From: "Li, Liang Z" <liang.z.li@intel.com>
To: "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: "aarcange@redhat.com" <aarcange@redhat.com>,
"yamahata@private.email.ne.jp" <yamahata@private.email.ne.jp>,
"quintela@redhat.com" <quintela@redhat.com>,
"luis@cs.umu.se" <luis@cs.umu.se>,
"amit.shah@redhat.com" <amit.shah@redhat.com>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"david@gibson.dropbear.id.au" <david@gibson.dropbear.id.au>
Subject: Re: [Qemu-devel] [PATCH v7 01/42] Start documenting how postcopy works.
Date: Thu, 18 Jun 2015 07:50:42 +0000 [thread overview]
Message-ID: <F2CBF3009FA73547804AE4C663CAB28E55056F@shsmsx102.ccr.corp.intel.com> (raw)
In-Reply-To: <1434450415-11339-2-git-send-email-dgilbert@redhat.com>
> diff --git a/docs/migration.txt b/docs/migration.txt index f6df4be..b4b93d1
> 100644
> --- a/docs/migration.txt
> +++ b/docs/migration.txt
> @@ -291,3 +291,170 @@ save/send this state when we are in the middle of a
> pio operation (that is what ide_drive_pio_state_needed() checks). If
> DRQ_STAT is not enabled, the values on that fields are garbage and don't
> need to be sent.
> +
> += Return path =
> +
> +In most migration scenarios there is only a single data path that runs
> +from the source VM to the destination, typically along a single fd
> +(although possibly with another fd or similar for some fast way of throwing
> pages across).
> +
> +However, some uses need two way communication; in particular the
> +Postcopy destination needs to be able to request pages on demand from
> the source.
> +
> +For these scenarios there is a 'return path' from the destination to
> +the source;
> +qemu_file_get_return_path(QEMUFile* fwdpath) gives the QEMUFile* for
> +the return path.
> +
> + Source side
> + Forward path - written by migration thread
> + Return path - opened by main thread, read by return-path thread
> +
> + Destination side
> + Forward path - read by main thread
> + Return path - opened by main thread, written by main thread AND
> postcopy
> + thread (protected by rp_mutex)
> +
> += Postcopy =
> +'Postcopy' migration is a way to deal with migrations that refuse to
> +converge; its plus side is that there is an upper bound on the amount
> +of migration traffic and time it takes, the down side is that during
> +the postcopy phase, a failure of
> +*either* side or the network connection causes the guest to be lost.
Hi David,
Do you have any idea or plan to deal with the failure happened during the postcopy phase?
Lost the guest is too frightening for a cloud provider, we have a discussion with
Alibaba, they said that they can't use the postcopy feature unless there is a mechanism to
find the guest back.
Liang
next prev parent reply other threads:[~2015-06-18 7:50 UTC|newest]
Thread overview: 209+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-16 10:26 [Qemu-devel] [PATCH v7 00/42] Postcopy implementation Dr. David Alan Gilbert (git)
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 01/42] Start documenting how postcopy works Dr. David Alan Gilbert (git)
2015-06-17 11:42 ` Juan Quintela
2015-06-17 12:30 ` Dr. David Alan Gilbert
2015-06-18 7:50 ` Li, Liang Z [this message]
2015-06-18 8:10 ` Dr. David Alan Gilbert
2015-06-18 8:28 ` Paolo Bonzini
2015-06-19 17:52 ` Dr. David Alan Gilbert
2015-06-26 6:46 ` Yang Hongyang
2015-06-26 7:53 ` zhanghailiang
2015-06-26 8:00 ` Yang Hongyang
2015-06-26 8:10 ` Dr. David Alan Gilbert
2015-06-26 8:19 ` Yang Hongyang
