In qemuDomainDetachNetDevice, detach was being used before it had been
validated. If no matching device was found, this resulted in a
dereference of a NULL pointer.
This behavior was a regression introduced in commit
cf90342be0, so it has not been a part of
any official libvirt release.
When host-model and host-passthrouh CPU modes were introduced, qemu
driver was properly modify to update guest CPU definition during
migration so that we use the right CPU at the destination. However,
similar treatment is needed for (managed)save and snapshots since they
need to save the exact CPU so that a domain can be properly restored.
To avoid repetition of such situation, all places that need live XML
share the code which generates it.
As a side effect, this patch fixes error reporting from
qemuDomainSnapshotWriteMetadata().
Thanks to cgroups, providing user vs. system time of the overall
guest is easy to add to our existing API.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_CPU_STATS_USERTIME)
(VIR_DOMAIN_CPU_STATS_SYSTEMTIME): New constants.
* src/util/virtypedparam.h (virTypedParameterArrayValidate)
(virTypedParameterAssign): Enforce checking the result.
* src/qemu/qemu_driver.c (qemuDomainGetPercpuStats): Fix offender.
(qemuDomainGetTotalcpuStats): Implement new parameters.
* tools/virsh.c (cmdCPUStats): Tweak output accordingly.
As documented in linux.git/Documentation/cgroups/cpuacct.txt,
cpuacct.stat returns user and system time in ticks (the same
unit used in times(2)). It would be a bit nicer if it were like
getrusage(2) and reported timeval contents, or like cpuacct.usage
and in nanoseconds, but we can't be picky.
* src/util/cgroup.h (virCgroupGetCpuacctStat): New function.
* src/util/cgroup.c (virCgroupGetCpuacctStat): Implement it.
(virCgroupGetValueStr): Allow for multi-line files.
* src/libvirt_private.syms (cgroup.h): Export it.
If there is a disk file with a comma in the name, QEmu expects a double
comma instead of a single one (e.g., the file "virtual,disk.img" needs
to be specified as "virtual,,disk.img" in QEmu's command line). This
patch fixes libvirt to work with that feature. Fix RHBZ #801036.
Based on an initial patch by Crístian Viana.
* src/util/buf.h (virBufferEscape): Alter signature.
* src/util/buf.c (virBufferEscape): Add parameter.
(virBufferEscapeSexpr): Fix caller.
* src/qemu/qemu_command.c (qemuBuildRBDString): Likewise. Also
escape commas in file names.
(qemuBuildDriveStr): Escape commas in file names.
* docs/schemas/basictypes.rng (absFilePath): Relax RNG to allow
commas in input file names.
* tests/qemuxml2argvdata/*-disk-drive-network-sheepdog.*: Update
test.
Signed-off-by: Eric Blake <eblake@redhat.com>
We found few more AMD-specific features in cpu64-rhel* models that
made it impossible to start qemu guest on Intel host (with this
setting) even though qemu itself starts correctly with them.
This impacts one test, thus the fix in tests/cputestdata/.
virNetworkDNSHostsDefParseXML was calling VIR_ALLOC(def->hosts) if
def->hosts was NULL. This is a waste of time, though, since
VIR_REALLOC_N is called a few lines further down, prior to any use of
def->hosts. (initializing def->nhosts to 0 is also redundant, because
the newly allocated memory will always be cleared to all 0's anyway).
One of the recent commits introduced support for
spice agent-mouse. However, test for this feature
require some tweaking: pass QEMU_CAPS_CHARDEV_SPICEVMC |
QEMU_CAPS_NODEFCONFIG and add "-vga cirrus".
If user hasn't supplied any tlsPort we default to setting it
to zero in our internal structure. However, when building command
line we test it against -1 which is obviously wrong.
