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.

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.

libvirt libxl picks its own default with respect to the default NIC
to use. libxlMakeNic is the one responsible for this and on boot it
picks LIBXL_NIC_TYPE_VIF_IOEMU for HVM domains such that it accomodates
both PV and emulated one. The good behaving guest at boot will then
select the pv and unplug the emulated device.

Now, on HVM when attaching an interface it will pick the same default
that is LIBXL_NIC_TYPE_VIF_IOEMU which as a result will fail the attach
(see xen commit 32e9d0f ("libxl: nic type defaults to vif in hotplug for
hvm guest"). Xen doesn't yet support the hotplug of emulated devices,
but we don't want to rule out that case either, which might get support
in the future. Hence we simply reverse the defaults when we are
attaching the interface which allows libvirt to prefer the PV nic first
without adding "model='netfront'" following the same pattern as above
commit. Also to avoid ruling out the emulated one we set to
LIBXL_NIC_TYPE_IOEMU when setting a model type that is not 'netfront'.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: NJim Fehlig <jfehlig@suse.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>

To support USB Controller in xen guest domains, just add
USB controller in domain config xml as following:
<controller type='usb' model='qusb2' ports='4'/>
Signed-off-by: NChunyan Liu <cyliu@suse.com>

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>

Prefer firmwares specified via --with-loader-nvram configure
option. If none are specified, use the Xen-provided default
firmwares found in LIBXL_FIRMWARE_DIR.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

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>

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>

This patch introduces keep alive messages support for P2P migration
and it adds two new configuration entries namely 'keepalive_interval'
'keepalive_count' to control it. Behavior of these entries is the
same as qemu driver thus the description is copied from there
with just a few simplifications.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

Use the newly added virCapabilitiesSetNetPrefix to set
the network prefix for the driver. This in return will
be use by NetDefFormat() and NetDefParseXML() routines
to free any interface name that start with the registered
prefix.
Acked-by: NDaniel P. Berrange <berrange@redhat.com>
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

Our domain_conf.* files are big enough. Not only they contain XML
parsing code, but they served as a storage of all functions whose
name is virDomain prefixed. This is just wrong as it gathers not
related functions (and modules) into one big file which is then
harder to maintain. Split virDomainObjList module into a separate
file called virdomainobjlist.[ch].
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

A later change will use the PortAllocator for SPICE too.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Provide integration with libvirt's lock manager in the libxl driver.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Introduce libxl.conf configuration file, adding the 'autoballoon'
setting as the first knob for controlling the libxl driver.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

xen.git commit babeca32 added a pkgconfig file for libxenlight,
allowing libxl apps to determine the location of Xen binaries
such as firmware blobs, device emulator, etc.

This patch adds support for xenlight.pc in the libxl driver, falling
back to the previous configure logic if not found.  It introduces
LIBXL_FIRMWARE_DIR and LIBXL_EXECBIN_DIR to define the firmware and
libexec_bin locations.  If xenlight.pc does not exist, the defines
are set to the current hardcoded paths.  The capabilities'
<emulator> and <loader> elements are updated to use the paths.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Specifying an explicit path to pygrub (e.g. BINDIR "/pygrub") only works if
Xen and libvirt happen to be installed to the same prefix. A more flexible
approach is to simply specify "pygrub" which will cause libxl to use the
correct path which it knows (since it is built with the same prefix as pygrub).

This is particular problematic in the Debian packaging, since the Debian Xen
package relocates pygrub into a libexec dir, however I think this change makes
sense upstream.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

This patch introduces a function to detect whether the specified
emulator is QEMU_XEN or QEMU_XEN_TRADITIONAL.  Detection is based on the
string "Options specific to the Xen version:" in '$qemu -help' output.
AFAIK, the only qemu containing that string in help output is the
old Xen fork (aka qemu-dm).

Note:
QEMU_XEN means a qemu that contains support for Xen.

QEMU_XEN_TRADITIONAL means Xen's old forked qemu 0.10.2
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

libxl interface for vcpu pinning is changing in Xen 4.5. Basically,
libxl_set_vcpuaffinity() now wants one more parameter. That is
representative of 'VCPU soft affinity', which libvirt does not use.

