When a user does not explicitly set a <driver> in the disk config,
libvirt defers selection of a default to libxl. This approach works
fine when starting a domain with such configuration or attaching a
disk to a running domain. But when detaching such a disk, libxl
will fail with "unrecognized disk backend type: 0". libxl makes no
attempt to recalculate a default backend (driver) on detach and
simply fails when uninitialized.

This patch updates the libvirt disk config with the backend selected
by libxl when starting a domain or attaching a disk to a running
domain. Another benefit of this approach is that the live XML is
also updated with the backend driver selected by libxl.

When starting a domian, a libxl_domain_config object is created from
virDomainDef. Any virDomainDiskDef devices with a format of
VIR_STORAGE_FILE_NONE are mapped to LIBXL_DISK_FORMAT_RAW in the
corresponding libxl_disk_device, but the virDomainDiskDef format is
never updated to reflect the change.

A better place to set a default format for disk devices is the
device post-parse callback, ensuring the virDomainDiskDef object
reflects the default format.

xen.git commit 57f8b13c changed several of the libxl memory
get/set functions to take 64 bit parameters. The libvirt
libxl driver still uses uint32_t variables for these various
parameters, which is particularly problematic for the
libxl_set_memory_target() function.

When dom0 autoballooning is enabled, libvirt (like xl) determines
the memory needed to start a domain and the memory available. If
memory available is less than memory needed, dom0 is ballooned
down by passing a negative value to libxl_set_memory_target()
'target_memkb' parameter. Prior to xen.git commit 57f8b13c,
'target_memkb' was an int32_t. Subtracting a larger uint32 from
a smaller uint32 and assigning it to int32 resulted in a negative
number. After commit 57f8b13c, the same subtraction is widened
to a int64, resulting in a large positive number. The simple
fix taken by this patch is to assign the difference of the
uint32 values to a temporary int32 variable, which is then
passed to 'target_memkb' parameter of libxl_set_memory_target().

Note that it is undesirable to change libvirt to use 64 bit
variables since it requires setting LIBXL_API_VERSION to 0x040800.
Currently libvirt supports LIBXL_API_VERSION >= 0x040400,
essentially Xen >= 4.4.

For HVM domains, pae is only set in libxl_domain_build_info when
explicitly specified in the hypervisor <features> config. This is
fine for i686 machines, but is incorrect behavior for x86_64 machines
where pae must always be enabled. See the following discussion for
additional details

https://www.redhat.com/archives/libvir-list/2017-January/msg00254.html

libxl doesn't provide a way to write one log for each domain. Thus
we need to demux the messages. If our logger doesn't know to which
domain to attribute a message, then it will write it to the default
log file.

Starting with Xen 4.9 (commit f9858025 and following), libxl will
write the domain ID in an easy to grab manner. The logger introduced
by this commit will use it to demux the libxl log messages.

Thanks to the default log file, this logger will also work with older
versions of Xen.

Change the virDomainChrDef to use a pointer to 'source' and allocate
that pointer during virDomainChrDefNew.

This has tremendous "fallout" in the rest of the code which mainly
has to change source.$field to source->$field.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Modeled after the qemuDomainHostdevPrivatePtr (commit id '27726d8c'),
create a privateData pointer in the _virDomainChardevDef to allow storage
of private data for a hypervisor in order to at least temporarily store
secret data for usage during qemuBuildCommandLine.

NB: Since the qemu_parse_command (qemuParseCommandLine) code is not
expecting to restore the secret data, there's no need to add code
code to handle this new structure there.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

This function for some weird reason returns integer instead of
virDomainNetType type. It is important to return the correct type
so that we know what values we can expect.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

And allow libxl to handle channel element which creates a Xen
console visible to the guest as a low-bandwitdh communication
channel. If type is PTY we also fetch the tty after boot using
libxl_channel_getinfo to fetch the tty path. On socket case,
we autogenerate a path if not specified in the XML. Path autogenerated
is slightly different from qemu driver: qemu stores also on
"channels/target" but it creates then a directory per domain with
each channel target name. libxl doesn't appear to have a clear
definition of private files associated with each domain, so for
simplicity we do it slightly different. On qemu each autogenerated
channel goes like:

channels/target/<domain-name>/<target name>

Whereas for libxl:

channels/target/<domain-name>-<target name>

Should note that if path is not specified it won't persist,
existing only on live XML, unless user had initially specified it.
Since support for libxl channels only came on Xen >= 4.5 we therefore
need to conditionally compile it with LIBXL_HAVE_DEVICE_CHANNEL.

