Commit Graph

146 Commits

Author SHA1 Message Date
John Ferlan
ffdf82a9da Determine whether to start balloon memory stats gathering.
At vm startup and attach attempt to set the balloon driver statistics
collection period based on the value found in the domain xml file. This
is not done at reconnect since it's possible that a collection period
was set on the live guest and making the set period call would reset to
whatever value is stored in the config file.

Setting the stats collection period has a side effect of searching through
the qom-list output for the virtio balloon driver and making sure that it
has the right properties in order to allow setting of a collection period
and eventually fetching of statistics.

The walk through the qom-list is expensive and thus the balloonpath will
be saved in the monitor private structure as well as a flag indicating
that the initialization has already been attempted (in the event that a
path is not found, no sense to keep checking).

This processing model conforms to the qom object model model which
requires setting object properties after device startup. That is, it's
not possible to pass the period along via the startup code as it won't
be recognized.
2013-07-16 08:44:52 -04:00
Michal Privoznik
0f7a7ce5ff qemu_monitor: Introduce qemuMonitorDetachCharDev
This function wraps 'chardev-remove' qemu monitor command around.
It takes chardev alias as its single argument besides qemu monitor
pointer.
2013-07-12 11:00:04 +02:00
Michal Privoznik
4a51447abe qemu_monitor: Introduce qemuMonitorAttachCharDev
The function being introduced is responsible for preparing and
executing 'chardev-add' qemu monitor command. Moreover, in case
of PTY chardev, the corresponding pty path is updated.
2013-07-12 11:00:01 +02:00
Chen Fan
9aa527dccb qemu: Implement 'oncrash' events when guest panicked
Add monitor callback API domainGuestPanic, that implements
'destroy', 'restart' and 'preserve' events of the 'on_crash'
in the XML when domain crashed.
2013-07-02 12:02:30 -06:00
Michal Novotny
ff96888991 qemu: Implement CPUs check against machine type's cpu-max
Implement check whether (maximum) vCPUs doesn't exceed machine
type's cpu-max settings.

On older versions of QEMU the check is disabled.

Signed-off-by: Michal Novotny <minovotn@redhat.com>
2013-07-01 14:30:42 +02:00
Peter Krempa
82e119f5cd qemu: Use bool instead of int in qemuMonitorSetCPU APIs
The 'online' parameter has only two possible values. Use a bool for it.
2013-06-07 15:57:03 +02:00
Michal Privoznik
1f24f68225 qemu: Adapt qemuBuildInterfaceCommandLine to to multiqueue net
In order to learn libvirt multiqueue several things must be done:

1) The '/dev/net/tun' device needs to be opened multiple times with
IFF_MULTI_QUEUE flag passed to ioctl(fd, TUNSETIFF, &ifr);

2) Similarly, '/dev/vhost-net' must be opened as many times as in 1)
in order to keep 1:1 ratio recommended by qemu and kernel folks.

3) The command line construction code needs to switch from 'fd=X' to
'fds=X:Y:...:Z' and from 'vhostfd=X' to 'vhostfds=X:Y:...:Z'.

4) The monitor handling code needs to learn to pass multiple FDs.
2013-05-22 17:24:27 +02:00
Eric Blake
bd56d0d813 qemu: query command line options in QMP
Ever since the conversion to using only QMP for probing features
of qemu 1.2 and newer, we have been unable to detect features
that are added only by additional command line options.  For
example, we'd like to know if '-machine mem-merge=on' (added
in qemu 1.5) is present.  To do this, we will take advantage
of qemu 1.5's query-command-line-parameters QMP call [1].

This patch wires up the framework for probing the command results;
if the QMP command is missing, or if a particular command line
option does not output any parameters (for example, -net uses
a polymorphic parser, which showed up as no parameters as of qemu
1.5), we silently treat that command as having no results.

[1] https://lists.gnu.org/archive/html/qemu-devel/2013-04/msg05180.html

* src/qemu/qemu_monitor.h (qemuMonitorGetOptions)
(qemuMonitorSetOptions)
(qemuMonitorGetCommandLineOptionParameters): New functions.
* src/qemu/qemu_monitor_json.h
(qemuMonitorJSONGetCommandLineOptionParameters): Likewise.
* src/qemu/qemu_monitor.c (_qemuMonitor): Add cache field.
(qemuMonitorDispose): Clean it.
(qemuMonitorGetCommandLineOptionParameters): Implement new function.
* src/qemu/qemu_monitor_json.c
(qemuMonitorJSONGetCommandLineOptionParameters): Likewise.
(testQemuMonitorJSONGetCommandLineParameters): Test it.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-13 15:15:54 -06:00
Eric Blake
764bb5e5aa qemu: use bool in monitor struct
Follows on the heels of other bool cleanups, such as commit 93002b98.

