From: Benjamin Herrenschmidt <benh@au1.ibm.com>
To: Alexander Graf <agraf@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Paul Mackerras <paulus@samba.org>, Gleb Natapov <gleb@redhat.com>,
Michael Ellerman <michael@ellerman.id.au>,
linux-kernel@vger.kernel.org, mpm@selenic.com,
herbert@gondor.hengli.com.au, linuxppc-dev@ozlabs.org,
kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, tytso@mit.edu
Subject: Re: [PATCH 3/3] KVM: PPC: Book3S: Add support for hwrng found on some powernv systems
Date: Wed, 02 Oct 2013 21:58:32 +0000 [thread overview]
Message-ID: <1380751112.645.64.camel@pasglop> (raw)
In-Reply-To: <668E4650-BC22-4CBF-A282-E7875DF29DB6@suse.de>
On Wed, 2013-10-02 at 11:11 +0200, Alexander Graf wrote:
> Right, and the difference for the patch in question is really whether
> we handle in in kernel virtual mode or in QEMU, so the bulk of the
> overhead (kicking threads out of guest context, switching MMU
> context, etc) happens either way.
>
> So the additional overhead when handling it in QEMU here really boils
> down to the user space roundtrip (plus another random number read
> roundtrip).
Hrm, Michael had a real mode version ... not sure where it went then.
Cheers,
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@au1.ibm.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, Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH 3/3] KVM: PPC: Book3S: Add support for hwrng found on some powernv systems
Date: Thu, 03 Oct 2013 07:58:32 +1000 [thread overview]
Message-ID: <1380751112.645.64.camel@pasglop> (raw)
In-Reply-To: <668E4650-BC22-4CBF-A282-E7875DF29DB6@suse.de>
On Wed, 2013-10-02 at 11:11 +0200, Alexander Graf wrote:
> Right, and the difference for the patch in question is really whether
> we handle in in kernel virtual mode or in QEMU, so the bulk of the
> overhead (kicking threads out of guest context, switching MMU
> context, etc) happens either way.
>
> So the additional overhead when handling it in QEMU here really boils
> down to the user space roundtrip (plus another random number read
> roundtrip).
Hrm, Michael had a real mode version ... not sure where it went then.
Cheers,
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@au1.ibm.com>
To: Alexander Graf <agraf@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Paul Mackerras <paulus@samba.org>, Gleb Natapov <gleb@redhat.com>,
Michael Ellerman <michael@ellerman.id.au>,
linux-kernel@vger.kernel.org, mpm@selenic.com,
herbert@gondor.hengli.com.au, linuxppc-dev@ozlabs.org,
kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, tytso@mit.edu
Subject: Re: [PATCH 3/3] KVM: PPC: Book3S: Add support for hwrng found on some powernv systems
Date: Thu, 03 Oct 2013 07:58:32 +1000 [thread overview]
Message-ID: <1380751112.645.64.camel@pasglop> (raw)
In-Reply-To: <668E4650-BC22-4CBF-A282-E7875DF29DB6@suse.de>
On Wed, 2013-10-02 at 11:11 +0200, Alexander Graf wrote:
> Right, and the difference for the patch in question is really whether
> we handle in in kernel virtual mode or in QEMU, so the bulk of the
> overhead (kicking threads out of guest context, switching MMU
> context, etc) happens either way.
>
> So the additional overhead when handling it in QEMU here really boils
> down to the user space roundtrip (plus another random number read
> roundtrip).
Hrm, Michael had a real mode version ... not sure where it went then.