After this patch and having a qemu guest agent:
 $ cat domain.xml | grep -a1 channel | head -n 5 | tail -n 4
 <channel type='unix'>
   <source mode='bind' path='/tmp/channel'/>
   <target type='xen' name='org.qemu.guest_agent.0'/>
 </channel>

 $ virsh create domain.xml
 $ echo '{"execute":"guest-network-get-interfaces"}' | socat
 stdio,ignoreeof  unix-connect:/tmp/channel

 {"execute":"guest-network-get-interfaces"}
 {"return": [{"name": "lo", "ip-addresses": [{"ip-address-type": "ipv4",
 "ip-address": "127.0.0.1", "prefix": 8}, {"ip-address-type": "ipv6",
 "ip-address": "::1", "prefix": 128}], "hardware-address":
 "00:00:00:00:00:00"}, {"name": "eth0", "ip-addresses":
 [{"ip-address-type": "ipv4", "ip-address": "10.100.0.6", "prefix": 24},
 {"ip-address-type": "ipv6", "ip-address": "fe80::216:3eff:fe40:88eb",
 "prefix": 64}], "hardware-address": "00:16:3e:40:88:eb"}, {"name":
 "sit0"}]}
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

libxl events are delivered to libvirt via the libxlDomainEventHandler
callback registered with libxl. Documenation in
$xensrc/tools/libxl/libxl_event.h states that the callback "may occur
on any thread in which the application calls libxl". This can result
in deadlock since many of the libvirt callees of libxl hold a lock on
the virDomainObj they are working on. When the callback is invoked, it
attempts to find a virDomainObj corresponding to the domain ID provided
by libxl. Searching the domain obj list results in locking each obj
before checking if it is active, and its ID equals the requested ID.
Deadlock is possible when attempting to lock an obj that is already
locked further up the call stack. Indeed, Max Ustermann reported an
instance of this deadlock

https://www.redhat.com/archives/libvir-list/2015-November/msg00130.html

Guido Rossmueller also recently stumbled across it

https://www.redhat.com/archives/libvir-list/2016-September/msg00287.html

Fix the deadlock by moving the lookup of virDomainObj to the
libxlDomainShutdownThread. After this patch, libxl events are
enqueued on the libvirt side and processed by dedicated thread,
avoiding the described deadlock.
Reported-by: NMax Ustermann <ustermann78@web.de>
Reported-by: NGuido Rossmueller <Guido.Rossmueller@gdata.de>

Just like virDomainDefPostParseCallback has gained new
parseOpaque argument, we need to follow the logic with
virDomainDeviceDefPostParse.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

We want to pass the proper opaque pointer instead of NULL to
virDomainDefParseString.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

We want to pass the proper opaque pointer instead of NULL to
virDomainDefParse and subsequently virDomainDefParseNode too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Some callers might want to pass yet another pointer to opaque
data to post parse callbacks. The driver generic one is not
enough because two threads executing post parse callback might
want to see different data (e.g. domain object pointer that
domain def belongs to).
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The code for replacing domain's transient definition with the persistent
one is repeated in several places and we'll need to add one more. Let's
make a nice helper for it.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Add support for multi serial devices, after this patch virsh can be used to
connect different serial devices of running domains. E.g.
vish # console <xxx> --devname serial<xxx>

Note:
This depends on a xen/libxl bug fix to have libxl_console_get_tty(...) correctly
returning the tty path (as opposed to always returning the first one).
[0] https://lists.xen.org/archives/html/xen-devel/2016-08/msg00438.htmlSigned-off-by: NBob Liu <bob.liu@oracle.com>

Commit id '7d3b2eb5' missed a closing parenthesis on the ignore_value
macro, causing the failure

Introduce libxl hook and use it for start, prepare, started,
stop, stopped, migrate events.

