Currently users who want to use virDomainQemuMonitorCommand() API or
it's virsh equivalent has to use the same protocol as libvirt uses for
communication to qemu. Since the protocol is QMP with current qemu and
HMP much more usable for humans, one ends up typing something like the
following:

    virsh qemu-monitor-command DOM \
'{"execute":"human-monitor-command","arguments":{"command-line":"info kvm"}}'

which is not a very convenient way of debugging qemu.

This patch introduces --hmp option to qemu-monitor-command, which says
that the provided command is in HMP. If libvirt uses QMP to talk with
qemu, the command will automatically be converted into QMP. So the
example above is simplified to just

    virsh qemu-monitor-command --hmp DOM "info kvm"

Also the result is converted from

    {"return":"kvm support: enabled\r\n"}

to just plain HMP:

    kvm support: enabled

If libvirt talks to qemu in HMP, --hmp flag is obviously a noop.

This patch fixes 2 occurrences of nla_put expression with a '!' in
front of them that basically prevented the detection that the buffer
is too small. However, code further below would then detect that the
buffer is too small when further parts are added to the netlink message.

* src/qemu/qemu_driver.c (qemudShutdownVMDaemon): Check that vm is
still active.
Reported by Wen Congyang as follows:

Steps to reproduce this bug:

1. use gdb to debug libvirtd, and set breakpoint in the function
   qemuConnectMonitor()
2. start a vm, and the libvirtd will be stopped in qemuConnectMonitor()
3. kill -STOP $(cat /var/run/libvirt/qemu/<domain>.pid)
4. continue to run libvirtd in gdb, and libvirtd will be blocked in the
   function qemuMonitorSetCapabilities()
5. kill -9 $(cat /var/run/libvirt/qemu/<domain>.pid)

Here is log of the qemu:
=========
LC_ALL=C PATH=/sbin:/usr/sbin:/bin:/usr/bin ...
char device redirected to /dev/pts/3
2011-01-27 09:38:48.101: shutting down
2011-01-27 09:41:26.401: shutting down
=========

The vm is shut down twice. I do not know whether this behavior has
side effect, but I think we should shutdown the vm only once.

When compiling libvirt with GCC 3.4.6 the following warning is being triggered quite a lot:

util/memory.h:60: warning: declaration of 'remove' shadows a global declaration
/usr/include/stdio.h:175: warning: shadowed declaration is here

Fix this by renaming the parameter to 'toremove'.

Use of saslDecoded field need to be guarded by #if HAVE_SASL/endif
* src/remote/remote_driver.c: fix remoteIOEventLoop accordingly

* src/qemu/THREADS.txt: Improve documentation.

Depending if the qemu binary supports multiple pci-busses, the device
options will contain "bus=pci" or "bus=pci.0".

Only x86_64 and i686 seem to have support for multiple PCI-busses. When
a guest of these architectures is started, set the
QEMUD_CMD_FLAG_PCI_MULTIBUS flag.
Signed-off-by: NNiels de Vos <ndevos@redhat.com>

In the SASL codepath we typically read far more data off the
wire than we immediately need. When using a connection from a
single thread this isn't a problem, since only our reply will
be pending (or an event we can handle directly). When using a
connection from multiple threads though, we may read the data
from replies from other threads. If those replies occur after
our own reply, they'll not be processed. The other thread will
then go into poll() and wait for its reply which has already
been received and decoded. The solution is to set poll() timeout
to 0 if there is pending SASL data.

* src/remote/remote_driver.c: Don't sleep in poll() if SASL
  data exists

This patch fixes a variable in the debugging output.

Command line building for incoming tunneled migration is missed,
as a result, all the tunneled migration will fail with "unknown
migration protocol".

* src/qemu/qemu_command.c

* dnsmasq listens on all defined IPv[46] addresses for network
* Add ip6tables rules to allow DNS traffic to host

* src/qemu/qemu_driver.c

Bug manifests itself by:

1. # virsh attach-disk --target sdb ...
2. # virsh attach-disk --target sdh ...
   error: Failed to attach disk
   error: operation failed: target scsi:0 already exists

sdh uses scsi:1, rather than scsi:0.

* src/qemu/qemu_hotplug.c: properly set controller idx in
  qemuDomainFindOrCreateSCSIDiskController()

commit f1fe9671 was supposed to make sure we use files.h
macros to avoid double close, but it didn't work.

Meanwhile, virCommand is vastly superior to system(), fork(),
and popen() (also to virExec, but we haven't completed that
conversion), so enforce that, too.

* cfg.mk (sc_prohibit_close): Fix typo that excluded close, and
add pclose.
(sc_prohibit_fork_wrappers): New rule, for fork, system, and popen.
* .x-sc_prohibit_close: More exemptions.
* .x-sc_prohibit_fork_wrappers: New file.
* Makefile.am (syntax_check_exceptions): Ship new file.
* src/datatypes.c (virReleaseConnect): Tweak comment to avoid
false positive.
* src/util/files.h (VIR_CLOSE): Likewise.

