Rather than having to do:

$ virsh snapshot-revert dom $(virsh snapshot-current dom --name)

I thought it would be nice to do:

$ virsh snapshot-revert dom --current

I didn't add 'virsh snapshot-dumpxml --current' since we already have
'virsh snapshot-current' for the same task.  snapshot-list accepted
a name but did not require it, and that remains the case, with
--current serving in place of that name.  For all other commands,
name used to be required, and can now be replaced by --current;
I intentionally made it so that omitting both --current and a name
is an error (having the absence of a name imply --current seems
just a bit too magic, so --current must be explicit).  I also had
to keep snapshot-edit backwards-compatible, as the only command
that already had a --current argument alongside a name, which still
works to both edit a named snapshot and make it current.

* tools/virsh.c (vshLookupSnapshot): New helper function.
(cmdSnapshotEdit, cmdSnapshotList, cmdSnapshotParent)
(cmdSnapshotDelete, cmdDomainSnapshotRevert): Use it, adding an
option where needed.
* tools/virsh.pod (snapshot-delete, snapshot-edit)
(snapshot-list, snapshot-parent, snapshot-revert): Document
use of --current.
(snapshot-dumpxml): Mention alternative.

Given a list of snapshots and their parents, finding all descendants
requires a hairy traversal.  This code is O(n^3); it could maybe be
made to scale O(n^2) with the use of a hash table, but that costs more
memory.  Hopefully there aren't too many people with a hierarchy
so large as to approach REMOTE_DOMAIN_SNAPSHOT_LIST_NAMES_MAX (1024).

* tools/virsh.c (cmdSnapshotList): Add final fallback.

Iterating over one level of children requires parsing all snapshots
and their parents; a bit of code shuffling makes it pretty easy
to do this as well.

* tools/virsh.c (cmdSnapshotList): Add another fallback.

Emulating --from requires grabbing the entire list of snapshots
and their parents, and recursively iterating over the list from
the point of interest - but we already do that for --tree.  This
turns on emulation for that situation.

* tools/virsh.c (__vshControl): Rename member.
(vshReconnect, cmdConnect, vshGetSnapshotParent): Update clients.
(cmdSnapshotList): Add fallback.

Sometimes, we only care about one branch of the snapshot hierarchy.
Make it easier to list a single branch, by using the new APIs.

Technically, I could emulate these new virsh options on old servers
by doing a complete dump, then scraping xml to filter out just the
snapshots that I care about, but I didn't want to do that in this patch.

* tools/virsh.c (cmdSnapshotList): Add --from, --descendants.
* tools/virsh.pod (snapshot-list): Document them.

I was a bit surprised that 'virsh snapshot-edit dom name' silently
allowed me to clone things, while still telling me the old name,
especially since other commands like 'virsh edit dom' reject rename
attempts (*).  This fixes things to be more explicit (**).

(*) Technically, 'virsh edit dom' relies on virDomainDefineXML
behavior, which rejects attempts to mix a new name with existing
uuid or new uuid with existing name, but you can create a new
domain by changing both uuid and name.  On the other hand, while
snapshot-edit --clone is a true clone, creating a new domain
would also have to decide whether to clone snapshot metadata,
managed save, and any other secondary data related to the domain.
Domain renames are not trivial either.

(**) Renaming or creating a clone is still a risky proposition -
for offline snapshots and system checkpoints, if the new name
does not match an actual name recorded in the qcow2 internal
snapshots, then you cannot revert to the new checkpoint.  But it
is assumed that anyone using the new virsh flags knows what they
are doing, and can deal with the fallout caused by a rename/clone;
that is, we can't completely prevent a user from shooting
themselves in the foot, so much as we are making the default
action less risky.

* tools/virsh.c (cmdSnapshotEdit): Add --rename, --clone.
* tools/virsh.pod (snapshot-edit): Document them.

Otherwise, the results are not repeatable.

* tools/virsh.c (cmdSnapshotList): Print tree in predictable order.

virsh undefine command can now undefine an active guest, but the help information is still the old.
This patch modifies it and make it coincident to the manpage of virsh.
Signed-off-by: Ntangchen <tangchen@cn.fujitsu.com>

It was impossible for 'virsh snapshot-current dom name' to set name
as the current snapshot, if name is a disk-only snapshot.

Using strstr rather than full-blown xml parsing is safe, since the
xml is assumed to be well-formed coming from libvirtd rather than
arbitrary text coming from the user.