Since VIR_DOMAIN_AFFECT_{LIVE,CONFIG,CURRENT} was created,
all new virsh commands use "--config" to represents the
persistent changing. This patch add "--config" option
for the old commands which still use "--persistent",
and "--persistent" is now alias of "--config".
tools/virsh.c: (use "--config", and "--persistent" is
alias of "--config" now).
cmdDomIfSetLink, cmdDomIfGetLink, cmdAttachDevice,
cmdDetachDevice, cmdUpdateDevice, cmdAttachInterface,
cmdDetachInterface, cmdAttachDisk, cmdDetachDisk
toos/virsh.pod: Update docs of the changed commands, and
add some missed docs for "--config" (detach-interface,
detach-disk, and detach-device).
The file daemon/probes.h used to be generated as part of a build, but
is no longer used. However, a stale copy of it lying around could
cause a build to fail. Removing it from .gitignore will make it more
likely someone will notice that they have it lying around.
This is nearly identical to an earlier patch for virnetlink.c.
There are special stub versions of all public functions in this file
that are compiled when the platform isn't linux. Each of these
functions had an almost identical message, differing only in the
function name included in the message. Since log messages already
contain the function name, we can just define a const char* with the
common part of the string, and use that same string for all the log
messages.
If nothing else, this at least makes for less strings that need
translating...
This function was freeing a virDomainNetDef with
VIR_FREE(). virDomainNetDef is a complex structure with many pointers
to other dynamically allocated data; to properly free it
virDomainNetDefFree() must be called instead, otherwise several
strings (and potentially other things) will be leaked.
For some reason, although live hotplug of <hostdev> devices is
supported, persistent hotplug is not. This patch adds the proper
VIR_DOMAIN_DEVICE_HOSTDEV cases to the switches in
qemuDomainAttachDeviceConfig and qemuDomainDetachDeviceConfig.
There are several functions that call virNetlinkCommand, and they all
follow a common pattern, with three exit labels: err_exit (or
cleanup), malformed_resp, and buffer_too_small. All three of these
labels do their own cleanup and have their own return. However, the
malformed_resp label usually frees the same items as the
cleanup/err_exit label, and the buffer_too_small label just doesn't
free recvbuf (because it's known to always be NULL at the time we goto
buffer_too_small.
In order to simplify and standardize the code, I've made the following
changes to all of these functions:
1) err_exit is replaced with the more libvirt-ish "cleanup", which
makes sense because in all cases this code is also executed in the
case of success, so labelling it err_exit may be confusing.
2) rc is initialized to -1, and set to 0 just before the cleanup
label. Any code that currently sets rc = -1 is made to instead goto
cleanup.
3) malformed_resp and buffer_too_small just log their error and goto
cleanup. This gives us a single return path, and a single place to
free up resources.
4) In one instance, rather then logging an error immediately, a char*
msg was pointed to an error string, then goto cleanup (and cleanup
would log an error if msg != NULL). It takes no more lines of code
to just log the message as we encounter it.
This patch should have 0 functional effects.
There are several functions in domain_conf.c that remove a device
object from the domain's list of that object type, but don't free the
object or return it to the caller to free. In many cases this isn't a
problem because the caller already had a pointer to the object and
frees it afterward, but in several cases the removed object was just
left floating around with no references to it.
In particular, the function qemuDomainDetachDeviceConfig() calls
functions to locate and remove net (virDomainNetRemoveByMac), disk
(virDomainDiskRemoveByName()), and lease (virDomainLeaseRemove())
devices, but neither it nor its caller qemuDomainModifyDeviceConfig()
ever obtain a pointer to the device being removed, much less free it.
