When looking for a port to allocate, the port allocator didn't take in
consideration ports that are statically set by the user. Defining
these two graphics elements in the XML would cause an error, as the
port allocator would try to use the same port for the spice graphics
element:
<graphics type='spice' autoport='yes'/>
<graphics type='vnc' port='5900' autoport='no'/>
The new *[pP]ortReserved variables keep track of the ports that were
successfully tracked as used by the port allocator but that weren't
bound.
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1081881
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
There are no options to parse here other than the name of the device,
and all three possible device names have the same prefix
("virtio-balloon" with "-ccw", "-pci", or "-device" appended), so the
code is fairly simple. It has been implemented such that it will be
easier to add handling for other -device entries that aren't otherwise
recognized - just add another "else if (STRPREFIX(opts, ....)" clause.
qemuParseCommandLineString() previously would always add a <memballoon
model='virtio'/> to every result (the comments erroneously say that it
is adding a <memballoon model='none'/>) This has been changed to add
model='none', and 84 test case xml's updated accordingly (so that
qemuxml2argvtest won't fail).
Now that the memballoon device is properly parsed, we can safely add a
test for properly ignoring -nodefconfig and -nodefaults. Rather than
adding an entire new test case for this (and memballoon), we just
randomly pick the clock-utc test and modify it slightly to fulfill the
purpose.
I'm going to add functions that will deal with individual image files
rather than whole disks. Rename the security function to make room for
the new one.
The image labels are stored in the virStorageSource struct. Convert the
virDomainDiskDefGetSecurityLabelDef helper not to use the full disk def
and move it appropriately.
There are two places where you'll find info on page sizes. The first
one is under <cpu/> element, where all supported pages sizes are
listed. Then the second one is under each <cell/> element which refers
to concrete NUMA node. At this place, the size of page's pool is
reported. So the capabilities XML looks something like this:
<capabilities>
<host>
<uuid>01281cda-f352-cb11-a9db-e905fe22010c</uuid>
<cpu>
<arch>x86_64</arch>
<model>Westmere</model>
<vendor>Intel</vendor>
<topology sockets='1' cores='1' threads='1'/>
...
<pages unit='KiB' size='4'/>
<pages unit='KiB' size='2048'/>
<pages unit='KiB' size='1048576'/>
</cpu>
...
<topology>
<cells num='4'>
<cell id='0'>
<memory unit='KiB'>4054408</memory>
<pages unit='KiB' size='4'>1013602</pages>
<pages unit='KiB' size='2048'>3</pages>
<pages unit='KiB' size='1048576'>1</pages>
<distances/>
<cpus num='1'>
<cpu id='0' socket_id='0' core_id='0' siblings='0'/>
</cpus>
</cell>
<cell id='1'>
<memory unit='KiB'>4071072</memory>
<pages unit='KiB' size='4'>1017768</pages>
<pages unit='KiB' size='2048'>3</pages>
<pages unit='KiB' size='1048576'>1</pages>
<distances/>
<cpus num='1'>
<cpu id='1' socket_id='0' core_id='0' siblings='1'/>
</cpus>
</cell>
...
</cells>
</topology>
...
</host>
<guest/>
</capabilities>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
For future work we want to get info for not only the free memory
but overall memory size too. That's why the function must have
new signature too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When the block job event was first added, it was for block pull,
where the active layer of the disk remains the same name. It was
also in a day where we only cared about local files, and so we
always had a canonical absolute file name. But two things have
changed since then: we now have network disks, where determining
a single absolute string does not really make sense; and we have
two-phase jobs (copy and active commit) where the name of the
active layer changes between the first event (ready, on the old
name) and second (complete, on the pivoted name).
Adam Litke reported that having an unstable string between events
makes life harder for clients. Furthermore, all of our API that
operate on a particular disk of a domain accept multiple strings:
not only the absolute name of the active layer, but also the
destination device name (such as 'vda'). As this latter name is
stable, even for network sources, it serves as a better string
to supply in block job events.
