Commit Graph

229 Commits

Author SHA1 Message Date
Matthew Garrett
40596834c0 migration: Fix rate limit
The migration thread appears to want to allow writeout to occur at full
speed rather than being rate limited during completion of state saving,
but sets the limit to INT_MAX when xfer_limit is INT64_MAX. This causes
problems if there's more than 2GB of state left to save at this point. It
probably ought to just be INT64_MAX instead.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2014-01-13 12:39:48 +01:00
Zhanghaoyu (A)
51cf4c1a99 introduce MIG_STATE_CANCELLING state
Introduce MIG_STATE_CANCELLING state to avoid starting a new migration task while the previous one still exist.

Signed-off-by: Zeng Junliang <zengjunliang@huawei.com>
Signed-off-by: Zhang Haoyu <haoyu.zhang@huawei.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2014-01-13 12:39:48 +01:00
Zhanghaoyu (A)
6f2b811a61 avoid a bogus COMPLETED->CANCELLED transition
Avoid a bogus COMPLETED->CANCELLED transition.
There is a period of time from the timing of setting COMPLETED state to that of migration thread exits, so during which it's problematic in COMPLETED->CANCELLED transition.

Signed-off-by: Zeng Junliang <zengjunliang@huawei.com>
Signed-off-by: Zhang Haoyu <haoyu.zhang@huawei.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2014-01-13 12:39:48 +01:00
Michael Tokarev
387eedebf6 migration: Fix compiler warning ('caps' may be used uninitialized)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
2013-10-05 14:02:29 +04:00
Christoffer Dall
5016e2df56 migration: Fix debug print type
The printf args are uint64_t and with -Werr QEMU doesn't compile with
migration debugging turned on unless this is fixed.  Fix it.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-09-24 13:22:50 +02:00
Alex Bligh
bc72ad6754 aio / timers: Switch entire codebase to the new timer API
This is an autogenerated patch using scripts/switch-timer-api.

Switch the entire code base to using the new timer API.

Note this patch may introduce some line length issues.

Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22 19:14:24 +02:00
Alex Bligh
6a1751b7aa aio / timers: Untangle include files
include/qemu/timer.h has no need to include main-loop.h and
doing so causes an issue for the next patch. Unfortunately
various files assume including timers.h will pull in main-loop.h.
Untangle this mess.

Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22 19:10:27 +02:00
Pawit Pornkitprasan
8c0426aed1 migration: don't use uninitialized variables
The qmp_migrate method uses the 'blk' and 'inc' parameter without
checking if they're valid or not (they may be uninitialized if
command is received via QMP)

Signed-off-by: Pawit Pornkitprasan <p.pawit@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-08-01 09:40:46 -04:00
Pawit Pornkitprasan
00c14997cb migration: send total time in QMP at "completed" stage
The "completed" stage sets total_time but not has_total_time and
thus it is not sent via QMP reply (but sent via HMP nevertheless)

Signed-off-by: Pawit Pornkitprasan <p.pawit@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-08-01 09:40:46 -04:00
Stefan Hajnoczi
02edd2e766 migration: fix spice migration
Commit 29ae8a4133 ("rdma: introduce
MIG_STATE_NONE and change MIG_STATE_SETUP state transition") changed the
state transitions during migration setup.

Spice used to be notified with MIG_STATE_ACTIVE and it detected this
using migration_is_active().  Spice is now notified with
MIG_STATE_SETUP and migration_is_active() no longer works.

Replace migration_is_active() with migration_in_setup() to fix spice
migration.

Cc: Michael R. Hines <mrhines@us.ibm.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-29 17:19:02 +02:00
Stefan Hajnoczi
9287ac271d migration: notify migration state before starting thread
The migration thread runs outside the QEMU global mutex when possible.
Therefore we must notify migration state change *before* starting the
migration thread.

This allows registered listeners to act before live migration iterations
begin.  Therefore they can get into a state that allows for live
migration.  When the migration thread starts everything will be ready.

Without this patch there is a race condition during migration setup,
depending on whether the migration thread has already transitioned from
SETUP to ACTIVE state.

Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-29 17:18:54 +02:00
Michael R. Hines
ed4fbd1082 rdma: account for the time spent in MIG_STATE_SETUP through QMP
Using the previous patches, we're now able to timestamp the SETUP
state. Once we have this time, let the user know about it in the
schema.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-07-23 13:06:37 +02:00
Michael R. Hines
29ae8a4133 rdma: introduce MIG_STATE_NONE and change MIG_STATE_SETUP state transition
As described in the previous patch, until now, the MIG_STATE_SETUP
state was not really a 'formal' state. It has been used as a 'zero' state
(what we're calling 'NONE' here) and QEMU has been unconditionally transitioning
into this state when the QMP migration command was called. Instead we want to
introduce MIG_STATE_NONE, which is our starting state in the state machine, and
then immediately transition into the MIG_STATE_SETUP state when the QMP migrate
command is issued.

