virsh: move command maxvcpus from domain group to host group.

Since the maxvcpus command query the maximum number of virtual
CPUs supported for a guest VM on this connection, it should be
in virsh-host.c but not virsh-domain.c.

Signed-off-by: yangdongsheng <yangds.fnst@cn.fujitsu.com>
util: Declare that virFileExists shall honor errno

Explicitly state that some parts of the code may require virFileExists
to set or preserve a correct errno so that future modifications don't
break.
cleanup: Kill usage of access(PATH, F_OK) in favor of virFileExists()

Semantics of the libvirt helper are more clear. This change also allows
to clean up some pieces of code.
cgroup: Move [qemu|lxc]GetCpuBWStatus to vicgroup.c and refactor it

The function existed in two identical instances in lxc and qemu. Move it
to vircgroup.c and simplify it. Refactor the callers too.
build: fix build with latest rawhide kernel headers

Bother those kernel developers.  In the latest rawhide, kernel
and glibc have now been unified so that <netinet/in.h> and
<linux/in6.h> no longer clash; but <linux/if_bridge.h> is still
not self-contained.  Because of the latest header change, the
build is failing with:

checking for linux/param.h... no
configure: error: You must install kernel-headers in order to compile libvirt with QEMU or LXC support

with details:

In file included from conftest.c:561:0:
/usr/include/linux/in6.h:71:18: error: field 'flr_dst' has incomplete type
  struct in6_addr flr_dst;

We need a workaround to avoid our workaround :)

* configure.ac (NETINET_LINUX_WORKAROUND): New test.
* src/util/virnetdevbridge.c (includes): Use it.

Signed-off-by: Eric Blake <eblake@redhat.com>
build: make autobuild require rpm build deps

I spent far too long on a new machine trying to figure out why
./autobuild.sh failed due to an rpm build failure (complaining
that libvirt_parthelper was supposed to be packaged but was not
built), and finally traced it to a missing parted-devel
installation.  I learned that --nodeps is in place for
autobuilder setups, but for developers, removing it would make
rpmbuild error out much sooner for a less cryptic failure.

* autobuild.sh: Conditionally drop --nodeps from rpmbuild lines.

Signed-off-by: Eric Blake <eblake@redhat.com>
Free slicename in virSystemdCreateMachine

https://bugzilla.redhat.com/show_bug.cgi?id=1008619

1,003 bytes in 1 blocks are definitely lost in loss record 599 of 635
==404== by 0x50728A7: virBufferAddChar (virbuffer.c:185)
==404== by 0x50BC466: virSystemdEscapeName (virsystemd.c:67)
==404== by 0x50BC6B2: virSystemdMakeSliceName (virsystemd.c:108)
==404== by 0x50BC870: virSystemdCreateMachine (virsystemd.c:169)
==404== by 0x5078267: virCgroupNewMachine (vircgroup.c:1498)
Always free network and graphics cookies

qemuMigrationEatCookie has flags to control if these should
be parsed, but it does not fill mig->flags. These cookies might
get leaked if these flags are not set by qemuMigrationBakeCookie.

42 (32 direct, 10 indirect) bytes in 1 blocks are definitely lost in
loss record 361 of 662
==123== by 0x1BA33FCA: qemuMigrationEatCookie (qemu_migration.c:678)
==123== by 0x1BA34A1E: qemuMigrationRun (qemu_migration.c:3108)
==123== by 0x1BA3622B: doNativeMigrate (qemu_migration.c:3343)
==123== by 0x1BA3B408: qemuMigrationPerform (qemu_migration.c:4138)
Allow LUN type disks to have no source

CD-ROMs and Floppies are allowed to have no source to imply they are
empty or disconnected. Since the LUN type is used for raw CD-ROM access
with QEMU (and VMWare in the future), it also needs to allow an empty
source when the raw CD-ROM device is disconnected from the domain.
virsh: Fix a wrong check in cmdEcho()

What should be checked here is xmlbuf rather than buf.
qemu: Fix checking of ABI stability when restoring external checkpoints

External checkpoints have a bug in the implementation where they use the
normal definition instead of the "migratable" one. This causes errors
when the snapshot is being reverted using the workaround method via
qemuDomainRestoreFlags() with a custom XML. This issue was introduced
when commit 07966f6a8b5ccb5bb4c716b25deb8ba2e572cc67 changed the code to
compare "migratable" XMLs from the user as we should have used
migratable in the image too.

This patch adds a compatibility layer, so that fixing the snapshot code
won't make existing snapshots fail to load.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1008340
qemu: Use "migratable" XML definition when doing external checkpoints

In the original implementation of external checkpoints I've mistakenly
used the live definition to be stored in the save image. The normal
approach is to use the "migratable" definition. This was discovered when
commit 07966f6a8b5ccb5bb4c716b25deb8ba2e572cc67 changed the behavior to
use a converted XML from the user to do the compatibility check to fix
problem when using the regular machine saving.

As the previous patch added a compatibility layer, we can now change the
type of the XML in the image.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1008340
virsh-domain: Remove spurious ATTRIBUTE_UNUSED from cmdDesc

The "cmd" variable is actually used so remove the attribute.
virsh-domain: Line up signal names array

Line up the array so that the grid is visible.
qemu: Factor out body of qemuDomainGetMetadata for universal use

The function implemented common behavior that can be reused for other
hypervisor drivers that use the virDomainObj data structures. Factor out
the core into a separate helper func.
qemu: Factor out body of qemuDomainSetMetadata for universal use

The function implemented common behavior that can be reused for other
hypervisor drivers that use the virDomainObj data structures. Factor out
the core into a separate helper func.
conf: Factor out setting of metadata to simplify code

The code to set the metadata in a domain definition is common to live
and inactive domains. Factor it out into a common func.
util: Add helper to convert libxml2 nodes to a string
virsh-domain: use virXMLNodeToString instead of xmlNodeDump
virsh-domain: Add command to allow modifications of XML metadata

The metadata modification functions will support modification of the XML
metadata. Add a virsh command to allow using this approach.