Commit Graph

13424 Commits

Author SHA1 Message Date
Luyao Huang
39449f70b9 qemu: use a wrong name for guest panic status
https://bugzilla.redhat.com/show_bug.cgi?id=1178652

We will get a warning when we have a guest in paused
status (caused by kernel panic) and restart libvirtd,
warning message like this:

Qemu reported unknown VM status: 'guest-panicked'

and this seems because we set a wrong status name in
qemu_monitor.c, and from qemu qapi-schema.json file
we know this status should named 'guest-panicked'.

Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2015-01-05 16:55:35 -07:00
Eric Blake
08eb2821f5 virnetlink: fix build on non-Linux
Commit 4dc04d3a added virNetlinkGetErrorCode, but forgot to provide
a fallback, which kills the build on mingw (among others):

  CCLD     libvirt.la
  Cannot export virNetlinkGetErrorCode: symbol not defined
  collect2: error: ld returned 1 exit status

* src/util/virnetlink.c (virNetlinkGetErrorCode): Provide fallback.

Signed-off-by: Eric Blake <eblake@redhat.com>
2015-01-05 16:38:25 -07:00
Cédric Bosdonnat
e85df0901d Report error if a driver can't handle multiple IP addresses
Drivers supporting one and only one IP address raise an error if more IP
addresses are configured.
2015-01-05 20:24:18 +01:00
Cédric Bosdonnat
a4e8639068 Openvz --ipadd can be provided multiple times
Vzctl man page says that --ipadd can be provided multiple times to add
several IP addresses. Looping over the configured ip addresses to add
one --ipadd for each. This would even handle the multiple IPs handled
by openvz_conf.c
2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
bbf1eafa57 LXC: honour network devices link state
Don't activate LXC network device if <link state='down'/> has been set
in its configuration.
2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
cef6eb77b8 LXC: use the new net devices routes definition
Actually set routes in lxc containers if there are defined ones.
2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
430e939127 lxc conf2xml: convert lxc.network.ipv[46].gateway 2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
c9a641f1e5 Domain network devices can now have a <route> element
Network interfaces devices and host devices with net capabilities can
now have IPv4 and/or an IPv6 routes configured.
2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
7100be40a5 lxc conf2xml: convert ip addresses for hostdev NICs 2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
2811cc611e Allow network capabilities hostdev to configure IP addresses 2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
12a75f371c lxc conf2xml: convert IP addresses 2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
ecdc93830e LXC: set IP addresses to veth devices in the container
Uses the new virDomainNetDef ips to set the IP addresses on the network
interfaces in the container.
2015-01-05 20:24:17 +01:00
Cédric Bosdonnat
aa2cc72100 Domain conf: allow more than one IP address for net devices
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.
2015-01-05 20:24:04 +01:00
Cédric Bosdonnat
c9ebdf9b7f Renamed virNetDevClearIPv4Address to virNetDevClearIPAddress
Make clear that virNetDevClearIPv4Address can also handle IPv6
addresses by changing the name
2015-01-05 20:24:04 +01:00
Cédric Bosdonnat
3c318dc910 virNetDevClearIPv4Address: netlink implementation 2015-01-05 20:24:04 +01:00
Cédric Bosdonnat
9c9da6022c virNetDevAddRoute: implementation using netlink 2015-01-05 20:24:04 +01:00
Cédric Bosdonnat
2b0598c836 Renamed virNetDevSetIPv4Address to virNetDevSetIPAddress
Renamed virNetDevSetIPv4Address as it also handles IPv6 addresses.
2015-01-05 20:24:04 +01:00
Cédric Bosdonnat
4dc04d3ab4 virNetDevSetIPv4Address: libnl implementation
Add a default implementation of virNetDevSetIPv4Address using netlink
and libnl. This avoids requiring /usr/sbin/ip or /usr/sbin/ifconfig
external binaries.
2015-01-05 20:24:03 +01:00
Cédric Bosdonnat
b11a75dcb4 Forgot to cleanup ifname_guest* in domain network def parsing 2015-01-05 20:24:03 +01:00
Cédric Bosdonnat
a58e1cb40a Fix error when starting a container after an error
The typical case for the problem is starting a domain needing a network
that isn't started. Even after starting the network, we get an unknown error
when starting the container.

This is due to dynamic security label not being removed.
2015-01-05 18:43:32 +01:00
Pavel Hrdina
703ef9667a src/Makefile.am: fix build breaker for xenconfig
Commit 2c78051a introduced build breaker with type in Makefile.am by
specifying wrong header file.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2015-01-05 08:23:28 +01:00
Chunyan Liu
90ed3bd0aa xenconfig: set HVM pae/apic/acpi/ default to 1
According to xm.config manual, HVM pae|apic|acpi feature default
is 1 (enabled). But in conversion from xm config to libvirt xml,
if xm config doesn't contain pae|apic|acpi, it sets default value
to 0, this causes some problems in HVM guest.