In order to do this, we must delay the transition into MIG_STATE_ACTIVE until
later in the migration_thread(). This is done to be able to timestamp the amount of
time spent in the SETUP state for proper accounting to the user during
an RDMA migration.

Furthermore, the management software, until now, has never been aware of the
existence of the SETUP state whatsoever. This must change, because, timing of this
state implies that the state actually exists.

These two patches cannot be separated because the 'query_migrate' QMP
switch statement needs to know how to handle this new state transition.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Tested-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-07-23 13:06:37 +02:00
Michael R. Hines
d58f574bf3 rdma: allow state transitions between other states besides ACTIVE
This patch is in preparation for the next ones: Until now the MIG_STATE_SETUP
state was not really a 'formal' state. It has been used as a 'zero' state
and QEMU has been unconditionally transitioning into this state when
the QMP migrate command was called. In preparation for timing this state,
we have to make this state a a 'real' state which actually gets transitioned
from later in the migration_thread() from SETUP => ACTIVE, rather than just
automatically dropping into this state at the beginninig of the migration.

This means that the state transition function (migration_finish_set_state())
needs to be capable of transitioning from valid states _other_ than just
MIG_STATE_ACTIVE.

The function is in fact already capable of doing that, but was not allowing the
old state to be a parameter specified as an input.

This patch fixes that and only makes the transition if the current state
matches the old state that the caller intended to transition from.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Tested-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-07-23 13:06:28 +02:00
Michael R. Hines
2da776db48 rdma: core logic
Code that does need to be visible is kept
well contained inside this file and this is the only
new additional file to the entire patch.

This file includes the entire protocol and interfaces
required to perform RDMA migration.

Also, the configure and Makefile modifications to link
this file are included.

Full documentation is in docs/rdma.txt

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-07-23 11:12:00 +02:00
Peter Lieven
323004a39d block-migration: efficiently encode zero blocks
this patch adds a efficient encoding for zero blocks by
adding a new flag indicating a block is completely zero.

additionally bdrv_write_zeros() is used at the destination
to efficiently write these zeroes. depending on the implementation
this avoids that the destination target gets fully provisioned.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-19 12:29:21 +08:00
Anthony Liguori
6453a3a694 Merge remote-tracking branch 'quintela/migration.next' into staging
# By Chegu Vinod
# Via Juan Quintela
* quintela/migration.next:
  Force auto-convegence of live migration
  Add 'auto-converge' migration capability
  Introduce async_run_on_cpu()

Message-id: 1373664508-5404-1-git-send-email-quintela@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-15 14:49:16 -05:00
Kevin Wolf
0e1146a7a0 migration: Fail migration on bdrv_flush_all() error
If bdrv_flush_all() returns an error, there is an inconsistency in the
view of an image file between the source and the destination host.
Completing the migration would lead to corruption. Better abort
migration in this case.

To reproduce this case, try the following (ensures that there is
something to flush, and then fails that flush):

$ qemu-img create -f qcow2 test.qcow2 1G
$ cat blkdebug.cfg
[inject-error]
event = "flush_to_os"
errno = "5"
$ qemu-system-x86_64 -hda blkdebug:blkdebug.cfg:test.qcow2 -monitor stdio
(qemu) qemu-io ide0-hd0 "write 0 4k"
(qemu) migrate ...

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-15 09:51:40 +02:00
Chegu Vinod
bde1e2ec21 Add 'auto-converge' migration capability
The auto-converge migration capability allows the user to specify if they
choose live migration seqeunce to automatically detect and force convergence.

Signed-off-by: Chegu Vinod <chegu_vinod@hp.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-07-12 20:34:58 +02:00
Paolo Bonzini
5444e768ee add a header file for atomic operations
We're already using them in several places, but __sync builtins are just
too ugly to type, and do not provide seqcst load/store operations.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-07-04 17:42:49 +02:00
Michael R. Hines
60d9222c8f rdma: introduce capability x-rdma-pin-all
This capability allows you to disable dynamic chunk registration
for better throughput on high-performance links.