This patch modifies the following "remove" functions to return a
pointer to the device object being removed from the domain device
arrays, to give the caller the option of freeing the device object
using that pointer if needed. In places where the object was
previously leaked, it is now freed:
virDomainDiskRemove
virDomainDiskRemoveByName
virDomainNetRemove
virDomainNetRemoveByMac
virDomainHostdevRemove
virDomainLeaseRemove
virDomainLeaseRemoveAt
The functions that had been leaking:
libxlDomainDetachConfig - leaked a virDomainDiskDef
qemuDomainDetachDeviceConfig - could leak a virDomainDiskDef,
a virDomainNetDef, or a
virDomainLeaseDef
qemuDomainDetachLease - leaked a virDomainLeaseDef
There were certain paths through the hostdev detach code that could
lead to the lower level function failing (and not removing the object
from the domain's hostdevs list), but the higher level function
free'ing the hostdev object anyway. This would leave a stale
hostdevdef pointer in the list, which would surely cause a problem
eventually.
This patch relocates virDomainHostdevRemove from the lower level
functions qemuDomainDetachThisHostDevice and
qemuDomainDetachHostPciDevice, to their caller
qemuDomainDetachThisHostDevice, placing it just before the call to
virDomainHostdevDefFree. This makes it easy to verify that either both
operations are done, or neither.
NB: The "dangling pointer" part of this problem was introduced in
commit 13d5a6, so it is not present in libvirt versions prior to
0.9.9. Earlier versions would return failure in certain cases even
though the the device object was removed/deleted, but the removal and
deletion operations would always both happen or neither.
There are special stub versions of all public functions in this file
that are compiled when either libnl isn't available or the platform
isn't linux. Each of these functions had two almost identical message,
differing only in the function name included in the message. Since log
messages already contain the function name, we can just define a const
char* with the common part of the string, and use that same string for
all the log messages.
Also, rather than doing #if defined ... #else ... #endif *inside the
error log macro invocation*, this patch does #if defined ... just
once, using it to decide which single string to define. This turns the
error log in each function from 6 lines, to 1 line.
This patch will allow OpenFlow controllers to identify which interface
belongs to a particular VM by using the Domain UUID.
ovs-vsctl get Interface vnet0 external_ids
{attached-mac="52:54:00:8C:55:2C", iface-id="83ce45d6-3639-096e-ab3c-21f66a05f7fa", iface-status=active, vm-id="142a90a7-0acc-ab92-511c-586f12da8851"}
V2 changes:
Replaced vm-uuid with vm-id. There was a discussion in Open vSwitch
mailinglist that we should stick with the same DB key postfixes for the
sake of consistency (e.g iface-id, vm-id ...).
The indentation on the final lines of the function was off by four
spaces, making me wonder for a second if there was something
missing. (There wasn't.)
Commit 5d4b0c4c80 tried to fix certain classes of VPATH builds,
but was too limited. In particular, Guannan Ren reported:
> For example: The libvirt source code resides in /home/testuser,
> I make dist in /tmp/buildvpath, the XDR routine .c file will
> include full path of the header file like:
>
> #include "/home/testuser/src/rpc/virnetprotocol.h"
> #include "internal.h"
> #include <arpa/inet.h>
>
> If we distribute the tarball to another machine to compile,
> it will report error as follows:
>
> rpc/virnetprotocol.c:7:59: fatal error:
> /home/testuser/src/rpc/virnetprotocol.h: No such file or directory
* src/rpc/genprotocol.pl: Fix more include lines.
If we need to virFork() to check assess() under different
UID+GID we need to translate returned status via WEXITSTATUS().
Otherwise, we may return values greater than 255 which is
obviously wrong.
The function sanlock_inquire can return NULL in the state string if the
message consists only of a header. The return value is arbitrary and
sent by the server. We should proceed carefully while touching such
pointers.
Some members are generated during XML parse (e.g. MAC address of
an interface); However, with current implementation, if we
are plugging a device both to persistent and live config,
we parse given XML twice: first time for live, second for config.
This is wrong then as the second time we are not guaranteed
to generate same values as we did for the first time.
To prevent that we need to create a copy of DeviceDefPtr;
This is done through format/parse process instead of writing
functions for deep copy as it is easier to maintain:
adding new field to any virDomain*DefPtr doesn't require change
of copying function.
