Commit Graph

16682 Commits

Author SHA1 Message Date
Michal Privoznik
16ebf10f34 nodedev: Introduce <pci-express/> to PCI devices
This new element is there to represent PCI-Express capabilities
of a PCI devices, like link speed, number of lanes, etc.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-16 17:40:49 +02:00
Michal Privoznik
a22a7a5ef3 virpci: Introduce virPCIDeviceIsPCIExpress and friends
These functions will handle PCIe devices and their link capabilities
to query some info about it.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-16 17:40:49 +02:00
Eric Blake
3e3c6ff10f blockcommit: require base below top
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>
2014-06-16 09:33:57 -06:00
Eric Blake
b10a0e9198 storage: better tests of lookup
Add some more tests of what happens when we restrict a lookup
to begin at a point in the middle of a chain.  In particular,
we want to ensure that a parent is not found when starting at
the child.  This commit also demonstrates that we have a slight
difference in behavior on what parent we report when filtering
is in effect; as the determination of the parent affects the
code in block commit, exposing this in the testsuite will help
justify changes in future patches that tweak the semantics of
what lookups are allowed.

* tests/virstoragetest.c (testStorageLookup): Test user input.
(TEST_LOOKUP_TARGET): Add parameter.
(mymain): Add lookup tests.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-16 09:33:57 -06:00
Eric Blake
54597c5698 storage: renumber lookup tests
The next patch will be adding tests, including adding a parameter
for testing more conditions.  For ease of review of that patch, I
want to create common context lines that don't change when the new
tests are added (it's easier to visually review additions than it
is to review an entire chunk of tests rewritten into another
larger chunk of tests).

* tests/virstoragetest.c (mymain): Add a parameter and renumber
the lookup tests.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-16 09:33:57 -06:00
Eric Blake
47aaceb7cc storage: add alias for less typing
Typing chain->backingStore->backingStore gets old after a while;
introduce some alias variables to make the test more compact.

* tests/virstoragetest.c (mymain): Introduce some shorthand.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-16 09:33:57 -06:00
Peter Krempa
b77d3d9b81 qemu: snapshot: Don't mark all block disks for metadata reuse
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.
2014-06-16 17:22:05 +02:00
Pavel Hrdina
647bdf02d8 leaseshelper: fix another crash
We create a 'lease_new' when we are adding new lease entry, then later
in the code we add the 'lease_new' into a 'leases_array_new' which
leads into the crash because we double free the 'lease_new'.

To prevent the double free we set the 'lease_new' to NULL after
successful append into the 'leases_array_new'.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2014-06-16 14:41:19 +02:00
Roman Bogorodskiy
f477f555f0 bhyve: silent destroy command errors on cleanup
When virBhyveProcessStart() fails, it tries to unload
a guest that could have been already loaded using
bhyveload(8) to make sure not to leave it hanging in memory.

However, we could fail before loading a VM into memory,
so 'bhyvectl --destroy' command will fail and print
an error message that looks confusing to users.

So ignore errors when running this in cleanup.
2014-06-14 00:22:35 +04:00
Roman Bogorodskiy
5c1f82efae bhyve: do not cleanup unallocated networks on fail
virBhyveProcessStart() calls bhyveNetCleanup() if it fails. However,
it might fail earlier than networks are allocated, so modify
bhyveNetCleanup() to check if net->ifname is not NULL before
going further with the cleanup.
2014-06-13 20:44:36 +04:00
Roman Bogorodskiy
381a3dbdab bhyve: fix crash in bhyveBuildNetArgStr
bhyveBuildNetArgStr() calls virNetDevTapCreateInBridgePort() and
passes tapfd = NULL, but tapfdSize = 1. That is wrong, because
if virNetDevTapCreateInBridgePort() crashes after successfully
creating a TAP device, it'll jump to 'error' label, that
loops over tapfd and calls VIR_FORCE_CLOSE:

   for (i = 0; i < tapfdSize && tapfd[i] >= 0; i++)

In that case we get a segfault.

