qemu: Allow enabling/disabling features with host-passthrough
QEMU supports feature specification with -cpu host and we just skip
using that. Since QEMU developers themselves would like to use this
feature, this patch modifies the code to work.
Michal Privoznik [Mon, 12 Jan 2015 14:47:52 +0000 (15:47 +0100)]
qemuxml2argvtest: Fix test after change of qxl vgamem_mb default
Well, apparently it's possible for a patch to sneak in through
review process and break 'make check'. It happened just lately
with 0e502466acb84a which changed the default of vgamem_mb for
qxl device. However, there were left some domain XMLs within our
test suite relying on the old default. These should be updated to
match the change.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Daniel Hansel [Fri, 19 Dec 2014 14:49:35 +0000 (15:49 +0100)]
cpu: Bugfix for s390 CPU driver to return a host CPU model
The curent libvirt CPU driver for s390 does not return a host CPU model.
This patch returns 'host' according to the other platforms that would
not decode any CPU model.
This is an intermediate bugfix due to a discussion on OpenStack mailing
list. The final patch introducing the CPU model support for s390x will
exchange the hard-coded decode method.
Signed-off-by: Daniel Hansel <daniel.hansel@linux.vnet.ibm.com>
John Ferlan [Fri, 9 Jan 2015 13:42:13 +0000 (08:42 -0500)]
virconf: Resolve a possible memory leak in virConfSetValue
Found this one by inspection... The API claims to "own" the input
value even in the case of error. However, in the initial entry
to the API if the value exists, was STRING, but without a str value
it just returned without freeing the 'value' which it claims to now
own. So I added the virConfFreeValue() call in order to resolve.
John Ferlan [Fri, 9 Jan 2015 15:48:37 +0000 (10:48 -0500)]
openvz: Check errors from virSocketAddrFormat
Commit id 'a4e86390' modified the command line to allow --ipadd multiple
times; however, it did not account for the condition where a NULL is
returned which will could lead to some interesting errors with multiple
--ipadd's without parameters.
John Ferlan [Fri, 9 Jan 2015 12:38:17 +0000 (07:38 -0500)]
openvz: Resolve Coverity RESOURCE_LEAK
Commit id 'a4e86390' modified the command line to allow --ipadd multiple
times, which caused Coverity to notice a latent memory leak with the
'ipAddr' string not being VIR_FREE()'d
Pavel Hrdina [Mon, 12 Jan 2015 12:18:46 +0000 (13:18 +0100)]
qxl: change the default value for vgamem_mb to 16 MiB
The default value should be 16 MiB instead of 8 MiB. Only really old
version of upstream QEMU used the 8 MiB as default for vga framebuffer.
Without this change if you update your libvirt where we introduced the
"vgamem" attribute for QXL video device the value will be set to 8 MiB,
but previously your guest had 16 MiB because we didn't pass any value to
QEMU command line which means QEMU used its own 16 MiB as default.
This will affect all users with guest's display resolution higher than
1920x1080.
docs: Document some -boot option limitations on UEFI
It was brought to my attention that some -boot options may not
work with UEFI. For instance, rebootTimeout is very SeaBIOS
specific,splash logo is not implemented yet on OVMF, and so on.
We should document this limitation at least.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Hao Liu [Thu, 11 Dec 2014 02:46:15 +0000 (10:46 +0800)]
virsh: Emit error for VSH_OT_DATA without VSH_OFLAG_REQ
Commit 6b9964 enforces checking invalid use of VSH_OT_STRING with
VSH_OFLAG_REQ. This commit tries to do the same thing to stop using
VSH_OT_DATA without VSH_OFLAG_REQ and also fix existing misuse.
Ján Tomko [Wed, 7 Jan 2015 15:49:00 +0000 (16:49 +0100)]
safezero: fall back to writing zeroes even when resizing
Remove the resize flag and use the same code path for all callers.
This flag was added by commit 18f0316 to allow virStorageFileResize
use 'safezero' while preserving the behavior.
Explicitly return -2 when a fallback to a different method should
be done, to make the code path more obvious.
Fail immediately when ftruncate fails in the mmap method,
as we did before commit 18f0316.
John Ferlan [Fri, 9 Jan 2015 12:36:01 +0000 (07:36 -0500)]
virsh.pod: Update description
The 'pool-build' command description for --overwrite and --no-overwrite
indicated usage for only 'filesystem' pools; however, the 'disk' pool
also supports the flags as of commit id 'afa1029a'. So add a description
for that usage.
Eric Blake [Thu, 8 Jan 2015 00:05:36 +0000 (17:05 -0700)]
maint: in src/Makefile.am, $(top_srcdir)/src is verbose
I noticed this while working on a previous commit. Why should
we be calling out '../src/' when it is sufficient to refer to just
'./'? Blind copy-and-paste runs rampant in this file :)
* src/Makefile.am (INCLUDES, *_CFLAGS): Shorten to $(srcdir).