But backwards-compatibility demands that we should not change the
name handed to users unless they explicitly request it. Therefore,
this patch adds a new event, BLOCK_JOB_2 (alas, I couldn't think of
any nicer name - but at least Migrate2 and Migrate3 are precedent
for a number suffix). We must double up on emitting both old-style
and new-style events according to what clients have registered for
(see also how IOError and IOErrorReason emits double events, but
there the difference was a larger struct rather than changed
meaning of one of the struct members).
Unfortunately, adding a new event isn't something that can easily
be broken into pieces, so the commit is rather large.
* include/libvirt/libvirt.h.in (virDomainEventID): Add a new id
for VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2.
(virConnectDomainEventBlockJobCallback): Document new semantics.
* src/conf/domain_event.c (_virDomainEventBlockJob): Rename field,
to ensure we catch all clients.
(virDomainEventBlockJobNew): Add parameter.
(virDomainEventBlockJobDispose)
(virDomainEventBlockJobNewFromObj)
(virDomainEventBlockJobNewFromDom)
(virDomainEventDispatchDefaultFunc): Adjust clients.
(virDomainEventBlockJob2NewFromObj)
(virDomainEventBlockJob2NewFromDom): New functions.
* src/conf/domain_event.h: Add new prototypes.
* src/libvirt_private.syms (domain_event.h): Export new functions.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Generate two
different events.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Likewise.
* src/remote/remote_protocol.x
(remote_domain_event_block_job_2_msg): New struct.
(REMOTE_PROC_DOMAIN_EVENT_BLOCK_JOB_2): New RPC.
* src/remote/remote_driver.c
(remoteDomainBuildEventBlockJob2): New handler.
(remoteEvents): Register new event.
* daemon/remote.c (remoteRelayDomainEventBlockJob2): New handler.
(domainEventCallbacks): Register new event.
* tools/virsh-domain.c (vshEventCallbacks): Likewise.
(vshEventBlockJobPrint): Adjust client.
* src/remote_protocol-structs: Regenerate.
Signed-off-by: Eric Blake <eblake@redhat.com>
The block commit code looks for an explicit base file relative
to the discovered top file; so for a chain of:
base <- snap1 <- snap2 <- snap3
and a command of:
virsh blockcommit $dom vda --base snap2 --top snap1
we got a sane message (here from libvirt 1.0.5):
error: invalid argument: could not find base 'snap2' below 'snap1' in chain for 'vda'
Meanwhile, recent refactoring has slightly reduced the quality of the
libvirt error messages, by losing the phrase 'below xyz':
error: invalid argument: could not find image 'snap2' in chain for 'snap3'
But we had a one-off, where we were not excluding the top file
itself in searching for the base; thankfully qemu still reports
the error, but the quality is worse:
virsh blockcommit $dom vda --base snap2 --top snap2
error: internal error unable to execute QEMU command 'block-commit': Base '/snap2' not found
Fix the one-off in blockcommit by changing the semantics of name
lookup - if a starting point is specified, then the result must
be below that point, rather than including that point. The only
other call to chain lookup was blockpull code, which was already
forcing the lookup to omit the active layer and only needs a
tweak to use the new semantics.
This also fixes the bug exposed in the testsuite, where when doing
a lookup pinned to an intermediate point in the chain, we were
unable to return the name of the parent also in the chain.
* src/util/virstoragefile.c (virStorageFileChainLookup): Change
semantics for non-NULL startFrom.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Adjust caller,
to keep existing semantics.
* tests/virstoragetest.c (mymain): Adjust to expose new semantics.
Signed-off-by: Eric Blake <eblake@redhat.com>
For block devices used as snapshot source the new snapshot code would
set the reuse flag. This inhibits to take snapshot without specially
preparing the block image before taking the snapshot.
Fortunately this is not a regression as only the new way of specifying
snapshot source is affected.