As the bhyve code doesn't use tapfd, pass NULL and set tapfdSize to 0.
2014-06-13 20:44:36 +04:00
Giuseppe Scrivano
d6e92bfa38 storage: report VIR_ERR_NO_STORAGE_VOL when the file doesn't exist
Report VIR_ERR_NO_STORAGE_VOL instead of a system error when lstat
fails because the file doesn't exist.

Fixes this problem in virt-install:

  https://bugzilla.redhat.com/show_bug.cgi?id=1108922

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
2014-06-13 10:05:33 -06:00
Roman Bogorodskiy
aad479dc4e bhyve: implement PCI address allocation
Automatically allocate PCI addresses for devices instead
of hardcoding them in the driver code. The current
allocation schema is to dedicate an entire slot for each devices.

Also, allow having arbitrary number of devices.
2014-06-13 19:25:27 +04:00
Michal Privoznik
90ba5ef1bb virNetDevGetLinkInfo: Don't report link speed if NIC's not up
The kernel's more broken than one would think. Various drivers report
various (usually spurious) values if the interface is in other state
than 'up' . While on some we experience -EINVAL when read()-ing the
speed sysfs file, with other drivers we might get anything from 0 to
UINT_MAX. If that's the case it's better to not report link speed.
Well, the interface is not up anyway.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-13 11:29:48 +02:00
Peter Krempa
51c439056b tests: virstoragetest: Fix output when hitting errors
When the test is failing but the debug output isn't enabled the
resulting line would look ugly like and would not contain the actual
difference.

TEST: virstoragetest
      .................chain member 1!chain member 1!chain member 1!

Store the member index in the actual checked string to hide this problem
2014-06-13 10:57:43 +02:00
Eric Blake
278c51af3a blockcommit: update error messages related to block jobs
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>
2014-06-12 20:54:32 -06:00
Eric Blake
1784037991 virsh: improve blockcopy UI
Peter's review of an early version of my addition of active block
commit pointed out some issues that I was copying from the block
copy code; fix them up now before perpetuating them.

For virsh commands that manage a single API call, it's nice to have
a 1:1 mapping of options to flags, so that we can test that
lower-layer software handles flag combinations correctly.  But where
virsh is introducing syntactic sugar to combine multiple API calls
into a single user interface, we might as well make that interface
compact.  That is, we should allow the shorter command-line of
'blockcopy $dom $disk --pivot' without having to explicitly specify
--wait, because this isn't directly a flag passed to a single
underlying API call.

Also, my use of embedded ?: ternaries bordered on unreadable.

* tools/virsh-domain.c (cmdBlockCopy): Make --pivot, --finish,
and --timeout imply --wait. Drop excess ?: operators.
* tools/virsh.pod (blockcopy): Update documentation.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-12 14:41:40 -06:00
Michal Privoznik
bab4558547 virNodeDevCapPCIDevParseXML: Initialize numa_node variable
With one of my recent patches (1c70277) libvirt's capable of
reporting NUMA node locality for PCI devices. The node ID is
stored in pci_dev.numa_node variable. However, since zero is
valid NUMA node ID, the default is -1 as it is in kernel too.
So, if the PCI device is not tied to any specific NUMA node, the
default is then NOT printed into XML. Therefore, when parsing
node device XML, the <node/> element is optional. But currently,
if it's not there, we must set sane default, otherwise after
parsing in the memory representation doesn't match the XML. We
are already doing this in other place: udevProcessPCI().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-12 17:18:29 +02:00
Eric Blake
519181d932 blockcommit: fix regression with explicit top argument
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>
2014-06-12 07:01:18 -06:00
Jincheng Miao
e430410480 virsh: forbid negative vcpu argument to vcpupin
The vcpupin command allowed specifying a negative number for the --vcpu
argument. This would the overflow when the underlying virDomainPinVcpu
API was called.

 $ virsh vcpupin r7 -1 0
 error: numerical overflow: input too large: 4294967295

Switch the vCPU variable to a unsigned int and parse it using the
corresponding function.

