From: "H. Peter Anvin" <hpa@zytor.com>
To: Andy Lutomirski <luto@amacapital.net>,
"Theodore Ts'o" <tytso@mit.edu>,
Florian Weimer <fweimer@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Kees Cook <kees@outflux.net>, kvm list <kvm@vger.kernel.org>
Subject: random: Providing a seed value to VM guests
Date: Thu, 01 May 2014 11:59:25 -0700 [thread overview]
Message-ID: <5362998D.3030102@zytor.com> (raw)
In-Reply-To: <CALCETrWwcuq_-Q+i1g9hspsddGUmx8_yf3EaOLjgPcF5+yBnYA@mail.gmail.com>
On 05/01/2014 11:53 AM, Andy Lutomirski wrote:
>
> A CPUID leaf or an MSR advertised by a CPUID leaf has another
> advantage: it's easy to use in the ASLR code -- I don't think there's
> a real IDT, so there's nothing like rdmsr_safe available. It also
> avoids doing anything complicated with the boot process to allow the
> same seed to be used for ASLR and random.c; it can just be invoked
> twice on boot.
>
At that point we are talking an x86-specific interface, and so we might
as well simply emulate RDRAND (urandom) and RDSEED (random) if the CPU
doesn't support them. I believe KVM already has a way to report CPUID
features that are "emulated but supported anyway", i.e. they work but
are slow.
> What's the right forum for this? This thread is probably not it.
Change the subject line?
-hpa
next prev parent reply other threads:[~2014-05-01 18:59 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20140428195913.E0A0143994596@oldenburg.str.redhat.com>
[not found] ` <20140428214112.GC7857@thunk.org>
[not found] ` <535FE68C.8060002@redhat.com>
[not found] ` <20140429182610.GA19325@thunk.org>
[not found] ` <53616293.3080308@mit.edu>
[not found] ` <20140501020627.GA25248@thunk.org>
[not found] ` <1be5350d-89f9-44b9-8d1b-e3e591741940@email.android.com>
[not found] ` <20140501150549.GA24388@thunk.org>
[not found] ` <CALCETrUQRqKEbWps5Nxqk57vCYmuvcA6pYAL7OiqJy8sE8yh=g@mail.gmail.com>
2014-05-01 18:53 ` [PATCH] random: Add "initialized" variable to proc Andy Lutomirski
2014-05-01 18:59 ` H. Peter Anvin [this message]
2014-05-01 19:02 random: Providing a seed value to VM guests Andy Lutomirski
2014-05-01 19:26 ` tytso
2014-05-01 19:40 ` H. Peter Anvin
2014-05-01 20:16 ` Andy Lutomirski
2014-05-01 20:30 ` H. Peter Anvin
2014-05-01 20:32 ` Andy Lutomirski
2014-05-01 20:39 ` tytso
2014-05-01 20:56 ` Andy Lutomirski
2014-05-01 21:01 ` H. Peter Anvin
2014-05-01 21:06 ` Andy Lutomirski
2014-05-01 22:28 ` tytso
2014-05-01 22:32 ` Andy Lutomirski
2014-05-01 22:46 ` H. Peter Anvin
2014-05-01 22:56 ` Andy Lutomirski
2014-05-01 23:00 ` H. Peter Anvin
2014-05-01 19:41 ` H. Peter Anvin
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