* src/qemu/qemu_monitor.h (qemuMonitorOpen, qemuMonitorOpenFD):
Update json parameter type.
* src/qemu/qemu_monitor.c (qemuMonitorOpen, qemuMonitorOpenFD):
Likewise.
(_qemuMonitor): Adjust field type.
* src/qemu/qemu_domain.h (_qemuDomainObjPrivate): Likewise.
* src/qemu/qemu_domain.c (qemuDomainObjPrivateXMLParse): Adjust
client.
* src/qemu/qemu_process.c (qemuProcessStart): Likewise.
* tests/qemumonitortestutils.c (qemuMonitorTestNew): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-13 15:15:54 -06:00
Stefan Berger
ed1f031850 Add QMP probing for TPM
Probe for QEMU's QMP TPM support by querying the lists of
supported TPM models (query-tpm-models) and backend types
(query-tpm-types). 

The setting of the capability flags following the strings
returned from the commands above is only provided in the
patch where domain_conf.c gets TPM support due to dependencies
on functions only introduced there. 

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Tested-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
2013-04-12 16:55:45 -04:00
Michal Privoznik
f1748e34e2 qemu: Introduce nbd-server-stop command
This will be used after all migration work is done
to stop NBD server running on destination.  It
doesn't take any arguments, just issues a command.
2013-02-23 08:16:42 +01:00
Michal Privoznik
c833d8111d qemu: Introduce nbd-server-add command
This will be used with new migration scheme.
This patch creates basically just monitor stub
functions. Wiring them into something useful
is done in later patches.
2013-02-23 08:06:37 +01:00
Michal Privoznik
bb6359e8d4 qemu: Introduce nbd-server-start command
This will be used with new migration scheme.
This patch creates basically just monitor stub
functions. Wiring them into something useful
is done in later patches.
2013-02-23 07:58:13 +01:00
Jiri Denemark
492afb8202 qemu: Implement virDomainMigrate*CompressionCache 2013-02-22 17:36:00 +01:00
Jiri Denemark
4121a77c1a qemu: Parse more fields from query-migrate QMP command
As a side effect, this also fixes reporting disk migration process.
It was added to memory migration progress, which was wrong. Disk
progress has dedicated fields in virDomainJobInfo structure.
2013-02-22 17:35:59 +01:00
Jiri Denemark
94f59b9ece qemu: Add support for compressed migration 2013-02-22 17:35:58 +01:00
Eric Blake
7b2c5893c2 qemu: expose qemu 1.3 add-fd monitor command
Add entry points for calling the qemu 'add-fd' and 'remove-fd'
monitor commands.  There is no entry point for 'query-fdsets';
the assumption is that a developer can use
 virsh qemu-monitor-command domain '{"execute":"query-fdsets"}'
when debugging issues, and that meanwhile, libvirt is responsible
enough to remember what fds it associated with what fdsets.
Likewise, on the 'add-fd' command, it is assumed that libvirt
will always pass a set id, rather than letting qemu autogenerate
the next available id number.

* src/qemu/qemu_monitor.c (qemuMonitorAddFd, qemuMonitorRemoveFd):
New functions.
* src/qemu/qemu_monitor.h (qemuMonitorAddFd, qemuMonitorRemoveFd):
New prototypes.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONAddFd)
(qemuMonitorJSONRemoveFd): New functions.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONAddFd)
(qemuMonitorJSONRemoveFd): New prototypes.
2013-01-31 10:23:28 -07:00
Daniel P. Berrange
325b02b5a3 Convert virDomainObj, qemuAgent, qemuMonitor, lxcMonitor to virObjectLockable
The  virDomainObj, qemuAgent, qemuMonitor, lxcMonitor classes
all require a mutex, so can be switched to use virObjectLockable

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-01-16 11:02:58 +00:00
Andres Lagar-Cavilla
aedfcce33e Add RESUME event listener to qemu monitor.
Perform all the appropriate plumbing.

When qemu/KVM VMs are paused manually through a monitor not-owned by libvirt,
libvirt will think of them as "paused" event after they are resumed and
effectively running. With this patch the discrepancy goes away.

This is meant to address bug 892791.

