Commit id '540c339a' to fix issues with reference counting and transient
domains moved the qemuDomainObjEndAsyncJob call prior to the attempt to
restart the guest CPU's resulting in an error:
error: Failed to save domain rhel70 to /tmp/pl/rhel70.save
error: internal error: unexpected async job 3
when (ret != 0) - eg, the error path from qemuDomainSaveMemory.
This patch will adjust the logic to call the EndAsyncJob only after
we've tried to restart the guest CPUs. It also needs to adjust the
test for qemuDomainRemoveInactive to add the ret == 0 condition.
Additionally, if we get to endjob: because of some error earlier, then
we need to save that error in the event the CPU restart logic fails.
We don't want to return the error from CPU restart failure, rather we
want to return the error from the failed save that caused us to fall
into the retry to start the CPU logic.
Signed-off-by: John Ferlan <jferlan@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1183890
When we try to update a xml to a image file, we will clear the
graphics passwd settings, because we do not pass VIR_DOMAIN_XML_SECURE
to qemuDomainDefCopy, qemuDomainDefFormatBuf won't format the passwd.
Add VIR_DOMAIN_XML_SECURE flag when we call qemuDomainDefCopy
in qemuDomainSaveImageUpdateDef.
Signed-off-by: Luyao Huang <lhuang@redhat.com>
For stateless, client side drivers, it is never correct to
probe for secondary drivers. It is only ever appropriate to
use the secondary driver that is associated with the
hypervisor in question. As a result the ESX & HyperV drivers
have both been forced to do hacks where they register no-op
drivers for the ones they don't implement.
For stateful, server side drivers, we always just want to
use the same built-in shared driver. The exception is
virtualbox which is really a stateless driver and so wants
to use its own server side secondary drivers. To deal with
this virtualbox has to be built as 3 separate loadable
modules to allow registration to work in the right order.
This can all be simplified by introducing a new struct
recording the precise set of secondary drivers each
hypervisor driver wants
struct _virConnectDriver {
virHypervisorDriverPtr hypervisorDriver;
virInterfaceDriverPtr interfaceDriver;
virNetworkDriverPtr networkDriver;
virNodeDeviceDriverPtr nodeDeviceDriver;
virNWFilterDriverPtr nwfilterDriver;
virSecretDriverPtr secretDriver;
virStorageDriverPtr storageDriver;
};
Instead of registering the hypervisor driver, we now
just register a virConnectDriver instead. This allows
us to remove all probing of secondary drivers. Once we
have chosen the primary driver, we immediately know the
correct secondary drivers to use.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The code modifies the domain configuration but doesn't take a MODIFY
type job to do so.
This patch also fixes a few very long lines of code around the touched
parts.
The ACL check didn't check the VIR_DOMAIN_XML_SECURE flag and the
appropriate permission for it. Found via code inspection while fixing
permissions for save images.
Depending on the context, either error out if the domain
has disappeared in the meantime, or just ignore the value
to allow marking the function as ATTRIBUTE_RETURN_CHECK.
https://bugzilla.redhat.com/show_bug.cgi?id=1161024
In the device type-specific functions, exit early
if the domain has disappeared, because the cleanup
should have been done by qemuProcessStop.
Check the return value in processDeviceDeletedEvent
and qemuProcessUpdateDevices.
Skip audit and removing the device from live def because
it has already been cleaned up.
The virDomainDefineXMLFlags and virDomainCreateXML APIs both
gain new flags allowing them to be told to validate XML.
This updates all the drivers to turn on validation in the
XML parser when the flags are set
Make a local copy of the disk alias instead of pointing
to the domain definition, which might get freed if
the domain dies while we're in monitor.
Also exit early if that happens.
Exit the monitor right after we've done with it to get
the virDomainObjPtr lock back, otherwise we might be accessing
vm->def while it's being cleaned up by qemuProcessStop.
If the domain crashed while we were in the monitor, exit
early instead of changing vm->def which is now the persistent
definition.
Commit e3435caf fixed hot-plugging of vcpus with strict memory pinning
on NUMA hosts, but unfortunately it also broke updating number of vcpus
for offline guests using our API.