Also improve the vcpupin test to cover all the defects.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1101059

Signed-off-by: Jincheng Miao <jmiao@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
2014-06-12 14:06:21 +02:00
Peter Krempa
c62125395b virsh: Reject negative numbers in vshCommandOptULongLong
To follow the new semantics of the vshCommandOptToU* functions convert
this one to reject negative numbers too. To allow using -1 for "maximum"
semantics for the vol-*load two bandwidth functions that use this helper
introduce vshCommandOptULongLongWrap.
2014-06-12 14:06:21 +02:00
Peter Krempa
0e2d73051a virsh: Reject negative numbers in vshCommandOptUL
To follow the new semantics of the vshCommandOptToU* functions convert
this one to reject negative numbers too. To allow using -1 for "maximum"
semantics for the two bandwidth functions that use this helper introduce
vshCommandOptULWrap. Although currently the migrate-setspeed function
for the qemu driver will reject -1 as maximum.
2014-06-12 14:06:20 +02:00
Peter Krempa
37e663adb6 virsh: Reject negative numbers in vshCommandOptUInt
Use virStrToLong_uip instead of virStrToLong_ui to reject negative
numbers in the helper. None of the callers expects the wraparound
"feature" for negative numbers.

Also add a function that allows wrapping of negative numbers as it might
be used in the future and be explicit about the new semantics in the
function docs.
2014-06-12 14:06:20 +02:00
Ján Tomko
7eb0ee175b Fix crash when saving a domain with type none dac label
qemuDomainGetImageIds did not check if there was a label
in the seclabel, thus crashing on
<seclabel type='none' model='dac'/>

https://bugzilla.redhat.com/show_bug.cgi?id=1108590
2014-06-12 12:01:35 +02:00
John Ferlan
fdfdbc0d12 vbox_snapshot_conf: Resolve Coverity warnings
Clean up some Coverity warnings from commit id '4dc5d8f1'
2014-06-12 05:44:47 -04:00
John Ferlan
70bd552e67 vbox_temp: Resolve Coverity warnings
Clean up code to resolve Coverity RESOURCE_LEAK's from commit id's
'632b9600' and 'b739f807'.
2014-06-12 05:36:37 -04:00
Peter Krempa
cc6484d486 security: Don't skip labelling for network disks
A network disk might actually be backed by local storage. Also the path
iterator actually handles networked disks well now so remove the code
that skips the labelling in dac and selinux security driver.
2014-06-12 10:32:12 +02:00
Peter Krempa
f332ffc0dc storage: volume: Rework lookup of volume objects
Add a helper to do all the lookup steps and remove a ton of duplicated
code.
2014-06-12 10:26:56 +02:00
Peter Krempa
30d99eb534 storage: Clean up unlocking of storage pool objects
Most of the APIs now don't reach the cleanup section when the pool
object wasn't found and thus don't need to check before unlocking it.
2014-06-12 09:55:17 +02:00
Peter Krempa
efd892761e storage: pool: Fix handling of errors on pool lookup failure
Rework internal pool lookup code to avoid printing the raw UUID buffer
in the case a storage pool can't be found:

 $ virsh pool-name e012ace0-0460-5810-39ef-1bce5fa5a4dd
 error: failed to get pool 'e012ace0-0460-5810-39ef-1bce5fa5a4dd'
 error: Storage pool not found: no storage pool with matching uuid à¬à`X9ï_¥¤Ý

The rework is mostly done by switching the lookup code to the newly
introduced helper virStoragePoolObjFromStoragePool

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1104993
2014-06-12 09:55:08 +02:00
Ján Tomko
046a441f3d build: prefer -fstack-protector-strong to -all
Try -fstack-protector-strong first on Linux. If that fails,
fall back to -fstack-protector-all.
2014-06-12 08:16:03 +02:00
Ján Tomko
5567baa973 build: remove ssp-buffer-size
This option only makes sense for -fstack-protector.
With -fstack-protector-all or -fstack-protector-strong,
functions are protected regardless of buffer size.

https://bugzilla.redhat.com/show_bug.cgi?id=1105456
2014-06-12 08:16:03 +02:00
Ján Tomko
fa3519cbe5 build: remove duplicit warning suppression
These warnings have already been added to $dontwarn.
2014-06-12 08:15:54 +02:00
John Ferlan
5ca7c95549 libxl: Resolve Coverity warnings
Resolve two Coverity issues introduced by commit id '9b8d6e1e'

