This commit adds qemu driver implementation to get xml description
for managed save state domain.
Signed-off-by: NKothapally Madhu Pavan <kmp@linux.vnet.ibm.com>

This API is definitely modifying state of @vm. Therefore it
should grab a job.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

At some places we either already have synchronous job or we just
released it. Also, some APIs might want to use this code without
having to release their job. Anyway, the job acquire code is
moved out to qemuDomainRemoveInactiveJob so that
qemuDomainRemoveInactive does just what it promises.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

Add code to support querying maximum allowable downtime during live migration.

Introduced by commit <41127244>.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1467245

Currently, there's a bug when undefining a domain with NVRAM
store. Basically, the unlink() of the NVRAM store file happens
during the undefine procedure iff domain is inactive. So, if
domain is running and undefine is called the file is left behind.
It won't be removed in the domain cleanup process either
(qemuProcessStop). One of the solutions is to remove if
regardless of the domain state and rely on qemu having the file
opened. This still has a downside that if the domain is defined
back the NVRAM store file is going to be new, any changes to the
current one are lost (just like with any other file that is
deleted while a process has it opened). But is it really a
downside?
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1458630

Introduce virQEMUDriverConfigTLSDirResetDefaults in order to check
if the defaultTLSx509certdir was changed, then change the default
for any other *TLSx509certdir that was not set to the default default.

Introduce virQEMUDriverConfigValidate to validate the existence of
any of the *_tls_x509_cert_dir values that were uncommented/set,
incuding the default.

Update the qemu.conf description for default to describe the consequences
if the default directory path does not exist.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Make it less confusing by naming the field which refers to the storage
object as 'nodestorage'.
Reviewed-by: NEric Blake <eblake@redhat.com>

The switch contains considerable amount of changes:

  virQEMUCapsRememberCached() is removed because this is now handled
  by virFileCacheSave().

  virQEMUCapsInitCached() is removed because this is now handled by
  virFileCacheLoad().

  virQEMUCapsNewForBinary() is split into two functions,
  virQEMUCapsNewData() which creates new data if there is nothing
  cached and virQEMUCapsLoadFile() which loads the cached data.
  This is now handled by virFileCacheNewData().

  virQEMUCapsCacheValidate() is removed because this is now handled by
  virFileCacheValidate().

  virQEMUCapsCacheFree() is removed because it's no longer required.

  Add virCapsPtr into virQEMUCapsCachePriv because for each call of
  virFileCacheLookup*() we need to use current virCapsPtr.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>

This is a preparation for following patches where we switch to
virFileCache for QEMU capabilities cache

The host arch will always remain the same but virCaps may change.  Now
the host arch is stored while creating new qemu capabilities cache.
It removes the need to pass virCaps into virQEMUCapsCache*() functions.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>

This way we can finally make it static and not use any externs anywhere.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Security impls of this function already raise errors, don't
overwrite them.

Use virStorageSource accessors to check the file and call
virStorageFileAccess before even attempting to stat the target. This
will be helpful once we try to add network destinations for block copy,
since there will be no need to stat them.

Move the code into a separate function so that the flow of creating the
copy is more obvious and split into logical pieces.

Rather than using the local-file only implementation 'qemuOpenFile'
switch to the imagelabel aware storage driver implementation.

When copying to a block device, the block device will already exist. To
allow users using a block device without any preparation, they need to
use the block copy without VIR_DOMAIN_BLOCK_COPY_REUSE_EXT.

This means that if the target is an existing block device we don't need
to prepare it, but we can't reject it as being existing.

To avoid breaking this feature, explicitly assume that existing block
devices will be reused even without that flag explicitly specified,
while skipping attempts to create it.

qemuMonitorDriveMirror still needs to honor the flag as specified by the
user, since qemu overwrites the metadata otherwise.

Extract the presence of the flag into a boolean to simplify conditions
and allow further manipulation of the state of the flag.

https://bugzilla.redhat.com/show_bug.cgi?id=1467826

Commit id 'b9b1aa63' was supposed to add logic to set the allocation
for sparse files when wr_highest_offset was zero; however, an unconditional
setting was done just prior. For block devices, this means allocation is
always returning 0 since 'actual-size' will be zero.

Remove the unconditional setting and add the note about it being possible
to still be zero for block devices. As soon as the guest starts writing to
the volume, the allocation value will then be obtainable from qemu via
the wr_highest_offset.

The API documents that it peeks into the VM disk. We can't do that
currently for non raw images so report an error.

Refactor the access to storage driver usage along with
qemuDomainStorageFileInit which ensures that we access the file with
correct DAC uid/gid.

Allow specifying offset to read an arbitrary position in the file. This
warrants a rename to virStorageFileRead.

The helper methods for actually accessing the storage objects don't
really belong to the main storage driver implementation file. Split them
out.