2015-08-04 5:20 ` Amit Shah
2015-08-05 12:21 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 02/42] Provide runtime Target page information Dr. David Alan Gilbert (git)
2015-06-17 11:43 ` Juan Quintela
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 03/42] Init page sizes in qtest Dr. David Alan Gilbert (git)
2015-06-17 11:49 ` Juan Quintela
2015-07-06 6:14 ` Amit Shah
2015-08-04 5:23 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 04/42] qemu_ram_block_from_host Dr. David Alan Gilbert (git)
2015-06-17 11:54 ` Juan Quintela
2015-07-10 8:36 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 05/42] Add qemu_get_buffer_less_copy to avoid copies some of the time Dr. David Alan Gilbert (git)
2015-06-17 11:57 ` Juan Quintela
2015-06-17 12:33 ` Dr. David Alan Gilbert
2015-07-13 9:08 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 06/42] Add wrapper for setting blocking status on a QEMUFile Dr. David Alan Gilbert (git)
2015-06-17 11:59 ` Juan Quintela
2015-06-17 12:34 ` Dr. David Alan Gilbert
2015-06-17 12:57 ` Juan Quintela
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 07/42] ram_debug_dump_bitmap: Dump a migration bitmap as text Dr. David Alan Gilbert (git)
2015-06-17 12:17 ` Juan Quintela
2015-06-19 17:04 ` Dr. David Alan Gilbert
2015-07-13 10:15 ` Juan Quintela
2015-07-13 9:12 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 08/42] migrate_init: Call from savevm Dr. David Alan Gilbert (git)
2015-06-17 12:18 ` Juan Quintela
2015-07-13 9:13 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 09/42] Rename save_live_complete to save_live_complete_precopy Dr. David Alan Gilbert (git)
2015-06-17 12:20 ` Juan Quintela
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 10/42] Return path: Open a return path on QEMUFile for sockets Dr. David Alan Gilbert (git)
2015-06-17 12:23 ` Juan Quintela
2015-06-17 17:07 ` Dr. David Alan Gilbert
2015-07-13 10:12 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 11/42] Return path: socket_writev_buffer: Block even on non-blocking fd's Dr. David Alan Gilbert (git)
2015-06-17 12:28 ` Juan Quintela
2015-06-19 17:18 ` Dr. David Alan Gilbert
2015-07-13 12:37 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 12/42] Migration commands Dr. David Alan Gilbert (git)
2015-06-17 12:31 ` Juan Quintela
2015-06-19 17:38 ` Dr. David Alan Gilbert
2015-07-13 12:45 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 13/42] Return path: Control commands Dr. David Alan Gilbert (git)
2015-06-17 12:49 ` Juan Quintela
2015-06-23 18:57 ` Dr. David Alan Gilbert
2015-07-13 12:55 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 14/42] Return path: Send responses from destination to source Dr. David Alan Gilbert (git)
2015-06-17 16:30 ` Juan Quintela
2015-06-19 18:42 ` Dr. David Alan Gilbert
2015-07-01 9:29 ` Juan Quintela
2015-08-06 12:18 ` Dr. David Alan Gilbert
2015-07-15 7:31 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 15/42] Return path: Source handling of return path Dr. David Alan Gilbert (git)
2015-07-13 10:29 ` Juan Quintela
2015-08-18 10:23 ` Dr. David Alan Gilbert
2015-07-15 7:50 ` Amit Shah
2015-07-16 11:32 ` Dr. David Alan Gilbert
2015-08-05 8:06 ` zhanghailiang
2015-08-18 10:45 ` Dr. David Alan Gilbert
2015-08-18 11:29 ` zhanghailiang
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 16/42] Rework loadvm path for subloops Dr. David Alan Gilbert (git)
2015-07-13 10:33 ` Juan Quintela
