Commit Graph
100 Commits
Author SHA1 Message Date
Jim Fehlig 4796d7b34b Xen: xenconfig: remove XEND_CONFIG_VERSION in common code
Remove use of XEND_CONFIG_VERSION_* from xenconfig/xen_common.c

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-12-17 21:22:33 -07:00
Jim Fehlig 9e6d721985 Xen: tests: use latest XEND_CONFIG_VERSION in xm/xl tests
Change all tests to use the latest XEND_CONFIG_VERSION
(XEND_CONFIG_VERSION_3_1_0 = 4). Fix tests that do not conform to
the latest version.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-12-17 21:22:33 -07:00
Jim Fehlig 134e05e005 Xen: tests: remove old xml2sexpr tests
Remove XML to s-expression converstion tests for old xend 3.0.2
config format.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-12-17 21:22:33 -07:00
Jim Fehlig ed5cf72035 Xen: tests: remove old sexpr2xml tests
Remove s-expression to XML conversion tests for old xend 3.0.2
config format.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-12-17 21:22:33 -07:00
Jim Fehlig f281926e1d Xen: tests: remove net-ioemu xm config test
Remove the fullvirt-net-ioemu test since explicitly specifying
'type=ioemu' has not been needed in xm/xend for a long time. It is
not used at all in xl/libxl.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-12-17 21:22:33 -07:00
Jim Fehlig 59baedd87f Xen: tests: remove old xm config tests
Remove xm config tests for old xend 3.0.2 config format.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-12-17 21:22:33 -07:00
Jim Fehlig e4ac5919ba Revert "libxl: implement virDomainInterfaceStats"
This reverts commit d2e5538b16.

A migration regression was introduced by this commit. When migrating
a domain, its active XML is sent to the destination libvirtd, where
it is parsed as inactive XML. d2e5538b copied the libxl generated
interface name into the active config, which was being passed to the
migration destination and being parsed into inactive config. Attempting
to start the config could result in failure if an interface with the
same generated name already exists.

The qemu driver behaves similarly, but the parser contains a hack to
skip interface names starting with 'vnet' when parsing inactive XML.
We could extend the hack to skip names starting with 'vif' too, but a
better fix would be to expose these hypervisor-specific interface name
prefixes in capabilities. See the following discussion thread for more
details

https://www.redhat.com/archives/libvir-list/2015-December/msg00262.html

For the pending 1.3.0 release, it is best to revert d2e5538b. It can
be added again post release, after moving the prefix to capabilities.
2015-12-08 08:04:40 -07:00
Jim Fehlig afbb8a4c8c libxl: don't unlock virDomainObj if refcnt is 0
Commit 6472e54a unlocks the virDomainObj even if libxlDomainObjEndJob
returns false, indicating that its refcnt has dropped to 0.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-11-19 08:53:44 -07:00
Jim Fehlig 97b56031a9 libxl: unref libxlDriverConfig object
Commits b6e19cf4 and 6472e54a missed unref'ing the
libxlDriverConfig object. Add missing calls to virObjectUnref.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-11-19 08:52:53 -07:00
Jim Fehlig a4604eb086 libxl: fix compiler error introduced by commit ba25c214
libxl/libxl_conf.c: In function 'libxlDriverConfigNew':
libxl/libxl_conf.c:1560:30: error: 'log_level' may be used uninitialized
in this function [-Werror=maybe-uninitialized]
2015-09-15 21:10:59 -06:00
Jim Fehlig ba25c214f7 libxl: open libxl log stream with libvirtd log_level
Instead of a hardcoded DEBUG log level, use the overall
daemon log level specified in libvirtd.conf when opening
a log stream with libxl. libxl is very verbose when DEBUG
log level is set, resulting in huge log files that can
potentially fill a disk. Control of libxl verbosity should
be placed in the administrator's hands.
2015-09-15 11:19:53 -06:00
Jim Fehlig 6ce939c247 libxl: don't overwrite error from virNetSocketNewConnectTCP()
Remove redundant error reporting in libxlDomainMigrationPerform().
virNetSocketNewConnectTCP() is perfectly capable of reporting
sensible errors.
2015-09-03 20:37:28 -06:00
Jim Fehlig 60acb38abb Revert "LXC: show used memory as 0 when domain is not active"
This reverts commit 1ce7c1d20c,
which introduced a significant semantic change to the
virDomainGetInfo() API. Additionally, the change was only
made to 2 of the 15 virt drivers.

Conflicts:
	src/qemu/qemu_driver.c

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-08-28 09:05:26 -06:00
Jim Fehlig e80b84a743 libxl: acquire a job when receiving a migrating domain
Commit f86ae403 moved acquiring a job from libxlDomainStart()
to its callers. One spot missed was in libxlDoMigrateReceive().
Acquire a job in libxlDoMigrateReceive() before calling
libxlDomainStart().

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-08-27 15:51:31 -06:00
Jim Fehlig 15120b8c61 libxl: don't attempt to resume domain when suspend fails
Failure of libxl_domain_suspend() does not leave the domain in
a suspended state, so no need to call libxl_domain_resume(),
which btw will fail with "domain not suspended".

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-08-27 15:51:31 -06:00
Jim Fehlig 44a54eb073 libxl: fix ref counting of libxlMigrationDstArgs
This patch fixes some flawed logic around ref counting the
libxlMigrationDstArgs object.