The issue is that we try to create a cpu cgroup for non-running guest
which fails as there are no cgroups for that domain. We should create
cgroups and update cpuset.mems only if we are hot-plugging.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
When create inactive external snapshot, after update disk definitions,
virDomainSaveConfig is needed, if not after restart libvirtd the new snapshot
file definitions in xml will be lost.
Reproduce steps:
1. prepare a shut off guest
$ virsh domstate rhel7 && virsh domblklist rhel7
shut off
Target Source
------------------------------------------------
vda /var/lib/libvirt/images/rhel7.img
2. create external disk snapshot
$ virsh snapshot-create rhel7 --disk-only && virsh domblklist rhel7
Domain snapshot 1417882967 created
Target Source
------------------------------------------------
vda /var/lib/libvirt/images/rhel7.1417882967
3. restart libvirtd then check guest source file
$ service libvirtd restart && virsh domblklist rhel7
Redirecting to /bin/systemctl restart libvirtd.service
Target Source
------------------------------------------------
vda /var/lib/libvirt/images/rhel7.img
This was first reported by Eric Blake
http://www.redhat.com/archives/libvir-list/2014-December/msg00369.html
Signed-off-by: Shanzhi Yu <shyu@redhat.com>
The virDomainDefParse* and virDomainDefFormat* methods both
accept the VIR_DOMAIN_XML_* flags defined in the public API,
along with a set of other VIR_DOMAIN_XML_INTERNAL_* flags
defined in domain_conf.c.
This is seriously confusing & error prone for a number of
reasons:
- VIR_DOMAIN_XML_SECURE, VIR_DOMAIN_XML_MIGRATABLE and
VIR_DOMAIN_XML_UPDATE_CPU are only relevant for the
formatting operation
- Some of the VIR_DOMAIN_XML_INTERNAL_* flags only apply
to parse or to format, but not both.
This patch cleanly separates out the flags. There are two
distint VIR_DOMAIN_DEF_PARSE_* and VIR_DOMAIN_DEF_FORMAT_*
flags that are used by the corresponding methods. The
VIR_DOMAIN_XML_* flags received via public API calls must
be converted to the VIR_DOMAIN_DEF_FORMAT_* flags where
needed.
The various calls to virDomainDefParse which hardcoded the
use of the VIR_DOMAIN_XML_INACTIVE flag change to use the
VIR_DOMAIN_DEF_PARSE_INACTIVE flag.
https://bugzilla.redhat.com/show_bug.cgi?id=1135339 documents some
confusing behavior when a user tries to start an inactive block
commit in a second connection while there is already an on-going
active commit from a first connection. Eventually, qemu will
support multiple simultaneous block jobs, but as of now, it does
not; furthermore, libvirt also needs an overhaul before we can
support simultaneous jobs. So, the best way to avoid confusing
ourselves is to quit relying on qemu to tell us about the situation
(where we risk getting in weird states) and instead forbid a
duplicate block commit ourselves.
Note that we are still relying on qemu to diagnose attempts to
interrupt an inactive commit (since we only track XML of an active
commit), but as inactive commit is less confusing for libvirt to
manage, there is less that can go wrong by leaving that detection
up to qemu.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Hoist check for
active commit to occur earlier outside of conditions.
Signed-off-by: Eric Blake <eblake@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1177723
When setting new bandwidth limits via
virDomainSetInterfaceParameters, the old ones are cleared first.
However, if setting the new ones fails, the old are already gone
and interface is left in inconsistent state. Therefore, right
before failing we ought to try to restore the old bandwidth.
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Add the possibility to have more than one IP address configured for a
domain network interface. IP addresses can also have a prefix to define
the corresponding netmask.
There is one problem that causes various errors in the daemon. When
domain is waiting for a job, it is unlocked while waiting on the
condition. However, if that domain is for example transient and being
removed in another API (e.g. cancelling incoming migration), it get's
unref'd. If the first call, that was waiting, fails to get the job, it
unref's the domain object, and because it was the last reference, it
causes clearing of the whole domain object. However, when finishing the
call, the domain must be unlocked, but there is no way for the API to
know whether it was cleaned or not (unless there is some ugly temporary
variable, but let's scratch that).