2015-07-15 9:34 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 17/42] Add migration-capability boolean for postcopy-ram Dr. David Alan Gilbert (git)
2015-06-16 15:43 ` Eric Blake
2015-06-16 15:58 ` Dr. David Alan Gilbert
2015-07-15 9:39 ` Amit Shah
2015-07-13 10:35 ` Juan Quintela
2015-07-15 9:40 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 18/42] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages Dr. David Alan Gilbert (git)
2015-07-13 11:02 ` Juan Quintela
2015-07-20 10:13 ` Amit Shah
2015-08-26 14:48 ` Dr. David Alan Gilbert
2015-07-20 10:06 ` Amit Shah
2015-07-27 9:55 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 19/42] MIG_CMD_PACKAGED: Send a packaged chunk of migration stream Dr. David Alan Gilbert (git)
2015-07-13 11:07 ` Juan Quintela
2015-07-21 6:11 ` Amit Shah
2015-07-27 17:28 ` Dr. David Alan Gilbert
2015-08-04 5:27 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 20/42] Modify save_live_pending for postcopy Dr. David Alan Gilbert (git)
2015-07-13 11:12 ` Juan Quintela
2015-07-31 16:13 ` Dr. David Alan Gilbert
2015-07-21 6:17 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 21/42] postcopy: OS support test Dr. David Alan Gilbert (git)
2015-07-13 11:20 ` Juan Quintela
2015-07-13 16:31 ` Dr. David Alan Gilbert
2015-07-21 7:29 ` Amit Shah
2015-07-27 17:38 ` Dr. David Alan Gilbert
2015-08-04 5:28 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 22/42] migrate_start_postcopy: Command to trigger transition to postcopy Dr. David Alan Gilbert (git)
2015-07-13 11:23 ` Juan Quintela
2015-07-13 17:13 ` Dr. David Alan Gilbert
2015-07-13 18:07 ` Juan Quintela
2015-07-21 7:40 ` Amit Shah
2015-09-24 9:59 ` Dr. David Alan Gilbert
2015-09-24 14:20 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 23/42] MIGRATION_STATUS_POSTCOPY_ACTIVE: Add new migration state Dr. David Alan Gilbert (git)
2015-07-13 11:27 ` Juan Quintela
2015-07-13 15:53 ` Dr. David Alan Gilbert
2015-07-13 16:26 ` Juan Quintela
2015-07-13 16:48 ` Dr. David Alan Gilbert
2015-07-13 18:05 ` Juan Quintela
2015-07-21 10:33 ` Amit Shah
2015-09-23 17:04 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 24/42] Add qemu_savevm_state_complete_postcopy Dr. David Alan Gilbert (git)
2015-07-13 11:35 ` Juan Quintela
2015-07-13 15:33 ` Dr. David Alan Gilbert
2015-07-21 10:42 ` Amit Shah
2015-07-27 17:58 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 25/42] Postcopy: Maintain sentmap and calculate discard Dr. David Alan Gilbert (git)
2015-07-13 11:47 ` Juan Quintela
2015-09-15 17:01 ` Dr. David Alan Gilbert
2015-07-21 11:36 ` Amit Shah
2015-07-31 16:51 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 26/42] postcopy: Incoming initialisation Dr. David Alan Gilbert (git)
2015-07-13 12:04 ` Juan Quintela
2015-09-23 19:06 ` Dr. David Alan Gilbert
2015-07-22 6:19 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 27/42] postcopy: ram_enable_notify to switch on userfault Dr. David Alan Gilbert (git)
2015-07-13 12:10 ` Juan Quintela
2015-07-13 17:36 ` Dr. David Alan Gilbert
2015-07-23 5:22 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 28/42] Postcopy: Postcopy startup in migration thread Dr. David Alan Gilbert (git)
2015-07-13 12:56 ` Juan Quintela
2015-07-13 17:56 ` Dr. David Alan Gilbert
2015-07-13 18:09 ` Juan Quintela
2015-09-23 17:56 ` Dr. David Alan Gilbert
2015-07-23 5:53 ` Amit Shah
2015-07-23 5:55 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 29/42] Postcopy end in migration_thread Dr. David Alan Gilbert (git)
2015-07-13 13:15 ` Juan Quintela