We have a temporary pointer to the currently processed parameter.
Use it to save three bytes per use.

We assign the unsigned long value of the currently processed
parameter to a temporary value_ul variable. Use it consistently
in all cases.

If a remote call fails during event registration (more than likely from
a network failure or remote libvirtd restart timed just right), then when
calling the virObjectEventStateDeregisterID we don't want to call the
registered @freecb function because that breaks our contract that we
would only call it after succesfully returning.  If the @freecb routine
were called, it could result in a double free from properly coded
applications that free their opaque data on failure to register, as seen
in the following details:

    Program terminated with signal 6, Aborted.
    #0  0x00007fc45cba15d7 in raise
    #1  0x00007fc45cba2cc8 in abort
    #2  0x00007fc45cbe12f7 in __libc_message
    #3  0x00007fc45cbe86d3 in _int_free
    #4  0x00007fc45d8d292c in PyDict_Fini
    #5  0x00007fc45d94f46a in Py_Finalize
    #6  0x00007fc45d960735 in Py_Main
    #7  0x00007fc45cb8daf5 in __libc_start_main
    #8  0x0000000000400721 in _start

The double dereference of 'pyobj_cbData' is triggered in the following way:

    (1) libvirt_virConnectDomainEventRegisterAny is invoked.
    (2) the event is successfully added to the event callback list
        (virDomainEventStateRegisterClient in
        remoteConnectDomainEventRegisterAny returns 1 which means ok).
    (3) when function remoteConnectDomainEventRegisterAny is hit,
        network connection disconnected coincidently (or libvirtd is
        restarted) in the context of function 'call' then the connection
        is lost and the function 'call' failed, the branch
        virObjectEventStateDeregisterID is therefore taken.
    (4) 'pyobj_conn' is dereferenced the 1st time in
        libvirt_virConnectDomainEventFreeFunc.
    (5) 'pyobj_cbData' (refered to pyobj_conn) is dereferenced the
         2nd time in libvirt_virConnectDomainEventRegisterAny.
    (6) the double free error is triggered.

Resolve this by adding a @doFreeCb boolean in order to avoid calling the
freeCb in virObjectEventStateDeregisterID for any remote call failure in
a remoteConnect*EventRegister* API. For remoteConnect*EventDeregister* calls,
the passed value would be true indicating they should run the freecb if it
exists; whereas, it's false for the remote call failure path.

Patch based on the investigation and initial patch posted by
fangying <fangying1@huawei.com>.

Commit 7456c4f5 introduced a regression by not reloading the backing
chain of a disk after snapshot. The regression was caused as
src->relPath was not set and thus the block commit code could not
determine the relative path.

This patch adds code that will load the backing store string if
VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT and store it in the correct place
when a snapshot is successfully completed.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1461303

Calls to qemuDomainDiskChainElementPrepare resets the original error,
thus we need to save it in the cleanup path of qemuDomainBlockCommit.

Changing labelling of the images does not need to happen after setting
the labeling and lock manager access. This saves the cleanup of the
labeling if the relative path can't be determined.

Most places which want to check ABI stability for an active domain need
to call this API rather than the original
qemuDomainDefCheckABIStability. The only exception is in snapshots where
we need to decide what to do depending on the saved image data.

https://bugzilla.redhat.com/show_bug.cgi?id=1460952Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

Commit v3.4.0-44-gac793bd7 fixed a memory leak, but failed to return
the special -3 value. Thus an attempt to start a domain with corrupted
managed save file would removed the corrupted file and report
"An error occurred, but the cause is unknown" instead of starting the
domain from scratch.

https://bugzilla.redhat.com/show_bug.cgi?id=1460962

Use ATTRIBUTE_FALLTHROUGH, introduced by commit
5d84f596, instead of comments to
indicate that the fall through is an intentional behavior.
Signed-off-by: NMarc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: NBjoern Walk <bwalk@linux.vnet.ibm.com>

Exiting early through the cleanup path did result in 'mirror'
being leaked.

If QEMU is new enough and we have the live updated CPU definition in
either save or migration cookie, we can use it to enforce ABI. The
original guest CPU from domain XML will be stored in private data.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

The destination host may not be able to start a domain using the live
updated CPU definition because either libvirt or QEMU may not be new
enough. Thus we need to send the original guest CPU definition.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

The following patches will add an actual content in the cookie and use
the data when restoring a domain.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

The new structure encapsulates save image header and associated data
(domain XML).
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

The function is now called virQEMUSaveDataWrite and it is now doing
everything it needs to save both the save image header and domain XML to
a file. Be it a new file or an existing file in which a user wants to
change the domain XML.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

The function is supposed to update the save image header after a
successful migration to the save image file.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

This is a preparation for creating a new virQEMUSaveData structure which
will encapsulate all save image header data.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>