The root cause is that our APIs don't ref the objects they are using and
all use the implicit reference that the object has when it is in the
domain list. That reference can be removed when the API is waiting for
a job. And because each domain doesn't do its ref'ing, it results in
the ugly checking of the return value of virObjectUnref() that we have
everywhere.
This patch changes qemuDomObjFromDomain() to ref the domain (using
virDomainObjListFindByUUIDRef()) and adds qemuDomObjEndAPI() which
should be the only function in which the return value of
virObjectUnref() is checked. This makes all reference counting
deterministic and makes the code a bit clearer.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Coverity flagged commit 0282ca45 as introducing a memory leak;
in all my refactoring to make capacity probing conditional on
whether the image is non-raw, I missed deleting the unconditional
probe.
* src/qemu/qemu_driver.c (qemuStorageLimitsRefresh): Drop
redundant assignment.
Signed-off-by: Eric Blake <eblake@redhat.com>
Wire up backing chain recursion. For the first time, it is now
possible to get libvirt to expose that qemu tracks read statistics
on backing files, as well as report maximum extent written on a
backing file during a block-commit operation.
For a running domain, where one of the two images has a backing
file, I see the traditional output:
$ virsh domstats --block testvm2
Domain: 'testvm2'
block.count=2
block.0.name=vda
block.0.path=/tmp/wrapper.qcow2
block.0.rd.reqs=1
block.0.rd.bytes=512
block.0.rd.times=28858
block.0.wr.reqs=0
block.0.wr.bytes=0
block.0.wr.times=0
block.0.fl.reqs=0
block.0.fl.times=0
block.0.allocation=0
block.0.capacity=1310720000
block.0.physical=200704
block.1.name=vdb
block.1.path=/dev/sda7
block.1.rd.reqs=0
block.1.rd.bytes=0
block.1.rd.times=0
block.1.wr.reqs=0
block.1.wr.bytes=0
block.1.wr.times=0
block.1.fl.reqs=0
block.1.fl.times=0
block.1.allocation=0
block.1.capacity=1310720000
vs. the new output:
$ virsh domstats --block --backing testvm2
Domain: 'testvm2'
block.count=3
block.0.name=vda
block.0.path=/tmp/wrapper.qcow2
block.0.rd.reqs=1
block.0.rd.bytes=512
block.0.rd.times=28858
block.0.wr.reqs=0
block.0.wr.bytes=0
block.0.wr.times=0
block.0.fl.reqs=0
block.0.fl.times=0
block.0.allocation=0
block.0.capacity=1310720000
block.0.physical=200704
block.1.name=vda
block.1.path=/dev/sda6
block.1.backingIndex=1
block.1.rd.reqs=0
block.1.rd.bytes=0
block.1.rd.times=0
block.1.wr.reqs=0
block.1.wr.bytes=0
block.1.wr.times=0
block.1.fl.reqs=0
block.1.fl.times=0
block.1.allocation=327680
block.1.capacity=786432000
block.2.name=vdb
block.2.path=/dev/sda7
block.2.rd.reqs=0
block.2.rd.bytes=0
block.2.rd.times=0
block.2.wr.reqs=0
block.2.wr.bytes=0
block.2.wr.times=0
block.2.fl.reqs=0
block.2.fl.times=0
block.2.allocation=0
block.2.capacity=1310720000
I may later do a patch that trims the output to avoid 0 stats,
particularly for backing files (which are more likely to have
0 stats, at least for write statistics when no block-commit
is performed). Also, I still plan to expose physical size
information (qemu doesn't expose it yet, so it requires a stat,
and for block devices, a further open/seek operation). But
this patch is good enough without worrying about that yet.
* src/qemu/qemu_driver.c (QEMU_DOMAIN_STATS_BACKING): New internal
enum bit.
(qemuConnectGetAllDomainStats): Recognize new user flag, and pass
details to...
(qemuDomainGetStatsBlock): ...here, where we can do longer recursion.
(qemuDomainGetStatsOneBlock): Output new field.
Signed-off-by: Eric Blake <eblake@redhat.com>
In order to report stats on backing chains, we need to separate
the output of stats for one block from how we traverse blocks.