The migrate hook will affect the migrated guest definition. Allow
these domains be marked as tainted in the libxl driver.

All the same information was already there, just in slightly different
places in the virDomainNetDef.

When domXML contains only <console type='pty'> and no corresponding
<serial>, the console is "stolen" [1] and used as the first <serial>
device. When this "stolen" console is accessed from the libxl driver
(in libxlConsoleCallback and libxlDomainOpenConsole), check if the
targetType is VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL, and use the
"stolen" device in def->serials[0] instead. Prior to this change,
creating a domain with input XML containing only a <console> device
and subsequently attempting to access its console with
'virsh console' would fail

error: internal error: character device <null> is not using a PTY

[1] See comments associated with virDomainDefAddConsoleCompat() in
    $LIBVIRT-SRC/src/conf/domain_conf.c:

Support creating guest with USB host device in config file.
Currently libxl only supports xen PV guest, and only supports
specifying USB host device by 'bus number' and 'device number',
for example:

    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <address bus='1' device='3'/>
      </source>
    </hostdev>
Signed-off-by: NChunyan Liu <cyliu@suse.com>
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Move capabilities code out of libxl_conf.{ch} and into new
libxl_capabilities.{ch} files.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

In libxl driver we do virObjectRef in libxlDomainObjBeginJob,
If virCondWaitUntil failed, it goes to error, do virObjectUnref,
There's a chance that someone undefine the vm at the same time,
and refs unref to zero, vm is freed in libxlDomainObjBeginJob.
But the vm outside function is not Null, we do virObjectUnlock(vm).
That's how we overwrite the vm memory after it's freed. I fix it.
Signed-off-by: NWang Yufei <james.wangyufei@huawei.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Until now we weren't able to add checks that would reject configuration
once accepted by the parser. This patch adds a new callback and
infrastructure to add such checks. In this patch all the places where
rejecting a now-invalid configuration wouldn't be a good idea are marked
with a new parser flag.

Remove the live attribute and mark the definition as transient
whether the domain is runing or not.

There were only two callers left calling with live=false:
* testDomainStartState, where the domain already is active
  because we assigned vm->def->id just a few lines above the call
* virDomainObjGetPersistentDef, which now only calls
  virDomainObjSetDefTransient for an active domain

Xen only supports network-based disks with the qemu (aka qdisk) driver.
Set the driverName to 'qemu' in libxlDomainDeviceDefPostParse() if
not already set. When starting a domain with network-based disks,
ensure the driverName is 'qemu'.

Resolves: https://bugzilla.opensuse.org/show_bug.cgi?id=981094

Convert to virGetLastErrorMessage() in the rest of the code

Xen 4.6 introduced a new migration stream commonly referred to as
"migration V2". Xen 4.6 and newer always produce this new stream,
whereas Xen 4.5 and older always produce the legacy stream.
Support for migration stream V2 can be detected at build time with
LIBXL_HAVE_SRM_V2 from libxl.h. The legacy and V2 streams are not
compatible, but a V2 host can accept and convert a legacy stream.

Commit e7440656 changed the libxl driver to use the lowest libxl
API version possible (version 0x040200) to ensure the driver
builds against older Xen releases. The old 4.2 restore API does
not support specifying a stream version and assumes a legacy
stream, even if the incoming stream is migration V2. Thinking it
has been given a legacy stream, libxl will fail to convert an
incoming stream that is already V2, which causes the entire
restore operation to fail. Xen's libvirt-related OSSTest has been
failing since commit e7440656 landed in libvirt.git master. One
of the more recent failures can be seen here

http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg00071.html

This patch changes the call to libxl_domain_create_restore() to
include the stream version if LIBXL_HAVE_SRM_V2 is defined. The
version field of the libxlSavefileHeader struct is also updated
to '2' when LIBXL_HAVE_SRM_V2 is defined, ensuring the stream
version in the header matches the actual stream version produced
by Xen. Along with bumping the libxl API requirement to 0x040400,
this patch fixes save/restore on a migration V2 Xen host.

