Since as the code indicates it doesn't work yet, so let's be
explicit about it.

By actually showing the Open() error to the user

"error" label in qemuMigrationCookieGraphicsAlloc is now used
unconditionally thanks to VIR_STRDUP.

Since f03dcc5d we use [::] as the listening address both on qemu
command line in -incoming and in nbd-server-start QMP command.
However the latter requires just :: without the braces.

Commit 7f15ebc7 introduced a bug
happening when guests without a <graphics> element are migrated.
The initialization of listenAddress happens unconditionally
from the cookie even if the cookie->graphics pointer was NULL.
Moved the initialization to where it is safe.
Signed-off-by: NViktor Mihajlovski <mihajlov@linux.vnet.ibm.com>

Currently the parsing of XML is pushed down into the various
migration helper APIs. This makes it difficult to insert the
correct access control checks, since one helper API services
many public APIs. Pull the parsing of XML up to the top level
of the QEMU driver APIs

Several APIs allow for custom XML to be passed in. This is
checked for ABI stability, which will ensure the UUID is
not being changed. There isn't validation that the name
did not change though. This could allow renaming of guests
via the backdoor, which in turn could allow for bypassing
access control restrictions based on names.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the virGetHostname() API has a bogus virConnectPtr
parameter. This is because virtualization drivers directly
reference this API in their virDriverPtr tables, tieing its
API design to the public virConnectGetHostname API design.

This also causes problems for access control checks since
these must only be done for invocations from the public
API, not internal invocation.

Remove the bogus virConnectPtr parameter, and make each
hypervisor driver provide a dedicated function for the
driver API impl. This will allow access control checks
to be easily inserted later.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Use virBufferAddLit or virBufferAddChar instead.

The QEMU migration code unconditionally sets the 'persistent'
cookie flag on the source host. The dest host, however, only
allows it during parsing if VIR_MIGRATE_PERSIST_DEST was
set. Make the source host only set it if this flag is
present.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.

Instead of calling virCgroupForDomain every time we need
the virCgrouPtr instance, just do it once at Vm startup
and cache a reference to the object in qemuDomainObjPrivatePtr
until shutdown of the VM. Removing the virCgroupPtr from
the QEMU driver state also means we don't have stale mount
info, if someone mounts the cgroups filesystem after libvirtd
has been started
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When migrating a domain with disk images stored locally (and using
storage migration), we should not complain about unsafe migration no
matter what cache policy is used for that disk.

https://bugzilla.redhat.com/show_bug.cgi?id=920441

Currently, we are discarding listen attribute from qemu cookie even though
we strive to gather it. This result in not so cool bug: if user have
different networks, one for management/migration, and one for VNC/SPICE we
pass incorrect host to the qemu in client_migrate_info. What we actually
pass is remote hostname, while we should be passing remote listen address.
It doesn't matter as long as these two are the same, but they don't need
necessary to be like that.

Move the xmlopt and caps arguments to the end of the argument list.

This patch is the result of running:

for i in $(git ls-files | grep -v html | grep -v \.po$ ); do
  sed -i -e "s/virDomainXMLConf/virDomainXMLOption/g" -e "s/xmlconf/xmlopt/g" $i
done

and a few manual tweaks.

Allow migration over IPv6 by listening on [::] instead of 0.0.0.0
when QEMU supports it (QEMU_CAPS_IPV6_MIGRATION) and there is
at least one v6 address configured on the system.

Use virURIParse in qemuMigrationPrepareDirect to allow parsing
IPv6 addresses, which would cause an 'incorrect :port' error
message before.

Move setting of migrateFrom from qemuMigrationPrepare{Direct,Tunnel}
after domain XML parsing, since we need the QEMU binary path from it
to get its capabilities.

Bug: https://bugzilla.redhat.com/show_bug.cgi?id=846013

Since we switched from direct host migration scheme to the one,
where we connect to the destination and then just pass a FD to a
qemu, we have uncovered a qemu bug. Qemu expects migration FD to
block. However, we are passing a nonblocking one which results in
cryptic error messages like:

  qemu: warning: error while loading state section id 2
  load of migration failed

The bug is already known to Qemu folks, but we should workaround
already released Qemus. Patch has been originally proposed by Stefan
Hajnoczi <stefanha@gmail.com>

The virCaps structure gathered a ton of irrelevant data over time that.
The original reason is that it was propagated to the XML parser
functions.

This patch aims to create a new data structure virDomainXMLConf that
will contain immutable data that are used by the XML parser. This will
allow two things we need:

1) Get rid of the stuff from virCaps

2) Allow us to add callbacks to check and add driver specific stuff
after domain XML is parsed.