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
2013-01-09 10:17:40 +01:00
Daniel P. Berrange
6a095d0851 Rename json.{c,h} to virjson.{c,h} 2012-12-21 11:17:13 +00:00
Daniel P. Berrange
a27e4fbb72 Rename bitmap.{c,h} to virbitmap.{c,h}
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-12-21 11:17:12 +00:00
Martin Kletzander
037a49dc66 Make non-KVM machines work with QMP probing
When there is no 'qemu-kvm' binary and the emulator used for a machine
is, for example, 'qemu-system-x86_64' that, by default, runs without
kvm enabled, libvirt still supplies '-no-kvm' option to this process,
even though it does not recognize such option (making the start of a
domain fail in that case).

This patch fixes building a command-line for QEMU machines without KVM
acceleration and is based on following assumptions:

 - QEMU_CAPS_KVM flag means that QEMU is running KVM accelerated
   machines by default (without explicitly requesting that using a
   command-line option).  It is the closest to the truth according to
   the code with the only exception being the comment next to the
   flag, so it's fixed in this patch as well.

 - QEMU_CAPS_ENABLE_KVM flag means that QEMU is, by default, running
   without KVM acceleration and in case we need KVM acceleration it
   needs to be explicitly instructed to do so.  This is partially
   true for the past (this option essentially means that QEMU
   recognizes the '-enable-kvm' option, even though it's almost the
   same).
2012-10-31 08:31:49 +01:00
Eric Blake
6d264c9182 blockjob: add qemu capabilities related to block jobs
Upstream qemu 1.3 is adding two new monitor commands, 'drive-mirror'
and 'block-job-complete'[1], which can drive live block copy and
storage migration.  [Additionally, RHEL 6.3 had backported an earlier
version of most of the same functionality, but under the names
'__com.redhat_drive-mirror' and '__com.redhat_drive-reopen' and with
slightly different JSON arguments, and has been using patches similar
to these upstream patches for several months now.]

The libvirt API virDomainBlockRebase as already committed for 0.9.12
is flexible enough to expose the basics of block copy, but some
additional features in the 'drive-mirror' qemu command, such as
setting error policy, setting granularity, or using a persistent
bitmap, may later require a new libvirt API virDomainBlockCopy.  I
will wait to add that API until we know more about what qemu 1.3
will finally provide.

This patch caters only to the upstream qemu 1.3 interface, although
I have proven that the changes for RHEL 6.3 can be isolated to
just qemu_monitor_json.c, and the rest of this series will
gracefully handle either interface once the JSON differences are
papered over in a downstream patch.

For consistency with other block job commands, libvirt must handle
the bandwidth argument as MiB/sec from the user, even though qemu
exposes the speed argument as bytes/sec; then again, qemu rounds
up to cluster size internally, so using MiB hides the worst effects
of that rounding if you pass small numbers.

[1]https://lists.gnu.org/archive/html/qemu-devel/2012-10/msg04123.html

* src/qemu/qemu_capabilities.h (QEMU_CAPS_DRIVE_MIRROR)
(QEMU_CAPS_DRIVE_REOPEN): New bits.
* src/qemu/qemu_capabilities.c (qemuCaps): Name them.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCheckCommands): Set
them.
(qemuMonitorJSONDriveMirror, qemuMonitorDrivePivot): New functions.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDriveMirror)
(qemuMonitorDrivePivot): Declare them.
* src/qemu/qemu_monitor.c (qemuMonitorDriveMirror)
(qemuMonitorDrivePivot): New passthroughs.
* src/qemu/qemu_monitor.h (qemuMonitorDriveMirror)
(qemuMonitorDrivePivot): Declare them.
2012-10-27 07:43:37 -06:00
Eric Blake
3f38c7e3a9 blockjob: manage qemu block-commit monitor command
qemu 1.3 will be adding a 'block-commit' monitor command, per
qemu.git commit ed61fc1.  It matches nicely to the libvirt API
virDomainBlockCommit.

