When an always-on migration capability is supposed to be enabled on both
sides of migration, each side can only enable the feature if it is
enabled by the other side.

Thus the source host sends a list of supported migration capabilities in
the migration cookie generated in the Begin phase. The destination host
consumes the list in the Prepare phase and decides what capabilities can
be enabled when starting a QEMU process for incoming migration. Once
done the destination sends the list of supported capabilities back to
the source where it is used during the Perform phase to determine what
capabilities can be automatically enabled.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Some migration capabilities may be enabled automatically, but only if
both sides of migration support them. Thus we need to be able transfer
the list of supported migration capabilities in migration cookie.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Since every parameter or capability set in qemuMigrationCompression
structure is now reflected in qemuMigrationParams structure, we can
replace qemuMigrationAnyCompressionDump with a new API which will work
on qemuMigrationParams.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

There's no need to call this API explicitly in the migration code. We
can pass the compression parameters to qemuMigrationParamsFromFlags and
it can internally call qemuMigrationParamsSetCompression to apply them
to the qemuMigrationParams structure.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The code really belongs to qemu_migration_params.c.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Propagate the calls up the stack to the point where
qemuMigrationParamsFromFlags is called. The end goal achieved in the
following few patches is to merge compression parameters into the
general migration parameters code.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Most migration capabilities are directly connected with
virDomainMigrateFlags so qemuMigrationParamsFromFlags can automatically
enable them.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Some migration capabilities are always enabled if QEMU supports them. We
can just drop the explicit code for them and let
qemuMigrationParamsCheck automatically set such capabilities.

QEMU_MONITOR_MIGRATION_CAPS_EVENTS would normally be one of the always
on features, but it is the only feature we want to enable even for other
jobs which internally use migration (such as save and snapshot). Hence
this capability is set very early after libvirtd connects to QEMU
monitor.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

It's just a tiny wrapper around qemuMigrationParamsSetCapability and
setting priv->job.postcopyEnabled is not something qemuMigrationParams
code should be doing anyway so let the callers do it.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Every migration entry point in qemu_driver is supposed to call
qemuMigrationParamsFromFlags to transform flags and parameters into
qemuMigrationParams structure and pass the result to qemuMigration*
APIs.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Instead of checking each capability at the time we want to set it in
qemuMigrationParamsSetCapability we can check all of them at once in
qemuMigrationParamsCheck.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

We reached the point when qemuMigrationParamsApply is the only API which
sends migration parameters and capabilities to QEMU. Thus all but the
TLS parameters can be set before we ask QEMU for the current values of
all parameters in qemuMigrationParamsCheck.

Supported migration capabilities are queried as soon as libvirt connects
to QEMU monitor so we can check them anytime.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

We reached the point when qemuMigrationParamsApply is the only API which
sends migration parameters and capabilities to QEMU. Thus all but the
TLS parameters can be set before we ask QEMU for the current values of
all parameters in qemuMigrationParamsCheck.

Supported migration capabilities are queried as soon as libvirt connects
to QEMU monitor so we can check them anytime.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Prefer xbzrle-cache-size migration parameter over the special
migrate-set-cache-size QMP command.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Migration capabilities are closely related to migration parameters and
it makes sense to keep them in a single data structure. Similarly to
migration parameters the capabilities are all send to QEMU at once in
qemuMigrationParamsApply, all other APIs operate on the
qemuMigrationParams structure.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The new name is qemuMigrationParamsApply and it will soon become the
only API which will send all requested migration parameters and
capabilities to QEMU. All other qemuMigrationParams* APIs will just
operate on the qemuMigrationParams structure.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

There's no real reason for qemuMigrationParamsEnableTLS to require the
callers to pass a valid virQEMUDriverConfigPtr, it can just call
virQEMUDriverGetConfig.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The new name is qemuMigrationParamsEnableTLS.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The new name is qemuMigrationParamsDisableTLS.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The function checks whether QEMU supports TLS migration and stores the
original value of tls-creds parameter to priv->migTLSAlias. This is no
longer needed because we already have the original value stored in
priv->migParams.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The code can be merged directly in qemuMigrationParamsAddTLSObjects.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Restore the original values of all migration parameters we store in
qemuDomainJobObj instead of explicitly resting only a limited set of
them.

The result is not strictly equivalent to the previous code wrt reseting
TLS state because the previous code would only reset it if we changed it
before while the new code will reset it always if QEMU supports TLS
migration. This is not a problem for the parameters themselves, but it
can cause spurious errors about missing TLS objects being logged at the
end of non-TLS migration. This issue will be fixed ~50 patches later.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Any job which touches migration parameters will first store their
original values (i.e., QEMU defaults) to qemuDomainJobObj to make it
easier to reset them back once the job finishes.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

When connection to the client which controls a non-p2p migration gets
closed between Perform and Confirm phase, we don't know whether the
domain was successfully migrated or not. Thus, we have to leave the
domain paused and just cleanup the migration job and reset migration
parameters.

Previously we didn't reset the parameters and future save or snapshot
operations would see wrong environment (and could fail because of it) in
case the domain stayed running on the source host.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Currently migration parameters are stored in a structure which mimics
the QEMU migration parameters handled by query-migrate-parameters and
migrate-set-parameters. The new structure will become a libvirt's
abstraction on top of QEMU migration parameters, capabilities, and
related stuff.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

It will get a bit more complicated soon and storing it on a stack with
{0} initializer will no longer work. We need a proper constructor.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The function is connected with the code which handles migration
parameters and capabilities, let's move it to qemu_migration_params.c.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

In the end, this will allow us to have most of the logic around
migration parameters and capabilities done in one place.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The function is now called qemuMigrationParamsFromFlags to better
reflect what it is doing: taking migration flags and params and
producing a struct with QEMU migration parameters.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Since virCloseCallbacksRun was ignoring the value anyway, let's
just change it to be a void function.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NMarc Hartmayer <mhartmay@linux.vnet.ibm.com>

In qemuMigrationSrcRun, we already checked for non-NULL mig
and then dereferenced it. It's only possible for mig to be
NULL in the error section.
Signed-off-by: NJán Tomko <jtomko@redhat.com>

This partially reverts 82592551.

When migrating a domain, qemuMigrationDstPrepareAny() is called
which eventually calls qemuProcessLaunch(conn = NULL, flags =
VIR_QEMU_PROCESS_START_AUTODESTROY); But the very first thing
that qemuProcessLaunch does is check if AUTODESTROY flag is set
and @conn is not NULL. Well, it is.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1494454

If a domain disk is stored on local filesystem (e.g. ext4) but is
not being migrated it is very likely that domain is not able to
run on destination. Regardless of share/cache mode.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

Range check in virPortAllocatorSetUsed is not useful anymore
when we manage ports for entire unsigned short range values.
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>

Ensure all enum cases are listed in switch statements, or cast away
enum type in places where we don't wish to cover all cases.
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

It is very difficult while reading the migration code trying to
understand whether a particular function is being called on the src side
or the dst side, or either. Putting "Src" or "Dst" in the method names will
make this much more obvious. "Any" is used in a few helpers which can be
called from both sides.
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

These APIs are not required anywhere outside the migration code so need
not be exported to the rest of the QEMU driver.
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The qemuMigrationPrecreateStorage method needs a connection
to access the storage driver. Instead of passing it around,
open it at time of use.
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>