From: "Daniel P. Berrange" <berrange@redhat.com>
To: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
Cc: Anthony Liguori <anthony@codemonkey.ws>,
kwolf@redhat.com, aliguori@us.ibm.com, dlaor@redhat.com,
ananth@in.ibm.com, kvm@vger.kernel.org, mst@redhat.com,
mtosatti@redhat.com, qemu-devel@nongnu.org,
vatsa@linux.vnet.ibm.com, blauwirbel@gmail.com,
ohmura.kei@lab.ntt.co.jp, avi@redhat.com, pbonzini@redhat.com,
psuriset@linux.vnet.ibm.com, stefanha@linux.vnet.ibm.com
Subject: Re: [Qemu-devel] [PATCH 02/18] Introduce read() to FdMigrationState.
Date: Thu, 10 Feb 2011 10:44:45 +0000 [thread overview]
Message-ID: <20110210104445.GH2842@redhat.com> (raw)
In-Reply-To: <AANLkTi=FiLMKULu_J_BhD0U8Q1RM3JPzei3BXtx6b=XB@mail.gmail.com>
On Thu, Feb 10, 2011 at 07:23:33PM +0900, Yoshiaki Tamura wrote:
> 2011/2/10 Daniel P. Berrange <berrange@redhat.com>:
> > On Thu, Feb 10, 2011 at 10:54:01AM +0100, Anthony Liguori wrote:
> >> On 02/10/2011 10:30 AM, Yoshiaki Tamura wrote:
> >> >Currently FdMigrationState doesn't support read(), and this patch
> >> >introduces it to get response from the other side.
> >> >
> >> >Signed-off-by: Yoshiaki Tamura<tamura.yoshiaki@lab.ntt.co.jp>
> >>
> >> Migration is unidirectional. Changing this is fundamental and not
> >> something to be done lightly.
> >
> > Making it bi-directional might break libvirt's save/restore
> > to file support which uses migration, passing a unidirectional
> > FD for the file. It could also break libvirt's secure tunnelled
> > migration support which is currently only expecting to have
> > data sent in one direction on the socket.
>
> Hi Daniel,
>
> IIUC, this patch isn't something to make existing live migration
> bi-directional. Just opens up a way for Kemari to use it. Do
> you think it's dangerous for libvirt still?
The key is for it to be a no-op for any usage of the existing
'migrate' command. I had thought this was wiring up read into
the event loop too, so it would be poll()ing for reads, but
after re-reading I see this isn't the case here.
Regards,
Daniel
--
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|: http://libvirt.org -o- http://virt-manager.org :|
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next prev parent reply other threads:[~2011-02-10 10:45 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-10 9:30 [PATCH 00/18] Kemari for KVM v0.2.10 Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 01/18] Make QEMUFile buf expandable, and introduce qemu_realloc_buffer() and qemu_clear_buffer() Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 02/18] Introduce read() to FdMigrationState Yoshiaki Tamura
2011-02-10 9:54 ` [Qemu-devel] " Anthony Liguori
2011-02-10 10:00 ` Yoshiaki Tamura
2011-02-10 10:18 ` Daniel P. Berrange
2011-02-10 10:23 ` Yoshiaki Tamura
2011-02-10 10:44 ` Daniel P. Berrange [this message]
2011-02-10 10:51 ` Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 03/18] Introduce skip_header parameter to qemu_loadvm_state() Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 04/18] qemu-char: export socket_set_nodelay() Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 05/18] vl.c: add deleted flag for deleting the handler Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 06/18] virtio: decrement last_avail_idx with inuse before saving Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 07/18] Introduce fault tolerant VM transaction QEMUFile and ft_mode Yoshiaki Tamura
2011-02-21 4:46 ` ya su
2011-02-21 9:42 ` [Qemu-devel] " Yoshiaki Tamura
2011-02-23 2:28 ` ya su
2011-02-23 5:05 ` [Qemu-devel] " Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 08/18] savevm: introduce util functions to control ft_trans_file from savevm layer Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 09/18] Introduce event-tap Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 10/18] Call init handler of event-tap at main() in vl.c Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 11/18] ioport: insert event_tap_ioport() to ioport_write() Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 12/18] Insert event_tap_mmio() to cpu_physical_memory_rw() in exec.c Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 13/18] net: insert event-tap to qemu_send_packet() and qemu_sendv_packet_async() Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 14/18] block: insert event-tap to bdrv_aio_writev(), bdrv_aio_flush() and bdrv_flush() Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 15/18] savevm: introduce qemu_savevm_trans_{begin,commit} Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 16/18] migration: introduce migrate_ft_trans_{put,get}_ready(), and modify migrate_fd_put_ready() when ft_mode is on Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 17/18] migration-tcp: modify tcp_accept_incoming_migration() to handle ft_mode, and add a hack not to close fd when ft_mode is enabled Yoshiaki Tamura
2011-02-10 9:30 ` [PATCH 18/18] Introduce "kemari:" to enable FT migration mode (Kemari) Yoshiaki Tamura
2011-02-10 9:52 ` Paolo Bonzini
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