* src/qemu/qemu_capabilities.h (QEMU_CAPS_BLOCK_COMMIT): New bit.
* src/qemu/qemu_capabilities.c (qemuCapsProbeQMPCommands): Set it.
* src/qemu/qemu_monitor.h (qemuMonitorBlockCommit): New prototype.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockCommit):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorBlockCommit): Implement it.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockCommit):
Likewise.
(qemuMonitorJSONHandleBlockJobImpl)
(qemuMonitorJSONGetBlockJobInfoOne): Handle new event type.
2012-10-19 17:35:11 -06:00
Martin Kletzander
7ba5defb5a Add support for SUSPEND_DISK event
This patch adds support for SUSPEND_DISK event; both lifecycle and
separated.  The support is added for QEMU, machines are changed to
PMSUSPENDED, but as QEMU sends SHUTDOWN afterwards, the state changes
to shut-off.  This and much more needs to be done in order for libvirt
to work with transient devices, wake-ups etc.  This patch is not
aiming for that functionality.
2012-10-15 12:09:10 +02:00
Daniel P. Berrange
1b21351b93 Move command/event capabilities detection out of QEMU monitor code
The qemuMonitorSetCapabilities() API is used to initialize the QMP
protocol capabilities. It has since been abused to initialize some
libvirt internal capabilities based on command/event existance too.
Move the latter code out into qemuCapsProbeQMP() in the QEMU
capabilities source file instead

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 11:06:04 +01:00
Daniel P. Berrange
c25746c216 Remove some unused includes in QEMU code
The qemu monitor does not require qemu_conf.h, and the
qemu capabilities code actually wants bitmap.h

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 11:06:01 +01:00
Daniel P. Berrange
364a77ff0f Add a qemuMonitorGetTargetArch() method for QMP query-target command
Add a new qemuMonitorGetTargetArch() method to support invocation
of the 'query-target' JSON monitor command. No HMP equivalent
is required, since this will only be present for QEMU >= 1.2

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 11:06:00 +01:00
Daniel P. Berrange
b785cec0dc Add a qemuMonitorGetObjectProps() method for QMP device-list-properties command
Add a new qemuMonitorGetObjectProps() method to support invocation
of the 'device-list-properties' JSON monitor command. No HMP equivalent
is required, since this will only be present for QEMU >= 1.2

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 11:05:16 +01:00
Daniel P. Berrange
2ccaa8e6ba Add a qemuMonitorGetObjectTypes() method for QMP qom-list-types command
Add a new qemuMonitorGetObjectTypes() method to support invocation
of the 'qom-list-types' JSON monitor command. No HMP equivalent
is required, since this will only be present for QEMU >= 1.2

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 11:05:00 +01:00
Daniel P. Berrange
3b565d3f46 Add a qemuMonitorGetEvents() method for QMP query-events command
Add a new qemuMonitorGetEvents() method to support invocation
of the 'query-events' JSON monitor command. No HMP equivalent
is required, since this will only be used when JSON is available

The existing qemuMonitorJSONCheckEvents() method is refactored
to use this new method

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 11:04:57 +01:00
Daniel P. Berrange
c70a6154b6 Add a qemuMonitorGetCommands() method for QMP query-commands command
Add a new qemuMonitorGetCPUCommands() method to support invocation
of the 'query-commands' JSON monitor command. No HMP equivalent
is required, since this will only be used when JSON is available

The existing qemuMonitorJSONCheckCommands() method is refactored
to use this new method

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 11:04:32 +01:00
Daniel P. Berrange
2ecec6e206 Add a qemuMonitorGetCPUDefinitions method for QMP query-cpu-definitions command
Add a new qemuMonitorGetCPUDefinitions() method to support invocation
of the 'query-cpu-definitions' JSON monitor command. No HMP equivalent
is required, since this will only be present for QEMU >= 1.2

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 10:53:24 +01:00
Daniel P. Berrange
3999372182 Add a qemuMonitorGetMachines() method for QMP query-machines command
Add a new qemuMonitorGetMachines() method to support invocation
of the 'query-machines' JSON monitor command. No HMP equivalent
is required, since this will only be present for QEMU >= 1.2

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 10:47:16 +01:00
Daniel P. Berrange
3dce0a829a Add a qemuMonitorGetVersion() method for QMP query-version command
Add a new qemuMonitorGetVersion() method to support invocation
of the 'query-version' JSON monitor command. No HMP equivalent
is provided, since this will only be used for QEMU >= 1.2

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-27 10:46:34 +01:00
Michal Privoznik
3521cd1c32 qemu: wait for SPICE to migrate
Recently, there have been some improvements made to qemu so it
supports seamless migration or something very close to it.
However, it requires libvirt interaction. Once qemu is migrated,
the SPICE server needs to send its internal state to the destination.
Once it's done, it fires SPICE_MIGRATE_COMPLETED event and this
fact is advertised in 'query-spice' output as well.
We must not kill qemu until SPICE server finishes the transfer.
2012-09-26 11:42:59 +02:00
Eric Blake
4ecb723b9e maint: fix up copyright notice inconsistencies
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/
2012-09-20 16:30:55 -06:00
Eric Blake
d239085e95 qemu: drop unused arguments for dump-guest-memory
Upstream qemu has raised a concern about whether dumping guest
memory by reading guest paging tables is a security hole:
https://lists.gnu.org/archive/html/qemu-devel/2012-09/msg02607.html

While auditing libvirt to see if we would be impacted, I noticed
that we had some dead code.  It is simpler to nuke the dead code
and limit our monitor code to just the subset we make use of.

