Now that most fields of libxlDriverPrivate struct are immutable
or self-locking, there is no need to acquire the driver lock in
much of the libxl driver.
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.
libxlDomainGetInfo() uses the driver-wide libxl ctx when
it would be more appropriate to use the per-domain ctx
associated with the domain. Switch to using the per-domain
libxl ctx.
libxlMakeDomCreateInfo() uses the driver-wide libxl ctx when
it would be more appropriate to use the per-domain ctx
associated with the domain. Switch to using the per-domain
libxl ctx.
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().
Detect early on in libxl driver initialization if the driver
should be loaded at all, avoiding needless initialization steps
that only have to be undone later. While at it, move the
detection to a helper function to improve readability.
After detecting that the driver should be loaded, subsequent
failures such as initializing the log stream, allocating libxl
ctx, etc. should be treated as failure to initialize the driver.
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.
More fallout from commit d72ef888. When reconnecting to running
domains, the libxl_ctx in libxlDomainObjPrivate was used before
initializing it, causing a segfault in libxl and consequently
crashing libvirtd.
Initialize the libxlDomainObjPrivate libxl_ctx in libxlReconnectDomain,
and while at it use this ctx in libxlReconnectDomain instead of the
driver-wide ctx.
If we reached cleanup: prior to allocating cpus, it was possible that
'nr_nodes' had a value, but cpus was NULL leading to a possible NULL
deref. Add a 'cpus' as an end condition to for loop
From: Dario Faggioli <dario.faggioli@citrix.com>
Starting from Xen 4.2, libxl has all the bits and pieces in place
for retrieving an adequate amount of information about the host
NUMA topology. It is therefore possible, after a bit of shuffling,
to arrange those information in the way libvirt wants to present
them to the outside world.
Therefore, with this patch, the <topology> section of the host
capabilities is properly populated, when running on Xen, so that
we can figure out whether or not we're running on a NUMA host,
and what its characteristics are.
[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// capabilities
<capabilities>
<host>
<cpu>
....
<topology>
<cells num='2'>
<cell id='0'>
<memory unit='KiB'>6291456</memory>
<cpus num='8'>
<cpu id='0' socket_id='1' core_id='0' siblings='0-1'/>
<cpu id='1' socket_id='1' core_id='0' siblings='0-1'/>
<cpu id='2' socket_id='1' core_id='1' siblings='2-3'/>
<cpu id='3' socket_id='1' core_id='1' siblings='2-3'/>
<cpu id='4' socket_id='1' core_id='9' siblings='4-5'/>
<cpu id='5' socket_id='1' core_id='9' siblings='4-5'/>
<cpu id='6' socket_id='1' core_id='10' siblings='6-7'/>
<cpu id='7' socket_id='1' core_id='10' siblings='6-7'/>
</cpus>
</cell>
<cell id='1'>
<memory unit='KiB'>6881280</memory>
<cpus num='8'>
<cpu id='8' socket_id='0' core_id='0' siblings='8-9'/>
<cpu id='9' socket_id='0' core_id='0' siblings='8-9'/>
<cpu id='10' socket_id='0' core_id='1' siblings='10-11'/>
<cpu id='11' socket_id='0' core_id='1' siblings='10-11'/>
<cpu id='12' socket_id='0' core_id='9' siblings='12-13'/>
<cpu id='13' socket_id='0' core_id='9' siblings='12-13'/>
<cpu id='14' socket_id='0' core_id='10' siblings='14-15'/>
<cpu id='15' socket_id='0' core_id='10' siblings='14-15'/>
</cpus>
</cell>
</cells>
</topology>
</host>
....
Cleanup the libxl capabilities code to be a bit more extensible,
splitting out the creation of host and guest capabilities. This
should make it easier to implement additional capabilities in the
future, such as NUMA topology reporting.
There is a potential leak of a newly created libxlDomainObjPrivate
when subsequent allocation of the object's chrdev field fails.
Unref the object on such an error so that it is properly disposed.