* src/qemu/qemu_driver.c (qemuDomainGetStatsBlock): Split...
(qemuDomainGetStatsOneBlock): ...into new helper.
Signed-off-by: Eric Blake <eblake@redhat.com>
A coming patch will make it optionally possible to list backing
chain block stats; in this mode of operation, block.counts is no
longer the number of <disks> in the domain, but the number of
blocks in the array being reported. We still want block.count
listed first, but rather than iterate the tree twice (once to
count, and once to list stats), it's easier to just touch things
up after the fact.
* src/qemu/qemu_driver.c (qemuDomainGetStatsBlock): Compute count
after the fact.
Signed-off-by: Eric Blake <eblake@redhat.com>
The prior refactoring can now be put to use. With the same domain
as the earlier commit 7b49926 (one qcow2 disk and an empty
cdrom drive):
$ virsh domstats --block foo
Domain: 'foo'
block.count=2
block.0.name=hda
block.0.path=/var/lib/libvirt/images/foo.qcow2
block.0.allocation=1309614080
block.0.capacity=42949672960
block.0.physical=1309671424
block.1.name=hdc
* src/qemu/qemu_driver.c (qemuDomainGetStatsBlock): Use
qemuStorageLimitsRefresh to report offline statistics.
Signed-off-by: Eric Blake <eblake@redhat.com>
Create a helper function that can be reused for gathering block
info from virDomainListGetStats.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Split guts...
(qemuStorageLimitsRefresh): ...into new helper function.
Signed-off-by: Eric Blake <eblake@redhat.com>
The documentation for virDomainBlockInfo was confusing: it stated
that 'physical' was the size of the container, then gave an example
of it being the amount of storage used by a sparse file (that is,
for a sparse raw image on a regular file, the wording implied
capacity==physical, while allocation was smaller; but the example
instead claimed physical==allocation). Since we use 'physical' for
the last offset of a block device, we should do likewise for
regular files.
Furthermore, the example claimed that for a qcow2 regular file,
allocation==physical. At the time the code was first written,
this was true (qcow2 files were allocated sequentially, and were
never sparse, so the last sector written happened to also match
the disk space occupied); but modern qemu does much better and
can punch holes for a qcow2 with allocation < physical.
Basically, after this patch, the three fields are now reliably
mapped as:
'capacity' - how much storage the guest can see (equal to
physical for raw images, determined by image metadata otherwise)
'allocation' - how much storage the image occupies (similar to
what 'du' would report)
'physical' - the last offset of the image (similar to what 'ls'
would report)
'capacity' can be larger than 'physical' (such as for a qcow2
image that does not vary much from a backing file) or smaller
(such as for a qcow2 file with lots of internal snapshots).
Likewise, 'allocation' can be (slightly) larger than 'physical'
(such as counting the tail of cluster allocations required to
round a file size up to filesystem granularity) or smaller
(for a sparse file). A block-resize operation changes capacity
(which, for raw images, also changes physical); many non-raw
images automatically grow physical and allocation as necessary
when starting with an allocation smaller than capacity; and even
when capacity and physical stay unchanged, allocation can change
when converting sectors from holes to data or back.
Note that this does not change semantics for qcow2 images stored
on block devices; there, we still rely on qemu to report the
highest written extent for allocation. So using this API to
track when to extend a block device because a qcow2 image is
about to exceed a threshold will not see any changes.
Also, note that virStorageVolInfo is unfortunately limited to
just 'capacity' and 'allocation' (we can't expand it to add
'physical', although we can expand the XML to add it there);
historically, that struct's 'allocation' value has reported
file size for qcow2 files (what this patch terms 'physical'
for a domain block device), but disk usage for raw files (what
this patch terms 'allocation'). So follow-up patches will be
needed to make storage volumes report the same allocation
values and get at physical values, where those differ.
* include/libvirt/libvirt-domain.h (_virDomainBlockInfo): Tweak
documentation to match saner definition.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): For regular
files, physical size is capacity, not allocation.
Signed-off-by: Eric Blake <eblake@redhat.com>
Ultimately, we want to avoid read()ing a file while qemu is running.