For the followin snapshot XML:
<domainsnapshot>
<disks>
<disk name='vda' type='block'>
<driver type='qcow2'/>
<source dev="/dev/andariel/testsnap" />
</disk>
</disks>
</domainsnapshot>
You'd get:
error: internal error: unable to execute QEMU command 'transaction': Image is not in qcow2 format
After this patch the snapshot is created successfully.
A future patch will add two-phase block commit jobs; as the
mechanism for managing them is similar to managing a block copy
job, existing errors should be made generic enough to occur
for either job type.
* src/conf/domain_conf.c (virDomainHasDiskMirror): Update
comment.
* src/qemu/qemu_driver.c (qemuDomainDefineXML)
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainBlockJobImpl, qemuDomainBlockCopy): Update error
message.
* src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Commit f586965 accidentally changed the semantics of the
virDomainBlockCommit command; where it previously looked for
an explicit top argument from the top of the chain, it now
starts from the backing file of the top. Of course, until
we allow active commits, the only difference it makes is in
the quality of the error message, but with code for active
commit coming soon, we need to support an explicit mention
of the active layer.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Start looking
from top of chain.
Signed-off-by: Eric Blake <eblake@redhat.com>
When saving domain with relabel=no, the file that gets created must have the
context set anyway. That way restore can be successful without the need of
relabelling the file.
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
Now that qemu 2.0 allows commit of the active layer, people are
attempting to use virsh blockcommit and getting into a stuck
state, because libvirt is unprepared to handle the two-phase
commit required by qemu.
Stepping back a bit, there are two valid semantics for a
commit operation:
1. Maintain a 'golden' base, and a transient overlay. Make
changes in the overlay, and if everything appears to work,
commit those changes into the base, but still keep the overlay
for the next round of changes; repeat the cycle as desired.
2. Create an external snapshot, then back up the stable state
in the backing file. Once the backup is complete, commit the
overlay back into the base, and delete the temporary snapshot.
Since qemu doesn't know up front which of the two styles is
preferred, a block commit of the active layer merely gets
the job into a synchronized state, and sends an event; then
the user must either cancel (case 1) or complete (case 2),
where qemu then sends a second event that actually ends the
job. However, until commit e6bcbcd, libvirt was blindly
assuming the semantics that apply to a commit of an
intermediate image, where there is only one sane conclusion
(the job automatically ends with fewer elements in the chain);
and getting stuck because it wasn't prepared for qemu to enter
a second phase of the job.
This patch adds a flag to the libvirt API that a user MUST
supply in order to acknowledge that they will be using two-phase
semantics. It might be possible to have a mode where if the
flag is omitted, we automatically do the case 2 semantics on
the user's behalf; but before that happens, I must do additional
patches to track the fact that we are doing an active commit
in the domain XML. Later patches will add support of the flag,
and once 2-phase semantics are working, we can then decide
whether to relax things to allow an omitted flag to cause an
automatic pivot.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_BLOCK_COMMIT_ACTIVE)
(VIR_DOMAIN_BLOCK_JOB_TYPE_ACTIVE_COMMIT): New enums.
* src/libvirt.c (virDomainBlockCommit): Document two-phase job
when committing active layer, through new flag.
(virDomainBlockJobAbort): Document that pivot also occurs after
active commit.
* tools/virsh-domain.c (vshDomainBlockJob): Cover new job.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Explicitly
reject active copy; later patches will add it in.
Signed-off-by: Eric Blake <eblake@redhat.com>
The qemu driver always adds these options to the qemu commandlines,
but the commandline parser didn't recognize them, so sending a
libvirt-generated qemu commandline to its own argvtoxml would always
result in a warning message and a qemu namespace added to the
xml. Since the options don't add any functionality to the domain, they
should just be ignored (similar to -S).
