Commit Graph

81 Commits

Author SHA1 Message Date
Peter Lieven
ee0b44aa9d page_cache: dup memory on insert
The page cache frees all data on finish, on resize and
if there is collision on insert. So it should be the caches
responsibility to dup the data that is stored in the cache.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
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
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
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
0cc3f3ccc9 qemu-file: add writable socket 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
817b9ed5eb migration: merge qemu_popen_cmd with qemu_popen
There is no reason for outgoing exec migration to do popen manually
anymore (the reason used to be that we needed the FILE* to make it
non-blocking).  Use qemu_popen_cmd.

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
05f28b837c qemu-file: make qemu_fflush and qemu_file_set_error private again
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
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
8c8de19d93 migration: reorder SaveVMHandlers members
This groups together the callbacks that later will have similar
locking rules.

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
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
4eb938102b qemu-file: temporarily expose qemu_file_set_error and qemu_fflush
Right now, migration cannot entirely rely on QEMUFile's automatic
drop of I/O after an error, because it does its "real" I/O outside
the put_buffer callback.  To fix this until buffering is gone, expose
qemu_file_set_error which we will use in buffered_flush.

Similarly, buffered_flush is not a complete flush because some data may
still reside in the QEMUFile's own buffer.  This somewhat complicates the
process of closing the migration thread.  Again, when buffering is gone
buffered_flush will disappear and calling qemu_fflush will not be needed;
in the meanwhile, we expose the function for use in migration.c.

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
fd7f0d6617 hw: move fifo.[ch] to libqemuutil
fifo.c is generic code that can be easily unit tested.  So it
belongs in libqemuutil.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-03-01 13:53:10 +01:00
Juan Quintela
90f8ae724a migration: calculate expected_downtime
We removed the calculation in commit e4ed1541ac

Now we add it back.  We need to create dirty_bytes_rate because we
can't include cpu-all.h from migration.c, and there is no other way to
include TARGET_PAGE_SIZE.

Signed-off-by: Juan Quintela <quintela@redhat.com>


Reviewed-by: Orit Wasserman <owasserm@redhat.com>
2013-02-22 10:12:52 +01:00
Stefan Hajnoczi
ad55ab42d4 migration: make qemu_ftell() public and support writable files
Migration .save_live_iterate() functions return the number of bytes
transferred.  The easiest way of doing this is by calling qemu_ftell(f)
at the beginning and end of the function to calculate the difference.

Make qemu_ftell() public so that block-migration will be able to use it.
Also adjust the ftell calculation for writable files where buf_offset
does not include buf_size.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-id: 1360661835-28663-2-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-12 16:26:44 -06:00
Juan Quintela
76f5933aea migration: move beginning stage to the migration thread
Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2013-01-17 13:54:18 +01:00
Paolo Bonzini
b9c961a8ff migration: make function static
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Reviewed-by: Eric Blake <eblake@redhat.com>
2013-01-17 13:54:16 +01:00
Juan Quintela
9848a40427 migration: merge QEMUFileBuffered into MigrationState
Avoid splitting the state of outgoing migration, more or less arbitrarily,
between two data structures.  QEMUFileBuffered anyway is used only during
migration.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2012-12-20 23:09:40 +01:00
Juan Quintela
2e45086533 migration: Inline qemu_fopen_ops_buffered into migrate_fd_connect
Signed-off-by: Juan Quintela <quintela@redhat.com>
2012-12-20 23:09:39 +01:00
Juan Quintela
0e288fa369 migration: move migration_fd_put_ready()
Put it near its use and un-export it.

Signed-off-by: Juan Quintela <quintela@redhat.com>
2012-12-20 23:09:39 +01:00
Juan Quintela
0d82d0e8b9 migration: move buffered_file.c code into migration.c
This only moves the code (also from buffered_file.h to migration.h).
Fix whitespace until checkpatch is happy.

Signed-off-by: Juan Quintela <quintela@redhat.com>
2012-12-20 23:09:36 +01:00
Juan Quintela
e4ed1541ac savevm: New save live migration method: pending
Code just now does (simplified for clarity)

    if (qemu_savevm_state_iterate(s->file) == 1) {
       vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
       qemu_savevm_state_complete(s->file);
    }

Problem here is that qemu_savevm_state_iterate() returns 1 when it
knows that remaining memory to sent takes less than max downtime.

But this means that we could end spending 2x max_downtime, one
downtime in qemu_savevm_iterate, and the other in
qemu_savevm_state_complete.

Changed code to:

    pending_size = qemu_savevm_state_pending(s->file, max_size);
    DPRINTF("pending size %lu max %lu\n", pending_size, max_size);
    if (pending_size >= max_size) {
        ret = qemu_savevm_state_iterate(s->file);
     } else {
        vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
        qemu_savevm_state_complete(s->file);
     }

So what we do is: at current network speed, we calculate the maximum
number of bytes we can sent: max_size.

Then we ask every save_live section how much they have pending.  If
they are less than max_size, we move to complete phase, otherwise we
do an iterate one.

This makes things much simpler, because now individual sections don't
have to caluclate the bandwidth (it was implossible to do right from
there).

Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-20 23:09:25 +01:00
Juan Quintela
188a428559 migration: remove unfreeze logic
Now that we have a thread, and blocking writes, we don't need it.

Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-20 23:09:25 +01:00
Juan Quintela
dd217b8732 migration: make writes blocking
Move all the writes to the migration_thread, and make writings
blocking.  Notice that are still using the iothread for everything
that we do.

Signed-off-by: Juan Quintela <quintela@redhat.com>
2012-12-20 23:09:25 +01:00
Juan Quintela
766bd1769e migration: move migration thread init code to migrate_fd_put_ready
This way everything related with migration is run on the migration
thread and no locking is needed.

Signed-off-by: Juan Quintela <quintela@redhat.com>
2012-12-20 23:09:25 +01:00
Juan Quintela
edfa1af52f migration: make qemu_fopen_ops_buffered() return void
We want the file assignment to happen before the thread is created to
avoid locking, so we just do it before creating the thread.

Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
2012-12-20 23:09:25 +01:00
Paolo Bonzini
1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini
caf71f86a3 migration: move include files to include/migration/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:32 +01:00