Oddly, migration has never used the libxlSavefileHeader. It
handles passing configuration in the Begin and Prepare phases,
and then calls libxl directly to transfer domain state/memory
in the Perform phase. A subsequent patch will add stream
version handling in the Begin and Prepare phase handshaking,
which will fix the migration related OSSTest failures.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

In LIBXL_API_VERSION 0x040400, the libxl_domain_create_restore API
gained a parameter for specifying restore parameters. Switch to
using version 0x040400, which will be useful in a subsequent commit
to specify the Xen migration stream version when restoring.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

To ensure the libvirt libxl driver will build with future versions
of Xen where the libxl API may change in incompatible ways,
explicitly use LIBXL_API_VERSION 0x040200. The libxl driver
does use new libxl APIs that have been added since Xen 4.2, but
currently it does not make use of any changes made to existing
APIs such as libxl_domain_create_restore or libxl_set_vcpuaffinity.
The version can be bumped if/when the libxl driver consumes the
changed APIs.

Further details can be found in the following discussion thread

https://www.redhat.com/archives/libvir-list/2016-April/msg00178.htmlSigned-off-by: NJim Fehlig <jfehlig@suse.com>

Add codes to support creating domain with network defition of assigning
SRIOV VF from a pool.
Signed-off-by: NChunyan Liu <cyliu@suse.com>
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

In the latest libxenlight code, libxl_domain_create_restore accepts a
new argument. Update libvirt's libxl driver for that. Use the macro
provided by libxenlight to detect which version should be used.

The new parameter (send_back_fd) is set to -1 because libvirt provides
no such fd.
Signed-off-by: NWei Liu <wei.liu2@citrix.com>
Message-id: 1459866012-27081-1-git-send-email-wei.liu2@citrix.com

Remove disabling domain death events from libxlDomainStart error
path. The domain death event is already disabled in libxlDomainCleanup.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

libxlDomainStart allocates and reserves resources that were not
being released in error paths. libxlDomainCleanup already handles
the job of releasing resources, and libxlDomainStart should call
it when encountering a failure.

Change the error handling logic to call libxlDomainCleanup on
failure. This includes acquiring the lease sooner and allowing
it to be released in libxlDomainCleanup on failure, similar to
the way other resources are reclaimed. With the lease now
released in libxlDomainCleanup, the release_dom label can be
renamed to cleanup_dom to better reflect its changed semantics.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Rename cleanup_dom label to destroy_dom, which better describes what
it does.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Introduce a helper to check supported device and domain config and move
the memory hotplug checks to it.

The advantage of this approach is that by default all new features are
considered unsupported by all hypervisors unless specifically changed
rather than the previous approach where every hypervisor would need to
declare that a given feature is unsupported.

Introduce support for domainInterfaceStats API call for querying
network interface statistics. Consequently it also enables the use of
`virsh domifstat <dom> <interface name>` command plus seeing the
interfaces names instead of "-" when doing `virsh domiflist <dom>`.

After successful guest creation we fill the network interfaces names
based on domain, device id and append suffix if it's emulated in the
following form: vif<domid>.<devid>[-emu].  We extract the network
interfaces info from the libxl_domain_config object in
libxlDomainCreateIfaceNames() to generate ifname. On domain cleanup we
also clear ifname, in case it was set by libvirt (i.e. being prefixed
with "vif"). We also skip these two steps in case the name of the
interface was manually inserted by the administrator. Since the
introduction of netprefix (commit a040ba9e), ifnames with a registered
prefix will be freed on virDomain{Obj,Def}Format*, thus eliminating
the migration issues observed with the reverted commit d2e5538b whereas
source and destination would have the same ifname.

For getting the interface statistics we resort to virNetInterfaceStats
and let libvirt handle the platform specific nits. Note that the
latter is not yet supported in FreeBSD.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

Signed-off-by: NChunyan Liu <cyliu@suse.com>