Note that we can't yet add a test for this to qemuargv2xmltest,
because we would have to add QEMU_CAPS_NODEFCONFIG and
QEMU_CAPS_DEVICE to the capabilities for any corresponding
xml2argvtest, and QEMU_CAPS_DEVICE would necessitate having support
for parsing a memballoon device in order for qemuargv2xmltest to
pass. So we wait to add a test for -nodefconfig and -nodefaults until
after adding support for parsing -device virtio-balloon-*.
The current implementation of 'virsh blockcopy' (virDomainBlockRebase)
is limited to copying to a local file name. But future patches want
to extend it to also copy to network disks. This patch converts over
to a virStorageSourcePtr, although it should have no semantic change
visible to the user, in anticipation of those future patches being
able to use more fields for non-file destinations.
* src/conf/domain_conf.h (_virDomainDiskDef): Change type of
mirror information.
* src/conf/domain_conf.c (virDomainDiskDefParseXML): Localize
mirror parsing into new object.
(virDomainDiskDefFormat): Adjust clients.
* src/qemu/qemu_domain.c (qemuDomainDeviceDefPostParse):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainBlockPivot)
(qemuDomainBlockJobImpl, qemuDomainBlockCopy): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
As part of the work on backing chains, I'm finding that it would
be easier to directly manipulate chains of pointers (adding a
snapshot merely adjusts pointers to form the correct list) rather
than copy data from one struct to another. This patch converts
domain disk source to be a pointer.
In this patch, the pointer is ALWAYS allocated (thanks in part to
the previous patch forwarding all disk def allocation through a
common point), and all other changse are just mechanical fallout of
the new type; there should be no functional change. It is possible
that we may want to leave the pointer NULL for a cdrom with no
medium in a later patch, but as that requires a closer audit of the
source to ensure we don't fault on a null dereference, I didn't do
it here.
* src/conf/domain_conf.h (_virDomainDiskDef): Change type of src.
* src/conf/domain_conf.c: Adjust all clients.
* src/security/security_selinux.c: Likewise.
* src/qemu/qemu_domain.c: Likewise.
* src/qemu/qemu_command.c: Likewise.
* src/qemu/qemu_conf.c: Likewise.
* src/qemu/qemu_process.c: Likewise.
* src/qemu/qemu_migration.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.
* src/lxc/lxc_controller.c: Likewise.
* tests/securityselinuxlabeltest.c: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
A future patch wants to create disk definitions with non-zero
default contents; to avoid crashes, all callers that allocate
a disk definition should go through a common point.
I found allocation points by looking for any code that increments
ndisks, as well as any matches for ALLOC.*disk. Most places that
modified ndisks were covered by the parse from XML to domain/device
definition by initial domain creation or device hotplug; I also
hand-checked all drivers that generate a device struct on the
fly during getXMLDesc.
* src/conf/domain_conf.h (virDomainDiskDefNew): New prototype.
* src/conf/domain_conf.c (virDomainDiskDefNew): New function.
(virDomainDiskDefParseXML): Use it.
* src/parallels/parallels_driver.c (parallelsAddHddInfo):
Likewise.
* src/qemu/qemu_command.c (qemuParseCommandLine): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc): Likewise.
* src/vmx/vmx.c (virVMXParseDisk): Likewise.
* src/xenxs/xen_sxpr.c (xenParseSxprDisks, xenParseSxpr):
Likewise.
* src/xenxs/xen_xm.c (xenParseXM): Likewise.
* src/libvirt_private.syms (domain_conf.h): Export it.
Signed-off-by: Eric Blake <eblake@redhat.com>
As part of the work on backing chains, I'm finding that it would
be easier to directly manipulate chains of pointers (adding a
snapshot merely adjusts pointers to form the correct list) rather
than copy data from one struct to another. This patch converts
snapshot source to be a pointer.
