In the future (my next patch in fact) we may want to make
decisions depending on qemu having a monitor command or not.
Therefore, we want to set qemuCaps flag instead of querying
on the monitor each time we are about to make that decision.
QEMU always sends details about all available block devices as an answer
for "info block"/"query-block" command. On the other hand, our
qemuMonitorGetBlockInfo was made for a single block devices queries
only. Thus, when asking for multiple devices, we asked qemu multiple
times to always get the same answer from which different parts were
filtered. This patch makes qemuMonitorGetBlockInfo return a hash table
of all block devices, which may later be used for getting details about
specific devices.
If an async job run on a domain will stop the domain at the end of the
job, a concurrently run query job can hang in qemu monitor and nothing
can be done with that domain from this point on. An attempt to start
such domain results in "Timed out during operation: cannot acquire state
change lock" error.
However, quite a few things have to happen at the right time... There
must be an async job running which stops a domain at the end. This race
was reported with dump --crash but other similar jobs, such as
(managed)save and migration, should be able to trigger this bug as well.
While this async job is processing its last monitor command, that is a
query-migrate to which qemu replies with status "completed", a new
libvirt API that results in a query job must arrive and stay waiting
until the query-migrate command finishes. Once query-migrate is done but
before the async job closes qemu monitor while stopping the domain, the
other thread needs to wake up and call qemuMonitorSend to send its
command to qemu. Before qemu gets a chance to respond to this command,
the async job needs to close the monitor. At this point, the query job
thread is waiting for a condition that no-one will ever signal so it
never finishes the job.
Implement the block I/O throttle setting and getting support to qemu
driver.
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Implements functions for both HMP and QMP mode.
For HMP mode, qemu uses "M" as the units by default, so the passed "sized"
is divided by 1024.
For QMP mode, qemu uses "Bytes" as the units by default, the passed "sized"
is multiplied by 1024.
All of the monitor functions return -1 on failure, 0 on success, or -2 if
not supported.
The QEMU monitor command 'add_client' can be used to connect to
a VNC or SPICE graphics display. This allows for implementation
of the virDomainOpenGraphics API
* src/qemu/qemu_driver.c: Implement virDomainOpenGraphics
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h:
Add binding for 'add_client' command
This change adds some systemtap/dtrace probes to the QEMU monitor
client code. In particular it allows watching of all operations
for a VM
* examples/systemtap/qemu-monitor.stp: Watch all monitor commands
* src/Makefile.am: Passing libdir/bindir/sbindir to dtrace2systemtap.pl
* src/dtrace2systemtap.pl: Accept libdir/bindir/sbindir as args
and look for '# binary:' comment to mark probes against libvirtd
vs libvirt.so
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor_json.c,
src/qemu/qemu_monitor_text.c: Add probes for key functions
If the daemon is restarted so we reconnect to monitor, cdrom media
can be ejected. In that case we don't want to show it in domain xml,
or require it on migration destination.
To check for disk status use 'info block' monitor command.
This patch adds handlers for modification of guest's interface
link state. Both HMP and QMP commands are supported, but as the
link state functionality is from the beginning supported in QMP
the HMP code will probably never be used.
The mainly changes are:
1) Update qemuMonitorGetBlockStatsInfo and it's children (Text/JSON)
functions to return the value of new latency fields.
2) Add new function qemuMonitorGetBlockStatsParamsNumber, which is
to count how many parameters the underlying QEMU supports.
3) Update virDomainBlockStats in src/qemu/qemu_driver.c to be
compatible with the changes by 1).
No one uses this yet, but it will be important once
virDomainSnapshotCreateXML learns a VIR_DOMAIN_SNAPSHOT_DISK_ONLY
flag, and the xml allows passing in the new file names.
* src/qemu/qemu_monitor.h (qemuMonitorDiskSnapshot): New prototype.
* src/qemu/qemu_monitor_text.h (qemuMonitorTextDiskSnapshot):
Likewise.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDiskSnapshot):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorDiskSnapshot): New
function.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDiskSnapshot):
Likewise.
When an operation started by virDomainBlockPull completes (either with
success or with failure), raise an event to indicate the final status.
This API allow users to avoid polling on virDomainGetBlockJobInfo if
they would prefer to use an event mechanism.
