For VMS_ARRAY typed vmsd fields, also dump the number of entries in the
array in -vmstate-dump.
Without such information, vmstate static checker can report false negatives
of incompatible vmsd on VMS_ARRAY typed fields, when the src/dst do not
have the same type of array defined. It's because in the checker we only
check against size of fields within a VMSD field.
One example: e1000e used to have a field defined as a boolean array with 5
entries, then removed it and replaced it with UNUSED (in 31e3f318c8):
- VMSTATE_BOOL_ARRAY(core.eitr_intr_pending, E1000EState,
- E1000E_MSIX_VEC_NUM),
+ VMSTATE_UNUSED(E1000E_MSIX_VEC_NUM),
It's a legal replacement but vmstate static checker is not happy with it,
because it checks only against the "size" field between the two
fields (here one is BOOL_ARRAY, the other is UNUSED):
For BOOL_ARRAY:
{
"field": "core.eitr_intr_pending",
"version_id": 0,
"field_exists": false,
"size": 1
},
For UNUSED:
{
"field": "unused",
"version_id": 0,
"field_exists": false,
"size": 5
},
It's not the script to blame because there's just not enough information
dumped to show the total size of the entry for an array. Add it.
Note that this will not break old vmstate checker because the field will
just be ignored.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Instead of print it to STDERR, bring the error upwards so that it can be
reported via QMP responses.
E.g.:
{ "execute": "migrate-set-capabilities" ,
"arguments": { "capabilities":
[ { "capability": "postcopy-ram", "state": true } ] } }
{ "error":
{ "class": "GenericError",
"desc": "Postcopy is not supported: Host backend files need to be TMPFS
or HUGETLBFS only" } }
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Once there, rename it to migrate_tls() and make it return bool for
consistency.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
Fix typos found by fabiano
Since the introduction of multifd, it's possible to perform a multifd
migration and finish it using postcopy.
A bug introduced by yank (fixed on cfc3bcf373) was previously preventing
a successful use of this migration scenario, and now thing should be
working on most scenarios.
But since there is not enough testing/support nor any reported users for
this scenario, we should disable this combination before it may cause any
problems for users.
Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
To be consistent with every other parameter, rename to
migrate_block_incremental().
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
Fixed missing space after comma (fabiano)
Once that we are there, we rename the function to migrate_return_path()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_block()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_xbzrle()
to be consistent with all other capabilities.
We change the type to return bool also for consistency.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to
migrate_zero_copy_send() to be consistent with all other capabilities.
We can remove the CONFIG_LINUX guard. We already check that we can't
setup this capability in migrate_caps_check().
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_multifd()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_events()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_compress()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_colo() to be
consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
We move there all capabilities helpers from migration.c.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
Following David advise:
- looked through the history, capabilities are newer than 2012, so we
can remove that bit of the header.
- This part is posterior to Anthony.
Original Author is Orit. Once there,
I put myself. Peter Xu also did quite a bit of work here.
Anyone else wants/needs to be there? I didn't search too hard
because nobody asked before to be added.
What do you think?
And remove the convoluted use of qmp_migrate_set_capabilities() to
enable disable MIGRATION_CAPABILITY_BLOCK.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
It has nothing to do with migration, except for the "migrate" in the
name of the command. Move it with the rest of the ui commands.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
It is only used there, so we can make it static.
Once there, remove spice.h that it is not used.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
fix David Edmonson ui/qemu-spice.h unintended removal
No need to declare a temporary variable.
Suggested-by: Juan Quintela <quintela@redhat.com>
Fixes: 1df36e8c6289 ("migration: Handle block device inactivation failures better")
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
We used to pass the old capabilities array and the new
capabilities as a list.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
It is clear from the context what that means, and such a long name
with the extra long names of the capabilities make very difficilut to
stay inside the 80 columns limit.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Postcopy requires the memory support userfaultfd to work. Right now we
check it but it's a bit too late (when switching to postcopy migration).
Do that early right at enabling of postcopy.
Note that this is still only a best effort because ramblocks can be
dynamically created. We can add check in hostmem creations and fail if
postcopy enabled, but maybe that's too aggressive.