First, when adding sockets to the event loop with
virNetSocketAddIOCallback(), the generic virObjectFreeCallback()
was registered as a free function, with libxlMigrationDstArgs as
its parameter. A reference was also taken on
libxlMigrationDstArgs for each successful call to
virNetSocketAddIOCallback(). The rational behind this logic was
that the libxlMigrationDstArgs object had to out-live the socket
objects. But virNetSocketAddIOCallback() already takes a
reference on socket objects, ensuring their life until removed
from the event loop and unref'ed in virNetSocketEventFree(). We
only need to ensure libxlMigrationDstArgs lives until
libxlDoMigrateReceive() finishes, which can be done by simply
unref'ing libxlMigrationDstArgs at the end of
libxlDoMigrateReceive().

The second flaw was unref'ing the sockets in the failure path of
libxlMigrateReceive() and at the end of libxlDoMigrateReceive().
As mentioned above, the sockets are already unref'ed by
virNetSocketEventFree() when removed from the event loop.
Attempting to unref the socket a second time resulted in a
libvirtd crash since the socket was previously unref'ed and
disposed.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-08-27 15:51:03 -06:00
Jim Fehlig 4ffb21c89a libxl: set dom0 state to running
Commit 45697fe5 added dom0 to driver->domains, but missed
setting its state to 'running'

$ virsh list
 Id    Name                           State
----------------------------------------------------
 0     Domain-0                       shut off
2015-07-10 11:36:57 -06:00
Jim Fehlig e9c2734441 libxl: rework setting the state of virDomainObj
Set the state of virDomainObj in the functions that
actually change the domain state, instead of the generic
libxlDomainCleanup function. This approach gives functions
calling libxlDomainCleanup more flexibility wrt when and
how they change virDomainObj state via virDomainObjSetState.

The prior approach of calling virDomainObjSetState in
libxlDomainCleanup resulted in the following incorrect
coding pattern in the various functions that change
domain state

 libxlDomain<DoStateTransition>
   call libxl function to do state transition
   emit lifecycle event
   libxlDomainCleanup
     virDomainObjSetState

Once simple manifestation of this bug is seeing a domain
running in virt-manager after selecting the shutdown button,
even after the domain has long shutdown.
2015-07-08 15:24:48 -06:00
Jim Fehlig 45697fe545 libxl: support dom0
In Xen, dom0 is really just another domain that supports ballooning,
adding/removing devices, changing vcpu configuration, etc. This patch
adds support to the libxl driver for managing dom0. Note that the
legacy xend driver has long supported managing dom0.

Operations that are not supported on dom0 are filtered in libvirt
where a sensible error is reported. Errors from libxl are not
always helpful. E.g., attempting a save on dom0 results in

2015-06-23 15:25:05 MDT libxl: debug: libxl_dom.c:1570:libxl__toolstack_save: domain=0 toolstack data size=8
2015-06-23 15:25:05 MDT libxl: debug: libxl.c:979:do_libxl_domain_suspend: ao 0x7f7e68000b70: inprogress: poller=0x7f7e68000930, flags=i
2015-06-23 15:25:05 MDT libxl-save-helper: debug: starting save: Success
2015-06-23 15:25:05 MDT xc: detail: xc_domain_save_suse: starting save of domid 0
2015-06-23 15:25:05 MDT xc: error: Couldn't map live_shinfo (3 = No such process): Internal error
2015-06-23 15:25:05 MDT xc: detail: Save exit of domid 0 with errno=3
2015-06-23 15:25:05 MDT libxl-save-helper: debug: complete r=1: No such process
2015-06-23 15:25:05 MDT libxl: error: libxl_dom.c:1876:libxl__xc_domain_save_done: saving domain: domain did not respond to suspend request: No such process
2015-06-23 15:25:05 MDT libxl: error: libxl_dom.c:2033:remus_teardown_done: Remus: failed to teardown device for guest with domid 0, rc -8

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-07-08 15:04:59 -06:00
Jim Fehlig 04597f8f0d libxl: Set def->vcpus after successfully modifying live vcpu count
def->vcpus was never updated after successfully changing the live
vcpu count of a domain. Subsequent queries for vcpu info would
return incorrect results.  E.g.:

virsh vcpucount test
maximum      config         4
maximum      live           4
current      config         4
current      live           4

virsh setvcpus test 2

virsh vcpucount test
maximum      config         4
maximum      live           4
current      config         4
current      live           4

After patch, live current config is reported correctly:

virsh vcpucount test
maximum      config         4
maximum      live           4
current      config         4
current      live           2

While fixing this, noticed that the live config was not saved
to cfg->stateDir via virDomainSaveStatus. Save the live config
and change error handling of virDomainSave{Config,Status} to
log a message via VIR_WARN, instead of failing the entire
DomainSetVcpusFlags operation.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-06-30 11:02:30 -06:00
Jim Fehlig 33be48d78e libxl: honor domainGetXMLDesc() --inactive flag
The libxl driver always uses virDomainObj->def when formatting
the domain XML description.  Use virDomainObj->newDef when
--inactive flag is set.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-06-30 11:02:30 -06:00
Jim Fehlig 4b53d0d4ac libxl: don't remove persistent domain on start failure
libxlDomainCreateXML() would remove a persistent domain if
libxlDomainStart() failed.  Check if domain is persistent
before removing.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-06-30 11:02:30 -06:00
Jim Fehlig 29b154e29a libxl: don't overwrite domain state from statedir config
When restarting libvirtd and reconnecting to running domains,
libxlReconnectDomain() would unconditionally set the domain state
to VIR_DOMAIN_RUNNING, overwriting the state maintained in
$statedir/<domname>.xml.  A domain in a paused state would have
the state changed to running, even though it was actually in a
paused state.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-06-30 11:02:29 -06:00
Jim Fehlig df37c26e73 spec: fixes for recently introduced libxl conf files
Commit 198cc1d3 introduced libxl-lockd and libxl-sanlock config
files but forgot to add them to the spec file.  Follow-up commit
62b18d98 added the files to daemon-driver-libxl, but missed adding
them to the daemon package when configuring libvirt
--without-driver-modules.  In addition, commit 62b18d98 added
libxl-sanlock to daemon-driver-libxl, but it should be included
in lock-sanlock when libvirt is configured --with-sanlock.
2015-06-01 12:01:18 -06:00
Jim Fehlig 75d650dc5e libxl: support QXL video device
libxl recently gained support for QXL video device.  Support
it in the libxl driver too.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-28 12:40:43 -06:00
Jim Fehlig 6baf881441 libxl: support SPICE graphics for HVM domains
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-28 12:40:43 -06:00
Jim Fehlig 5a10fb1d2c libxl: change reservedVNCPorts to reservedGraphicsPorts
A later change will use the PortAllocator for SPICE too.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-28 12:40:43 -06:00
Jim Fehlig 09f2faf933 libxl: populate build_info vfb in separate function
For HVM domains, vfb info must be populated in the libxl_domain_build_info
struct.  Currently this is done in the libxlMakeVfbList function, but IMO
it would be cleaner to populate the build_info vfb in a separate
libxlMakeBuildInfoVfb function.  libxlMakeVfbList would then handle only
vfb devices, simiar to the other libxlMake<device>List functions.