* daemon/remote.c: Dispatch events to client
* include/libvirt/libvirt.h.in: Define event ID and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
src/libvirt_private.syms: Extend API to handle the new event
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
for block_stream completion and emit a libvirt block pull event
* src/remote/remote_driver.c: Receive and dispatch events to application
* src/remote/remote_protocol.x: Wire protocol definition for the event
* src/remote_protocol-structs: structure definitions for protocol verification
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c: Watch for BLOCK_STREAM_COMPLETED event
from QEMU monitor
The virDomainBlockPull* family of commands are enabled by the
following HMP/QMP commands: 'block_stream', 'block_job_cancel',
'info block-jobs' / 'query-block-jobs', and 'block_job_set_speed'.
* src/qemu/qemu_driver.c src/qemu/qemu_monitor_text.[ch]: implement disk
streaming by using the proper qemu monitor commands.
* src/qemu/qemu_monitor_json.[ch]: implement commands using the qmp monitor
When qemuMonitorCloseFileHandle is called in error path, we need to
preserve the original error since a possible further error when running
closefd monitor command is not very useful to users.
Continuation of commit 313ac7fd, and enforce things with a syntax
check.
Technically, virNetServerClientCalculateHandleMode is not printing
a mode_t, but rather a collection of VIR_EVENT_HANDLE_* bits;
however, these bits are < 8, so there is no different in the
output, and that was the easiest way to silence the new syntax check.
* cfg.mk (sc_flags_debug): New syntax check.
(exclude_file_name_regexp--sc_flags_debug): Add exemptions.
* src/fdstream.c (virFDStreamOpenFileInternal): Print flags in
hex, mode_t in octal.
* src/libvirt-qemu.c (virDomainQemuMonitorCommand)
(virDomainQemuAttach): Likewise.
* src/locking/lock_driver_nop.c (virLockManagerNopInit): Likewise.
* src/locking/lock_driver_sanlock.c (virLockManagerSanlockInit):
Likewise.
* src/locking/lock_manager.c: Likewise.
* src/qemu/qemu_migration.c: Likewise.
* src/qemu/qemu_monitor.c: Likewise.
* src/rpc/virnetserverclient.c
(virNetServerClientCalculateHandleMode): Print mode with %o.
When attaching to an external QEMU process, it is neccessary
to check if the process is using KVM or not. This can be done
using a monitor command
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
API for checking if KVM is enabled
The 'char control[CMSG_SPACE(sizeof(int))];' was not being
wiped, so could potentially contain uninitialized bytes.
While this was harmless in this case, it caused complaints
from valgrind
* src/qemu/qemu_monitor.c: memset 'control' variable
in qemuMonitorIOWriteWithFD
For controlled shutdown we issue a 'system_powerdown' command
to the QEMU monitor. This triggers an ACPI event which (most)
guest OS wire up to a controlled shutdown. There is no equiv
ACPI event to trigger a controlled reboot. This patch attempts
to fake a reboot.
- In qemuDomainObjPrivatePtr we have a bool fakeReboot
flag.
- The virDomainReboot method sets this flag and then
triggers a normal 'system_powerdown'.
- The QEMU process is started with '-no-shutdown'
so that the guest CPUs pause when it powers off the
guest
- When we receive the 'POWEROFF' event from QEMU JSON
monitor if fakeReboot is not set we invoke the
qemuProcessKill command and shutdown continues
normally
- If fakeReboot was set, we spawn a background thread
which issues 'system_reset' to perform a warm reboot
of the guest hardware. Then it issues 'cont' to
start the CPUs again
* src/qemu/qemu_command.c: Add -no-shutdown flag if
we have JSON support
* src/qemu/qemu_domain.h: Add 'fakeReboot' flag to
qemuDomainObjPrivate struct
* src/qemu/qemu_driver.c: Fake reboot using the
system_powerdown command if JSON support is available
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
binding for system_reset command
* src/qemu/qemu_process.c: Reset the guest & start CPUs if
fakeReboot is set
Since we virEventRegisterDefaultImpl is now a public API, callers need
a way to invoke the default registered Handle and Timeout functions. We
already have general functions for these internally, so promote
them to the public API.
v2:
Actually add APIs to libvirt.h
When an operation started by virDomainBlockPullAll completes (either with
success or with failure), raise an event to indicate the final status. This
allows an API user to avoid polling on virDomainBlockPullInfo if they would
prefer to use the event mechanism.
* daemon/remote.c: Dispatch events to client
* include/libvirt/libvirt.h.in: Define event ID and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
src/libvirt_private.syms: Extend API to handle the new event
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
for block_stream completion and emit a libvirt block pull event
* src/remote/remote_driver.c: Receive and dispatch events to application
* src/remote/remote_protocol.x: Wire protocol definition for the event
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c: Watch for BLOCK_STREAM_COMPLETED event
from QEMU monitor
Signed-off-by: Adam Litke <agl@us.ibm.com>
The virDomainBlockPull* family of commands are enabled by the
'block_stream' and 'info block_stream' qemu monitor commands.