Cheers,
Ben.
next prev parent reply other threads:[~2013-10-02 21:58 UTC|newest]
Thread overview: 146+ 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 ` Michael Ellerman
2013-09-26 6:31 ` Michael Ellerman
2013-09-26 6:31 ` 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 6:31 ` Michael Ellerman
2013-09-26 6:31 ` Michael Ellerman
2013-09-26 6:31 ` Michael Ellerman
2013-09-26 8:01 ` Benjamin Herrenschmidt
2013-09-26 8:01 ` Benjamin Herrenschmidt
2013-09-26 8:01 ` Benjamin Herrenschmidt
2013-10-01 8:25 ` Michael Ellerman
2013-10-01 8:25 ` Michael Ellerman
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 6:31 ` Michael Ellerman
2013-09-26 6:31 ` Michael Ellerman
2013-09-26 6:31 ` Michael Ellerman
2013-09-26 9:06 ` Paolo Bonzini
2013-09-26 9:06 ` Paolo Bonzini
2013-09-26 9:06 ` Paolo Bonzini
2013-09-26 9:06 ` Paolo Bonzini
2013-10-01 8:34 ` Michael Ellerman
2013-10-01 8:34 ` Michael Ellerman
2013-10-01 8:34 ` Michael Ellerman
2013-10-01 8:34 ` Michael Ellerman
2013-10-01 8:39 ` Gleb Natapov
2013-10-01 8:39 ` Gleb Natapov
2013-10-01 8:39 ` Gleb Natapov
2013-10-01 9:23 ` Paul Mackerras
2013-10-01 9:23 ` Paul Mackerras
2013-10-01 9:23 ` Paul Mackerras
2013-10-01 9:57 ` Gleb Natapov
2013-10-01 9:57 ` Gleb Natapov
2013-10-01 9:57 ` Gleb Natapov
2013-10-01 10:00 ` Alexander Graf
2013-10-01 10:00 ` Alexander Graf
2013-10-01 10:00 ` Alexander Graf
2013-10-01 9:38 ` Benjamin Herrenschmidt
2013-10-01 9:38 ` Benjamin Herrenschmidt
2013-10-01 9:38 ` Benjamin Herrenschmidt
2013-10-01 11:19 ` Paolo Bonzini
2013-10-01 11:19 ` Paolo Bonzini
2013-10-01 11:19 ` Paolo Bonzini
2013-10-01 21:44 ` Benjamin Herrenschmidt
2013-10-01 21:44 ` Benjamin Herrenschmidt
2013-10-01 21:44 ` Benjamin Herrenschmidt
2013-10-02 8:38 ` Paolo Bonzini
2013-10-02 8:38 ` Paolo Bonzini
2013-10-02 8:38 ` Paolo Bonzini
2013-10-02 5:09 ` Paul Mackerras
2013-10-02 5:09 ` Paul Mackerras
2013-10-02 5:09 ` Paul Mackerras
2013-10-02 8:46 ` Paolo Bonzini
2013-10-02 8:46 ` Paolo Bonzini
2013-10-02 8:46 ` Paolo Bonzini
2013-10-02 9:06 ` Benjamin Herrenschmidt
2013-10-02 9:06 ` Benjamin Herrenschmidt
2013-10-02 9:06 ` Benjamin Herrenschmidt
2013-10-02 9:11 ` Alexander Graf
2013-10-02 9:11 ` Alexander Graf
2013-10-02 9:11 ` Alexander Graf
2013-10-02 9:50 ` Alexander Graf
2013-10-02 9:50 ` Alexander Graf
2013-10-02 9:50 ` Alexander Graf
2013-10-02 10:02 ` Gleb Natapov
2013-10-02 10:02 ` Gleb Natapov
2013-10-02 10:02 ` Gleb Natapov
2013-10-02 13:57 ` Michael Ellerman
2013-10-02 13:57 ` Michael Ellerman
2013-10-02 13:57 ` Michael Ellerman
2013-10-02 14:08 ` Alexander Graf
2013-10-02 14:08 ` Alexander Graf
2013-10-02 14:08 ` Alexander Graf