A future patch will extend libxlMakeBuildInfoVfb to support SPICE.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-28 12:40:43 -06:00
Jim Fehlig a5b55bd931 xenconfig: fix spice mousemode and copypaste
From xl.cfg950 man page:

spiceagent_mouse=BOOLEAN
Whether SPICE agent is used for client mouse mode. The default is
true (1) (turn on)

spicevdagent=BOOLEAN
Enables spice vdagent. The Spice vdagent is an optional component for
enhancing user experience and performing guest-oriented management
tasks. Its features includes: client mouse mode (no need to grab
mouse by client, no mouse lag), automatic adjustment of screen
resolution, copy and paste (text and image) between client and domU.
It also requires vdagent service installed on domU o.s. to work.
The default is 0.

spice_clipboard_sharing=BOOLEAN
Enables Spice clipboard sharing (copy/paste). It requires spicevdagent
enabled. The default is false (0).

So if spiceagent_mouse is enabled (client mouse mode) or
spice_clipboard_sharing is enabled, spicevdagent must be enabled.
Along with this change, s/spicedvagent/spicevdagent, set
spiceagent_mouse correctly, and add a test for these spice
features.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-18 12:46:16 -06:00
Jim Fehlig a460295f4e xenconfig: fix spicepasswd handling
The logic related to spicedisable_ticketing and spicepasswd was
inverted.  As per man xl.cfg(5), 'spicedisable_ticketing = 1'
means no passwd is required.  On the other hand, a passwd is
required if 'spicedisable_ticketing = 0'.  Fix the logic and
produce and error if 'spicedisable_ticketing = 0' but spicepasswd
is not provided.  Also fix the spice cfg test file.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-18 12:46:16 -06:00
Jim Fehlig e21b1180a9 xenconfig: format spice listenAddr when formating ports
Move formating of spice listenAddr to the section of code
where spice ports are formatted.  It is more logical to
format address and ports together.  Account for the change
in spice cfg test file by moving 'spicehost'.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-18 12:46:16 -06:00
Jim Fehlig 096b39c961 xenconfig: use local variable for graphics def
'graphics->' is a bit easier to read and type, and makes for
shorter lines than 'def->graphics[0]->'.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-18 12:46:16 -06:00
Jim Fehlig 99a42f3c0f libxl: provide impl for nodeGetSecurityModel
Currently, the libxl driver does not support any security drivers.
When the qemu driver has no security driver configued,
nodeGetSecurityModel succeeds but returns an empty virSecurityModel
object.  Do the same in the libxl driver instead of reporting

this function is not supported by the connection driver:
virNodeGetSecurityModel
2015-05-15 14:07:01 -06:00
Jim Fehlig fa33c0b8af libxl: support VNC passwd
While implementing support for SPICE, I noticed VNC passwd was
never copied to libxl_device_vfb's vnc.passwd field.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-05-12 15:32:04 -06:00
Jim Fehlig c0d3f608d6 libxl: support soundhw for hvm domains
The xend driver and the parsing/formating code in src/xenconfig
have long supported soundhw.  Add support in the libxl driver too.
2015-05-05 09:19:37 -06:00
Jim Fehlig 77664cb406 libxl: add logrotate config file
Add logrotate config for log files in /var/log/libvirt/libxl.
2015-05-05 09:08:11 -06:00
Jim Fehlig 198cc1d339 libxl: provide integration with lock manager
Provide integration with libvirt's lock manager in the libxl driver.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-04-29 10:51:36 -06:00
Jim Fehlig 247b2c5388 libxl: initialize sdl.opengl defbool in libxlMakeVfb
Commit bf32462b missed initializing sdl.opengl.  Without the
initialization, libvirtd will be terminated by an assert from libxl:

Assertion `!libxl_defbool_is_default(db)' failed.

Reported-by: Olaf Hering <olaf@aepfle.de>
2015-04-24 14:11:26 -06:00
Jim Fehlig ee3eddb332 locking: relax PID requirement
Some hypervisors like Xen do not have PIDs associated with domains.
Relax the requirement for PID != 0 in the locking code so it can
be used by hypervisors that do not represent domains as a process
running on the host.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-04-22 14:16:44 -06:00
Jim Fehlig d0baac09e6 libxl: Introduce configuration file for libxl driver
Introduce libxl.conf configuration file, adding the 'autoballoon'
setting as the first knob for controlling the libxl driver.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-04-21 14:23:40 -06:00
Jim Fehlig 6dfec1efba libxl: drop virDomainObj lock when destroying a domain
A destroy operation can take considerable time on large memory
domains due to scrubbing the domain's memory.  Unlock the
virDomainObj while libxl_domain_destroy is executing.