For example, using an 8GB RAM virtual machine with all 8GB of memory in
active use and the VM itself is completely idle using a 40 gbps infiniband link:

1. x-rdma-pin-all disabled total time: approximately 7.5 seconds @ 9.5 Gbps
2. x-rdma-pin-all enabled total time: approximately 4 seconds @ 26 Gbps

These numbers would of course scale up to whatever size virtual machine
you have to migrate using RDMA.

Enabling this feature does *not* have any measurable affect on
migration *downtime*. This is because, without this feature, all of the
memory will have already been registered already in advance during
the bulk round and does not need to be re-registered during the successive
iteration rounds.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-06-27 02:38:36 +02:00
Michael R. Hines
7e114f8cf2 rdma: export throughput w/ MigrationStats QMP
This exposes throughput (in megabits/sec) through QMP.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-06-27 02:38:36 +02:00
Lei Li
12cd30e9c0 migration: Remove duplicate bandwidth_limit set
bandwidth_limit is double set in migrate_init(), remove one.

Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-01 14:25:38 +04:00
Michael Roth
77417f1070 Revert "migration: don't account sleep time for calculating bandwidth"
This reverts commit 7161082c8d.

Reverting this patch fixes a divide-by-zero error in qemu that can be
fairly reliably triggered by doing block migration. In this case, the
configuration/error was:

source: temp/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -L temp-bios
-M pc-i440fx-1.4 -m 512M -kernel boot/vmlinuz-x86_64 -initrd
boot/test-initramfs-x86_64.img.gz -vga std -append seed=1234 -drive
file=disk1.img,if=virtio -drive file=disk2.img,if=virtio -device
virtio-net-pci,netdev=net0 -netdev user,id=net0 -monitor
unix:/tmp/vm-hmp.sock,server,nowait -qmp
unix:/tmp/vm-qmp.sock,server,nowait -vnc :100

16837 Floating point exception(core dumped)

target: temp/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -L temp-bios
-M pc-i440fx-1.4 -m 512M -kernel boot/vmlinuz-x86_64 -initrd
boot/test-initramfs-x86_64.img.gz -vga std -append seed=1234 -drive
file=target_disk1.img,if=virtio -drive file=target_disk2.img,if=virtio
-device virtio-net-pci,netdev=net0 -netdev user,id=net0 -incoming
unix:/tmp/migrate.sock -monitor
unix:/tmp/vm-hmp-incoming.sock,server,nowait -qmp
unix:/tmp/vm-qmp-incoming.sock,server,nowait -vnc :101

Receiving block device images
20 %
21 %
load of migration failed

This revert potentially re-introduces a bug that was present in 1.4,
but fixes a prevalent issue with block migration so we should revert
it for now and take an updated patch later.

Conflicts:

	migration.c

* fixed up to remove logic introduced in 7161082c while leaving
  changes in HEAD intact

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Message-id: 1368739544-31021-1-git-send-email-mdroth@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-17 09:58:57 -05:00
Eric Blake
4aead69241 migration: reflect incoming failure to shell
Management apps like libvirt don't know to pay attention to
stderr unless there is a non-zero exit status.

* migration.c (process_incoming_migration_co): Exit with non-zero
status on failure.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1366149041-626-1-git-send-email-eblake@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-17 10:24:24 -05:00
Stefan Hajnoczi
f9e8cacc55 oslib-posix: rename socket_set_nonblock() to qemu_set_nonblock()
The fcntl(fd, F_SETFL, O_NONBLOCK) flag is not specific to sockets.
Rename to qemu_set_nonblock() just like qemu_set_cloexec().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-04-02 11:47:37 -04:00
Peter Lieven
f1c72795af migration: do not sent zero pages in bulk stage
during bulk stage of ram migration if a page is a
zero page do not send it at all.
the memory at the destination reads as zero anyway.

even if there is an madvise with QEMU_MADV_DONTNEED
at the target upon receipt of a zero page I have observed
that the target starts swapping if the memory is overcommitted.
it seems that the pages are dropped asynchronously.

this patch also updates QMP to return the number of
skipped pages in MigrationStats.

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-26 13:32:33 +01:00
Paolo Bonzini
6f190a0641 migration: inline migrate_fd_close
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:03 +01:00
Paolo Bonzini
b352365f5a migration: eliminate s->migration_file
The indirection is useless now.  Backends can open s->file directly.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:03 +01:00
Paolo Bonzini
404a7c05bc migration: move contents of migration_close to migrate_fd_cleanup
With this patch, the migration_file is not needed anymore.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:03 +01:00
Paolo Bonzini
1964a39706 migration: move rate limiting to QEMUFile
Rate limiting is now simply a byte counter; client call
qemu_file_rate_limit() manually to determine if they have to exit.
So it is possible and simple to move the functionality to QEMUFile.