* src/fdstream.c (virFDStreamOpenFile, virFDStreamCreateFile):
Use VIR_FORCE_CLOSE instead of close.
* tests/commandtest.c (mymain): Likewise.
* tools/virsh.c (editFile): Use virCommand instead of system.
* src/util/util.c (__virExec): Special case preservation of std
file descriptors to child.

Pure cosmetic change.

Use it in all places where a memory or storage request size is converted
to a larger granularity. This avoids requesting too small memory or storage
sizes that could result from the truncation done by a simple division.

This extends the round up fix in 6002e040
to the whole codebase.

Instead of reporting errors for odd values in the VMX code round them up.

Update the QEMU Argv tests accordingly as the original memory size 219200
isn't a even multiple of 1024 and is rounded up to 215 megabyte now. Change
it to 219100 and 219136. Use two different values intentionally to make
sure that rounding up works.

Update virsh.pod accordingly, as rounding down and rejecting are replaced
by rounding up.

Fixes test failure that was overlooked after commit 1e1f7a89.

* daemon/Makefile.am (check-local): Let 'make check' fail on error.
* daemon/test_libvirtd.aug: Move qemu-specific option...
* src/qemu/test_libvirtd_qemu.aug: ...into correct test.
* src/qemu/libvirtd_qemu.aug: Parse new option.

Report an VIR_ERR_OPERATION_INVALID error in that case instead of letting
the SOAP call fail with an VIR_ERR_INTERNAL_ERROR error.

qemu allows the user to choose what io storage api should be used,
either the default (threads) or native (linux aio) which in the latter
case can result in better performance.

Based on a patch originally by Matthias Dahl.

Red Hat Bugzilla #591703
Signed-off-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NEric Blake <eblake@redhat.com>

Allows io={threads|native} as an optional attribute to <driver>.
Signed-off-by: NEric Blake <eblake@redhat.com>

The refactoring of QEMU command startup was comitted with
a couple of VIR_WARN lines left in from debugging.

* src/qemu/qemu_driver.c: Remove log warning lines

When qemuMonitorSetCapabilities() fails, there is no need to
call qemuMonitorClose(), because the caller will already see
the error code and tear down the entire VM. The extra call to
qemuMonitorClose resulted in a double-free due to it removing
a ref count prematurely.

* src/qemu/qemu_driver.c: Remove premature close of monitor

Regression in commit caa805ea let a lot of bad messages slip in.

* cfg.mk (msg_gen_function): Fix function name.
* src/qemu/qemu_cgroup.c (qemuRemoveCgroup): Fix fallout from
'make syntax-check'.
* src/qemu/qemu_driver.c (qemudDomainGetInfo)
(qemuDomainWaitForMigrationComplete, qemudStartVMDaemon)
(qemudDomainSaveFlag, qemudDomainAttachDevice)
(qemuDomainUpdateDeviceFlags): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachHostUsbDevice)
(qemuDomainDetachPciDiskDevice, qemuDomainDetachSCSIDiskDevice):
Likewise.

When attaching device from a xml file and the device is mis-configured,
virsh gives mis-leading message "out of memory". This patch fixes this.
Signed-off-by: NEric Blake <eblake@redhat.com>

* src/qemu/qemu_command.c (qemuBuildChrChardevStr): Alter the
chardev alias.
(qemuBuildCommandLine): Output an id for the chardev counterpart.
* tests/qemuxml2argvdata/*: Update tests to match.
Reported by Daniel P. Berrange.

Steps to reproduce this bug:
1. service libvirtd start
2. virsh start <domain>
3. kill -STOP $(cat /var/run/libvirt/qemu/<domain>.pid)
4. service libvirtd restart
5. kill -9 $(cat /var/run/libvirt/qemu/<domain>.pid)

Then libvirtd will core dump or be in deadlock state.

Make sure that json is built into libvirt and the version
of qemu is newer than 0.13.0.

The reason of libvirtd cores dump is that:
We add vm->refs when we alloc the memory, and decrease it
in the function qemuHandleMonitorEOF() in other thread.

We add vm->refs in the function qemuConnectMonitor() and
decrease it when the vm is inactive.

The libvirtd will block in the function qemuMonitorSetCapabilities()
because the vm is stopped by signal SIGSTOP. Now the vm->refs is 2.

Then we kill the vm by signal SIGKILL. The function
qemuMonitorSetCapabilities() failed, and then we will decrease vm->refs
in the function qemuMonitorClose().
In another thread, mon->fd is broken and the function
qemuHandleMonitorEOF() is called.

If qemuHandleMonitorEOF() decreases vm->refs before qemuConnectMonitor()
returns, vm->refs will be decrease to 0 and the memory is freed.

We will call qemudShutdownVMDaemon() as qemuConnectMonitor() failed.
The memory has been freed, so qemudShutdownVMDaemon() is too dangerous.