Implement libxlDomainDestroyInternal wrapper to handle unlocking,
calling destroy, and locking.  Change all callers of
libxl_domain_destroy to use the wrapper.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-04-16 16:43:19 -06:00
Jim Fehlig 894d2ff759 libxl: acquire a job when destroying a domain
A job should be acquired at the beginning of a domain destroy operation,
not at the end when cleaning up the domain.  Fix two occurrences of this
late job acquisition in the libxl driver.  Doing so renders
libxlDomainCleanupJob unused, so it is removed.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-04-16 16:43:18 -06:00
Jim Fehlig f86ae40324 libxl: Move job acquisition in libxlDomainStart to callers
Let callers of libxlDomainStart decide when it is appropriate to
acquire a job on the associated virDomainObj.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-04-16 16:42:53 -06:00
Jim Fehlig 13e2c22099 libxl: support HVM direct kernel boot
Add support for HVM direct kernel boot in libxl.  Also add a
test to verify domXML <-> native conversions.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-04-16 16:14:51 -06:00
Jim Fehlig 0fe504f15a xenconfig: don't use "kernel" for hvmloader
In xl config, hvmloader is implied for hvm guests.  It is not
specified with the "kernel" option like xm config.  The "kernel"
option, along with "ramdisk" and "extra", is used for HVM direct
kernel boot.  Instead of using "kernel" option to populate
virDomainDef object's os.loader->path, use hvmloader discovered
when gathering capabilities.

This change required fixing initialization of capabilities in
the test utils and removing 'kernel = "/usr/lib/xen/boot/hvmloader"'
from the test config files.
2015-04-16 16:11:01 -06:00
Jim Fehlig 717a92513d xenconfig: move <os> parsing/formating to config-specific files
xl and xm differ a bit in how <os> configuration is represented.
E.g. xl config supports <os><nvram .../></os> via its "bios"
setting.

Move the xenParseOS and xenFormatOS functions from xen_common.c
and copy to xen_xl.c and xen_xm.c so they can be customized for
xm vs xl config.  An unfortunate fallout is reordering of entries
in the test config files.
2015-04-16 16:11:01 -06:00
Jim Fehlig a9b0d647bc xenconfig: remove redunant parsing of device_model
device_model is parsed in xenParseOS(), then later in
xenParseConfigCommon().  <emulator> is not part of <os>,
so makes sense to remove the parsing in xenParseOS().
2015-04-16 16:11:01 -06:00
Jim Fehlig 8680a19bc8 xenconfig: export xenConfigCopyString
Export xenConfigCopyString for use outside of xen_common.c

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-04-16 16:11:01 -06:00
Jim Fehlig d685c0f91b libxl: fix dom0 balloon logic
Recent testing on large memory systems revealed a bug in the Xen xl
tool's freemem() function.  When autoballooning is enabled, freemem()
is used to ensure enough memory is available to start a domain,
ballooning dom0 if necessary.  When ballooning large amounts of memory
from dom0, freemem() would exceed its self-imposed wait time and
return an error.  Meanwhile, dom0 continued to balloon.  Starting the
domain later, after sufficient memory was ballooned from dom0, would
succeed.  The libvirt implementation in libxlDomainFreeMem() suffers
the same bug since it is modeled after freemem().

In the end, the best place to fix the bug on the Xen side was to
slightly change the behavior of libxl_wait_for_memory_target().
Instead of failing after caller-provided wait_sec, the function now
blocks as long as dom0 memory ballooning is progressing.  It will return
failure only when more memory is needed to reach the target and wait_sec
have expired with no progress being made.  See xen.git commit fd3aa246.
There was a dicussion on how this would affect other libxl apps like
libvirt

http://lists.xen.org/archives/html/xen-devel/2015-03/msg00739.html

If libvirt containing this patch was build against a Xen containing
the old libxl_wait_for_memory_target() behavior, libxlDomainFreeMem()
will fail after 30 sec and domain creation will be terminated.
Without this patch and with old libxl_wait_for_memory_target() behavior,
libxlDomainFreeMem() does not succeed after 30 sec, but returns success
anyway.  Domain creation continues resulting in all sorts of fun stuff
like cpu soft lockups in the guest OS.  It was decided to properly fix
libxl_wait_for_memory_target(), and if anything improve the default
behavior of apps using the freemem reference impl in xl.

xl was patched to accommodate the change in libxl_wait_for_memory_target()
with xen.git commit 883b30a0.  This patch does the same in the libxl
driver.  While at it, I changed the logic to essentially match
freemem() in $xensrc/tools/libxl/xl_cmdimpl.c.  It was a bit cleaner
IMO and will make it easier to spot future, potentially interesting
divergences.
2015-04-02 09:41:03 -06:00
Jim Fehlig a5bf06ba34 libxl: remove per-domain libxl_ctx
Although needed in the Xen 4.1 libxl days, there is no longer any
benefit to having per-domain libxl_ctx.  On the contrary, their use
makes the code unecessarily complicated and prone to deadlocks under
load.  As suggested by the libxl maintainers, use a single libxl_ctx
as a handle to libxl instead of per-domain ctx's.