Update parser codes to set HVM pae|apic|acpi default value to 1
to match xm config convension.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
2015-01-04 11:09:34 -07:00
Kiarie Kahurani
4f524212ce libxl: Add support for parsing/formating Xen XL config
Now that xenconfig supports parsing and formatting Xen's
XL config format, integrate it into the libxl driver's
connectDomainXML{From,To}Native functions.

Signed-off-by: Kiarie Kahurani <davidkiarie4@gmail.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-03 22:41:26 -07:00
Kiarie Kahurani
2c78051a14 src/xenconfig: Xen-xl parser
Introduce a Xen xl parser

This parser allows for users to convert the new xl disk format and
spice graphics config to libvirt xml format and vice versa. Regarding
the spice graphics config, the code is pretty much straight forward.
For the disk {formating, parsing}, this parser takes care of the new
xl format which include positional parameters and key/value parameters.
In xl format disk config a <diskspec> consists of parameters separated by
commas. If the parameters do not contain an '=' they are automatically
assigned to certain options following the order below

   target, format, vdev, access

The above are the only mandatory parameters in the <diskspec> but there
are many more disk config options. These options can be specified as
key=value pairs. This takes care of the rest of the options such as

  devtype, backend, backendtype, script, direct-io-safe,

The positional paramters can also be specified in key/value form
for example

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

are interpleted to one config.

In xm format, the above diskspec would be written as

phy:/dev/vg/guest-volume,hda,w

The disk parser is based on the same parser used successfully by
the Xen project for several years now.  Ian Jackson authored the
scanner, which is used by this commit with mimimal changes.  Only
the PREFIX option is changed, to produce function and file names
more consistent with libvirt's convention.

Signed-off-by: Kiarie Kahurani <davidkiarie4@gmail.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-03 22:41:07 -07:00
Kiarie Kahurani
7ad117b2e3 src/xenconfig: Export helper functions
Export helper functions for reuse in getting values
from a virConfPtr object

Signed-off-by: Kiarie Kahurani <davidkiarie4@gmail.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2015-01-03 21:57:33 -07:00
Michal Privoznik
2360fe5d24 capabilities: Format <domain/> properly
The <domain/> element under /capabilities/guest/arch/ can have no
child elements. If that's the case we format:

        <domain type='xen'>
        </domain>

instead of simpler:

        <domain type='xen'/>

This commit fixes that.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-12-24 18:01:44 +01:00
Dmitry Guryanov
7c6dbf3518 parallels: report, that cdrom image is raw
VIR_STORAGE_FILE_AUTO should be used only in xml provided to
libvirt by user, if I understood correctly. Driver should
set storage source format to specific disk format in
*DomainGetXMLDesc.

CDROMs in PCS use raw image format.

Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
2014-12-23 15:13:13 +01:00
Martin Kletzander
31354b5b32 qemu: Fix coverity issues after refcount refactoring
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-12-23 05:34:05 +01:00
Stefan Berger
3865941be1 test: fix nwfilter tests following changes in virfirewall.c
Some of the nwfilter tests are now failing since --concurrent shows
up in the ebtables command. To avoid this, implement a function
preventing the probing for lock support in the eb/iptables tools
and use it in the tests.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
2014-12-22 16:57:21 -05:00
Martin Kletzander
540c339a25 qemu: completely rework reference counting
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>
2014-12-21 10:48:56 +01:00
Martin Kletzander
3b0f05573f util: Fix possible NULL dereference
Commit 1a80b97d, which added the virCgroupHasEmptyTasks() function
forgot that the parameter @cgroup may be NULL and did not check that.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-12-21 10:30:49 +01:00
Daniel P. Berrange
65686e5a81 disable vCPU pinning with TCG mode
Although QMP returns info about vCPU threads in TCG mode, the
data it returns is mostly lies. Only the first vCPU has a valid
thread_id returned. The thread_id given for the other vCPUs is
in fact the main emulator thread. All vCPUs actually run under
the same thread in TCG mode.