* tools/virsh.c (cmdSnapshotCurrent, cmdSnapshotEdit): Pass
disk_only flag when redefining a disk snapshot.

* tools/virsh.c (cmdSnapshotList): Spell exclusive correctly.

Although reverting to a snapshot is a form of data loss, this is
normally expected.  However, there are two cases where additional
surprises (failure to run the reverted state, or a break in
connectivity to the domain) can come into play.  Requiring extra
acknowledgment in these cases will make it less likely that
someone can get into an unrecoverable state due to a default revert.

Also create a new error code, so users can distinguish when forcing
would make a difference, rather than having to blindly request force.

* include/libvirt/libvirt.h.in (VIR_DOMAIN_SNAPSHOT_REVERT_FORCE):
New flag.
* src/libvirt.c (virDomainRevertToSnapshot): Document it.
* include/libvirt/virterror.h (VIR_ERR_SNAPSHOT_REVERT_RISKY): New
error value.
* src/util/virterror.c (virErrorMsg): Implement it.
* tools/virsh.c (cmdDomainSnapshotRevert): Add --force to virsh.
* tools/virsh.pod (snapshot-revert): Document it.

Previously, virsh 'snapshot-parent' and 'snapshot-current' were
completely silent in the case where the code conclusively proved
there was no parent or current snapshot, but differed in exit
status; this silence caused some confusion on whether the commands
worked.  Furthermore, commit d1be48f9 introduced a regression where
snapshot-parent would leak output about an unknown function, but
only on the first attempt, when talking to an older server that
lacks virDomainSnapshotGetParent.  This changes things to consistenly
report an error message and exit with status 1 when no snapshot
exists, and to avoid leaking unknown function warnings when using
fallbacks.

* tools/virsh.c (vshGetSnapshotParent): Alter signature, to
distinguish between real error and missing parent.  Don't pollute
last_error on success.
(cmdSnapshotParent): Adjust caller.  Always output message on
failure.
(cmdSnapshotList): Adjust caller.
(cmdSnapshotCurrent): Always output message on failure.

error:could not take a screenshot of xp
==6216== Syscall param unlink(pathname) points to unaddressable byte(s)
==6216==    at 0x373A0D4937: unlink (syscall-template.S:82)
==6216==    by 0x40FD73: cmdScreenshot (virsh.c:3070)
==6216==    by 0x42BA0D: vshCommandRun (virsh.c:14920)
==6216==    by 0x42EC97: main (virsh.c:16379)
==6216==  Address 0x0 is not stack'd, malloc'd or (recently) free'd
==6216==
error:Requested operation is not valid: domain is not running

Signed-off-by: NXu He Jie <xuhj@linux.vnet.ibm.com>

Reuse the tree listing of nodedev-list, coupled with the new helper
function to efficiently grab snapshot parent names, to produce
tree output for a snapshot hierarchy.  For example:

$ virsh snapshot-list dom --tree
root1
 |
  +- sibling1
  +- sibling2
  |   |
  |   +- grandchild
  |
  +- sibling3

root2
 |
  +- child

* tools/virsh.c (cmdSnapshotList): Add --tree.
* tools/virsh.pod (snapshot-list): Document it.

Make parent computation reusable, using virDomainSnapshotGetParent
when possible.

* tools/virsh.c (vshGetSnapshotParent): New helper.
(cmdSnapshotParent): Use it.

This patch cleans the cpu baseline function using new libvirt helper
functions and fixes XPath expression that selects <cpu> elements from
the source file, that can contain concatenated <capabilities> XMLs,
domain XMLs and bare <cpu> elements. The fixed XPath expression ensures
not to select NUMA <cpu id=... elements.

This patch also removes vshRealloc function, that remained unused after
cleaning up cpu-baseline.

https://bugzilla.redhat.com/show_bug.cgi?id=731645

This patch adds extraction of the <cpu> element from capabilities and
domain definition XML documents to improve user experience.

https://bugzilla.redhat.com/show_bug.cgi?id=731151

Introduced by commit 42c52d53, which added the support for new
flags, but forgot to update the API use to pass the flags.

Prior to commit 85d28108, we had an issue where:

snapshot-create-as dom name --diskspec spec --diskspec spec

failed to parse the second spec, because the first spec had marked
that option as no longer requiring an argument.

In commit 85d28108, I fixed it by making argv options no longer mark
the option as seen.  But this in turn breaks mandatory argv options,
which now complain that the argv option is missing.