Commit d72ef888 introduced a bug in the libxl driver that will
segfault libvirtd if libxl reports an error message, e.g. when
attempting to initialize the driver on a non-Xen system. I
assumed it was valid to pass a NULL logger to libxl_ctx_alloc(),
but that is not the case since any errors associated with the ctx
that are emitted by libxl will dereference the logger and crash
libvirtd.
Errors associated with the libxl driver-wide ctx could be useful
for debugging anyway, so create a 'libxl-driver.log' to capture
these errors.
introduced by cs 4b9eec50fe ("libxl: implement per
NUMA node free memory reporting"). What was wrong was that
libxl_get_numainfo() put in nr_nodes the actual number of
host NUMA nodes, not the highest node ID (like libnuma's
numa_max_node() does instead).
While at it, turn the failure of libxl_get_numainfo() from
a simple warning to a proper error, as requested during the
review of another patch of the original series.
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Currently, only one log file is created by the libxl driver, with
all output from libxl for all domains going to this one file.
Create a per-domain log file based on domain name, making sifting
through the logs a bit easier. This required deferring libxl_ctx
allocation until starting the domain, which is fine since the
ctx is not used when the domain is inactive.
Tested-by: Dario Faggioli <dario.faggioli@citrix.com>
this patch introduce the console api in libxl driver for both pv and
hvm guest. and import and update the libxlMakeChrdevStr function
which was deleted in commit dfa1e1dd.
Signed-off-by: Bamvor Jian Zhang <bjzhang@suse.com>
The avail_vcpu bitmap has to be allocated before it can be used (using
the maximum allowed value for that). Then for each available VCPU the
bit in the mask has to be set (libxl_bitmap_set takes a bit position
as an argument, not the number of bits to set).
Without this, I would always only get one VCPU for guests created
through libvirt/libxl.
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Although, having it depending on Xen >= 4.3 (by using the proper
libxl feature flag).
Xen currently implements a NUMA placement policy which is basically
the same as the 'interleaved' policy of `numactl', although it can
be applied on a subset of the available nodes. We therefore hardcode
"interleave" as 'numa_mode', and we use the newly introduced libxl
interface to figure out what nodes a domain spans ('numa_nodeset').
With this change, it is now possible to query the NUMA node
affinity of a running domain:
[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// list
Id Name State
----------------------------------------------------
23 F18_x64 running
[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// numatune 23
numa_mode : interleave
numa_nodeset : 1
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
domainGetNumaParameters has a string typed parameter, hence it
is necessary for the libxl driver to support this.
This change implements the connectSupportsFeature hook for the
libxl driver, advertising that VIR_DRV_FEATURE_TYPED_PARAM_STRING
is supported.
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Eric Blake <eblake@redhat.com>
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Use virDomainObjListRemoveLocked instead of virDomainObjListRemove, as
driver->domains is already taken by virDomainObjListForEach.
Above deadlock can be triggered when libvirtd is started after some
domain have been started by hand (in which case driver will not find
libvirt-xml domain config).
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
By providing the implementation of nodeGetCellsFreeMemory for
the driver. This is all just a matter of properly formatting, in
a way that libvirt like, what Xen provides via libxl_get_numainfo().
[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// freecell --all
0: 25004 KiB
1: 105848 KiB
--------------------
Total: 130852 KiB
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
libxl supports the LIBXL_DISK_BACKEND_QDISK disk backend, where qemu
is used to provide the disk backend. This patch simply maps the
existing <driver name='qemu'/> to LIBXL_DISK_BACKEND_QDISK.
Specifying an unsupported disk format with the tap driver resulted in
a less than helpful error message
error: Failed to start domain test-hvm
error: internal error libxenlight does not support disk driver qed
Change the message to state that the qed format is not supported by
the tap driver, e.g.
error: Failed to start domain test-hvm
error: internal error libxenlight does not support disk format qed
with disk driver tap
While at it, check for unsupported formats in the other driver
backends.
libxl contains logic to determine an appropriate devid for new devices
that do not specify one in their configuration. For all device types
except NICs, the libxl driver allows libxl to determine devid. Do the
same for NICs.