One downside to using a single libxl_ctx is there are no longer
per-domain log files for log messages emitted by libxl.  Messages
for all domains will be sent to /var/log/libvirt/libxl/libxl-driver.log.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-24 15:03:55 -06:00
Jim Fehlig 6728645a41 libxl: make libxlDomainFreeMem static
libxlDomainFreeMem() is only used in libxl_domain.c and thus should
be declared static.  While at it, change the signature to take a
libxl_ctx instead of libxlDomainObjPrivatePtr, since only the
libxl_ctx is needed.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-24 15:03:54 -06:00
Jim Fehlig 1cca1d25a0 libxl: remove unnecessary libxlDomainEventsRegister
This function now only enables domain death events.  Simply call
libxl_evenable_domain_death() instead of an unnecessary wrapper.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-24 15:03:54 -06:00
Jim Fehlig 0b0a3d63bb libxl: use global libxl_ctx in event handler
Change the domain event handler code to use the driver-wide
libxl_ctx instead of the domain-specific one.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-24 15:03:54 -06:00
Jim Fehlig 109cf8d89c libxl: move event registration to driver initialization
Register a domain event handler with the driver-wide libxl_ctx
during driver initialization.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-24 15:03:54 -06:00
Jim Fehlig 331a02a701 libxl: Move setup of child processing code to driver initialization
Informing libxl how to handle its child proceses should be done once
during driver initialization, not once for each domain-specific
libxl_ctx object.  The related libxl documentation in
$xen-src/tools/libxl/libxl_event.h even mentions that "it is best to
call this at initialisation".

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-24 15:03:54 -06:00
Jim Fehlig 57db83ae3b libxl: use driver-wide ctx in fd and timer event handling
Long ago I incorrectly associated libxl fd and timer registrations
with per-domain libxl_ctx objects.  When creating a libxlDomainObjPrivate,
a libxl_ctx is allocated, and libxl_osevent_register_hooks is called
passing a pointer to the libxlDomainObjPrivate.  When an fd or timer
registration occurred, the registration callback received the
libxlDomainObjPrivate, containing the per-domain libxl_ctx.  This
libxl_ctx was then used when informing libxl about fd events or
timer expirations.

The problem with this approach is that fd and timer registrations do not
share the same lifespan as libxlDomainObjPrivate, and hence the per-domain
libxl_ctx ojects.  The result is races between per-domain libxl_ctx's being
destoryed and events firing on associated fds/timers, typically manifesting
as an assert in libxl

libxl_internal.h:2788: libxl__ctx_unlock: Assertion `!r' failed

There is no need to associate libxlDomainObjPrivate objects with libxl's
desire to use libvirt's event loop.  Instead, the driver-wide libxl_ctx can
be used for the fd and timer registrations.

This patch moves the fd and timer handling code away from the
domain-specific code in libxl_domain.c into libxl_driver.c.  While at it,
function names were changed a bit to better describe their purpose.

The unnecessary locking was also removed since the code simply provides a
wrapper over the event loop interface.  Indeed the locks may have been
causing some deadlocks when repeatedly creating/destroying muliple domains.
There have also been rumors about such deadlocks during parallel OpenStack
Tempest runs.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-24 15:03:54 -06:00
Jim Fehlig 2adba7d3ab libxl: use xenlight pkgconfig file if present
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: Jim Fehlig <jfehlig@suse.com>
2015-03-19 16:13:26 -06:00
Jim Fehlig bd235cd873 libxl: Don't overwrite errors from xenconfig
When converting domXML from native, the libxl driver was overwriting
useful errors from the xenconfig parsing code with a useless, generic
error.  E.g. "internal error: parsing xm config failed" vs
"internal error: config value usbdevice was malformed".  Remove the
redundant (and useless) error reporting in the libxl driver.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-18 20:55:33 -06:00
Jim Fehlig a7d6b94a00 libxl: fix regression introduced by commit 4ab8cd77
Commit 4ab8cd77 added a check requiring input devices to have
a bus type of VIR_DOMAIN_INPUT_BUS_USB, failing to start the
domain otherwise.  But virDomainDefParseXML adds implicit mouse
and keyboard if a graphics device is configured.  See calls to
virDomainDefMaybeAddInput.

The regression is fixed by removing the check requiring USB input
devices, and skipping non-USB input devices when populating USB
'usbdevice' in libxl_domain_build_info struct.
2015-03-16 11:49:58 -06:00
Jim Fehlig 3b7f589571 libxl: remove unneeded cleanup_unlock label
In the old days of a global driver lock, it was necessary to unlock
the driver after a domain restore operation.  When the global lock
was removed from the driver, some remnants were left behind in
libxlDomainRestoreFlags.  Remove this unneeded (and incorrect) code.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-05 09:05:35 -07:00
Jim Fehlig b1d159d889 libxl: use libxl_ctx passed to libxlConsoleCallback
Instead of using the libxl_ctx in the libxlDomainObjPrivatePtr,
use the ctx passed to the callback.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-05 09:05:34 -07:00
Jim Fehlig fc3ef44ea4 libxl: remove redundant calls to libxl_evdisable_domain_death
Domain death watch is already disabled in libxlDomainCleanup.  No
need to disable it a second and third time.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-03-05 09:05:34 -07:00
Jim Fehlig e274d5882e tests: fix xlconfigtest build failure
When libvirt is configured --without-xen, building the xlconfigtest
fails with

  CCLD   xlconfigtest
  /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/crt1.o
  In function `_start': (.text+0x20): undefined reference to `main'
  collect2: error: ld returned 1 exit status

Introduced in commit 4ed5fb91 by too much copy and paste from
xmconfigtest.
2015-01-20 21:03:09 -07:00
Jim Fehlig 4689cdf779 Introduce support for parsing/formatting Xen xl config format
Introduce a parser/formatter for the xl config format.  Since the
deprecation of xm/xend, the VM config file format has diverged as
new features are added to libxl.  This patch adds support for parsing
and formating the xl config format.  It supports the existing xm config
format, plus adds support for spice graphics and xl disk config syntax.