Signed-off-by: John Ferlan <jferlan@redhat.com>
2014-06-11 14:58:20 -04:00
Roman Bogorodskiy
aec0c6d3d5 virsh: include bhyve in virsh -V output
Add 'Bhyve' in hypervisor list reported by 'virsh -V'
if it's compiled it.
2014-06-11 22:16:09 +04:00
Pavel Hrdina
a93504cca4 leaseshelper: fix crash
Commit baafe668 introduced new leaseshelper with a crash of freeing
env string. Calling 'getenv()' inside 'virGetEnvAllowSUID()' may
return a static string and we definitely should not free it.

The author probably want to free the copy of that string.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2014-06-11 17:21:11 +02:00
Eric Blake
de43582bf5 maint: exempt graphic binaries from syntax check
Roman Bogorodskiy reported a syntax-check failure when using
FreeBSD; complaining that:

prohibit_empty_first_line
tools/libvirt_win_icon_16x16.ico:1:
tools/libvirt_win_icon_32x32.ico:1:
tools/libvirt_win_icon_48x48.ico:1:
tools/libvirt_win_icon_64x64.ico:1:
maint.mk: Prohibited empty first line

In reality, the first 'line' of that file is NOT empty; but since
it is a binary file, awk is not required to handle it gracefully.
The simplest solution is to exempt all image files from syntax
checks in the first place - after all, we only store them in git
because they are inconvenient to regenerate, but they are not our
preferred format for making modifications, and syntax check should
only cover files that we are likely to modify.

* cfg.mk (VC_LIST_ALWAYS_EXCLUDE_REGEX): Exempt images.
(exclude_file_name_regexp--sc_prohibit_empty_lines_at_EOF): Simplify.
(exclude_file_name_regexp--sc_trailing_blank): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-11 08:41:37 -06:00
Shivaprasad G Bhat
edc80e2344 qemu: Properly label FDs when restoring domain with static label
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>
2014-06-11 16:33:51 +02:00
Jean-Baptiste Rouault
775bb9b15f vmware: make version parsing more robust
Since commit d69415d4, vmware version is parsed from both stdout and
stderr. This patch makes version parsing work even if there is garbage
(libvirt debug messages for example) in the command output.

Add test data for this case.
2014-06-11 14:56:18 +02:00
Michal Privoznik
3c43b6a7b2 virnetdev: Use ifname in virNetDevGetLinkInfo
If we're compiling on non-Linux platform, the virNetDevGetLinkInfo()
is a dummy function which barely logs debug message that getting link
info is not supported. However, while the debug message was prepared
for printing the interface name too, I actually forgot to pass the
variable which resulted in build error on platforms like mingw or
FreeBSD.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-11 13:05:17 +02:00
Michal Privoznik
0311ef3d65 node_device: Expose link state & speed
While exposing the info under <interface/> in previous patch works, it
may work only in cases where interface is configured on the host.
However, orchestrating application may want to know the link state and
speed even in that case. That's why we ought to expose this in nodedev
XML too:

virsh # nodedev-dumpxml net_eth0_f0_de_f1_2b_1b_f3
<device>
  <name>net_eth0_f0_de_f1_2b_1b_f3</name>
  <path>/sys/devices/pci0000:00/0000:00:19.0/net/eth0</path>
  <parent>pci_0000_00_19_0</parent>
  <capability type='net'>
    <interface>eth0</interface>
    <address>f0🇩🇪f1:2b:1b:f3</address>
    <link speed='1000' state='up'/>
    <capability type='80203'/>
  </capability>
</device>

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-11 10:59:39 +02:00
Michal Privoznik
b2019ee470 interface_backend_udev: Implement link speed & state
In the previous commit the helper function was prepared, so now
we can wire it up and benefit from it. The Makefile change is
required because we're including virnedev,h which includes
virnetlink.h which tries to include netlink/msg.h. However this
file is not under /usr/include directly but is dependent on libnl
used.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-11 09:57:45 +02:00
Michal Privoznik
05630cf4e5 virnetdev: Introduce virNetDevGetLinkInfo
The purpose of this function is to fetch link state
and link speed for given NIC name from the SYSFS.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-11 09:57:39 +02:00
Michal Privoznik
3db89662c2 virInterface: Expose link state & speed
Currently it is not possible to determine the speed of an interface
and whether a link is actually detected from the API. Orchestrating
platforms want to be able to determine when the link has failed and
where multiple speeds may be available which one the interface is
actually connected at. This commit introduces an extension to our
interface XML (without implementation to interface driver backends):