Do not leave uninitialized variables, not all parameters are set in
libxlMake*.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
libxl uses some xenstore entries for hints in memory management
(especially when starting new domain). This includes dom0 memory limit
and Xen free memory margin, based on current system state. Entries are
created at first function usage, so force such call at daemon startup,
which most likely will be before any domain startup.
Also prevent automatic memory management if dom0_mem= option passed to
xen hypervisor - it is known to be incompatible with autoballoon.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
When creating a timer/event handler reference counting is used. So it could
be possible (in theory) that libxlDomainObjPrivateFree is called with
reference counting >1. The problem is that libxlDomainObjPrivateFree leave
the object in an invalid state with ctx freed (but still having dandling
pointer). This can lead timer/event handler to core.
This patch implements a dispose method for libxlDomainObjPrivate, and moves
freeing the libxl ctx to the dispose method, ensuring the ctx is valid while
the object's reference count is > 0.
Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Actually only those interface types are handled correctly so reject
others instead of ignoring settings (i.e. treating as bridge/ethernet
anyway).
Also allow <script/> in 'ethernet' (which should be the only
script-allowing type). Keep <script/> allowed in bridge to be compatible
with legacy 'xen' driver.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
The legacy xen toolstack will set pygrub as the bootloader if not
specified. For compatibility, do the same in the libxl driver
iff not using direct kernel boot.
Currently, the libxl driver reports a connection type of "xenlight".
To be compatible with the legacy Xen driver, it should return "Xen".
Note: I noticed this while testing the libxl driver on OpenStack.
After switching my Xen compute nodes to use the libxl stack, I
could no longer launch instances on those nodes since
hypervisor_type was reported as "xenlight" instead of "xen".
libxl expects the event handler to free the event passed to it. From
libxl_event.h:
event becomes owned by the application and must be freed, either
by event_occurs or later
Xen 4.3 fixes a mistake in the libxl event handler signature where the
event owned by the application was defined as const. Detect this and
define the libvirt libxl event handler signature appropriately.
This resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=851411https://bugzilla.redhat.com/show_bug.cgi?id=955500
The first problem was that virFileOpenAs was returning fd (-1) in one
of the error cases rather than ret (-errno), so the caller thought
that the error was EPERM rather than ENOENT.
The second problem was that some log messages in the general purpose
qemuOpenFile() function would always say "Failed to create" even if
the caller hadn't included O_CREAT (i.e. they were trying to open an
existing file).
This fixes virFileOpenAs to jump down to the error return (which
returns ret instead of fd) in the previously mentioned incorrect
failure case of virFileOpenAs(), removes all error logging from
virFileOpenAs() (since the callers report it), and modifies
qemuOpenFile to appropriately use "open" or "create" in its log
messages.
NB: I seriously considered removing logging from all callers of
virFileOpenAs(), but there is at least one case where the caller
doesn't want virFileOpenAs() to log any errors, because it's just
going to try again (qemuOpenFile()). We can't simply make a silent
variation of virFileOpenAs() though, because qemuOpenFile() can't make
the decision about whether or not it wants to retry until after
virFileOpenAs() has already returned an error code.
Likewise, I also considered changing virFileOpenAs() to return -1 with
errno set on return, and may still do that, but only as a separate
patch, as it obscures the intent of this patch too much.
The LXC, QEMU, and LibXL drivers have all merged their handling of
the attach/update/modify device APIs into one large
'xxxxDomainModifyDeviceFlags'
which then does a 'switch()' based on the actual API being invoked.
While this saves some lines of code, it is not really all that
significant in the context of the driver API impls as a whole.
This merger of the handling of different APIs creates pain when
wanting to automated analysis of the code and do things which
are specific to individual APIs. The slight duplication of code
from unmerged the API impls, is preferrable to allow for easier
automated analysis.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the virGetHostname() API has a bogus virConnectPtr
parameter. This is because virtualization drivers directly
reference this API in their virDriverPtr tables, tieing its
API design to the public virConnectGetHostname API design.
This also causes problems for access control checks since
these must only be done for invocations from the public
API, not internal invocation.