In this patch, the pointer is ALWAYS allocated (any code that
increases ndisks now also allocates a source pointer for each
new disk), and all other changes are just mechanical fallout of
the new type; there should be no functional change. It is
possible that we may want to leave the pointer NULL for internal
snapshots in a later patch, but as that requires a closer audit
of the source to ensure we don't fault on a null dereference, I
didn't do it here.
* src/conf/snapshot_conf.h (_virDomainSnapshotDiskDef): Change
type of src.
* src/conf/snapshot_conf.c: Adjust all clients.
* src/qemu/qemu_conf.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
This simplifies the usage in {libxl,qemu}DomainGetNumaParameters
and it's needed for consistent error reporting in virBitmapFormat.
Also remove the forgotten ATTRIBUTE_NONNULL marker.
qemuMonitorJSONSendKey declares the "holdtime" argument as unsigned int
while the command was constructed in qemuMonitorJSONMakeCommand using
the "P" modifier which took a unsigned long from the variable
arguments which then made it possible to access uninitialized memory.
This broke the qemumonitorjsontest on 32bit fedora 20:
64) qemuMonitorJSONSendKey
... libvirt: QEMU Driver error : internal error: unsupported data type 'W' for arg 'WVSì D$0èwÿÿÃAå' FAILED
Uncovered by upstream commit f744b831c6.
Additionally add test for the hold-time option.
Some of the APIs already return int since they can produce errors that
need to be propagated. For consistency reasons, this patch changes the
rest of the APIs to also return int even though they do not fail or
report any errors.
In general, we should only remove a backend after seeing DEVICE_DELETED
event for a corresponding frontend.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
In general, we should only remove a backend after seeing DEVICE_DELETED
event for a corresponding frontend. This doesn't make any difference for
disks attached using -drive or drive_add since QEMU automatically
removes their backends but it's still better to make our code
consistent. And it may start making difference in case we switch to
attaching disks using -blockdev.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
[1] reported that we are removing network's backend too early. I didn't
really get the reproducer but libvirt behaves strangely when a guest
does not confirm the removal, e.g., it does not support PCI hotplug. In
such case, detaching a network device leaves its frontend in place but
removes the backend, which makes the device unusable for the guest.
Moreover attaching the same device again succeeds and both the guest and
libvirt will see two network interfaces attached but only one of them is
actually working.
I checked with Paolo Bonzini and he confirmed we should only remove a
backend after seeing DEVICE_DELETED event for a corresponding frontend.
[1] https://www.redhat.com/archives/libvir-list/2014-March/msg01740.html
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
This patch adds option to specify that a json qemu command argument is
optional without the need to use if's or ternary operators to pass the
list. Additionally all the modifier characters are documented to avoid
user confusion.
My future work will modify the metadata crawler function to use the
storage driver file APIs to access the files instead of accessing them
directly so that we will be able to request the metadata for remote
files too. To avoid linking the storage driver to every helper file
using the utils code, the backing chain traversal function needs to be
moved to the storage driver source.
Additionally the virt-aa-helper and virstoragetest programs need to be
linked with the storage driver as a result of this change.
In "src/conf/domain_conf.h" there are many enum declarations. The
cleanup in this header filer was started, but it wasn't enough and
there are many other files that has enum variables declared. So, the
commit was starting to be big. This commit finish the cleanup in this
header file and in other files that has enum variables, parameters,
or functions declared.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
In "src/conf/domain_conf.h" there are many enumerations (enum)
declarations to be converted as a typedef too. As mentioned before,
it's better to use a typedef for variable types, function types and
other usages. I think this file has most of those enum declarations
at "src/conf/". So, me and Eric Blake plan to keep the cleanups all
over the source code. This time, most of the files changed in this
commit are related to part of one file: "src/conf/domain_conf.h".
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Currently, we don not acquire any job when removing a device after
DEVICE_DELETED event was received from QEMU. This means that if there is
another API running at the time DEVICE_DELETED is delivered and the API
acquired a job, we may happily change the definition of the domain the
API is working with whenever it unlocks the domain object (e.g., to talk
with its monitor). That said, we have to acquire a job before finishing
device removal to make things safe. However, doing so in the main event
loop would cause a deadlock so we need to move most of the event handler
into a separate thread.