Pavel Hrdina [Thu, 8 Jan 2015 06:54:22 +0000 (07:54 +0100)]
src/Makefile: Fix parallel build after xen_xl_disk parser introduction
Well, the parallel build doesn't work as there are not dependencies
set correctly. When running 'make -j' I see this error:
make[2]: Entering directory '/home/zippy/work/libvirt/libvirt.git/src'
GEN util/virkeymaps.h
GEN locking/lock_protocol.h
make[2]: *** No rule to make target 'xenconfig/xen_xl_disk.h', needed by 'all'. Stop.
make[2]: *** Waiting for unfinished jobs....
GEN lxc/lxc_controller_dispatch.h
The fix is to correctly set dependencies by letting make know that .c
and .h are to be generated from .l. Moreover, the section is moved
closer to the other section which uses it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Geoff Hickey [Wed, 7 Jan 2015 23:45:42 +0000 (18:45 -0500)]
vmx: Fix a VMX parsing problem
VMware ESX does not always set the "serialX.fileType" tag in VMX files. The
default value for this tag is "device", and when adding a new serial port
of this type VMware will omit the fileType tag. This caused libvirt to
fail to parse the VMX file. Fixed by making this tag optional and using
"device" as a default value. Also updated vmx2xmltest to test for this
case.
Eric Blake [Wed, 7 Jan 2015 23:32:32 +0000 (16:32 -0700)]
build: fix xenconfig VPATH builds
Ever since commit 2c78051 split out a helper library for the sake of
changing CFLAGS, a VPATH build with xenconfig enabled has failed:
CC xenconfig/libvirt_xenxldiskparser_la-xen_xl_disk.lo
../../src/xenconfig/xen_xl_disk.l:37:21: fatal error: xen_xl.h: No such file or directory
# include "xen_xl.h"
^
compilation terminated.
Makefile:9462: recipe for target 'xenconfig/libvirt_xenxldiskparser_la-xen_xl_disk.lo' failed
The solution is to tell the build to look for xen_xl.h relative
to $(srcdir), since we keep that file under version control.
[Not fixed here - the raw use of -Wno-unused-parameter in CFLAGS
is NOT portable; ideally, we should be doing a configure test
and only supplying that argument when we know the compiler supports
-Wunused-parameter; but that's a patch for another day]
[Not fixed here - there are still issues with parallel builds hitting
a race between generating the files and trying to compile/distribute
them]
* src/Makefile.am (libvirt_xenxldiskparser_la_CFLAGS): Add another
include directory.
qemu: Fix system pages handling in <memoryBacking/>
In one of my previous commits (311b4a67) I've tried to allow to
pass regular system pages to <hugepages>. However, there was a
little bug that wasn't caught. If domain has guest NUMA topology
defined, qemuBuildNumaArgStr() function takes care of generating
corresponding command line. The hugepages backing for guest NUMA
nodes is handled there too. And here comes the bug: the hugepages
setting from XML is stored in KiB internally, however, the system
pages size was queried and stored in Bytes. So the check whether
these two are equal was failing even if it shouldn't.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Stefan Berger [Wed, 7 Jan 2015 16:41:49 +0000 (11:41 -0500)]
nwfilter: Add support for icmpv6 filtering
Make use of the ebtables functionality to be able to filter certain
parameters of icmpv6 packets. Extend the XML parser for icmpv6 types,
type ranges, codes, and code ranges. Extend the nwfilter documentation,
schema, and test cases.
Being able to filter icmpv6 types and codes helps extending the DHCP
snooper for IPv6 and filtering at least some parameters of IPv6's NDP
(Neighbor Discovery Protocol) packets. However, the filtering will not
be as good as the filtering of ARP packets since we cannot
check on IP addresses in the payload of the NDP packets.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Peter Krempa [Wed, 7 Jan 2015 10:35:08 +0000 (11:35 +0100)]
qemu: Don't unref domain after exit from nested async job
In commit 540c339a2535ec30d79e5ef84d8f50a17bc60723 the whole domain
reference counting was refactored in the qemu driver. Domain jobs now
don't need to reference the domain object as they now expect the
reference from the calling function.
However, the patch forgot to remove the unref call in case we exit the
monitor when we were acquiring a nested job. This caused the daemon to
crash on a subsequent access to the domain object once we've done an
operation requiring a nested job for a monitor access.
An easy reproducer case:
1) Start a vm with qcow disks
2) virsh snapshot-create-as DOMNAME
3) virsh dumpxml DOMNAME
4) daemon crashes in a semi-random spot while accessing a now-removed VM
object.
