From: Paolo Bonzini <pbonzini@redhat.com>
To: "Daniel P. Berrange" <berrange@redhat.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] RFC: Universal encryption on QEMU I/O channels
Date: Wed, 04 Feb 2015 16:04:33 +0100 [thread overview]
Message-ID: <54D23501.5020200@redhat.com> (raw)
In-Reply-To: <20150204143452.GV3032@redhat.com>
On 04/02/2015 15:34, Daniel P. Berrange wrote:
> > GIO doesn't provide writev either, so it's not a good match for
> > non-encrypted migration, which really tries hard to do no copies in
> > userspace.
>
> Ok, maybe RDMA will still need QEMUFile, but for non-encrypted TCP
> I'd hope to be able to achieve zero-copy with the new API too - it
> would certainly be my intention/goal.
For GIO/GIOChannel, you'd have to choose between zerocopy and many
syscalls, or one copy and few syscalls. Since every page has two iov
entries, one of which is just 8 bytes, one copy and few syscalls is
probably faster---but still only half the speed of writev.
Paolo
next prev parent reply other threads:[~2015-02-04 15:04 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-04 11:32 [Qemu-devel] RFC: Universal encryption on QEMU I/O channels Daniel P. Berrange
2015-02-04 12:43 ` Paolo Bonzini
2015-02-04 13:00 ` Daniel P. Berrange
2015-02-04 13:42 ` Paolo Bonzini
2015-02-04 14:08 ` Daniel P. Berrange
2015-02-04 14:23 ` Paolo Bonzini
2015-02-04 14:34 ` Daniel P. Berrange
2015-02-04 15:04 ` Paolo Bonzini [this message]
2015-02-04 15:11 ` Daniel P. Berrange
2015-02-04 15:22 ` Paolo Bonzini
2015-02-04 15:26 ` Daniel P. Berrange
2015-02-04 16:46 ` Paolo Bonzini
2015-02-05 14:38 ` Stefan Hajnoczi
2015-02-05 14:44 ` Cornelia Huck
2015-02-05 14:45 ` Peter Maydell
2015-02-04 13:49 ` Markus Armbruster
2015-02-04 13:55 ` Peter Maydell
2015-02-04 16:33 ` Markus Armbruster
2015-02-04 16:41 ` Daniel P. Berrange
2015-02-04 20:41 ` Peter Maydell
2015-02-04 21:06 ` Paolo Bonzini
2015-02-05 7:57 ` Markus Armbruster
2015-02-04 13:08 ` Dr. David Alan Gilbert
2015-02-04 14:02 ` Daniel P. Berrange
2015-02-04 14:28 ` Paolo Bonzini
2015-02-04 14:48 ` Marcel Apfelbaum
2015-02-04 14:50 ` Daniel P. Berrange
2015-02-04 18:34 ` Eric Blake
2015-02-05 9:11 ` Dr. David Alan Gilbert
2015-02-04 14:27 ` Paolo Bonzini
2015-02-04 14:37 ` Dr. David Alan Gilbert
2015-03-06 17:18 ` Daniel P. Berrange
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