Currently, startupPolicy='requisite' was determining cold boot
by migrateFrom != NULL. That means, if domain was started up
with migrateFrom set we didn't require disk source path and allowed
it to be dropped. However, on snapshot-revert domain wasn't migrated
but according to documentation, requisite should drop disk source
as well.
The last vestige of the inaccurate 'kilobytes' when we meant 1024 is
now gone. And virsh is now useful for setting memory in units other
than KiB.
* tools/virsh.c (cmdSetmem, cmdSetmaxmem): Use new helper routine,
allow passing bogus arguments on to hypervisor to test driver
sanity checking, and fix leak on parse error.
(vshMemtuneGetSize): New helper.
(cmdMemtune): Use it.
* tools/virsh.pod (setmem, setmaxmem, memtune): Document this.
Now can now do:
virsh vol-resize $vol 10M
virsh blockresize $dom $vol 10M
to get both interfaces to resize to 10MiB. The remaining wart
is that vol-resize defaults to bytes, but blockresize defaults
to KiB, but we can't break existing scripts; oh well, it's no
worse than the same wart of the underlying virDomainBlockResize.
The API for virStorageVolResize states that capacity must always
be positive, and that the presence of shrink and delta flags is
what implies a negative change.
* tools/virsh.c (vshCommandOptScaledInt): New function.
(cmdVolResize): Don't pass negative size.
(cmdVolSize): Rename...
(vshVolSize): ...and use new helper routine.
(cmdBlockResize): Use new helper routine, and support new bytes
flag.
* tools/virsh.pod (NOTES): Document suffixes.
(blockresize, vol-create-as, vol-resize): Point to notes.
Just because our public API has a typo doesn't mean that virsh
has to keep the typo.
* tools/virsh.c (VSH_CMD_FLAG_ALIAS): New flag.
(nodedevCmds): Use it.
(cmdHelp): Omit alias commands.
(cmdNodeDeviceDettach): Rename...
(cmdNodeDeviceDetach): ...to this.
* tools/virsh.pod (nodedev-detach): Document it.
Command line interfaces should use dash, not underscore, as many
keyboard layouts allow that to be typed with fewer shift key presses.
Also, the US spelling of --tunneled gets more google hits than the
UK spelling of --tunnelled.
* tools/virsh.c (opts_migrate): Allow US variant.
(opts_blkdeviotune): Prefer - over _.
* tools/virsh.pod (blkdeviotune): Fix spelling.
In the past, we have created some virsh options with less-than-stellar
names. For back-compat reasons, those names must continue to parse,
but we don't want to document them in help output. This introduces
a new option type, an alias, which points to a canonical option name
later in the option list.
I'm actually quite impressed that our code has already been factored
to do all option parsing through common entry points, such that I
got this added in relatively few lines of code!
* tools/virsh.c (VSH_OT_ALIAS): New option type.
(opts_echo): Hook up an alias, for easy testing.
(vshCmddefOptParse, vshCmddefHelp, vshCmddefGetOption): Allow for
aliases.
* tools/virsh.pod (NOTES): Document promise of back-compat.
* tests/virshtest.c (mymain): Test new feature.
Output is still in kibibytes, but input can now be in different
scales for ease of typing.
* src/conf/domain_conf.c (virDomainParseMemory): New helper.
(virDomainDefParseXML): Use it when parsing.
* docs/schemas/domaincommon.rng: Expand XML; rename memoryKBElement
to memoryElement and update callers.
* docs/formatdomain.html.in (elementsMemoryAllocation): Document
scaling.
* tests/qemuxml2argvdata/qemuxml2argv-memtune.xml: Adjust test.
* tests/qemuxml2xmltest.c: Likewise.
* tests/qemuxml2xmloutdata/qemuxml2xmlout-memtune.xml: New file.