Remove the bogus virConnectPtr parameter, and make each
hypervisor driver provide a dedicated function for the
driver API impl. This will allow access control checks
to be easily inserted later.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
libxlBuildDomainConfig() was disposing the libxl_domain_config object
on error, only to have it disposed again by libxlBuildDomainConfig()'s
caller, which resulted in a segfault. Leave disposing of the config
object to it's owner.
this patch fix the wrong sequence for fd and timeout register. the sequence
was right in dfa1e1dd for fd register, but it changed in e0622ca2.
in this patch, set priv, xl_priv in info and increase info->priv ref count
before virEventAddHandle. if do this after virEventAddHandle, the fd
callback or fd deregister maybe got the empty priv, xl_priv or wrong ref
count.
after apply this patch, test more than 100 rounds passed compare to fail
within 3 rounds without this patch. each round includes define -> start ->
destroy -> create -> suspend -> resume -> reboot -> shutdown -> save ->
resotre -> dump -> destroy -> create -> setmem -> setvcpus -> destroy.
Signed-off-by: Bamvor Jian Zhang <bjzhang@suse.com>
Ensure that all drivers implementing public APIs use a
naming convention for their implementation that matches
the public API name.
eg for the public API virDomainCreate make sure QEMU
uses qemuDomainCreate and not qemuDomainStart
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Ensure that the driver struct field names match the public
API names. For an API virXXXX we must have a driver struct
field xXXXX. ie strip the leading 'vir' and lowercase any
leading uppercase letters.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Detected by a simple Shell script:
for i in $(git ls-files -- '*.[ch]'); do
awk 'BEGIN {
fail=0
}
/# *include.*\.h/{
match($0, /["<][^">]*[">]/)
arr[substr($0, RSTART+1, RLENGTH-2)]++
}
END {
for (key in arr) {
if (arr[key] > 1) {
fail=1
printf("%d %s\n", arr[key], key)
}
}
if (fail == 1)
exit 1
}' $i
if test $? != 0; then
echo "Duplicate header(s) in $i"
fi
done;
A later patch will add the syntax-check to avoid duplicate
headers.
This patch refactors various places to allow removing of the
defaultConsoleTargetType callback from the virCaps structure.
A new console character device target type is introduced -
VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_NONE - to mark that no type was
specified in the XML. This type is at the end converted to the standard
VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL. Other types that are
different from this default have to be processed separately in the
device post parse callback.
Use the virDomainXMLConf structure to hold this data and tweak the code
to avoid semantic change.
Without configuration the KVM mac prefix is used by default. I chose it
as it's in the privately administered segment so it should be usable for
any purposes.
This patch adds instrumentation that will allow hypervisor drivers to
fill and validate domain and device definitions after parsed by the XML
parser.
With this patch, after the XML is parsed, a callback to the driver is
issued requesting to fill and validate driver specific details of the
configuration. This allows to use sensible defaults and checks on a per
driver basis at the time the XML is parsed.
Two callback pointers are stored in the new virDomainXMLConf object:
* virDomainDeviceDefPostParseCallback (devicesPostParseCallback)
- called for a single device parsed and for every single device in a
domain config. A virDomainDeviceDefPtr is passed along with the
domain definition and virCaps.
* virDomainDefPostParseCallback, (domainPostParseCallback)
- A callback that is meant to process the domain config after it's
parsed. A virDomainDefPtr is passed along with virCaps.
Both types of callbacks support arbitrary opaque data passed for the
callback functions.
Errors may be reported in those callbacks resulting in a XML parsing
failure.
This patch is the result of running:
for i in $(git ls-files | grep -v html | grep -v \.po$ ); do
sed -i -e "s/virDomainXMLConf/virDomainXMLOption/g" -e "s/xmlconf/xmlopt/g" $i
done
and a few manual tweaks.
The virCaps structure gathered a ton of irrelevant data over time that.
The original reason is that it was propagated to the XML parser
functions.
This patch aims to create a new data structure virDomainXMLConf that
will contain immutable data that are used by the XML parser. This will
allow two things we need:
1) Get rid of the stuff from virCaps
2) Allow us to add callbacks to check and add driver specific stuff
after domain XML is parsed.
This first attempt removes pointers to private data allocation functions
to this new structure and update all callers and function that require
them.