Our vCPU pinning code is not at all able to cope with this
so if you try to set CPU affinity per-vCPU you end up with
wierd errors

error: Failed to start domain instance-00000007
error: cannot set CPU affinity on process 24365: Invalid argument

Since few people will care about the performance of TCG with
strict CPU pinning, lets just disable that for now, so we get
a clear error message

error: Failed to start domain instance-00000007
error: Requested operation is not valid: cpu affinity is not supported
2014-12-19 11:32:21 +00:00
Daniel P. Berrange
b07f3d821d Don't setup fake CPU pids for old QEMU
The code assumes that def->vcpus == nvcpupids, so when we setup
fake CPU pids for old QEMU with nvcpupids == 1, we cause the
later code to read off the end of the array. This has fun results
like sche_setaffinity(0, ...) which changes libvirtd's own CPU
affinity, or even better sched_setaffinity($RANDOM, ...) which
changes the affinity of a random OS process.
2014-12-19 11:32:21 +00:00
Michal Privoznik
f309db1f4d qemu: Create memory-backend-{ram,file} iff needed
Libvirt BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1175397
QEMU BZ:    https://bugzilla.redhat.com/show_bug.cgi?id=1170093

In qemu there are two interesting arguments:

1) -numa to create a guest NUMA node
2) -object memory-backend-{ram,file} to tell qemu which memory
region on which host's NUMA node it should allocate the guest
memory from.

Combining these two together we can instruct qemu to create a
guest NUMA node that is tied to a host NUMA node. And it works
just fine. However, depending on machine type used, there might
be some issued during migration when OVMF is enabled (see QEMU
BZ). While this truly is a QEMU bug, we can help avoiding it. The
problem lies within the memory backend objects somewhere. Having
said that, fix on our side consists on putting those objects on
the command line if and only if needed. For instance, while
previously we would construct this (in all ways correct) command
line:

    -object memory-backend-ram,size=256M,id=ram-node0 \
    -numa node,nodeid=0,cpus=0,memdev=ram-node0

now we create just:

    -numa node,nodeid=0,cpus=0,mem=256

because the backend object is obviously not tied to any specific
host NUMA node.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-12-19 07:44:44 +01:00
Ján Tomko
1adda68a1b Remove redundant cleanup in qemuDomainAttachVirtioDiskDevice
Commit ca91ba7 moved these into the qemuDomainPrepareDisk helper,
but forgot to remove them from here as well.
2014-12-18 12:53:56 +01:00
Ján Tomko
1cddf0001f Fix hotplugging of block device-backed usb disks
Commit ca91ba7 moved qemuSetupDiskCgroup into the qemuDomainPrepareDisk
helper, but failed to call it for usb disks.

https://bugzilla.redhat.com/show_bug.cgi?id=1175668`
2014-12-18 12:53:56 +01:00
Boris Fiuczynski
531aef2e1b Buffer size too small when reading sysinfo
On a system with 160 CPUs the /proc/cpuinfo size grows beyond
the currently set limit of 10KB causing an internal error.

This patch increases the buffer size to 1MB.

Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
2014-12-17 17:00:58 -07:00
Eric Blake
af5c3a1015 qemu: fix memory leak in blockinfo
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>
2014-12-17 16:10:45 -07:00
Ján Tomko
952f8a7394 Fix error message on redirdev caps detection 2014-12-17 16:23:45 +01:00
John Ferlan
cafb934db8 logical: Add "--type snapshot" to lvcreate command
A recent lvm change has resulted in a change for the "default" type of
logical volume created when the "--virtualsize" or "--V" is supplied on
the command line (e.g. when the allocation and capacity values of a to
be created volume differ). It seems that at the very least the following
change adjusts the default type:

https://git.fedorahosted.org/cgit/lvm2.git/commit/?id=e0164f21

and the following may also have some impact.

https://git.fedorahosted.org/cgit/lvm2.git/commit/?id=87fc3b71

When using the virsh vol-create-as or vol-create xmlfile commands, the
result is that libvirt will now create a "thin logical volume" and a
"thin logical volume pool" rather than just a "thin snapshot logical
volume". For example the following sequence:

  # lvcreate --name test -L 2M -V 5M lvm_test
    Rounding up size to full physical extent 4.00 MiB
    Rounding up size to full physical extent 8.00 MiB
    Logical volume "test" created.
  # lvs lvm_test
    LV    VG       Attr       LSize Pool  Origin Data%  Meta%  Move Log Cpy%Sync Convert
    lvol1 lvm_test twi-a-tz-- 4.00m              0.00   0.98
    test  lvm_test Vwi-a-tz-- 8.00m lvol1        0.00

compared to the former code which had the following:

    LV   VG       Attr       LSize  Pool Origin         Data%  Move Log Cpy%Sync Convert
    test LVM_Test swi-a-s---  4.00m      [test_vorigin]   0.00

Since libvirt doesn't know how to parse the thin logical volume
and pool, it will fail to find the newly created volume and pool
even though it exists in the volume group.