Using 'unsigned long' for memory values is risky on 32-bit platforms,
as a PAE guest can have more than 4GiB memory. Our API is
(unfortunately) locked at 'unsigned long' and a scale of 1024, but
the rest of our system should consistently use 64-bit values,
especially since the previous patch centralized overflow checking.
* src/conf/domain_conf.h (_virDomainDef): Always use 64-bit values
for memory. Change hugepage_backed to a bool.
* src/conf/domain_conf.c (virDomainDefParseXML)
(virDomainDefCheckABIStability, virDomainDefFormatInternal): Fix
clients.
* src/vmx/vmx.c (virVMXFormatConfig): Likewise.
* src/xenxs/xen_sxpr.c (xenParseSxpr, xenFormatSxpr): Likewise.
* src/xenxs/xen_xm.c (xenXMConfigGetULongLong): New function.
(xenXMConfigGetULong, xenXMConfigSetInt): Avoid truncation.
(xenParseXM, xenFormatXM): Fix clients.
* src/phyp/phyp_driver.c (phypBuildLpar): Likewise.
* src/openvz/openvz_driver.c (openvzDomainSetMemoryInternal):
Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainDefineXML): Likewise.
* src/qemu/qemu_command.c (qemuBuildCommandLine): Likewise.
* src/qemu/qemu_process.c (qemuProcessStart): Likewise.
* src/qemu/qemu_monitor.h (qemuMonitorGetBalloonInfo): Likewise.
* src/qemu/qemu_monitor_text.h (qemuMonitorTextGetBalloonInfo):
Likewise.
* src/qemu/qemu_monitor_text.c (qemuMonitorTextGetBalloonInfo):
Likewise.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONGetBalloonInfo):
Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONGetBalloonInfo):
Likewise.
* src/qemu/qemu_driver.c (qemudDomainGetInfo)
(qemuDomainGetXMLDesc): Likewise.
* src/uml/uml_conf.c (umlBuildCommandLine): Likewise.
On 64-bit platforms, unsigned long and unsigned long long are
identical, so we don't have to worry about overflow checks.
On 32-bit platforms, anywhere we narrow unsigned long long back
to unsigned long, we have to worry about overflow; it's easier
to do this in one place by having most of the code use the same
or wider types, and only doing the narrowing at the last minute.
Therefore, the memory set commands remain unsigned long, and
the memory get command now centralizes the overflow check into
libvirt.c, so that drivers don't have to repeat the work.
This also fixes a bug where xen returned the wrong value on
failure (most APIs return -1 on failure, but getMaxMemory
must return 0 on failure).
* src/driver.h (virDrvDomainGetMaxMemory): Use long long.
* src/libvirt.c (virDomainGetMaxMemory): Raise overflow.
* src/test/test_driver.c (testGetMaxMemory): Fix driver.
* src/rpc/gendispatch.pl (name_to_ProcName): Likewise.
* src/xen/xen_hypervisor.c (xenHypervisorGetMaxMemory): Likewise.
* src/xen/xen_driver.c (xenUnifiedDomainGetMaxMemory): Likewise.
* src/xen/xend_internal.c (xenDaemonDomainGetMaxMemory):
Likewise.
* src/xen/xend_internal.h (xenDaemonDomainGetMaxMemory):
Likewise.
* src/xen/xm_internal.c (xenXMDomainGetMaxMemory): Likewise.
* src/xen/xm_internal.h (xenXMDomainGetMaxMemory): Likewise.
* src/xen/xs_internal.c (xenStoreDomainGetMaxMemory): Likewise.
* src/xen/xs_internal.h (xenStoreDomainGetMaxMemory): Likewise.
* src/xenapi/xenapi_driver.c (xenapiDomainGetMaxMemory):
Likewise.
* src/esx/esx_driver.c (esxDomainGetMaxMemory): Likewise.
* src/libxl/libxl_driver.c (libxlDomainGetMaxMemory): Likewise.