To mark such change, the macro LIBXL_HAVE_VCPUINFO_SOFT_AFFINITY is
defined. Use it as a gate and, if present, re-#define the calls from
the old to the new interface, to avoid breaking the build.
Signed-off-by: NDario Faggioli <dario.faggioli@citrix.com>
Cc: Jim Fehlig <jfehlig@suse.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>

This patch adds initial migration support to the libxl driver,
using the VIR_DRV_FEATURE_MIGRATION_PARAMS family of migration
functions.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

To allow the test suite to creat the XML option object,
move the virDomainXMLOptionNew call into a libxlCreateXMLConf
method.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To make it easier to test, change libxlBuildDomainConfig so
that it takes a virPortAllocatorPtr instead of the larger
libxlDriverPrivatePtr object.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To make it easier to unit test, change libxlBuildDomainConfig
so that it takes 'virDomainDefPtr' and 'libxl_ctx *' objects
as separate parameters.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Since it is an abbreviation, PCI should always be fully
capitalized or full lower case, never Pci.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Move libxlDoNodeGetInfo from libxl_driver to libxl_conf
for use by other libxl modules.  For consistency, rename to
libxlDriverNodeGetInfo.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Add pci passthrough to libxl driver, support attach-device, detach-device and
start a vm with pci hostdev specified.

Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Due to some misunderstanding of requirements libxl places on timer
handling, I introduced the half-brained idea of maintaining a list
of timeouts that the driver could force to expire before freeing a
libxlDomainObjPrivate (and hence libxl_ctx).  But testing all
the latest versions of Xen supported by the libxl driver (4.2.3,
4.3.1, 4.4.0 RC3), I see that libxl will handle this just fine and
there is no need to force expiration behind libxl's back.  Indeed it
may be harmful to do so.

This patch removes the timer list, allowing libxl to handle cleanup
of its timer registrations.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

The libvirt_internal.h header was included by the internal.h header.
This made it painful to add new stuff to the header file that would
require some more specific types. Remove inclusion by internal.h and add
it to appropriate places manually.

As pointed out by the Xen folks [1], HVM nics should always be set
to type LIBXL_NIC_TYPE_VIF_IOEMU unless the user explicity requests
LIBXL_NIC_TYPE_VIF via model='netfront'.  The current logic in
libxlMakeNic() only sets the nictype to LIBXL_NIC_TYPE_VIF_IOEMU if
a model is specified that is not 'netfront', which breaks PXE booting
configurations where no model is specified (i.e. use the hypervisor
default).
Reported-by: NStefan Bader <stefan.bader@canonical.com>

[1] https://www.redhat.com/archives/libvir-list/2013-December/msg01156.html

Leave virDomainEventRegister and its Deregister brother as these are
legacy functions only for domain lifecycle events.

Change source file copyright notice to prevailing libvirt style.

Move the libxl driver lock/unlock functions from libxl_driver.c
to libxl_conf.h so they can be used by other source files.

Similar to the QEMU and LXC drivers, annotate the fields of
libxlDriverPrivate struct to indicate the locking rules for
their use.

The libxlDriverPrivate struct contains an variety of data with
varying access needs. Similar to the QEMU and LXC drivers,
move all the static config data into a dedicated libxlDriverConfig
object. The only locking requirement is to hold the driver lock
while obtaining an instance of libxlDriverConfig. Once a reference
is held on the config object, it can be used completely lockless
since it is immutable.

libxl version info is static data as far as the libxl driver
is concerned, so retrieve this info when the driver is initialized
and stash it in the libxlDriverPrivate object.  Subsequently use
the stashed info instead of repeatedly calling libxl_get_version_info().

Create libxl_domain.[ch] and move all functions operating on
libxlDomainObjPrivate to these files.  This will be useful for
future patches that e.g. add job support for libxlDomainObjPrivate.

Detecting whether or not to autoballoon is configuration related,
so move the code to libxl_conf.