2013-10-02 14:33 ` Paolo Bonzini
2013-10-02 14:33 ` Paolo Bonzini
2013-10-02 14:33 ` Paolo Bonzini
2013-10-02 14:36 ` Alexander Graf
2013-10-02 14:36 ` Alexander Graf
2013-10-02 14:36 ` Alexander Graf
2013-10-02 14:38 ` Paolo Bonzini
2013-10-02 14:38 ` Paolo Bonzini
2013-10-02 14:38 ` Paolo Bonzini
2013-10-02 22:45 ` Paul Mackerras
2013-10-02 22:45 ` Paul Mackerras
2013-10-02 22:45 ` Paul Mackerras
2013-10-03 5:48 ` Gleb Natapov
2013-10-03 5:48 ` Gleb Natapov
2013-10-03 5:48 ` Gleb Natapov
2013-10-03 10:06 ` Paul Mackerras
2013-10-03 10:06 ` Paul Mackerras
2013-10-03 10:06 ` Paul Mackerras
2013-10-03 12:08 ` Gleb Natapov
2013-10-03 12:08 ` Gleb Natapov
2013-10-03 12:08 ` Gleb Natapov
2013-10-02 14:37 ` Gleb Natapov
2013-10-02 14:37 ` Gleb Natapov
2013-10-02 14:37 ` Gleb Natapov
2013-10-02 22:21 ` Benjamin Herrenschmidt
2013-10-02 22:21 ` Benjamin Herrenschmidt
2013-10-02 22:21 ` Benjamin Herrenschmidt
2013-10-03 6:08 ` Gleb Natapov
2013-10-03 6:08 ` Gleb Natapov
2013-10-03 6:08 ` Gleb Natapov
2013-10-02 22:13 ` Benjamin Herrenschmidt
2013-10-02 22:13 ` Benjamin Herrenschmidt
2013-10-02 22:13 ` Benjamin Herrenschmidt
2013-10-02 14:10 ` Gleb Natapov
2013-10-02 14:10 ` Gleb Natapov
2013-10-02 14:10 ` Gleb Natapov
2013-10-02 22:15 ` Benjamin Herrenschmidt
2013-10-02 22:15 ` Benjamin Herrenschmidt
2013-10-02 22:15 ` Benjamin Herrenschmidt
2013-10-02 22:02 ` Benjamin Herrenschmidt
2013-10-02 22:02 ` Benjamin Herrenschmidt
2013-10-02 22:02 ` Benjamin Herrenschmidt
2013-10-03 5:43 ` Gleb Natapov
2013-10-03 5:43 ` Gleb Natapov
2013-10-03 5:43 ` Gleb Natapov
2013-10-03 7:22 ` Benjamin Herrenschmidt
2013-10-03 7:22 ` Benjamin Herrenschmidt
2013-10-03 7:22 ` Benjamin Herrenschmidt
2013-10-02 22:07 ` Benjamin Herrenschmidt
2013-10-02 22:07 ` Benjamin Herrenschmidt
2013-10-02 22:07 ` Benjamin Herrenschmidt
2013-10-03 6:28 ` Gleb Natapov
2013-10-03 6:28 ` Gleb Natapov
2013-10-03 6:28 ` Gleb Natapov
2013-10-02 21:58 ` Benjamin Herrenschmidt [this message]
2013-10-02 21:58 ` Benjamin Herrenschmidt
2013-10-02 21:58 ` Benjamin Herrenschmidt
2013-10-01 9:58 ` Paolo Bonzini
2013-10-01 9:58 ` Paolo Bonzini
2013-10-01 9:58 ` Paolo Bonzini
2013-10-01 9:58 ` Paolo Bonzini
2013-09-27 14:15 ` Anshuman Khandual
2013-09-27 14:27 ` Anshuman Khandual
2013-09-27 14:15 ` Anshuman Khandual
2013-09-27 14:15 ` Anshuman Khandual
2013-10-01 8:36 ` Michael Ellerman
2013-10-01 8:36 ` Michael Ellerman
2013-10-01 8:36 ` Michael Ellerman
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
2013-09-26 7:58 ` Benjamin Herrenschmidt
2013-09-26 7:58 ` Benjamin Herrenschmidt
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