This patch reverts that part of 85d28108, and instead replaces it with
fixes to no longer clear opts_need_arg of an argv argument.

* tools/virsh.c (vshCmddefGetOption, vshCmddefGetData)
(vshCommandParse): Fix option parsing for required argv option.
(vshCmddefOptParse): Check that argv option is last.
* tests/virsh-optparse: Enhance test.

There are 3 ways to lookup a volume, only virStorageVolLookupByName
needs pool object. So if no --pool is specified, it will tries to
get the volume via virStorageVolLookupByPath/virStorageVolLookupByKey.

But if all 3 ways fails, and no --pool is specified, a friendly
error might help the user get right way quickly.

Variable "name" is never used in the codes, it's useless.

Translators are likely to botch trailing spacing; by doing the
formatting outside of the translation, we can generally get
better alignment.  Also, for consistency, use 'bytes read' to
match 'bytes written'.

* tools/virsh.c (domblkstat_output): Drop trailing space. Tweak
rd_bytes output.
(cmdDomblkstat, DOMBLKSTAT_LEGACY_PRINT): Update formatting.

Users of virsh complain that output of the domblkstat command
is not intuitive enough. This patch adds explanation of fields
returned by this command to the help section for domblkstat and
the man page of virsh. Also a switch --human is added for
domblkstat that prints the fields with more descriptive
texts.

This patch also changes sequence of the output fields and their
names back to the order and spelling established by previous
versions of virsh to maintain compatibility with scripts.

Example of ordered and "translated" output:

PRE-patch:

virsh # domblkstat 1 vda
vda wr_bytes 5170176
vda wr_operations 511
vda rd_bytes 82815488
vda rd_operations 3726

POST-patch:

virsh # domblkstat 1 vda
vda rd_req 3726
vda rd_bytes 82815488
vda wr_req 478
vda wr_bytes 4965376

Example of human readable output:

virsh # domblkstat 1 vda --human
Device: vda
 number of read operations:      3726
 number of read bytes:           82815488
 number of write operations:     478
 number of bytes written:        4965376

https://bugzilla.redhat.com/show_bug.cgi?id=731656

Qemu sends STOP event as part of the shutdown process. Detect such STOP
event and consider shutdown to be reason of emitting such event. That's
the best we can do until qemu provides us the reason directly in STOP
event. This allows us to report shutdown reason for paused state so that
apps can detect domains that failed to finish the shutdown process
(e.g., because qemu is buggy and doesn't exit on SIGTERM or it is
blocked in flushing disk buffers).

This reverts commit 799912fa; now
that the rpc regression is fixed, virsh no longer needs the special
case here.

With this patch, it is hopefully a bit more obvious that for
snapshot-create-as, a literal '--diskspec' is mandatory if name
or description was omitted, but optional if all earlier options
were provided.

These all denote two diskspecs and a description:
virsh snapshot-create-as dom name desc vda vdb
virsh snapshot-create-as dom name desc --diskspec vda --diskspec vdb
virsh snapshot-create-as dom name desc --diskspec vda vdb
virsh snapshot-create-as dom name desc vda --diskspec vdb
virsh snapshot-create-as dom --diskspec vda --diskspec vdb name desc

This gives two diskspecs but no description:
virsh snapshot-create-as dom name --diskspec vda --diskspec vdb

And this treats 'vda' as the description, with only one diskspec:
virsh snapshot-create-as dom name vda vdb

The help output now shows:
    snapshot-create-as <domain> [<name>] [<description>] [--print-xml] [--no-metadata] [--halt] [--disk-only] [[--diskspec] <string>]...

I also checked the help output for echo and send-key, which are two
other variants of argv commands.

* tools/virsh.pod (snapshot-create-as): Document when a literal
--diskspec must preceed a diskspec argument.
* tools/virsh.c (vshCmddefHelp): Update help output for argv when
naming the option is useful.
(vshCmddefGetData): Fix logic on when argv was seen.
* tests/virsh-optparse: Add tests to avoid regressions.

Commit 498d7833 cleans up some of virtual file names for parsing strings
in memory. This patch cleans up (hopefuly) the rest forgotten by the
first patch.

This patch also changes all of the previously modified "filenames" to
valid URI's replacing spaces for underscores.

Changes to v1:
- Replace all spaces for underscores, so that the strings form valid
  URI's
- Replace spaces in places changed by commit 498d7833

Commit ffe28ab7 introduced regression
while communicating with older libvirtd command 'domblkstat' used the new
API and did not check for VIR_ERR_RPC error code signalling the remote
server does not support this API and did not fall back to older API.
Thereafter 'domblkstat' ended with "error: unknown procedure: 243".