Disk config is specified a bit differently in xl as compared to xm.  In
xl, disk config consists of comma-separated positional parameters and
keyword/value pairs separated by commas. Positional parameters are
specified as follows

   target, format, vdev, access

Supported keys for key=value options are

  devtype, backendtype

The positional paramters can also be specified in key/value form.  For
example the following xl disk config are equivalent

    /dev/vg/guest-volume,,hda
    /dev/vg/guest-volume,raw,hda,rw
    format=raw, vdev=hda, access=rw, target=/dev/vg/guest-volume

See $xen_sources/docs/misc/xl-disk-configuration.txt for more details.

xl disk config is parsed with the help of xlu_disk_parse() from
libxlutil, libxl's utility library.  Although the library exists
in all Xen versions supported by the libxl virt driver, only
recently has the corresponding header file been included.  A check
for the header is done in configure.ac.  If not found, xlu_disk_parse()
is declared externally.

Signed-off-by: Kiarie Kahurani <davidkiarie4@gmail.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-14 08:28:50 -07:00
Jim Fehlig f7a30375bd Revert "src/xenconfig: Xen-xl parser"
This reverts commit 2c78051a14.

Conflicts:
	src/Makefile.am

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:15:13 -07:00
Jim Fehlig cb4befc748 Revert "tests: Tests for the xen-xl parser"
This reverts commit 6b818d3b09.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:15:09 -07:00
Jim Fehlig 4d77c136f8 Revert "libxl: Add support for parsing/formating Xen XL config"
This reverts commit 4f524212ce.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:15:04 -07:00
Jim Fehlig 88e34a9479 Revert "src/Makefile.am: fix build breaker for xenconfig"
This reverts commit 703ef9667a.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:14:59 -07:00
Jim Fehlig 0f2cd69b5a Revert "build: fix xenconfig VPATH builds"
This reverts commit 1b21d30069.

Conflicts:
	src/Makefile.am

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:14:54 -07:00
Jim Fehlig 3ac24305a8 Revert "Revert "src/Makefile.am: fix build breaker for xenconfig""
This reverts commit e662968fd9.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:14:48 -07:00
Jim Fehlig 1cb2667c12 Revert "src/Makefile: move the new xen_xl_disk parser code at the correct place"
This reverts commit edacdb3d12.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:14:42 -07:00
Jim Fehlig dc8f62a9f9 Revert "src/Makefile: Fix parallel build after xen_xl_disk parser introduction"
This reverts commit 533349ff43.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:14:37 -07:00
Jim Fehlig d2f80a772f Revert "bootstrap.conf: add check for flex"
This reverts commit cab767831f.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-12 10:14:30 -07:00
Jim Fehlig 42874fa45f libxl: destroy domain in migration finish phase on failure
This patch contains three domain cleanup improvements in the migration
finish phase, ensuring a domain is properly disposed when a failure is
detected or the migration is cancelled.

The check for virDomainObjIsActive is moved to libxlDomainMigrationFinish,
where cleanup can occur if migration failed and the domain is inactive.

The 'cleanup' label was missplaced in libxlDomainMigrationFinish, causing
a migrated domain to remain in the event of an error or cancelled migration.

In cleanup, the domain was not removed from the driver's list of domains.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-11-21 13:11:47 -07:00
Jim Fehlig 6038682564 libxl: start domain paused on migration dst
During the perform phase of migration, the domain is started on
the dst host in a running state if VIR_MIGRATE_PAUSED flag is not
specified.  In the finish phase, the domain is also unpaused if
VIR_MIGRATE_PAUSED flag is unset.  I've noticed this second unpause
fails if the domain was already unpaused following the perform phase.

This patch changes the perform phase to always start the domain
paused, and defers unpausing, if requested, to the finish phase.
Unpausing should occur in the finish phase anyhow, where the domain
can be properly destroyed if the perform phase fails and migration
is cancelled.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-11-21 13:11:47 -07:00
Jim Fehlig a1f389515c libxl: acquire job in migration finish phase
Moving data reception of the perform phase of migration to a
thread introduces a race with the finish phase, where checking
if the domain is active races with the thread finishing the
perform phase.  The race is easily solved by acquiring a job in
the finish phase, which must wait for the perform phase job to
complete.

While wrapping the finish phase in a job, noticed the virDomainObj
was being unlocked in a callee - libxlDomainMigrationFinish.  Move
the unlocking to libxlDomainMigrateFinish3Params, where the lock
is acquired.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-11-21 13:11:47 -07:00
Jim Fehlig cb88d4333a libxl: Receive migration data in a thread
The libxl driver receives migration data within an IO callback invoked
by the event loop, effectively disabling the event loop while migration
occurs.