1. The virObjectLock() call was unconditional, but Unlock was conditional
on vm being valid. Removed the check
2. A call to virDomainEventNewFromObj() isn't guaranteed to return an
event - that check needs to be made prior to libxlDomainEventQueue()
of the event. Did not add libxlDriverLock/Unlock around the call since
some callers already have lock taken
3. Need to initialize fd = -1 in libxlDoDomainSave() since we can jump
to cleanup before it's set.
4. Missing break;'s in libxlDomainModifyDeviceFlags() for case
LIBXL_DEVICE_UPDATE. The default: case would report an error
To enable virCapabilities instances to be reference counted,
turn it into a virObject. All cases of virCapabilitiesFree
turn into virObjectUnref
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The duplicate VM checking should be done atomically with
virDomainObjListAdd, so shoud not be a separate function.
Instead just use flags to indicate what kind of checks are
required.
This pair, used in virDomainCreateXML:
if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, false)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
NULL)))
goto cleanup;
This pair, used in virDomainRestoreFlags:
if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, true)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
VIR_DOMAIN_OBJ_LIST_ADD_LIVE |
VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
NULL)))
goto cleanup;
This pair, used in virDomainDefineXML:
if (virDomainObjListIsDuplicate(privconn->domains, def, 0) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, false)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
0, NULL)))
goto cleanup;
As a step towards making virDomainObjList thread-safe turn it
into an opaque virObject, preventing any direct access to its
internals.
As part of this a new method virDomainObjListForEach is
introduced to replace all existing usage of virHashForEach
Since libxl provides the domain ID in the event handler callback,
find the domain object based on the ID. This approach prevents
processing the callback on a domain that has already been reaped.
Also, similar to the xl implementation, ignore the SUSPEND shutdown
reason. By calling libxl_domain_suspend(), we know a shutdown
event with SUSPEND reason will be generated, but it can be safely
ignored since any subsequent cleanup will be done by the callers.
libxlDoDomainSave() was removing non-persistent domains, but
required callers to have the virDomainObj locked. Callers could
potentially unlock an already freed virDomainObj. Move this
logic to the callers of libxlDoDomainSave().
I've noticed that libxl can invoke timeout reregister/modify hooks
after returning from libxl_ctx_free. Explicitly remove the
timeouts before freeing the libxl ctx to avoid executing hooks on
stale objects.
It is possible to destroy and cleanup a VM, resulting in freeing the
libxlDomainObjPrivate object and associated libxl ctx, before all fds and
timeouts have been deregistered and destroyed.
Fix this race by incrementing the reference count on libxlDomainObjPrivate
for each fd and timeout registration. Only when all fds and timeouts are
deregistered and destroyed will the libxlDomainObjPrivate be destroyed.
The libxl driver is racy in it's interactions with libxl and libvirt's
event loop. The event loop can invoke callbacks after libxl has
deregistered the event, and possibly access freed data associated with
the event.
This patch fixes the race by converting libxlDomainObjPrivate to a
virObjectLockable, and locking it while executing libxl upcalls and
libvirt event loop callbacks.
Note that using the virDomainObj lock is not satisfactory since it may
be desirable to hold the virDomainObj lock even when libxl events such
as reading and writing to xenstore need processed.
xen-unstable changeset 26469 makes changes wrt modifying and deregistering
timeouts.
First, timeout modify callbacks will only be invoked with an
abs_t of {0,0}, i.e. make the timeout fire immediately. Prior to this
commit, timeout modify callbacks were never invoked.
Second, timeout deregister hooks will no longer be called.
This patch makes changes in the libvirt libxl driver that should be
compatible before and after changeset 26469.
While at it, fix a potential overflow in the timeout register callback.
Commit dfa1e1dd added functions whose definitions do not conform
to the style used in the libxl driver. Change these functions to
be consistent throughout the driver.
The virDomainObj, qemuAgent, qemuMonitor, lxcMonitor classes
all require a mutex, so can be switched to use virObjectLockable
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Convert the host capabilities and domain config structs to
use the virArch datatype. Update the parsers and all drivers
to take account of datatype change
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