Another good reason for both acquiring a job and handling the event in a
separate thread is that we currently remove a device backend immediately
after removing its frontend while we should only remove the backend once
we already received DEVICE_DELETED event. That is, we will have to talk
to QEMU monitor from the event handler.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
If QEMU supports DEVICE_DELETED event, we always call
qemuDomainRemoveDevice from the event handler. However, we will need to
push this call away from the main event loop and begin a job for it (see
the following commit), we need to make sure the device is fully removed
by the original thread (and within its existing job) in case the
DEVICE_DELETED event arrives before qemuDomainWaitForDeviceRemoval times
out.
Without this patch, device removals would be guaranteed to never finish
before the timeout because the could would be blocked by the original
job being still active.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Currently we don't support mixed (external + internal) snapshots. The
code detecting the snapshot type didn't make sure that the memory image
was consistent with the snapshot type leading into strange error
message:
$ virsh snapshot-create-as --domain VM --diskspec vda,snapshot=internal --memspec snapshot=external,file=/tmp/blah
error: internal error: unexpected code path
Fix the mixed detection code to detect this kind of mistake:
$ virsh snapshot-create-as --domain VM --diskspec vda,snapshot=internal --memspec snapshot=external,file=/tmp/blah
error: unsupported configuration: mixing internal and external targets for a snapshot is not yet supported
A internal snapshot of a active VM with the memory snapshot disabled
explicitly would actually still take the memory snapshot. Reject it
explicitly.
Before:
$ virsh snapshot-create-as --domain VM --diskspec vda,snapshot=internal --memspec snapshot=no
Domain snapshot 1401353155 created
After:
$ virsh snapshot-create-as --domain VM --diskspec vda,snapshot=internal --memspec snapshot=no
error: Operation not supported: internal snapshot of a running VM must include the memory state
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1083345
Even successful start of a VM from a managed save image would spam the
logs with the following message:
Unable to restore from managed state [path]. Maybe the file is
corrupted?
Re-arrange the logic to output the warning only when the image is
corrupted.
The flaw was introduced in commit cfc28c66.
Add argument to return backing file format of a file probed by
virStorageFileGetMetadataFromFD so that it can be used in place of
virStorageFileGetMetadataFromBuf.
qemu 2.0 added the ability to commit the active layer, but slightly
differently than what libvirt had been anticipating in its
implementation of the virDomainBlockCommit call. As a result, if
you attempt to do a 'virsh blockcommit $dom vda', qemu gets into a
state where it is waiting on libvirt to end the job, while libvirt
is waiting on qemu to end the job, and the guest is effectively
hung with regards to further commands for that block device.
I have patches coming down the pipeline that will add full support
for blockcommit of the active layer when coupled with qemu 2.0 or
later; but they depend on Peter's improvements to block job handling
and form enough of a new feature that they are not ready for
inclusion in the 1.2.5 release. So for now, just reject the
attempt, rather than letting the user get stuck. This is no worse
than the behavior of qemu 1.7 rejecting the job.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Reject active
commit.
Signed-off-by: Eric Blake <eblake@redhat.com>
QEMU ppce500 board uses the legacy -serial option.
Other PPC boards don't give any way to explicitly wire in a -chardev
except pseries which uses -device spapr-vty with -chardev.
Add test case for -serial option for ppce500
Signed-off-by: Olivia Yin <Hong-Hua.Yin@freescale.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1088787
Clean up unix socket files for chardevs using mode='bind',
like we clean up the monitor socket.
They are created by QEMU on startup and not really useful
after shutting it down.