2015-07-23 6:41 ` Amit Shah
2015-08-04 11:31 ` Dr. David Alan Gilbert
2015-07-23 6:41 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 30/42] Page request: Add MIG_RP_MSG_REQ_PAGES reverse command Dr. David Alan Gilbert (git)
2015-07-13 13:24 ` Juan Quintela
2015-08-06 14:15 ` Dr. David Alan Gilbert
2015-07-23 6:50 ` Amit Shah
2015-08-06 14:21 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 31/42] Page request: Process incoming page request Dr. David Alan Gilbert (git)
2015-07-14 9:18 ` Juan Quintela
2015-08-06 10:45 ` Dr. David Alan Gilbert
2015-10-20 10:29 ` Juan Quintela
2015-07-23 12:23 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 32/42] Page request: Consume pages off the post-copy queue Dr. David Alan Gilbert (git)
2015-07-14 9:40 ` Juan Quintela
2015-09-16 18:36 ` Dr. David Alan Gilbert
2015-07-27 6:05 ` Amit Shah
2015-09-16 18:48 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 33/42] postcopy_ram.c: place_page and helpers Dr. David Alan Gilbert (git)
2015-07-14 10:05 ` Juan Quintela
2015-07-27 6:11 ` Amit Shah
2015-09-23 16:45 ` Dr. David Alan Gilbert
2015-07-27 6:11 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 34/42] Postcopy: Use helpers to map pages during migration Dr. David Alan Gilbert (git)
2015-07-14 12:34 ` Juan Quintela
2015-07-17 17:31 ` Dr. David Alan Gilbert
2015-07-27 7:39 ` Amit Shah
2015-08-06 11:22 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 35/42] Don't sync dirty bitmaps in postcopy Dr. David Alan Gilbert (git)
2015-07-14 12:36 ` Juan Quintela
2015-07-14 13:13 ` Dr. David Alan Gilbert
2015-07-27 7:43 ` Amit Shah
2015-07-31 9:50 ` Dr. David Alan Gilbert
2015-08-04 5:46 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 36/42] Host page!=target page: Cleanup bitmaps Dr. David Alan Gilbert (git)
2015-07-14 15:01 ` Juan Quintela
2015-07-31 15:53 ` Dr. David Alan Gilbert
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 37/42] Postcopy; Handle userfault requests Dr. David Alan Gilbert (git)
2015-07-14 15:10 ` Juan Quintela
2015-07-14 15:15 ` Dr. David Alan Gilbert
2015-07-14 15:25 ` Juan Quintela
2015-07-27 14:29 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 38/42] Start up a postcopy/listener thread ready for incoming page data Dr. David Alan Gilbert (git)
2015-07-14 15:12 ` Juan Quintela
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 39/42] postcopy: Wire up loadvm_postcopy_handle_ commands Dr. David Alan Gilbert (git)
2015-07-14 15:14 ` Juan Quintela
2015-07-28 5:53 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 40/42] End of migration for postcopy Dr. David Alan Gilbert (git)
2015-07-14 15:15 ` Juan Quintela
2015-07-28 5:55 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 41/42] Disable mlock around incoming postcopy Dr. David Alan Gilbert (git)
2015-07-14 15:22 ` Juan Quintela
2015-07-28 6:02 ` Amit Shah
2015-07-28 11:32 ` Juan Quintela
2015-08-06 14:55 ` Dr. David Alan Gilbert
2015-08-07 3:05 ` zhanghailiang
2015-09-24 10:36 ` Dr. David Alan Gilbert
2015-07-28 6:02 ` Amit Shah
2015-06-16 10:26 ` [Qemu-devel] [PATCH v7 42/42] Inhibit ballooning during postcopy Dr. David Alan Gilbert (git)
2015-07-14 15:24 ` Juan Quintela
2015-07-28 6:15 ` Amit Shah
2015-07-28 9:08 ` Dr. David Alan Gilbert
2015-07-28 10:01 ` Amit Shah
2015-07-28 11:16 ` Dr. David Alan Gilbert
2015-07-28 6:21 ` [Qemu-devel] [PATCH v7 00/42] Postcopy implementation Amit Shah
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