While parsing XML strings from memory, the previous convention in
libvirt was to set the virtual file name to "domain.xml" or something
similar. This could potentialy trick the user into looking for a file
named domain.xml on the disk in an attempt to fix the error.

This patch changes these filenames to something that can't be as easily
confused for a valid filename.

Examples of error messages:
---------------------------
Error while loading file from disk:

15:07:59.015: 527: error : catchXMLError:709 : /path/to/domain.xml:1: StartTag: invalid element name
<domain type='kvm'><
--------------------^

Error while parsing definition in memory:

15:08:43.581: 525: error : catchXMLError:709 : (domain definition):2: error parsing attribute name
  <name>vm1</name>
--^

This has the added benefit of making 'snapshot-create dom --no-metadata'
now able to tell you the name of the just-generated snapshot.

* tools/virsh.c (vshSnapshotCreate, cmdSnapshotCurrent): Don't get
XML just for name.

* tools/virsh.c: millseconds should be milliseconds in opts_send_key.
Signed-off-by: NAlex Jia <ajia@redhat.com>

Because it's a define used in MSCOM and its usage as
identifier results in a compile error.

Two new commands are added to virsh that wrap usage of
virDomainUpdateDeviceFlags for changing link state of domain's network
interfaces. These wrappers extract network devices's xml configuration
and modify the link state for easy manipulation from an user's perspective.

 - domif-setlink - set link state of a domains virtual network interface
 - domif-getlink - get link state

* tools/virsh.c   - Add functionality to virsh
* tools/virsh.pod - Manpage documentation

The modified function fallbacks to use virDomainBlockStats if
virDomainBlockStatsFlags is not supported by the hypervisor driver.
If the new API is supported, it will be invoked instead of the
old API.

Expose the disk-only flag through virsh.  Additionally, make
virsh snapshot-create-as take an arbitrary number of diskspecs,
which can be used to build up the xml for <domainsnapshot>.

* tools/virsh.c (cmdSnapshotCreate): Add --disk-only.
(cmdSnapshotCreateAs): Likewise, and add argv diskspec.
(vshParseSnapshotDiskspec): New helper function.
(vshCmddefGetOption): Allow naming of argv field.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
them.
* tests/virsh-optparse: Test snapshot-create-as parsing.

This adds a convenience function to virsh that parses out block
information from the domain xml, making it much easier to see
what strings can be used in all other contexts that demand a
specific block name, especially when given the previous patch
that allows using either target or unique source name.

As an example on a domain with one disk and an empty cdrom drive:

Target     Source
-------------------------------------------
vda        /var/lib/libvirt/images/fedora_12.img
hdc        -

* tools/virsh.c (cmdDomblklist): New function.
* tools/virsh.pod (domblklist): Document it.

In order to distinguish disk snapshots from system checkpoints, a
new state value that is only valid for snapshots is helpful.

* include/libvirt/libvirt.h.in (VIR_DOMAIN_LAST): New placeholder.
* src/conf/domain_conf.h (virDomainSnapshotState): New enum mapping.
(VIR_DOMAIN_DISK_SNAPSHOT): New internal enum value.
* src/conf/domain_conf.c (virDomainState): Use placeholder.
(virDomainSnapshotState): Extend mapping by one for use in snapshot.
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Handle new state.
(virDomainObjSetState, virDomainStateReasonToString)
(virDomainStateReasonFromString): Avoid compiler warnings.
* tools/virsh.c (vshDomainState, vshDomainStateReasonToString):
Likewise.
* src/libvirt_private.syms (domain_conf.h): Export new functions.
* docs/schemas/domainsnapshot.rng: Tighten state definition.
* docs/formatsnapshot.html.in: Document it.
* tests/domainsnapshotxml2xmlout/disk_snapshot.xml: New test.

Easy enough to emulate even with older servers.

* tools/virsh.c (cmdSnapshotCreate, cmdSnapshotCreateAs): Add
--halt flag.
(vshSnapshotCreate): Emulate halt when flag is unsupported.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
it.

It would technically be possible to have virsh compute the list
of descendants of a given snapshot, then delete those one at
a time.  But it's complex, and not worth writing for a first
cut at implementing the new flags.

* tools/virsh.c (cmdSnapshotDelete): Add --children-only,
--metadata.
* tools/virsh.pod (snapshot-delete): Document them.