* src/qemu/qemu_monitor.h (QEMU_MONITOR_DUMP): Drop poorly named
and mostly-unused enum.
* src/qemu/qemu_monitor.c (qemuMonitorDumpToFd): Drop arguments.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDump): Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDump): Likewise.
* src/qemu/qemu_driver.c (qemuDumpToFd): Update caller.
2012-09-17 20:44:29 -06:00
Daniel P. Berrange
97a1f07681 Remove upfront check for hmp - just try it cope with failure
Don't bother checking for the existance of the HMP passthrough
command. Just try to execute it, and propagate the failure.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-14 12:59:25 +01:00
Daniel P. Berrange
beac09fd68 Turn QEMU capabilities object into a full virObjectPtr
The current qemu capabilities are stored in a virBitmapPtr
object, whose type is exposed to callers. We want to store
more data besides just the flags, so we need to move to a
struct type. This object will also need to be reference
counted, since we'll be maintaining a cache of data per
binary. This change introduces a 'qemuCapsPtr' virObject
class. Most of the change is just renaming types and
variables in all the callers

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-13 12:24:12 +01:00
Daniel P. Berrange
cf5491e5ba Add API for opening a QEMU monitor from a socket FD
Currently qemuMonitorOpen() requires an address of the QEMU
monitor. When doing QMP based capabilities detection it is
easier if a pre-opened FD can be provided, since then the
monitor can be run on the STDIO console. Add a new API
qemuMonitorOpenFD() for such usage

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-12 17:20:57 +01:00
Daniel P. Berrange
1f490138ba Add non-null annotations to qemuMonitorOpen
Add some non-null annotations to qemuMonitorOpen and also
check that the error callback is set, since it is mandatory

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-07 13:18:00 +01:00
Shradha Shah
f9150c8158 conf: move DevicePCIAddress functions to separate file
Move the functions the parse/format, and validate PCI addresses to
their own file so they can be conveniently used in other places
besides device_conf.c

Refactoring existing code without causing any functional changes to
prepare for new code.

This patch makes the code reusable.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
2012-08-17 15:43:25 -04:00
Daniel P. Berrange
b57ee0921e Turn qemuAgentPtr and qemuMonitorPtr into virObjectPtr instances
Make qemuAgentPtr and qemuMonitorPtr types use the virObject APIs
for reference counting

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-08-07 11:47:41 +01:00
Osier Yang
f9ce7dad60 Desert the FSF address in copyright
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c
2012-07-23 10:50:50 +08:00
Daniel P. Berrange
1d9d5103b4 Wire up handling for QMP's BALLOON_EVENT
If QEMU supports the BALLOON_EVENT QMP event, then we can
avoid invoking 'query-balloon' when returning XML or the
domain info.

* src/qemu/qemu_capabilities.c, src/qemu/qemu_capabilities.h:
  Add QEMU_CAPS_BALLOON_EVENT
* src/qemu/qemu_driver.c: Skip query-balloon in
  qemudDomainGetInfo and qemuDomainGetXMLDesc if we have
  QEMU_CAPS_BALLOON_EVENT set
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h: Check
  for BALLOON_EVENT at connect to monitor. Add callback
  for balloon change notifications
* src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h:
  Add handling of BALLOON_EVENT and impl 'query-events'
  check

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-07-14 16:02:34 +08:00
Wen Congyang
6fe26d89cc qemu: implement qemu's dump-guest-memory
dump-guest-memory is a new dump mechanism, and it can work when the
guest uses host devices. This patch adds a API to use this new
monitor command.
We will always use json mode if qemu's version is >= 0.15, so I
don't implement the API for text mode.
2012-06-15 20:36:14 +08:00
Eric Blake
2eabac008e blockjob: fix block-stream bandwidth race
With RHEL 6.2, virDomainBlockPull(dom, dev, bandwidth, 0) has a race
with non-zero bandwidth: there is a window between the block_stream
and block_job_set_speed monitor commands where an unlimited amount
of data was let through, defeating the point of a throttle.

