From: Gleb Natapov <gleb@kernel.org>
To: Daniel Borkmann <dborkman@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>,
kvm@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Theodore Ts'o <tytso@mit.edu>,
linux-kernel@vger.kernel.org, Kees Cook <keescook@chromium.org>,
x86@kernel.org, Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Subject: Re: [PATCH 0/4] random,x86,kvm: Add and use MSR_KVM_GET_RNG_SEED
Date: Wed, 16 Jul 2014 10:23:16 +0300 [thread overview]
Message-ID: <20140716072315.GW18167@minantech.com> (raw)
In-Reply-To: <53C62563.6050106@redhat.com>
On Wed, Jul 16, 2014 at 09:10:27AM +0200, Daniel Borkmann wrote:
> On 07/16/2014 08:41 AM, Gleb Natapov wrote:
> >On Tue, Jul 15, 2014 at 07:48:06PM -0700, Andy Lutomirski wrote:
> >>virtio-rng is both too complicated and insufficient for initial rng
> >>seeding. It's far too complicated to use for KASLR or any other
> >>early boot random number needs. It also provides /dev/random-style
> >>bits, which means that making guest boot wait for virtio-rng is
> >>unacceptably slow, and doing it asynchronously means that
> >>/dev/urandom might be predictable when userspace starts.
> >>
> >>This introduces a very simple synchronous mechanism to get
> >>/dev/urandom-style bits.
> >
> >Why can't you use RDRAND instruction for that?
>
> You mean using it directly? I think simply for the very same reasons
> as in c2557a303a ...
So you trust your hypervisor vendor more than you trust your CPU vendor? :)
--
Gleb.
next prev parent reply other threads:[~2014-07-16 7:23 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-16 2:48 [PATCH 0/4] random,x86,kvm: Add and use MSR_KVM_GET_RNG_SEED Andy Lutomirski
2014-07-16 2:48 ` [PATCH 1/4] x86,kvm: Add MSR_KVM_GET_RNG_SEED and a matching feature bit Andy Lutomirski
2014-07-16 2:48 ` [PATCH 2/4] random,x86: Add arch_get_slow_rng_u64 Andy Lutomirski
2014-07-16 2:48 ` [PATCH 3/4] random: Seed pools from arch_get_slow_rng_u64 at startup Andy Lutomirski
2014-07-16 2:48 ` [PATCH 4/4] x86,kaslr: Use MSR_KVM_GET_RNG_SEED for KASLR if available Andy Lutomirski
2014-07-16 6:41 ` [PATCH 0/4] random,x86,kvm: Add and use MSR_KVM_GET_RNG_SEED Gleb Natapov
2014-07-16 7:10 ` Daniel Borkmann
2014-07-16 7:23 ` Gleb Natapov [this message]
2014-07-16 7:36 ` Paolo Bonzini
2014-07-16 14:07 ` Andy Lutomirski
2014-07-16 14:32 ` Paolo Bonzini
2014-07-16 14:53 ` Gleb Natapov
2014-07-16 15:56 ` Andy Lutomirski
2014-07-16 16:03 ` H. Peter Anvin
2014-07-16 16:08 ` Paolo Bonzini
2014-07-16 16:13 ` H. Peter Anvin
2014-07-16 16:21 ` Gleb Natapov
2014-07-16 20:20 ` H. Peter Anvin
2014-07-16 21:32 ` Andy Lutomirski
2014-07-16 21:36 ` H. Peter Anvin
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