This patch moves receving of the migration data to a thread.  The
incoming connection is still accepted in the IO callback, but control
is immediately returned to the event loop after spawning the thread.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-11-21 13:11:47 -07:00
Jim Fehlig 720be2eb5f libxl: fix double-free of libxl_domain_build_info
On error, libxlMakeDomBuildInfo() frees the caller-provided
libxl_domain_build_info struct embedded in libxl_domain_config,
causing a segfault

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f9c13020700 (LWP 40988)]
(gdb) bt
0  0x00007f9c162f95b4 in free () from /lib64/libc.so.6
1  0x00007f9c0d0965ad in libxl_bitmap_dispose () from
   /usr/lib64/libxenlight.so.4.4
2  0x00007f9c0d0a73bf in libxl_domain_build_info_dispose ()
   from /usr/lib64/libxenlight.so.4.4
3  0x00007f9c0d0a7974 in libxl_domain_config_dispose () from
   /usr/lib64/libxenlight.so.4.4
4  0x00007f9c0d2e00c5 in libxlDomainStart (driver=0x7f9c0400e4e0,
   vm=0x7f9c0412b0d0, start_paused=false, restore_fd=-1) at
   libxl/libxl_domain.c:1323
5  0x00007f9c0d2e1d4b in libxlDomainCreateXML (conn=0x7f9c000009a0,...)
   at libxl/libxl_driver.c:660

Remove the call to libxl_domain_build_info_dispose() from
libxlMakeDomBuildInfo().  On error, callers will dispose the
libxl_domain_config object, which in turn disposes the build info.
2014-10-30 10:23:18 -06:00
Jim Fehlig 1c0bf509ef libxl: Support user-specified <emulator>
With the introduction of the libxlDomainGetEmulatorType function,
it is trivial to support a user-specfied <emulator> in the libxl
driver.  This patch is based loosely on David Scott's old patch
to do the same

https://www.redhat.com/archives/libvir-list/2013-April/msg02119.html
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-10-30 10:23:18 -06:00
Jim Fehlig 793a91f8e1 libxl: add missing 'break' from commit 1298daca
Add missing 'break's from commit 1298daca, as noted by John Ferlan

https://www.redhat.com/archives/libvir-list/2014-October/msg00430.html
2014-10-16 12:42:13 -06:00
Jim Fehlig c5a003508f libxl: Add function to determine device model type
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: Jim Fehlig <jfehlig@suse.com>
2014-10-10 15:08:40 -06:00
Jim Fehlig 9320c3ff19 Xen: Defer setting default vram value to Xen drivers
Allow the Xen drivers to determine default vram values.  Sane
default vaules depend on the device model being used, so the
drivers are in the best position to determine the defaults.

For the legacy xen driver, it is best to maintain the existing
logic for setting default vram values to ensure there are no
regressions.  The libxl driver currently does not support
configuring a video device.  Support will be added in a
subsequent patch, where the benefit of this change will be
reaped.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-10-10 15:08:36 -06:00
Jim Fehlig be28ae1658 libxl: Copy user-specified keymap to libxl build info struct
Commit 4dfc34c3 missed copying the user-specified keymap to
libxl_domain_build_info struct when creating a VFB device.

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-10-10 15:08:33 -06:00
Jim Fehlig a9bad1a337 libvirt-guests: run after time-sync.target
When libvirt-guests is configured to start guests on host
boot, it is possible for guests start and read the host
clock before it is synchronized.  Services such as
libvirt-guests that require correct time should use the
Special Passive System Unit time-sync.target

http://www.freedesktop.org/software/systemd/man/systemd.special.html#time-sync.target
2014-09-23 14:35:43 -06:00
Jim Fehlig c78923732d libxl: Drop driver lock in libxlDomainDefineXML
There is no need to acquire the driver-wide lock in
libxlDomainDefineXML.  When switching to jobs in the libxl
driver, most driver-wide locks were removed.  The locking here
was preserved since I mistakenly thought virDomainObjListAdd
needed protection.  This is not the case, so remove the
unnecessary locking.
2014-09-19 08:15:52 -06:00
Jim Fehlig 817206cdc8 libxl: fix mapping of libvirt and libxl lifecycle actions
The libxl driver was blindly assigning libvirt's
virDomainLifecycleAction to libxl's libxl_action_on_shutdown, when
in fact the various actions take on different values in these enums.

Introduce helpers to properly map the enum values.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-09-11 15:40:56 -06:00
Jim Fehlig 4dfc34c301 libxl: fix memory corruption introduced by commit b55cc5f4e
Commit b55cc5f4e did a shallow copy of libxl_{sdl,vnc}_info from the
domain config to the build info, which resulted in double-freeing
strings contained in the structures during cleanup, which later
resulted in a libvirtd crash.  Fix by performing a deep copy of the
structure, VIR_STRDUP'ing embedded strings instead of simply copying
their pointers.

Fixes the following issue reported on the libvirt dev list

https://www.redhat.com/archives/libvir-list/2014-August/msg01112.html
2014-08-25 17:35:12 -06:00
Jim Fehlig 337a136282 src/xenconfig: move common parsing/formatting to xen_common
XM and XL config are very similar.  Disks are specified differently
in XL, but the old XM disk config is still supported by XL.  XL also
supports new config like spice that was never supported by XM.

This patch moves all the common parsing and formatting functions to
the new file xen_common.c and adapts the XM parser/formatter accordingly.
This restructuring paves way for introducing an XL parser/formatter in
the future.

While moving the code, fixup whitespace, comments, and style issues.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-08-18 20:47:38 -06:00
Jim Fehlig 870c90c70f xen: rename xenxs to xenconfig
src/xenxs contains parsing/formating functions for the various xen
config formats, and is better named src/xenconfig.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2014-08-18 20:36:24 -06:00
Jim Fehlig 62c817e516 src/xenxs: Refactor code formating vif device config
Handle formating of VIF config in a new function xenFormatXMVif().