* src/qemu/qemu_driver.c (qemudDomainGetMaxMemory): Likewise.
* src/lxc/lxc_driver.c (lxcDomainGetMaxMemory): Likewise.
* src/uml/uml_driver.c (umlDomainGetMaxMemory): Likewise.
The test domain allows <memory>0</memory>, but the RNG was stating
that memory had to be at least 4096000 bytes. Hypervisors should
enforce their own limits, rather than complicating the RNG.
Meanwhile, some copy and paste had introduced some fishy constructs
in various unit tests.
* docs/schemas/domaincommon.rng (memoryKB, memoryKBElement): Drop
limit that isn't enforced in code.
* src/conf/domain_conf.c (virDomainDefParseXML): Require current
<= maximum.
* tests/qemuxml2argvdata/*.xml: Fix offenders.
Disk manufacturers are fond of quoting sizes in powers of 10,
rather than powers of 2 (after all, 2.1 GB sounds larger than
2.0 GiB, even though the exact opposite is true). So, we might
as well follow coreutils' lead in supporting three types of
suffix: single letter ${u} (which we already had) and ${u}iB
for the power of 2, and ${u}B for power of 10.
Additionally, it is impossible to create a file with more than
2**63 bytes, since off_t is signed (if you have enough storage
to even create one 8EiB file, I'm jealous). This now reports
failure up front rather than down the road when the kernel
finally refuses an impossible size.
* docs/schemas/basictypes.rng (unit): Add suffixes.
* src/conf/storage_conf.c (virStorageSize): Use new function.
* docs/formatstorage.html.in: Document it.
* tests/storagevolxml2xmlin/vol-file-backing.xml: Test it.
* tests/storagevolxml2xmlin/vol-file.xml: Likewise.
Make it obvious to 'dumpxml' readers what unit we are using,
since our default of KiB for memory (1024) differs from qemu's
default of MiB; and differs from our use of bytes for storage.
Tests were updated via:
$ find tests/*data tests/*out -name '*.xml' | \
xargs sed -i 's/<\(memory\|currentMemory\|hard_limit\|soft_limit\|min_guarantee\|swap_hard_limit\)>/<\1 unit='"'KiB'>/"
$ find tests/*data tests/*out -name '*.xml' | \
xargs sed -i 's/<\(capacity\|allocation\|available\)>/<\1 unit='"'bytes'>/"
followed by a few fixes for the stragglers.
Note that with this patch, the RNG for <memory> still forbids
validation of anything except unit='KiB', since the code silently
ignores the attribute; a later patch will expand <memory> to allow
scaled input in the code and update the RNG to match.
* docs/schemas/basictypes.rng (unit): Add 'bytes'.
(scaledInteger): New define.
* docs/schemas/storagevol.rng (sizing): Use it.
* docs/schemas/storagepool.rng (sizing): Likewise.
* docs/schemas/domaincommon.rng (memoryKBElement): New define; use
for memory elements.
* src/conf/storage_conf.c (virStoragePoolDefFormat)
(virStorageVolDefFormat): Likewise.
* src/conf/domain_conf.h (_virDomainDef): Document unit used
internally.
* src/conf/storage_conf.h (_virStoragePoolDef, _virStorageVolDef):
Likewise.
* tests/*data/*.xml: Update all tests.
* tests/*out/*.xml: Likewise.
* tests/define-dev-segfault: Likewise.
* tests/openvzutilstest.c (testReadNetworkConf): Likewise.
* tests/qemuargv2xmltest.c (blankProblemElements): Likewise.
The code supported unit='E' for "exabyte", but the RNG did not;
conversely, the RNG supported "z" and "y" but the code did not
(I'm jealous if you have that much storage, particularly since
it won't fit in 64-bit off_t). Also, the code supported
<allocation unit='...'>, but not the RNG.
In an effort to make 'unit' more worthwhile in future patches,
it's easier to share it between files.