We will reference NULL pointer in the function virDomainConfVMNWFilterTeardown():
=============
void
virDomainConfVMNWFilterTeardown(virDomainObjPtr vm) {
    int i;

    if (nwfilterDriver != NULL) {
        for (i = 0; i < vm->def->nnets; i++)
            virDomainConfNWFilterTeardown(vm->def->nets[i]);
    }
}
============
vm->def->nnets is not 0 but vm->def->nets is NULL(We don't set vm->def->nnets
to 0 when we free vm).

We should add an extra reference of vm to avoid vm to be deleted if
qemuConnectMonitor() failed.
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>

This new parameter allows user specifies where the client
cerficate, client key, CA certificate of x509 is, instead of
hardcoding it. If 'pkipath' is not specified, and the user
is not root, try to find files in $HOME/.pki/libvirt, as long
as one of client cerficate, client key, CA certificate can
not be found, use default global location (LIBVIRT_CACERT,
LIBVIRT_CLIENTCERT, LIBVIRT_CLIENTKEY, see
src/remote/remote_driver.h)

Example of use:

[root@Osier client]# virsh -c qemu+tls://10.66.93.111/system?pkipath=/tmp/pki/client
error: Cannot access CA certificate '/tmp/pki/client/cacert.pem': No such file
or directory
error: failed to connect to the hypervisor
[root@Osier client]# ls -l
total 24
-rwxrwxr-x. 1 root root 6424 Jan 24 21:35 a.out
-rw-r--r--. 1 root root 1245 Jan 23 19:04 clientcert.pem
-rw-r--r--. 1 root root  132 Jan 23 19:04 client.info
-rw-r--r--. 1 root root 1679 Jan 23 19:04 clientkey.pem

[root@Osier client]# cp /tmp/cacert.pem .
[root@Osier client]# virsh -c qemu+tls://10.66.93.111/system?pkipath=/tmp/pki/client
Welcome to virsh, the virtualization interactive terminal.

Type:  'help' for help with commands
'quit' to quit

virsh #

* src/remote/remote_driver.c: adds support for the new pkipath URI parameter

If vol->capacity is odd, the capacity will be rounded down
by devision, this patch is to round it up instead of rounding
down, to be safer in case of one writes to the volume with the
size he used to create.

- src/storage/storage_backend_logical.c: make sure size is not rounded down

Per the discussion in:

https://bugzilla.redhat.com/show_bug.cgi?id=670394

The port numbering should start from 1, not 0.  We assign maxport + 1,
so start maxport at 0.

If a guest image is saved in compressed format, and the restore fails
in some way after the intermediate process used to uncompress the
image has been started, but before qemu has been started to hook up to
the uncompressor, libvirt will endlessly wait for the uncompressor to
finish, but it never will because it's still waiting to have something
hooked up to drain its output.

The solution is to close the pipes on both sides of the uncompressor,
then send a SIGTERM before calling waitpid on it (only if the restore
has failed, of course).

Handle poll errors in the same way as hangup event

* src/qemu/qemu_monitor.c: Handle error events

Add a hook to the error reporting APIs to allow specific
error messages to be filtered out. Wire up libvirtd to
remove VIR_ERR_NO_DOMAIN & similar error codes from the
logs. They are still logged at DEBUG level.

* daemon/libvirtd.c: Filter VIR_ERR_NO_DOMAIN and friends
* src/libvirt_private.syms, src/util/virterror.c,
  src/util/virterror_internal.h: Hook for changing error
  reporting level

This reverts the additions in commit

  abff683f

taking us back to state where all errors are fully logged
in both libvirtd and normal clients.

THe intent was to stop VIR_ERR_NO_DOMAIN (No such domain
with UUID XXXX) messages from client apps polluting syslog
The change affected all error codes, but more seriously,
it also impacted errors from internal libvirtd infrastructure
For example guest autostart no longer logged errors. The
libvirtd network code no longer logged some errors. This
makes debugging incredibly hard

* daemon/libvirtd.c: Remove error log priority filter
* src/util/virterror.c, src/util/virterror_internal.h: Remove
  callback for overriding log priority

Remove use of brackets around following return statement.
Fix indentation of two switch statements

This patch is a partial resolution to the following bug:

   https://bugzilla.redhat.com/show_bug.cgi?id=667756

(to complete the fix, an updated selinux-policy package is required,
to add the policy that allows libvirt to set the context of a fifo,
which was previously not allowed).

Explanation : When an incoming migration is over a pipe (for example,
if the image was compressed and is being fed through gzip, or was on a
root-squash nfs server, so needed to be opened by a child process
running as a different uid), qemu cannot read it unless the selinux
context label for the pipe has been set properly.

The solution is to check the fd used as the source of the migration
just before passing it to qemu; if it's a fifo (implying that it's a
pipe), we call the newly added virSecurityManagerSetFDLabel() function
to set the context properly.