The effect of this patch with current block migration is that its stage
2, ie. the first full walk-through of the block devices will be
performed completely before RAM migration starts. This ensures that
continuously changing RAM pages are not re-synchronized all the time
while block migration is not completed.

Future versions of block migration which will respect the specified
downtime will generate a different pattern: After RAM migration has
started as well, block migration may also continue to inject dirty
blocks into the RAM stream once it detects that the number of pending
blocks would extend the downtime unacceptably.

Note that all this relies on the current registration order: block
before RAM migration.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

No need to migrate emptiness (risking divide by zero later on).
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

4K is too small for efficiently saving and restoring multi-GB block
devices.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Inject progress report in percentage into the block live stream. This
can be read out and displayed easily on restore.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Report progress of an outgoing live migration to the monitor instead of
stdout.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

In order to allow proper progress reporting to the monitor that
initiated the migration, forward the monitor reference through the
migration layer down to SaveLiveStateHandler.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

So far progress reporting only works for the first block device. Fix
this by keeping an overall sum of sectors to be migratated, calculating
the sum of all processed sectors, and finally basing the progress
display on those values.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Introduce qemu_savevm_state_cancel and inject a stage -1 to cancel a
live migration. This gives the involved subsystems a chance to clean up
dynamically allocated resources. Namely, the block migration layer can
now free its device descriptors and pending blocks.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Besides catching real errors, this also allows to interrrupt the qemu
process during restore.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Based on the original patch by Pierre Riteau: Use a common blk_send
function to transmit a block.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Both functions share a lot of code, so make them one.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

We already save total_sectors in BlkMigDevState, let's use this value
during the migration and avoid to recalculate it needlessly.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

In case we restart a migration, submitted, read_done, transferred, and
print_completion need to be reinitialized to 0.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Based on the original patch by Pierre Riteau.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NPierre Riteau <Pierre.Riteau@irisa.fr>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

No need to push block_mig_state to the heap and, thus, establish an
indirection.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Move a potentially large buffer from stack to heap.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This switches the dirty bitmap to a true bitmap, reducing its footprint
(specifically in caches). It moreover fixes off-by-one bugs in
set_dirty_bitmap (nb_sectors+1 were marked) and bdrv_get_dirty (limit
check allowed one sector behind end of drive). And is drops redundant
dirty_tracking field from BlockDriverState.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Instead of duplicating the definition of constants or introducing
trivial retrieval functions move the SECTOR constants into the public
block API. This also obsoletes sector_per_block in BlkMigState.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

No functional changes.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

qemu_fclose frees the passed file structure, but do_migrate_set_speed
may access it later on. Fix it by setting file NULL in
migrate_fd_cleanup and checking for this.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Now vmstate_unregister have the right type
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

When the size that we want to transmit is in another field, but in an
unit different that bytes
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Support for buffer that are pointed by a pointer (i.e. not embedded)
where the size that we want to use is a field in the state.
We also need a new place to store where to start in the middle of the
buffer, as now it is a pointer, not the offset of the 1st field.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Seeking on vmstate save/load does not work if the underlying file is a
stream. We could try to make all QEMUFile* forward-seek-aware, but first
attempts in this direction indicated that it's saner to convert the few
qemu_fseek-on-vmstates users to plain reads/writes.

This fixes various subtle vmstate corruptions where unused fields were
involved.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The critical part of this change is how to deal with simultaneaous
generation of interrupts. The only (normal) case when this happens in
the emulation is near simultaneous reselection + selection. If selection
comes first, there is no problem, since the target attempting
reselection loses the arbitration (in the emulation it only means that
the reselect function will not be started). In the worst case the host
adapter is reselected, but the device driver already started a
selection, so we jump to the alternative address to handle the
situation.

The SCRIPTS code can trigger another interrupt to notify the driver that
the new task has to be postponed. I suppose that on real hardware there
is enough time after the reselection interrupt to set the SIP bit before
the next interrupt comes, so it would result in 2 stacked interrupts (a
SCSI and a DMA one). However, in the emulation there is no interrupt
stacking, so there is a good chance that the 2 interrupts will get to
the interrupt handler at the same time.

Nevertheless, it should not make a big difference in interrupt handling,
since in both cases both interrupts have to be fetched first, and after
that the new task (that failed during the selection phase) has to be
prepared/reset for a later restart, and the reconnected device has to be
serviced.

The changes do not modify the host adapter's behavior if this interrupt
is not enabled.

See also LSI53C895A technical manual, SCID and SIEN0.
Signed-off-by: NLaszlo Ast <laszlo.ast@siemens-enterprise.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

See SCRIPTS, 3.2.17 SELECT.
Signed-off-by: NLaszlo Ast <laszlo.ast@siemens-enterprise.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

See SCRIPTS Programming Guide, 3.2.17 SELECT.
Signed-off-by: NLaszlo Ast <laszlo.ast@siemens-enterprise.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>