From: Paolo Bonzini <pbonzini@redhat.com>
To: Alexander Graf <agraf@suse.de>
Cc: tytso@mit.edu, kvm@vger.kernel.org,
Gleb Natapov <gleb@redhat.com>,
linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org,
kvm-ppc@vger.kernel.org, herbert@gondor.hengli.com.au,
Paul Mackerras <paulus@samba.org>,
mpm@selenic.com
Subject: Re: [PATCH 3/3] KVM: PPC: Book3S: Add support for hwrng found on some powernv systems
Date: Wed, 02 Oct 2013 16:38:19 +0200 [thread overview]
Message-ID: <524C2FDB.4080203@redhat.com> (raw)
In-Reply-To: <C4834CF8-F81C-4B82-B1A7-1751D50AADB7@suse.de>
Il 02/10/2013 16:36, Alexander Graf ha scritto:
>> >
>> > With Michael's earlier patch in this series, the hwrng is accessible by
>> > host userspace via /dev/hwrng, no?
> Yes, but there's not token from user space that gets passed into the
> kernel to check whether access is ok or not. So while QEMU may not have
> permission to open /dev/hwrng it could spawn a guest that opens it,
> drains all entropy out of it and thus stall other processes which try to
> fetch entropy, no?
>
> Maybe I haven't fully grasped the interface yet though :).
Yes, that's right. I don't think it's a huge problem, but it's another
point in favor of just doing the hypercall in userspace.
Paolo
next prev parent reply other threads:[~2013-10-02 14:38 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-26 6:31 [PATCH 1/3] powerpc: Implement arch_get_random_long/int() for powernv Michael Ellerman
2013-09-26 6:31 ` [PATCH 2/3] hwrng: Add a driver for the hwrng found in power7+ systems Michael Ellerman
2013-09-26 8:01 ` Benjamin Herrenschmidt
2013-10-01 8:25 ` Michael Ellerman
2013-09-26 6:31 ` [PATCH 3/3] KVM: PPC: Book3S: Add support for hwrng found on some powernv systems Michael Ellerman
2013-09-26 9:06 ` Paolo Bonzini
2013-10-01 8:34 ` Michael Ellerman
2013-10-01 8:39 ` Gleb Natapov
2013-10-01 9:23 ` Paul Mackerras
2013-10-01 9:57 ` Gleb Natapov
2013-10-01 10:00 ` Alexander Graf
2013-10-01 9:38 ` Benjamin Herrenschmidt
2013-10-01 11:19 ` Paolo Bonzini
2013-10-01 21:44 ` Benjamin Herrenschmidt
2013-10-02 8:38 ` Paolo Bonzini
2013-10-02 5:09 ` Paul Mackerras
2013-10-02 8:46 ` Paolo Bonzini
2013-10-02 9:06 ` Benjamin Herrenschmidt
2013-10-02 9:11 ` Alexander Graf
2013-10-02 9:50 ` Alexander Graf
2013-10-02 10:02 ` Gleb Natapov
2013-10-02 13:57 ` Michael Ellerman
2013-10-02 14:08 ` Alexander Graf
2013-10-02 14:33 ` Paolo Bonzini
2013-10-02 14:36 ` Alexander Graf
2013-10-02 14:38 ` Paolo Bonzini [this message]
2013-10-02 22:45 ` Paul Mackerras
2013-10-03 5:48 ` Gleb Natapov
2013-10-03 10:06 ` Paul Mackerras
2013-10-03 12:08 ` Gleb Natapov
2013-10-02 14:37 ` Gleb Natapov
2013-10-02 22:21 ` Benjamin Herrenschmidt
2013-10-03 6:08 ` Gleb Natapov
2013-10-02 22:13 ` Benjamin Herrenschmidt
2013-10-02 14:10 ` Gleb Natapov
2013-10-02 22:15 ` Benjamin Herrenschmidt
2013-10-02 22:02 ` Benjamin Herrenschmidt
2013-10-03 5:43 ` Gleb Natapov
2013-10-03 7:22 ` Benjamin Herrenschmidt
2013-10-02 22:07 ` Benjamin Herrenschmidt
2013-10-03 6:28 ` Gleb Natapov
2013-10-02 21:58 ` Benjamin Herrenschmidt
2013-10-01 9:58 ` Paolo Bonzini
2013-09-27 14:15 ` Anshuman Khandual
2013-10-01 8:36 ` Michael Ellerman
2013-09-26 7:58 ` [PATCH 1/3] powerpc: Implement arch_get_random_long/int() for powernv Benjamin Herrenschmidt
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