Fortunately, the commit wasn't released yet, so there are no security
implications.
Reported-by: Shanzi Yu <shyu@redhat.com> Signed-off-by: Peter Krempa <pkrempa@redhat.com>
When migrate a vm, we will generate a xml via qemuDomainDefFormatLive and
pass this xml to target libvirtd. Libvirt will use the current network
state in def->data.network.actual to generate the xml, this will make
migrate failed when we set a network type guest interface use a macvtap
network as a source in a vm then migrate vm to another host(which has the
different macvtap network settings: different interface name, bridge name...)
Add a flag check in virDomainNetDefFormat, if we set a VIR_DOMAIN_XML_MIGRATABLE
flag when call virDomainNetDefFormat, we won't get the current vm interface
state.
Add missing VNC setup via Parallels SDK.
Parallels Cloud Server starts one VNC server per domain,
so we could process only one VNC server definition.
Network-based listening currently is unimplemented.
Signed-off-by: Alexander Burluka <aburluka@parallels.com>
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.
Lack of a lease (whether mac is given or not) is a normal expected
scenario, since we are already filling in rv with nleases (which is
okay as 0 if there is no lease). There is no need to raise an error.
This fixes:
> virsh # net-dhcp-leases --mac 00:50:56:c0:00:01 default
> error: Failed to get leases info for default
> error: internal error: no lease with matching MAC address: 00:50:56:c0:00:01
Signed-off-by: Nehal J Wani <nehaljw.kkd1@gmail.com> Signed-off-by: Eric Blake <eblake@redhat.com>
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>
Eric Blake [Mon, 5 Jan 2015 23:38:50 +0000 (16:38 -0700)]
maint: update to latest gnulib
Another update is required to pick up today's gnulib fix for mingw
builds (now that gnulib turns on mingw's replacement printf that
understands %lld, it must also tell the compiler to respect the
improved definition of PRIdMAX and friends).
Cédric Bosdonnat [Wed, 12 Nov 2014 08:30:09 +0000 (09:30 +0100)]
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
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.
Add a default implementation of virNetDevSetIPv4Address using netlink
and libnl. This avoids requiring /usr/sbin/ip or /usr/sbin/ifconfig
external binaries.
Cédric Bosdonnat [Thu, 18 Dec 2014 14:42:06 +0000 (15:42 +0100)]
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.
Chunyan Liu [Tue, 23 Dec 2014 06:36:05 +0000 (14:36 +0800)]
Add tests to xmconfigtest
Add tests to testing HVM default features (pae, acpi, apic)
conversion from xm config to libvirt xml. If no pae|acpi|apic
specified in xm config, after conversion, libvirt xml should
by default include:
<features>
<pae/>
<apic/>
<acpi/>
</features>
Chunyan Liu [Tue, 23 Dec 2014 06:36:04 +0000 (14:36 +0800)]
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.
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>
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
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>
Dmitry Guryanov [Tue, 23 Dec 2014 13:23:34 +0000 (16:23 +0300)]
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.
Stefan Berger [Mon, 22 Dec 2014 21:57:21 +0000 (16:57 -0500)]
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>
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>
Claudio Bley [Thu, 18 Dec 2014 20:50:20 +0000 (21:50 +0100)]
docs: split typedef and struct definition for apibuild.py
The members of struct virSecurityLabel and struct virSecurityModel
were not shown in the libvirt API docs because the corresponding
<field> elements were missing from the libvirt-api.xml.
The reason is that apibuild.py does not cope well with typedef's
using inline struct definitions. It fails to associate the comment
with the typedef and because of this refuses to write out the
field of the struct.
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
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.
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:
Eric Blake [Wed, 17 Dec 2014 23:10:45 +0000 (16:10 -0700)]
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.
John Ferlan [Tue, 16 Dec 2014 14:15:03 +0000 (09:15 -0500)]
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:
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:
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
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>
Eric Blake [Sat, 6 Dec 2014 07:14:43 +0000 (00:14 -0700)]
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:
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.
Eric Blake [Tue, 25 Nov 2014 15:46:49 +0000 (08:46 -0700)]
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.
Eric Blake [Fri, 5 Dec 2014 23:19:00 +0000 (16:19 -0700)]
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.
Eric Blake [Sat, 6 Dec 2014 06:01:05 +0000 (23:01 -0700)]
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.
Eric Blake [Wed, 17 Dec 2014 06:18:51 +0000 (23:18 -0700)]
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.
Eric Blake [Wed, 17 Dec 2014 06:13:04 +0000 (23:13 -0700)]
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.
Eric Blake [Fri, 12 Dec 2014 16:53:33 +0000 (09:53 -0700)]
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.
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