For a clock element as above, libvirt simply converts current system
time with localtime_r(), then starts qemu with a time string that
doesn't contain any timezone information. So, from qemu's point of
view, the -rtc string it gets for:
<clock offset='variable' basis='utc' adjustment='10800'/>
is identical to the -rtc string it gets for:
<clock offset='variable' basis='localtime' adjustment='0'/>
(assuming the host is in a timezone that is 10800 seconds ahead of
UTC, as is the case on the machine where this message is being
written).
Since the commandlines are identical, qemu will behave identically
after this point in either case.
There are two problems in the case of basis='localtime' though:
Problem 1) If the guest modifies its RTC, for example to add 20
seconds, the RTC_CHANGE event from qemu will then contain offset:20 in
both cases. But libvirt will have saved the original adjustment into
adjustment0, and will add that value onto the offset in the
event. This means that in the case of basis=;utc', it will properly
emit an event with offset:10820, but in the case of basis='localtime'
the event will contain offset:20, which is *not* the new offset of the
RTC from UTC (as the event it documented to provide).
Problem 2) If the guest is migrated to another host that is in a
different timezone, or if it is migrated or saved/restored after the
DST status has changed from what it was when the guest was originally
started, the newly restarted guest will have a different RTC (since it
will be based on the new localtime, which could have shifted by
several hours).
The solution to both of these problems is simple - rather than
maintaining the original adjustment value along with
"basis='localtime'" in the domain status, when the domain is started
we convert the adjustment offset to one relative to UTC, and set the
status to "basis='utc'". Thus, whatever the RTC offset was from UTC
when it was initially started, that offset will be maintained when
migrating across timezones and DST settings, and the RTC_CHANGE events
will automatically contain the proper offset (which should by
definition always be relative to UTC).
This fixes a problem that was implied but not openly stated in:
https://bugzilla.redhat.com/show_bug.cgi?id=964177
commit e31b5cf393 attempted to fix libvirt's
VIR_DOMAIN_EVENT_ID_RTC_CHANGE, which is documentated to always
provide the new offset of the domain's real time clock from UTC. The
problem was that, in the case that qemu is provided with an "-rtc
base=x" where x is an absolute time (rather than "utc" or
"localtime"), the offset sent by qemu's RTC_CHANGE event is *not* the
new offset from UTC, but rather is the sum of all changes to the
domain's RTC since it was started with base=x.
So, despite what was said in commit e31b5cf393, if we assume that
the original value stored in "adjustment" was the offset from UTC at
the time the domain was started, we can always determine the current
offset from UTC by simply adding the most recent (i.e. current) offset
from qemu to that original adjustment.
This patch accomplishes that by storing the initial adjustment in the
domain's status as "adjustment0". Each time a new RTC_CHANGE event is
received from qemu, we simply add adjustment0 to the value sent by
qemu, store that as the new adjustment, and forward that value on to
any event handler.
This patch (*not* e31b5cf393, which should be reverted prior to
applying this patch) fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=964177
(for the case where basis='utc'. It does not fix basis='localtime')
This reverts commit e31b5cf393.
This commit attempted to work around a bug in the offset value
reported by qemu's RTC_CHANGE event in the case that a variable base
date was given on the qemu commandline. The patch mixed up the math
involved in arriving at the corrected offset to report, and in the
process added an unnecessary private attribute to the clock
element. Since that element is private/internal and not used by anyone
else, it makes sense to simplify things by removing it.
Currently the protocol type with index 0 was NBD which made it hard to
distinguish whether the protocol type was actually assigned. Add a new
protocol type with index 0 to distinguish it explicitly.
The gluster volume name was previously stored as part of the source path
string. This is unfortunate when we want to do operations on the path as
the volume is used separately.
Parse and store the volume name separately for gluster storage volumes
and use the newly stored variable appropriately.
Refactor the function to accept a virStorageSourcePtr instead of just
the path, add a check to run it only on local storage and fix callers
(possibly by using a newly introduced wrapper that wraps a path in the
virStorageSource struct for legacy code)