This race was first identified in commit a9d3495e, and libvirt was
able to reduce the size of the window for that race.  In the meantime,
the qemu developers decided to fix things properly; per this message:
https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg03793.html
the fix will be in qemu 1.1, and changes block-job-set-speed to use
a different parameter name, as well as adding a new optional parameter
to block-stream, which eliminates the race altogether.

Since our documentation already mentioned that we can refuse a non-zero
bandwidth for some hypervisors, I think the best solution is to do
just that for RHEL 6.2 qemu, so that the race is obvious to the user
(anyone using stock RHEL 6.2 binaries won't have this patch, and anyone
building their own libvirt with this patch for RHEL can also rebuild
qemu to get the modern semantics, so it is no real loss in behavior).

Meanwhile the code must be fixed to honor actual qemu 1.1 naming.
Rename the parameter to 'modern', since the naming difference now
covers more than just 'async' block-job-cancel.  And while at it,
fix an unchecked integer overflow.

* src/qemu/qemu_monitor.h (enum BLOCK_JOB_CMD): Drop unused value,
rename enum to match conventions.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Reflect enum rename.
* src/qemu_qemu_monitor_json.h (qemuMonitorJSONBlockJob): Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Likewise,
and support difference between RHEL 6.2 and qemu 1.1 block pull.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Reject
bandwidth during pull with too-old qemu.
* src/libvirt.c (virDomainBlockPull, virDomainBlockRebase):
Document this.
2012-04-27 13:00:56 -06:00
Eric Blake
a9d3495e67 blockjob: allow for fast-finishing job
In my testing, I was able to provoke an odd block pull failure:

$ virsh blockpull dom vda --bandwidth 10000
error: Requested operation is not valid: No active operation on device: drive-virtio-disk0

merely by using gdb to artifically wait to do the block job set speed
until after the pull had already finished.  But in reality, that should
be a success, since the pull finished before we had a chance to set
speed.  Furthermore, using a double job lock is not only annoying, but
a bug in itself - if you do parallel virDomainBlockRebase, and hit
the race window just right, the first call grabs the VM job to start
a fast block job, then the second call grabs the VM job to start
a long-running job with unspecified speed, then the first call finally
regrabs the VM job and sets the speed, which ends up running the
second job under the speed from the first call.  By consolidating
things into a single job, we avoid opening that race, as well as reduce
the time between starting the job and changing the speed, for less
likelihood of the speed change happening after block job completion
in the first place.

* src/qemu/qemu_monitor.h (BLOCK_JOB_CMD): Add new mode.
* src/qemu/qemu_driver.c (qemuDomainBlockRebase): Move secondary
job call...
(qemuDomainBlockJobImpl): ...here, for fewer locks.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Change
return value on new internal mode.
2012-04-11 21:45:43 -06:00
Eric Blake
2b085f5bc5 blockjob: add qemu capabilities related to block pull jobs
RHEL 6.2 was released with an early version of block jobs, which only
worked on the qed file format, where the commands were spelled with
underscore (contrary to QMP style), and where 'block_job_cancel' was
synchronous and did not trigger an event.

The upcoming qemu 1.1 release has fixed these short-comings [1][2]:
the commands now work on multiple file types, are spelled with dash,
and 'block-job-cancel' is asynchronous and emits an event upon conclusion.

[1]qemu commit 370521a1d6f5537ea7271c119f3fbb7b0fa57063
[2]https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg01248.html

This patch recognizes the new spellings, and fixes virDomainBlockRebase
to give a graceful error when talking to a too-old qemu on a partial
rebase attempt.  Fixes for the new semantics will come later.  This
patch also removes a bogus ATTRIBUTE_NONNULL mistakenly added in
commit 10ec36e2.

* src/qemu/qemu_capabilities.h (QEMU_CAPS_BLOCKJOB_SYNC)
(QEMU_CAPS_BLOCKJOB_ASYNC): New bits.
* src/qemu/qemu_capabilities.c (qemuCaps): Name them.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCheckCommands): Set
them.
(qemuMonitorJSONBlockJob): Manage both command names.
(qemuMonitorJSONDiskSnapshot): Minor formatting fix.
* src/qemu/qemu_monitor.h (qemuMonitorBlockJob): Alter signature.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockJob): Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Pass through
capability bit.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Update callers.
2012-04-11 20:43:53 -06:00