We still have to open() block devices to determine their physical
size, but that is safer. This patch rearranges code to group
together all code that reads the image, to make it easier for later
patches to skip the metadata collection when possible.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Check for empty
disk up front. Place metadata reading next to use.
Signed-off-by: Eric Blake <eblake@redhat.com>
A future patch will allow recursion into backing chains when
collecting block stats. This patch should not change behavior,
but merely moves out the common code that will be reused once
recursion is enabled, and adds the parameter that will turn on
recursion.
* src/qemu/qemu_monitor.h (qemuMonitorGetAllBlockStatsInfo)
(qemuMonitorBlockStatsUpdateCapacity): Add recursion parameter,
although it is ignored for now.
* src/qemu/qemu_monitor.h (qemuMonitorGetAllBlockStatsInfo)
(qemuMonitorBlockStatsUpdateCapacity): Likewise.
* src/qemu/qemu_monitor_json.h
(qemuMonitorJSONGetAllBlockStatsInfo)
(qemuMonitorJSONBlockStatsUpdateCapacity): Likewise.
* src/qemu/qemu_monitor_json.c
(qemuMonitorJSONGetAllBlockStatsInfo)
(qemuMonitorJSONBlockStatsUpdateCapacity): Add parameter, and
split...
(qemuMonitorJSONGetOneBlockStatsInfo)
(qemuMonitorJSONBlockStatsUpdateCapacityOne): ...into helpers.
(qemuMonitorJSONGetBlockStatsInfo): Update caller.
* src/qemu/qemu_driver.c (qemuDomainGetStatsBlock): Update caller.
* src/qemu/qemu_migration.c (qemuMigrationCookieAddNBD): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Right now, grabbing blockinfo always calls stat on the disk, then
opens the image to determine the capacity, using a throw-away
virStorageSourcePtr. This has a couple of drawbacks:
1. We are calling stat and opening a file on every invocation of
the API. However, there are cases where the stats should NOT be
changing between successive calls (if a domain is running, no
one should be changing the physical size of a block device or raw
image behind our backs; capacity of read-only files should not
be changing; and we are the gateway to the block-resize command
to know when the capacity of read-write files should be changing).
True, we still have to use stat in some cases (a sparse raw file
changes allocation if it is read-write and the amount of holes is
changing, and a read-write qcow2 image stored in a file changes
physical size if it was not fully pre-allocated). But for
read-only images, even this should be something we can remember
from the previous time, rather than repeating every call.
2. We want to enhance the power of virDomainListGetStats, by
sharing code. But we already have a virStorageSourcePtr for
each disk, and it would be easier to reuse the common structure
than to have to worry about the one-off virDomainBlockInfoPtr.
While this patch does not optimize reuse of information in point
1, it does get us closer to being able to do so; by updating a
structure that survives between consecutive calls.
* src/util/virstoragefile.h (_virStorageSource): Add physical, to
mirror virDomainBlockInfo; rearrange fields to match public struct.
(virStorageSourceCopy): Copy the new field.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Store into
storage source, then copy to block info.
Signed-off-by: Eric Blake <eblake@redhat.com>
In order for a future patch to virDomainListGetStats to reuse
some code for determining disk usage of offline domains, we
need to make it easier to pull out part of the guts of grabbing
blockinfo. The current implementation grabs a job fairly late
in the game, while getstats will already own a job; reordering
things so that the job is always grabbed up front in both
functions will make it easier to pull out the common code.
This patch results in grabbing a job in cases where one was not
previously needed, but as it is a query job, it should not be
noticeably slower.
This patch touches the same code as the fix for CVE-2014-6458
(commit b799259); in that patch, we avoided hotplug changing
a disk reference during the time of obtaining a monitor lock
by copying all data we needed and no longer referencing disk;
this patch goes the other way and ensures that by holding the
job, the disk cannot be changed so we no longer need to worry
about the disk being invalidated across the monitor lock.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Rearrange job
control to be outside of disk information.
