bandwidth_limit is double set in migrate_init(), remove one.
Signed-off-by: NLei Li <lilei@linux.vnet.ibm.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

This reverts commit 7161082c.

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: NMichael Roth <mdroth@linux.vnet.ibm.com>
Message-id: 1368739544-31021-1-git-send-email-mdroth@linux.vnet.ibm.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

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: NEric Blake <eblake@redhat.com>
Message-id: 1366149041-626-1-git-send-email-eblake@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

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: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

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: NPeter Lieven <pl@kamp.de>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

The indirection is useless now.  Backends can open s->file directly.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

With this patch, the migration_file is not needed anymore.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Prepare for when s->bytes_xfer will be removed.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Second, drop the file descriptor indirection, and write directly to the
QEMUFile.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

migration_put_buffer is never called if there has been an error.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

We will go around the loop exactly once after setting last_round.
Eliminate the variable altogether.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

This is consistent once that we have moved everything to migration.c
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Only the migration_bitmap_sync() call needs the iothread lock.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Signed-off-by: NKazuya Saito <saito.kazuya@jp.fujitsu.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Including data that resided in the QEMUFile's own buffer.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

The next patch will add more cases where qemu_savevm_state_cancel
needs to be called; prepare for that already, the function can be
called twice with no ill effect.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

vm_stop_force_state does:

    if (runstate_is_running()) {
        vm_stop(state);
    } else {
        runstate_set(state);
    }

migration.c does:

    if (runstate_is_running()) {
        vm_stop(state);
    } else {
        vm_stop_force_state(state);
    }

The code run is the same even if we always use vm_stop_force_state in
migration.c.
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Unify the goto around the loop, with the exit condition at the end of it.
Both can be expressed as "while (ret >= 0)".
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

We removed the calculation in commit e4ed1541

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: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>

While we are sleeping we are not sending, so we should not use that
time to estimate our bandwidth.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>

0 is a very bad initial value, what we are trying to get is
max_downtime, so that is a much better estimation.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NOrit Wasserman <owasserm@redhat.com>

The incoming migration is processed in a coroutine and uses an fd read
handler to enter the yielded coroutine when data becomes available.

The read handler was set too broadly, so that spurious coroutine entries
were be triggered if other coroutine users yielded (like the block
layer's bdrv_write() function).

Install the fd read only only when yielding for more data to become
available.  This prevents spurious coroutine entries which break code
that assumes only a specific set of places can re-enter the coroutine.

This patch fixes crashes in block/raw-posix.c that are triggered with
"migrate -b" when qiov becomes a dangling pointer due to a spurious
coroutine entry that frees qiov early.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1360598505-5512-1-git-send-email-stefanha@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Commit 6daf194d and be62a2eb got rid of a bunch, but they keep coming
back.  Tracked down with this Coccinelle semantic patch:

    @r@
	expression err, eno, cls, fmt;
	position p;
    @@
    (
	error_report(fmt, ...)@p
    |
	error_set(err, cls, fmt, ...)@p
    |
	error_set_errno(err, eno, cls, fmt, ...)@p
    |
	error_setg(err, fmt, ...)@p
    |
	error_setg_errno(err, eno, fmt, ...)@p
    )
    @script:python@
	fmt << r.fmt;
	p << r.p;
    @@
    if "\\n" in str(fmt):
	print "%s:%s:%s:%s" % (p[0].file, p[0].line, p[0].column, fmt)
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-id: 1360354939-10994-4-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NReviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>

Signed-off-by: NOrit Wasserman <owasserm@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NReviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>

This will allow us finer control in next patches.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NReviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>