Signed-off-by: Kiarie Kahurani <davidkiarie4@gmail.com>
2014-08-14 11:49:53 -06:00
Jim Fehlig 72a8453948 libxl: fix crash in migrate confirm for transient domains
In libxlDomainMigrationConfirm(), a transient domain is removed
from the domain list after successful migration.  Later in cleanup,
the domain object is unlocked, resulting in a crash

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fb4208ed700 (LWP 12044)]
0x00007fb4267251e6 in virClassIsDerivedFrom (klass=0xdeadbeef,
  parent=0x7fb42830d0c0) at util/virobject.c:169
169	        if (klass->magic == parent->magic)
(gdb) bt
0  0x00007fb4267251e6 in virClassIsDerivedFrom (klass=0xdeadbeef,
  parent=0x7fb42830d0c0) at util/virobject.c:169
1  0x00007fb42672591b in virObjectIsClass (anyobj=0x7fb4100082b0,
  klass=0x7fb42830d0c0) at util/virobject.c:365
2  0x00007fb42672583c in virObjectUnlock (anyobj=0x7fb4100082b0)
  at util/virobject.c:338
3  0x00007fb41a8c7d7a in libxlDomainMigrationConfirm (driver=0x7fb4100404c0,
  vm=0x7fb4100082b0, flags=1, cancelled=0) at libxl/libxl_migration.c:583

Fix by setting the virDomainObjPtr to NULL after removing it from
the domain list.
2014-07-08 17:14:50 -06:00
Jim Fehlig bab7ad4ceb libxl: acquire job though begin phase only
During migration, the libxl driver starts a modify job in the
begin phase, ending the job in the confirm phase.  This is
essentially VIR_MIGRATE_CHANGE_PROTECTION semantics, but the
driver does not support that flag.  Without CHANGE_PROTECTION
support, the job would never be terminated in error conditions
where migrate confirm phase is not executed.  Further attempts
to modify the domain would result in failure to acquire a job
after LIBXL_JOB_WAIT_TIME.

Similar to the qemu driver, end the job in the begin phase.
Protecting the domain object across all phases of migration can
be done in a future patch adding CHANGE_PROTECTION support.
2014-07-08 17:14:50 -06:00
Jim Fehlig c4f66bb8be libxl: remove domain when migration prepare fails
In libxlDomainMigrationPrepare(), a new virDomainObj is created
from the incoming domain def and added to the driver's domain
list, but never removed if there are subsequent failures during
the prepare phase.

targethost# virsh list --all

sourcehost# virsh migrate --live dom xen+ssh://targethost/system
   error: operation failed: Fail to create socket for incoming migration.

targethost# virsh list --all
error: Failed to list domains
error: name in virGetDomain must not be NULL

After adding code to remove the domain on prepare failure, noticed
that libvirtd crashed due to double free of the virDomainDef.  Similar
to the qemu driver, pass a pointer to virDomainDefPtr so it can be set
to NULL once a virDomainObj is created from it.
2014-07-08 17:14:50 -06:00
Jim Fehlig 92cd6b677e libxl: rename goto label
In libxlDomainMigrationPrepare(), the cleanup label handles error
conditions and should be renamed as such for clarity.
2014-07-08 17:14:50 -06:00
Jim Fehlig ec7b922576 libxl: add PV console if not explicitly specified
Xen PV domains always have a PV console, so add one to the domain
config via post-parse callback if not explicitly specified in
the XML.  The legacy Xen driver behaves similarly, causing a
regression when switching to the new Xen toolstack.  I.e.

  virsh console pv-domain

will no longer work after upgrading a xm/xend stack to xl/libxl.
2014-06-30 18:56:44 -06:00
Jim Fehlig dc16534213 build: fix 'make syntax-check' after commit c6cf5df3
The commit caused prohibit_long_lines to fail in src/Makefile.am.
2014-06-30 18:48:19 -06:00
Jim Fehlig c6cf5df32a vbox: fix linker error
Noticed the following error when building the vbox driver
in the openSUSE build service

CCLD     vboxsnapshotxmltest
/usr/lib64/gcc/x86_64-suse-linux/4.8/../../../../x86_64-suse-linux/bin/ld:
../src/.libs/libvirt_driver_vbox_impl.a
(libvirt_driver_vbox_impl_la-vbox_snapshot_conf.o):
undefined reference to symbol 'xmlXPathRegisterNs@@LIBXML2_2.4.30'
/usr/lib64/libxml2.so: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

Fixed by adding LIBXML_LIBS to libvirt_driver_vbox_impl_la_LIBADD
2014-06-30 16:34:46 -06:00
Jim Fehlig 1d37a4c46b libxl: detect support for save and restore
libxl does not support save, restore, or migrate on all architectures,
notably ARM.  Detect whether libxl supports these operations using
LIBXL_HAVE_NO_SUSPEND_RESUME.  If not supported, drop advertisement of
<migration_features>.

Found by Ian Campbell while improving Xen's OSSTEST infrastructure

http://lists.xen.org/archives/html/xen-devel/2014-06/msg02171.html
2014-06-26 12:00:15 -06:00
Jim Fehlig 887e648a98 libxl: fix version annotation of migration functions
Commit 9b8d6e1e missed updating the libvirt version which
introduced support for domainMigrate*3Params functions.
2014-06-24 11:12:21 -06:00
Jim Fehlig 48d81cef3b libxl: prefer qdisk for <driver name='file'>
The libxl driver currently sets the disk backend to
LIBXL_DISK_BACKEND_TAP when <driver name='file'> is specified
in the <disk> config.  qdisk should be prefered with this
configuration, otherwise existing configuration such as the
following, which worked with the old Xen driver, will not work
with the libxl driver

  <disk type='file' device='cdrom'>
    <driver name='file'/>
    <source file='/path/to/some/iso'/>
    <target dev='hdc' bus='ide'/>
    <readonly/>
  </disk>

In addition, tap performs poorly compared to qdisk.
2014-06-23 15:52:14 -06:00