Still, we have chance to fail the most obvious where we know there's an
existing unsupported ramblock.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Consider what happens when performing a migration between two host
machines connected to an NFS server serving multiple block devices to
the guest, when the NFS server becomes unavailable. The migration
attempts to inactivate all block devices on the source (a necessary
step before the destination can take over); but if the NFS server is
non-responsive, the attempt to inactivate can itself fail. When that
happens, the destination fails to get the migrated guest (good,
because the source wasn't able to flush everything properly):
(qemu) qemu-kvm: load of migration failed: Input/output error
at which point, our only hope for the guest is for the source to take
back control. With the current code base, the host outputs a message, but then appears to resume:
(qemu) qemu-kvm: qemu_savevm_state_complete_precopy_non_iterable: bdrv_inactivate_all() failed (-1)
(src qemu)info status
VM status: running
but a second migration attempt now asserts:
(src qemu) qemu-kvm: ../block.c:6738: int bdrv_inactivate_recurse(BlockDriverState *): Assertion `!(bs->open_flags & BDRV_O_INACTIVE)' failed.
Whether the guest is recoverable on the source after the first failure
is debatable, but what we do not want is to have qemu itself fail due
to an assertion. It looks like the problem is as follows:
In migration.c:migration_completion(), the source sets 'inactivate' to
true (since COLO is not enabled), then tries
savevm.c:qemu_savevm_state_complete_precopy() with a request to
inactivate block devices. In turn, this calls
block.c:bdrv_inactivate_all(), which fails when flushing runs up
against the non-responsive NFS server. With savevm failing, we are
now left in a state where some, but not all, of the block devices have
been inactivated; but migration_completion() then jumps to 'fail'
rather than 'fail_invalidate' and skips an attempt to reclaim those
those disks by calling bdrv_activate_all(). Even if we do attempt to
reclaim disks, we aren't taking note of failure there, either.
Thus, we have reached a state where the migration engine has forgotten
all state about whether a block device is inactive, because we did not
set s->block_inactive in enough places; so migration allows the source
to reach vm_start() and resume execution, violating the block layer
invariant that the guest CPUs should not be restarted while a device
is inactive. Note that the code in migration.c:migrate_fd_cancel()
will also try to reactivate all block devices if s->block_inactive was
set, but because we failed to set that flag after the first failure,
the source assumes it has reclaimed all devices, even though it still
has remaining inactivated devices and does not try again. Normally,
qmp_cont() will also try to reactivate all disks (or correctly fail if
the disks are not reclaimable because NFS is not yet back up), but the
auto-resumption of the source after a migration failure does not go
through qmp_cont(). And because we have left the block layer in an
inconsistent state with devices still inactivated, the later migration
attempt is hitting the assertion failure.
Since it is important to not resume the source with inactive disks,
this patch marks s->block_inactive before attempting inactivation,
rather than after succeeding, in order to prevent any vm_start() until
it has successfully reactivated all devices.
See also https://bugzilla.redhat.com/show_bug.cgi?id=2058982
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Acked-by: Lukas Straub <lukasstraub2@web.de>
Tested-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Rest of counters that refer to pages has a _pages suffix.
And historically, this showed the number of full pages transferred.
The name "normal" refered to the fact that they were sent without any
optimization (compression, xbzrle, zero_page, ...).
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Rest of counters that refer to pages has a _pages suffix.
And historically, this showed the number of pages composed of the same
character, here comes the name "duplicated". But since years ago, it
refers to the number of zero_pages.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
In the spirit of:
commit 394d323bc3451e4d07f13341cb8817fac8dfbadd
Author: Peter Xu <peterx@redhat.com>
Date: Tue Oct 11 17:55:51 2022 -0400
migration: Use atomic ops properly for page accountings
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Using MgrationStats as type for ram_counters mean that we didn't have
to re-declare each value in another struct. The need of atomic
counters have make us to create MigrationAtomicStats for this atomic
counters.
Create RAMStats type which is a merge of MigrationStats and
MigrationAtomicStats removing unused members.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
Fix typos found by David Edmondson