  <interface type='ethernet' name='eth0'>
    <start mode='none'/>
    <mac address='aa:bb:cc:dd:ee:ff'/>
    <link speed='1000' state='up'/>
    <mtu size='1492'/>
    ...
  </interface>

Where @speed is negotiated link speed in Mbits per second, and state
is the current NIC state (can be one of the following:  "unknown",
"notpresent", "down", "lowerlayerdown","testing", "dormant", "up").

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-06-11 09:13:32 +02:00
Eric Blake
10c10f4380 nodeinfo: avoid uninitialized variable on error
Commit 8ba0a58 introduced a compiler warning that I hit during
a run of ./autobuild.sh:

../../src/nodeinfo.c: In function 'nodeCapsInitNUMA':
../../src/nodeinfo.c:1853:43: error: 'nsiblings' may be used uninitialized in this function [-Werror=maybe-uninitialized]
         if (virCapabilitiesAddHostNUMACell(caps, n, memory,
                                           ^

Sure enough, nsiblings starts uninitialized, and is set by a call
to virNodeCapsGetSiblingInfo, but that function fails to assign
through the pointer if virNumaGetDistances fails.

* src/nodeinfo.c (nodeCapsInitNUMA): Initialize nsiblings.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-10 16:27:34 -06:00
Eric Blake
1c7eb95c84 storage: fix memory leak with encrypted images
Jim Fehlig reported a regression found by libvirt-TCK tests:

> ~ # perl /usr/share/libvirt-tck/tests/qemu/100-disk-encryption.t
...
> ok 4 - defined persistent domain config
> # Starting inactive domain config
> libvirt error code: 1, message: internal error: unable to execute QEMU command
> 'cont': 'drive-ide0-0-1'
> (/var/cache/libvirt-tck/300-disk-encryption/demo.qcow2) is encrypted

Commit 2279d560 converted a boolean into a pointer with the intent of
transferring that pointer out of a temporary object into the caller's
data structure.  The temporary structure meant that meta->encryption
was always NULL on entry, so we could get away with blindly allocating
the pointer when the header said so.  But later, commit 8823272d
tweaked things to do backing chain detection in-place, rather than via
a temporary object; this has the net result that meta->encryption can
be non-NULL on entry.  Not only did this turn the latent behavior into
a memory leak, it is also a behavior regression: blindly allocating a
new pointer wipes out what secrets we already knew about the chain,
making it impossible to restart the domain.

Of course, no one in their right mind should be relying on qcow2
encryption - it is fundamentally flawed.  And sadly, the TCK tests
don't get run often enough, and this shows that our virstoragetest
does not exercise encrypted images at all.  Otherwise, we could
have avoided a release containing this regression.

* src/util/virstoragefile.c (virStorageFileGetMetadataInternal):
Don't nuke an already-existing encryption.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-10 11:41:59 -06:00
Roman Bogorodskiy
0568db02a5 vbox: fix compilation error
clang complains about possibly uninitialized variable:

vbox/vbox_snapshot_conf.c:1355:9: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
    if (!(xPathContext = xmlXPathNewContext(xml))) {
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

So init 'ret' with NULL.
2014-06-10 21:30:44 +04:00
Chen Fan
c85b09cd7a virsh: Add details about specified migration host
the 'migration_host' description may be a bit difficult to
understand for some users, so enhance the manual

Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-10 11:20:06 -06:00
Eric Blake
b298025063 blockcommit: document semantics of committing active layer
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>
2014-06-10 11:11:16 -06:00
Wangrui (K)
350f816a00 docs: fix a typo in hacking.html.in
Signed-off-by: Wang Rui <moon.wangrui@huawei.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-06-10 08:53:03 -06:00