvin wrote:
>
> There is a huge disadvantage to the fact that CPUID is a user space
> instruction, though.
But if the goal is to provide something like getrandom(2) direct from
the Host OS, it's not necessarily harmful to allow the Guest ring 3
code to be able to fetch randomness in that way. The hypervisor can
implement rate limiting to protect against the guest using this too
frequently, but this is something that you should be doing for guest
ring 0 code anyway, since from the POV of the hypervisor Guest ring 0
is not necessarily any more trusted than Guest ring 3.
- Ted
next prev parent reply other threads:[~2014-09-19 22:05 UTC|newest]
Thread overview: 73+ 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
[not found] ` <2aa00301e9af4826b5781e01709f81e7@BY2PR0301MB0711.namprd03.prod.outlook.com>
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
[not found] ` <5b9c7dcde3824e49a25f3ee00844b868@BY2PR0301MB0711.namprd03.prod.outlook.com>
2014-09-18 17:13 ` Nakajima, Jun
2014-09-18 17:17 ` Paolo Bonzini
[not found] ` <541B13B8.1020006@redhat.com>
2014-09-18 17:20 ` Jake Oshins
2014-09-18 17:20 ` KY Srinivasan
[not found] ` <b697ef83ae594d8fb34347339dd52dfa@BY2PR0301MB0711.namprd03.prod.outlook.com>
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
[not found] ` <572ba53a2e1e4278823f718a421e2c1d@BY2PR03MB585.namprd03.prod.outlook.com>
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
[not found] ` <0180a8dfcad746a895755c4374853c16@BY2PR03MB585.namprd03.prod.outlook.com>
2014-09-18 21:57 ` H. Peter Anvin
2014-09-18 22:07 ` Andy Lutomirski
2014-09-19 0:49 ` Nakajima, Jun
[not found] ` <CAL54oT1Q8kABge=t4s5REVWWakboON-6vfszMRkVz=ks_3vRoA@mail.gmail.com>
2014-09-19 1:03 ` Andy Lutomirski
2014-09-19 1:28 ` Andy Lutomirski
[not found] ` <CALCETrWZ1cF23aT82yGfTKS48d2G+_Od7hEkAzDWzDhqpHNVqA@mail.gmail.com>
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 [this message]
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
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
2014-09-18 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 17:49 ` 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 17:18 ` H. Peter Anvin
2014-09-19 17:21 ` Andy Lutomirski
2014-09-19 17:59 ` Gleb Natapov
2014-09-18 18:56 ` Paolo Bonzini
2014-09-19 18:30 ` Christopher Covington
2014-09-19 18:42 ` Andy Lutomirski
2014-09-19 20:21 ` Nadav Amit
[not found] ` <15C8041A-3488-4693-B329-3A9FE77A0CB9@gmail.com>
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
2014-09-22 13:33 ` Christopher Covington
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