This first attempt removes pointers to private data allocation functions
to this new structure and update all callers and function that require
them.

qemuProcessStart expects to be run with a job already set and every
caller except for qemuMigrationPrepareAny use it correctly. This bug can
be observed in libvirtd logs during incoming migration as

    warning : qemuDomainObjEnterMonitorInternal:979 : This thread seems
    to be the async job owner; entering monitor without asking for a
    nested job is dangerous

s/VIR_QEMU_PROCESS_START_AUTODESROY/VIR_QEMU_PROCESS_START_AUTODESTROY/
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

If a migration fails, we need to stop all block jobs running so
qemu doesn't try to send data to destination over and over again.

At the end of migration, it is important to stop NBD
server and thus release all allocated resources.

This function does the source part of NBD magic. It
invokes drive-mirror on each non shared and RW disk with
a source and wait till the mirroring process completes.
When it does we can proceed with migration.

Currently, an active waiting is done: every 500ms libvirt
asks qemu if block-job is finished or not.  However, once
the job finishes, qemu doesn't report its progress so we
can only assume if the job finished successfully or not.
The better solution would be to listen to the event which
is sent as soon as the job finishes. The event does
contain the result of job.

We need to start NBD server and feed it with all non-<shared/>,
RW and source-full disks. Moreover, with new virPortAllocator we
must ensure the borrowed port for NBD server will be returned if
either migration completes or qemu process is torn down.

This migration cookie is meant for two purposes. The first is to be sent
in begin phase from source to destination to let it know we support new
implementation of VIR_MIGRATE_NON_SHARED_{DISK,INC} so destination can
start NBD server. Then, the second purpose is, destination can let us
know, on which port the NBD server is running.

As a side effect, this also fixes reporting disk migration process.
It was added to memory migration progress, which was wrong. Disk
progress has dedicated fields in virDomainJobInfo structure.

To avoid having to hold the qemu driver lock while iterating through
close callbacks and calling them. This fixes a real deadlock when a
domain which is being migrated from another host gets autodestoyed as a
result of broken connection to the other host.

Due to "feature"/"features" nasty typo, any features marked as mandatory
by one side of a migration are silently considered optional by the other
side. The following is the code that formats mandatory features in
migration cookie:

    for (i = 0 ; i < QEMU_MIGRATION_COOKIE_FLAG_LAST ; i++) {
        if (mig->flagsMandatory & (1 << i))
            virBufferAsprintf(buf, "  <feature name='%s'/>\n",
                              qemuMigrationCookieFlagTypeToString(i));
    }

With the majority of fields in the virQEMUDriverPtr struct
now immutable or self-locking, there is no need for practically
any methods to be using the QEMU driver lock. Only a handful
of helper APIs in qemu_conf.c now need it

The 'driver->caps' pointer can be changed on the fly. Accessing
it currently requires the global driver lock. Isolate this
access in a single helper, so a future patch can relax the
locking constraints.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To avoid confusion between 'virCapsPtr' and 'qemuCapsPtr'
do some renaming of various fucntions/variables. All
instances of 'qemuCapsPtr' are renamed to 'qemuCaps'. To
avoid that clashing with the 'qemuCaps' typedef though,
rename the latter to virQEMUCaps.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The duplicate VM checking should be done atomically with
virDomainObjListAdd, so shoud not be a separate function.
Instead just use flags to indicate what kind of checks are
required.

This pair, used in virDomainCreateXML:

   if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
     goto cleanup;
   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def, false)))
     goto cleanup;

Changes to

   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def,
                                   VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
                                   NULL)))
     goto cleanup;

This pair, used in virDomainRestoreFlags:

   if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
     goto cleanup;
   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def, true)))
     goto cleanup;

Changes to

   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def,
                                   VIR_DOMAIN_OBJ_LIST_ADD_LIVE |
                                   VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
                                   NULL)))
     goto cleanup;

This pair, used in virDomainDefineXML:

   if (virDomainObjListIsDuplicate(privconn->domains, def, 0) < 0)
     goto cleanup;
   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def, false)))
     goto cleanup;

Changes to

   if (!(dom = virDomainObjListAdd(privconn->domains,
                                   privconn->caps,
                                   def,
                                   0, NULL)))
     goto cleanup;

The APIs names for accessing the domain list object are
very inconsistent. Rename them all to have a standard
virDomainObjList prefix.

Currently the virQEMUDriverPtr struct contains an wide variety
of data with varying access needs. Move all the static config
data into a dedicated virQEMUDriverConfigPtr object. The only
locking requirement is to hold the driver lock, while obtaining
an instance of virQEMUDriverConfigPtr. Once a reference is held
on the config object, it can be used completely lockless since
it is immutable.

NB, not all APIs correctly hold the driver lock while getting
a reference to the config object in this patch. This is safe
for now since the config is never updated on the fly. Later
patches will address this fully.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

If a compression binary prints something to stderr, currently
it is discarded. However, it can contain useful data from
debugging POV, so we should catch it.

We are already logging other arguments passed, however, @flags
were missing there.