Signed-off-by: Eric Blake <eblake@redhat.com>
Commit e3435caf added cleanup code to qemuDomainSetVcpusFlags() that was
not supposed to reset the error. Usual procedure was done, saving the
error to temporary variable, but it was never free'd, but rather leaked.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
When hot-plugging a VCPU into the guest, kvm needs to allocate some data
from the DMA zone, which might be in a memory node that's not allowed in
cpuset.mems. Basically the same problem as there was with starting the
domain and due to which commit 7e72ac7878
exists. This patch just extends it to hotplugging as well.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1161540
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Instead of setting the value of cpuset.mems once when the domain starts
and then re-calculating the value every time we need to change the child
cgroup values, leave the cgroup alone and rather set the child data
every time there is new cgroup created. We don't leave any task in the
parent group anyway. This will ease both current and future code.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1174154
When we use attach-device add a hostdev or chr device which have a
iscsi address or others (just like guest agent, subsys iscsi disk...),
we will find there is no basic controller for our new attached device.
Somtimes this will make guest cannot start after we add them (although
they can start at the second time).
Signed-off-by: Luyao Huang <lhuang@redhat.com>
We can change vnc password by using virDomainUpdateDeviceFlags API with
live flag. But it can't be changed with config flag. Error is reported as
below.
error: Operation not supported: persistent update of device 'graphics' is not supported
This patch supports the graphics arguments changed with config flag.
Signed-off-by: Wang Rui <moon.wangrui@huawei.com>
A logic bug in qemuConnectGetAllDomainStats makes the code mark the
monitor as available when qemuDomainObjBeginJob fails, instead of when
it succeeds, as the correct flow requires.
This patch fixes the check and updates the code documentation
accordingly.
Broken by commit 57023c0a3a.
Signed-off-by: Francesco Romani <fromani@redhat.com>
When user doesn't have read access on one of the domains he requested,
the for loop could exit abruptly or continue and override pointer which
pointed to locked object.
This patch fixed two issues at once. One is that domflags might have
had QEMU_DOMAIN_STATS_HAVE_JOB even when there was no job started (this
is fixed by doing domflags |= QEMU_DOMAIN_STATS_HAVE_JOB only when the
job was acquired and cleaning domflags on every start of the loop.
Second one is that the domain is kept locked when
virConnectGetAllDomainStatsCheckACL() fails and continues the loop when
it didn't end. Adding a simple virObjectUnlock() and clearing the
pointer ought to do.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Avoid leaving the domain locked on a failed ACL check in
qemuDomainMigratePerform() and qemuDomainMigrateFinish2().
Introduced in commit abf75aea24 (Add ACL checks into the QEMU driver).
I'm about to make block stats optionally more complex to cover
backing chains, where block.count will no longer equal the number
of <disks> for a domain. For these reasons, it is nicer if the
statistics output includes the source path (for local files).
This patch doesn't add anything for network disks, although we
may decide to add that later.
With this patch, I now see the following for the same domain as
in the previous patch (one qcow2 file, and an empty cdrom drive):
$ virsh domstats --block foo
Domain: 'foo'
block.count=2
block.0.name=hda
block.0.path=/var/lib/libvirt/images/foo.qcow2
block.1.name=hdc
* src/libvirt-domain.c (virConnectGetAllDomainStats): Document
new field.
* tools/virsh.pod (domstats): Document new field.
* src/qemu/qemu_driver.c (qemuDomainGetStatsBlock): Return the new
stat for local files/block devices.
(QEMU_ADD_NAME_PARAM): Add parameter.
(qemuDomainGetStatsInterface): Update caller.
Signed-off-by: Eric Blake <eblake@redhat.com>
I noticed that for an offline domain, 'virsh domstats --block $dom'
was producing just the domain name, with no stats. But the older
'virsh domblkinfo' works just fine on offline domains. This patch
starts to get us closer, by at least reporting the disk names for
an offline domain.
With this patch, I now see the following for an offline domain
with one qcow2 disk and an empty cdrom drive:
$ virsh domstats --block foo
Domain: 'foo'
block.count=2
block.0.name=hda
block.1.name=hdc
* src/qemu/qemu_driver.c (qemuDomainGetStatsBlock): Don't short-circuit
output of block name.
Signed-off-by: Eric Blake <eblake@redhat.com>