* src/qemu/qemu_driver.c src/qemu/qemu_monitor_text.[ch]: implement disk
streaming by using the stream and info stream text monitor commands
* src/qemu/qemu_monitor_json.[ch]: implement commands using the qmp monitor
Signed-off-by: Adam Litke <agl@us.ibm.com>
Acked-by: Daniel P. Berrange <berrange@redhat.com>
The below patch decreases the response time of libvirt to errors reported by Qemu upon startup by checking whether the qemu process is still alive while polling for the local socket to show up.
This patch also introduces a special handling of signal for the Win32 part of virKillProcess.
Commit 4454a9efc728b91e791b1f14c26ea23a19d57f48 introduced bad
behaviour on the VIR_EVENT_HANDLE_ERROR condition. This condition
is only hit when an invalid FD is used in poll() (typically due
to a double-close bug). The QEMU monitor code was treating this
condition as non-fatal, and thus libvirt would poll() in a fast
loop forever burning 100% CPU. VIR_EVENT_HANDLE_ERROR must be
handled in the same way as VIR_EVENT_HANDLE_HANGUP, killing the
QEMU instance.
* src/qemu/qemu_monitor.c: Treat VIR_EVENT_HANDLE_ERROR as EOF
Currently the QEMU monitor I/O handler code uses errno values
to report errors. This results in a sub-optimal error messages
on certain conditions, in particular when parsing JSON strings
malformed data simply results in 'EINVAL'.
This changes the code to use the standard libvirt error reporting
APIs. The virError is stored against the qemuMonitorPtr struct,
and when a monitor API is run, any existing stored error is copied
into that thread's error local
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_text.c: Use
virError APIs for all monitor I/O handling code
Currently whenever there is any failure with parsing the monitor,
this is treated in the same was as end-of-file (ie QEMU quit).
The domain is terminated, if not already dead.
With this change, failures in parsing the monitor stream do not
result in the death of QEMU. The guest continues running unchanged,
but all further use of the monitor will be disabled.
The VMM_FAILURE event will be emitted, and the mgmt application
can decide when to kill/restart the guest to re-gain control
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h: Run a
different callback for monitor EOF vs error conditions.
* src/qemu/qemu_process.c: Emit VMM_FAILURE event when monitor
fails
Use the graphics information from the QEMU migration cookie to
issue a 'client_migrate_info' monitor command to QEMU. This causes
the SPICE client to automatically reconnect to the target host
when migration completes
* src/qemu/qemu_migration.c: Set data for SPICE client relocation
before starting migration on src
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
new qemuMonitorGraphicsRelocate() command
These VIR_XXXX0 APIs make us confused, use the non-0-suffix APIs instead.
How do these coversions works? The magic is using the gcc extension of ##.
When __VA_ARGS__ is empty, "##" will swallow the "," in "fmt," to
avoid compile error.
example: origin after CPP
high_level_api("%d", a_int) low_level_api("%d", a_int)
high_level_api("a string") low_level_api("a string")
About 400 conversions.
8 special conversions:
VIR_XXXX0("") -> VIR_XXXX("msg") (avoid empty format) 2 conversions
VIR_XXXX0(string_literal_with_%) -> VIR_XXXX(%->%%) 0 conversions
VIR_XXXX0(non_string_literal) -> VIR_XXXX("%s", non_string_literal)
(for security) 6 conversions
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
We already have virAsprintf, so picking a similar name helps for
seeing a similar purpose. Furthermore, the prefix V before printf
generally implies 'va_list', even though this variant was '...', and
the old name got in the way of adding a new va_list version.
global rename performed with:
$ git grep -l virBufferVSprintf \
| xargs -L1 sed -i 's/virBufferVSprintf/virBufferAsprintf/g'
then revert the changes in ChangeLog-old.
If qemu quited unexpectedly when we call qemuMonitorJSONHMP(),
libvirt will crash.
Steps to reproduce this bug:
1. use gdb to attach libvirtd, and set a breakpoint in the function
qemuMonitorSetCapabilities()
2. start a vm
3. let the libvirtd to run until qemuMonitorJSONSetCapabilities() returns.
4. kill the qemu process
5. continue running libvirtd
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
If the monitor met a error, and we will call qemuProcessHandleMonitorEOF().
But we may try to send monitor command after qemuProcessHandleMonitorEOF()
returned. Then libvirtd will be blocked in qemuMonitorSend().
Steps to reproduce this bug:
1. use gdb to attach libvirtd, and set a breakpoint in the function
qemuConnectMonitor()
2. start a vm
3. let the libvirtd to run until qemuMonitorOpen() returns.