It cannot find since the command used to find/parse returns a thin volume
'test' with no associated device, for example the output is:

  lvol1##UgUwkp-fTFP-C0rc-ufue-xrYh-dkPr-FGPFPx#lvol1_tdata(0)#thin-pool#1#4194304#4194304#4194304#twi-a-tz--
  test##NcaIoH-4YWJ-QKu3-sJc3-EOcS-goff-cThLIL##thin#0#8388608#4194304#8388608#Vwi-a-tz--

as compared to the former which had the following:

      test#[test_vorigin]#Dt5Of3-4WE6-buvw-CWJ4-XOiz-ywOU-YULYw6#/dev/sda3(1300)#linear#1#4194304#4194304#4194304#swi-a-s---

While it's possible to generate code to handle the new thin lv and pool, this
patch will add a "--type snapshot" onto the lvcreate command libvirt uses
in order to "for now" be able to continue to utilize the thin snapshots
2014-12-17 06:14:21 -05:00
Luyao Huang
dddd832735 conf: fix cannot start a guest have a shareable network iscsi hostdev
https://bugzilla.redhat.com/show_bug.cgi?id=1174569

There's nothing we need to do for shared iSCSI devices in
qemuAddSharedHostdev and qemuRemoveSharedHostdev. The iSCSI layer
takes care about that for us.

Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-12-17 11:23:00 +01:00
Eric Blake
3937ef9cf4 getstats: crawl backing chain for qemu
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>
2014-12-17 02:07:44 -07:00
Eric Blake
c2d380bff8 getstats: split block stats reporting for easier recursion
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>
2014-12-17 02:07:44 -07:00
Eric Blake
4bffafb2eb getstats: add new flag for block backing chain
This patch introduces access to allocation information about
a backing chain of a live domain.  While querying storage
volumes for read-only disks could provide some of the details,
we do NOT want to read() a file while qemu is writing it.
Also, there is one case where we have to rely on qemu: when
doing a block commit into a backing file, where that file is
stored in qcow2 format on a host block device, we want to know
the current highest write offset into that image, in order to
know if the disk must be resized larger.  qemu-img does not
(currently) show this information, and none of the earlier
block APIs were extensible enough to expose it.  But
virDomainListGetStats is perfect for the job!

We don't need a new group of statistics, as the existing block
group is sufficient.  On the other hand, as existing libvirt
releases already report 1:1 mapping of block.count to <disk>
devices, changing the array size could confuse older clients;
and even with newer clients, the time and memory taken to
report additional statistics is not always necessary (backing
files are generally read-only except for block-commit, so while
read statistics may change, sizing statistics will not).  So
the choice here is to add a new flag that only newer callers
will pass, when they are prepared for the additional information.

This patch introduces the new API, but it will take more
patches to get it implemented for qemu.

* include/libvirt/libvirt-domain.h
(VIR_CONNECT_GET_ALL_DOMAINS_STATS_BACKING): New flag.
* src/libvirt-domain.c (virConnectGetAllDomainStats): Document it,
and add a new field when it is in use.
* tools/virsh-domain-monitor.c (cmdDomstats): Use new flag.
* tools/virsh.pod (domstats): Document it.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-12-17 01:41:38 -07:00
Eric Blake
14ef1f62e3 getstats: prepare for dynamic block.count stat
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>
2014-12-17 00:20:21 -07:00
Eric Blake
596a137134 getstats: report block sizes for offline domains
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>
2014-12-17 00:20:21 -07:00
Eric Blake
8de6544e98 qemu: refactor blockinfo data gathering
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>
2014-12-16 23:28:36 -07:00
Eric Blake
0282ca45a0 qemu: fix bugs in blockstats
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>
2014-12-16 23:19:08 -07:00
Eric Blake
05e702cfd4 getstats: rearrange blockinfo gathering
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>
2014-12-16 23:13:04 -07:00
Eric Blake
b1802714da getstats: perform recursion in monitor collection
When requested in a later patch, the QMP command results are now
examined recursively.  As qemu_driver will eventually have to
read items out of the hash table as stored by this patch, the
computation of backing alias string is done in a shared location.

* src/qemu/qemu_domain.h (qemuDomainStorageAlias): New prototype.
* src/qemu/qemu_domain.c (qemuDomainStorageAlias): Implement it.
* src/qemu/qemu_monitor_json.c
(qemuMonitorJSONGetOneBlockStatsInfo)
(qemuMonitorJSONBlockStatsUpdateCapacityOne): Perform recursion.
(qemuMonitorJSONGetAllBlockStatsInfo)
(qemuMonitorJSONBlockStatsUpdateCapacity): Update callers.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-12-16 16:14:55 -07:00