In making this factorization, note that absFilePath is more
permissive than 'path', so storage pools and storage volumes
will now validate with a wider set of file names than before.
I don't think this should be a problem in practice.
* docs/schemas/storagepool.rng: Include basic types, rather than
repeating things here.
* docs/schemas/storagevol.rng: Likewise.
* docs/schemas/basictypes.rng: Add 'unsignedLong', 'unit', and fix
to match storage code.
Scaling an integer based on a suffix is something we plan on reusing
in several contexts: XML parsing, virsh CLI parsing, and possibly
elsewhere. Make it easy to reuse, as well as adding in support for
powers of 1000.
* src/util/util.h (virScaleInteger): New function.
* src/util/util.c (virScaleInteger): Implement it.
* src/libvirt_private.syms (util.h): Export it.
Overflow can be user-induced, so it deserves more than being called
an internal error. Note that in general, 32-bit platforms have
far more places to trigger this error (anywhere the public API
used 'unsigned long' but the other side of the connection is a
64-bit server); but some are possible on 64-bit platforms (where
the public API computes the product of two numbers).
* include/libvirt/virterror.h (VIR_ERR_OVERFLOW): New error.
* src/util/virterror.c (virErrorMsg): Translate it.
* src/libvirt.c (virDomainSetVcpusFlags, virDomainGetVcpuPinInfo)
(virDomainGetVcpus, virDomainGetCPUStats): Use it.
* daemon/remote.c (HYPER_TO_TYPE): Likewise.
* src/qemu/qemu_driver.c (qemuDomainBlockResize): Likewise.
Yes, I like kilobytes better than kibibytes (when I say kilobytes,
I generally mean 1024). But since the term is ambiguous, it can't
hurt to say what we mean, by using both the correct name and
calling out the numeric equivalent.
* src/libvirt.c (virDomainGetMaxMemory, virDomainSetMaxMemory)
(virDomainSetMemory, virDomainSetMemoryFlags)
(virNodeGetFreeMemory): Tweak wording.
* docs/formatdomain.html.in: Likewise.
* docs/formatstorage.html.in: Likewise.
ATTRIBUTE_UNUSED was accidentally forgotten on one arg of a stub
function for functionality that's not present on non-linux
platforms. This causes a non-linux build with
--enable-compile-warnings=error to fail.
The RPC code assumed that the array returned by the driver would be
fully populated; that is, ncpus on entry resulted in ncpus * return
value on exit. However, while we don't support holes in the middle
of ncpus, we do want to permit the case of ncpus on entry being
longer than the array returned by the driver (that is, it should be
safe for the caller to pass ncpus=128 on entry, and the driver will
stop populating the array when it hits max_id).
Additionally, a successful return implies that the caller will then
use virTypedParamArrayClear on the entire array; for this to not
free uninitialized memory, the driver must ensure that all skipped
entries are explicitly zeroed (the RPC driver did this, but not
the qemu driver).
There are now three cases:
server 0.9.10 and client 0.9.10 or newer: No impact - there were no
hypervisor drivers that supported cpu stats
server 0.9.11 or newer and client 0.9.10: if the client calls with
ncpus beyond the max, then the rpc call will fail on the client side
and disconnect the client, but the server is no worse for the wear
server 0.9.11 or newer and client 0.9.11: the server can return a
truncated array and the client will do just fine
I reproduced the problem by using a host with 2 CPUs, and doing:
virsh cpu-stats $dom --start 1 --count 2
* daemon/remote.c (remoteDispatchDomainGetCPUStats): Allow driver
to omit tail of array.
* src/remote/remote_driver.c (remoteDomainGetCPUStats):
Accommodate driver that omits tail of array.
* src/libvirt.c (virDomainGetCPUStats): Document this.
* src/qemu/qemu_driver.c (qemuDomainGetPercpuStats): Clear all
unpopulated entries.