4. kill the qemu process
5. continue running libvirtd
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Add the compiler attribute to ensure we don't introduce any more
ref bugs like were just patched in commit 9741f34, then explicitly
mark the remaining places in code that are safe.
* src/qemu/qemu_monitor.h (qemuMonitorUnref): Mark
ATTRIBUTE_RETURN_CHECK.
* src/conf/domain_conf.h (virDomainObjUnref): Likewise.
* src/conf/domain_conf.c (virDomainObjParseXML)
(virDomainLoadStatus): Fix offenders.
* src/openvz/openvz_conf.c (openvzLoadDomains): Likewise.
* src/vmware/vmware_conf.c (vmwareLoadDomains): Likewise.
* src/qemu/qemu_domain.c (qemuDomainObjBeginJob)
(qemuDomainObjBeginJobWithDriver)
(qemuDomainObjExitRemoteWithDriver): Likewise.
* src/qemu/qemu_monitor.c (QEMU_MONITOR_CALLBACK): Likewise.
Suggested by Daniel P. Berrange.
A future patch will change reference counting idioms; consolidating
this pattern now makes the next patch smaller (touch only the new
macro rather than every caller).
* src/qemu/qemu_monitor.c (QEMU_MONITOR_CALLBACK): New helper.
(qemuMonitorGetDiskSecret, qemuMonitorEmitShutdown)
(qemuMonitorEmitReset, qemuMonitorEmitPowerdown)
(qemuMonitorEmitStop, qemuMonitorEmitRTCChange)
(qemuMonitorEmitWatchdog, qemuMonitorEmitIOError)
(qemuMonitorEmitGraphics): Use it to reduce duplication.
With only a single caller to these two monitor commands, I
didn't need to wrap a new WithFds version, but just change
the command itself.
* src/qemu/qemu_monitor.h (qemuMonitorAddNetdev)
(qemuMonitorAddHostNetwork): Add parameters.
* src/qemu/qemu_monitor.c (qemuMonitorAddNetdev)
(qemuMonitorAddHostNetwork): Add support for fd passing.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Use it to
simplify code.
This is also a bug fix - on the error path, qemu_hotplug would
leave the configfd file leaked into qemu. At least the next
attempt to hotplug a PCI device would reuse the same fdname,
and when the qemu getfd monitor command gets a new fd by the
same name as an earlier one, it closes the earlier one, so there
is no risk of qemu running out of fds.
* src/qemu/qemu_monitor.h (qemuMonitorAddDeviceWithFd): New
prototype.
* src/qemu/qemu_monitor.c (qemuMonitorAddDevice): Move guts...
(qemuMonitorAddDeviceWithFd): ...to new function, and add support
for fd passing.
* src/qemu/qemu_hotplug.c (qemuDomainAttachHostPciDevice): Use it
to simplify code.
Suggested by Daniel P. Berrange.
qemu_monitor was already returning -1 and setting errno to EINVAL
on any attempt to send an fd without a unix socket, but this was
a silent failure in the case of qemuDomainAttachHostPciDevice.
Meanwhile, qemuDomainAttachNetDevice was doing some sanity checking
for a better error message; it's better to consolidate that to a
central point in the API.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Move sanity
checking...
* src/qemu/qemu_monitor.c (qemuMonitorSendFileHandle): ...into
central location.
Suggested by Chris Wright.
Steps to reproduce this bug:
# virsh qemu-monitor-command domain 'cpu_set 2 online' --hmp
The domain has 2 cpus, and we try to set the third cpu online.
The qemu crashes, and this command will hang.
The reason is that the refs is not 1 when we unwatch the monitor.
We lock the monitor, but we do not unlock it. So virCondWait()
will be blocked.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
POSIX states about dd:
If the bs=expr operand is specified and no conversions other than
sync, noerror, or notrunc are requested, the data returned from each
input block shall be written as a separate output block; if the read
returns less than a full block and the sync conversion is not
specified, the resulting output block shall be the same size as the
input block. If the bs=expr operand is not specified, or a conversion
other than sync, noerror, or notrunc is requested, the input shall be
processed and collected into full-sized output blocks until the end of
the input is reached.
Since we aren't using conv=sync, there is no zero-padding, but our
use of bs= means that a short read results in a short write. If
instead we use ibs= and obs=, then short reads are collected and dd
only has to do a single write, which can make dd more efficient.
* src/qemu/qemu_monitor.c (qemuMonitorMigrateToFile):
Avoid 'dd bs=', since it can cause short writes.