This makes the remaining functionality of s->file redundant;
in the next patch we can remove it and write directly to s->migration_file.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
442773cef1 migration: small changes around rate-limiting
This patch extracts a few small changes from the next patch, which
are unrelated to adding generic rate-limiting functionality to
QEMUFile.  Make migration_set_rate_limit a simple accessor, and
use qemu_file_set_rate_limit consistently.  Also fix a typo where
INT_MAX should have been SIZE_MAX.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
be7172e22a migration: use qemu_ftell to compute bandwidth
Prepare for when s->bytes_xfer will be removed.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
e6a1cf2132 migration: use QEMUFile for writing outgoing migration data
Second, drop the file descriptor indirection, and write directly to the
QEMUFile.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
f8bbc12863 migration: use QEMUFile for migration channel lifetime
As a start, use QEMUFile to store the destination and close it.
qemu_get_fd gets a file descriptor that will be used by the write
callbacks.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
a0ff044b8e migration: use qemu_file_rate_limit consistently
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
db2f25309a migration: remove useless qemu_file_get_error check
migration_put_buffer is never called if there has been an error.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
fd45ee2c64 migration: detect error before sleeping
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
059f896cef migration: eliminate last_round
We will go around the loop exactly once after setting last_round.
Eliminate the variable altogether.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Juan Quintela
5f496a1be3 Rename buffered_ to migration_
This is consistent once that we have moved everything to migration.c

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
edaae611f6 migration: yay, buffering is gone
Buffering was needed because blocking writes could take a long time
and starve other threads seeking to grab the big QEMU mutex.

Now that all writes (except within _complete callbacks) are done
outside the big QEMU mutex, we do not need buffering at all.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:02 +01:00
Paolo Bonzini
9b09503752 migration: run setup callbacks out of big lock
Only the migration_bitmap_sync() call needs the iothread lock.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00
Paolo Bonzini
32c835ba39 migration: run pending/iterate callbacks out of big lock
This makes it possible to do blocking writes directly to the socket,
with no buffer in the middle.  For RAM, only the migration_bitmap_sync()
call needs the iothread lock.  For block migration, it is needed by
the block layer (including bdrv_drain_all and dirty bitmap access),
but because some code is shared between iterate and complete, all of
mig_save_device_dirty is run with the lock taken.

In the savevm case, the iterate callback runs within the big lock.
This is annoying because it complicates the rules.  Luckily we do not
need to do anything about it: the RAM iterate callback does not need
the iothread lock, and block migration never runs during savevm.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00
Paolo Bonzini
bb1fadc444 migration: cleanup migration (including thread) in the iothread
Perform final cleanup in a bottom half, and add joining the thread to
the series of cleanup actions.

migrate_fd_error remains for connection error, but it doesn't need
to cleanup anything anymore.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00
Paolo Bonzini
f4410a5d99 migration: prepare to access s->state outside critical sections
Accessing s->state outside the big QEMU lock will simplify a bit the
locking/unlocking of the iothread lock.

We need to keep the lock in migrate_fd_error and migrate_fd_completed,
however, because they call migrate_fd_cleanup.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00
Kazuya Saito
c09e5bb1d8 migration: add migrate_set_state tracepoint
Signed-off-by: Kazuya Saito <saito.kazuya@jp.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00
Paolo Bonzini
a3fa1d78cb migration: do not nest flushing of device data
Completion of migration is currently done with a "nested" loop that
invokes buffered_flush: migrate_fd_completed is called by
buffered_file_thread, which calls migrate_fd_cleanup, which calls
buffered_close (via qemu_fclose), which flushes the buffer.

Simplify this, by reusing the buffered_flush call of buffered_file_thread.
Then if qemu_savevm_state_complete was called, and the buffer is empty
(including the QEMUFile buffer, for which we need the previous patch), we
are done.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00
Paolo Bonzini
dba433c03a migration: simplify error handling
Always use qemu_file_get_error to detect errors, since that is how
QEMUFile itself drops I/O after an error occurs.  There is no need
to propagate and check return values all the time.

Also remove the "complete" member, since we know that it is set (via
migrate_fd_cleanup) only when the state changes.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00
Paolo Bonzini
63dfbd7ee0 migration: use qemu_file_set_error
Remove the return value of buffered_flush, pass it via the error code
of s->file.  Once this is done, the error can be retrieved simply
via migrate_fd_close's call to qemu_fclose.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00
Paolo Bonzini
f5821518ed migration: flush all data to fd when buffered_flush is called
Including data that resided in the QEMUFile's own buffer.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:01 +01:00