Before:
$ virsh iface-list
Name State MAC Address
--------------------------------------------
br0 active f0🇩🇪f1:dc:b8:b0
virbr2 active 52:54:00:61:78:0c
After:
$ virsh iface-list
Name State MAC Address
---------------------------------------------------
br0 active f0🇩🇪f1:dc:b8:b0
virbr2 active 52:54:00:61:78:0c
Change the alignment to match the domain listing function.
Before:
$ virsh pool-list
Name State Autostart
-----------------------------------------
boot-scratch active no
default active no
glusterpool active no
$ virsh pool-list --details
Name State Autostart Persistent Capacity Allocation Available
-------------------------------------------------------------------------------
boot-scratch running no yes 117.99 GiB 101.40 GiB 16.60 GiB
default running no yes 117.99 GiB 101.40 GiB 16.60 GiB
glusterpool running no yes 29.40 GiB 44.23 MiB 29.36 GiB
After:
$ virsh pool-list
Name State Autostart
-------------------------------------------
boot-scratch active no
default active no
glusterpool active no
$ virsh pool-list --details
Name State Autostart Persistent Capacity Allocation Available
---------------------------------------------------------------------------------
boot-scratch running no yes 117.99 GiB 101.40 GiB 16.60 GiB
default running no yes 117.99 GiB 101.40 GiB 16.60 GiB
glusterpool running no yes 29.40 GiB 44.23 MiB 29.36 GiB
When opening a new connection to the driver, nwfilterOpen
only succeeds if the driverState has been allocated.
Move the privilege check in driver initialization before
the state allocation to disable the driver.
This changes the nwfilter-define error from:
error: cannot create config directory (null): Bad address
To:
this function is not supported by the connection driver:
virNWFilterDefineXML
https://bugzilla.redhat.com/show_bug.cgi?id=1029266
ifdef LIBXL_HAVE_DOMAIN_CREATE_RESTORE_PARAMS hides a multi-line body
for a brace-less else. Add braces to ensure proper logic is applied.
Without this fix, new domains cannot be started. Both
libxl_domain_create_new and libxl_domain_create_restore are called when
starting a new domain leading to this error:
libxl: error: libxl.c:324:libxl__domain_rename: domain with name "guest" already exists.
libxl: error: libxl_create.c:800:initiate_domain_create: cannot make domain: -6
The QOM path in qemu that contains the CPUID registers of a running VM
may not be present (introduced in QEMU 1.5).
Since commit d94b781771 we have a regression with QEMU that don't
support reporting of the CPUID register state via the monitor as the
process startup code expects the path to exist.
This patch adds code that checks with the monitor if the requested path
already exists and uses it only in this case.
There were two separate places with that were stringifying type of a
volume. One of the places was out of sync with types implemented
upstream.
To avoid such problems in the future, this patch adds a common function
to convert the type to string and reuses it across the two said places.
Add an extra space before the first column as we have when listing
domains.
Previous output:
$ virsh vol-list glusterpool
Name Path
-----------------------------------------
asdf gluster://gluster-node-1/gv0/asdf
c gluster://gluster-node-1/gv0/c
cd gluster://gluster-node-1/gv0/cd
$ virsh vol-list glusterpool --details
Name Path Type Capacity Allocation
----------------------------------------------------------------------
asdf gluster://gluster-node-1/gv0/asdf unknown 0.00 B 0.00 B
c gluster://gluster-node-1/gv0/c unknown 16.00 B 16.00 B
cd gluster://gluster-node-1/gv0/cd unknown 0.00 B 0.00 B
New output:
$ virsh vol-list glusterpool
Name Path
------------------------------------------------------------------------------
asdf gluster://gluster-node-1/gv0/asdf
c gluster://gluster-node-1/gv0/c
cd gluster://gluster-node-1/gv0/cd
$ virsh vol-list glusterpool --details
Name Path Type Capacity Allocation
------------------------------------------------------------------------
asdf gluster://gluster-node-1/gv0/asdf unknown 0.00 B 0.00 B
c gluster://gluster-node-1/gv0/c unknown 16.00 B 16.00 B
cd gluster://gluster-node-1/gv0/cd unknown 0.00 B 0.00 B
As of libvirt 1.1.1 and systemd 205, the cgroups layout used by
libvirt has some changes. Update the 'cgroups.html' file from
the website to describe how it works in a systemd world.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the host side of an LXC container console disconnected
and the guest side continued to write data, until the PTY
buffer filled up, the LXC controller would busy wait. It
would repeatedly see POLLHUP from poll() and not disable
the watch.
This was due to some bogus logic detecting blocking
conditions. Upon seeing a POLLHUP we must disable all
reading & writing from the PTY, and setup the epoll to
wake us up again when the connection comes back.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The 'none' machine type is something only intended for use
by libvirt probing capabilities. It isn't something that
is useful for running real VM instances. As such it should
not be exposed to users in the capabilities.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virQEMUCapsProbeQMPMachineTypes method iterates over machine
types copying them into the qemuCapsPtr object. It only updates
the qemuCaps->nmachinetypes value at the end though. So if OOM
occurs in the middle, the destructor of qemuCapsPtr will not
free the partially initialized machine types.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To avoid code duplication between snapshot configuration code that
parses the disk source too we need to split out this code that will be
reused later on.
This patch tries to be code movement, some aspects of this function will
be refactored later.
If the managedsave image is corrupted, e.g. the XML part is, we fail to
parse it and throw an error, e.g.:
error: Failed to start domain jms8
error: XML error: missing security model when using multiple labels
This is okay, as we can't really start the machine and avoid undefined
qemu behaviour. On the other hand, the error message doesn't give a
clue to users what should they do. The consensus here would be to thrown
a warning to logs saying "Hey, you've got a corrupted file".
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1027096
If there's the following snippet in the domain XML, the domain will be
lost upon the daemon restart (if the domain is started prior restart):
<seclabel type='dynamic' relabel='yes'/>
The problem is, the 'label', 'imagelabel' and 'baselabel' are parsed
whenever the VIR_DOMAIN_XML_INACTIVE is *not* present or the label is
static. The latter is not our case, obviously. So, when libvirtd starts
up, it finds domain state xml and parse it. During parsing, many XML
flags are enabled but VIR_DOMAIN_XML_INACTIVE. Hence, our parser tries
to extract 'label', 'imagelabel' and 'baselabel' from the XML which
fails for model='none'. Err, this model - even though not specified in
XML - can be taken from qemu wide config file: /etc/libvirtd/qemu.conf.
However, in order to know we are dealing with model='none' the code in
question must be moved forward a bit. Then a new check must be
introduced. This is what the first two chunks are doing.
But this alone is not sufficient. The domain state XML won't contain the
model attribute without slight modification. The model should be
inserted into the XML even if equal to 'none' and the state XML is being
generated - what if the origin (the @security_driver variable in
qemu.conf) changes during libvirtd restarts?
At the end, a test to catch this scenario is introduced.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The 'vcpucount' command is a getter command for the vCPUu count. When
one or more of the filtering flags are specified the command returns the
value only for the selected combination. In this case the --live and
--config combination isn't valid. This however didn't cause errors as
the combination of flags was rejected by the libvirt API but then the
fallback code kicked in and requested the count in a way where the clash
of the flags didn't matter.
Mark the flag combination mutually exclusive so that users aren't
confused.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1024245
In virDomainRestoreFlags with VIR_DOMAIN_SAVE_BYPASS_CACHE, it risks
slowing restores from NFS, but not saves to NFS.
Signed-off-by: Wang Yufei <james.wangyufei@huawei.com>
This patch moves some code in the qemuDomainAttachSCSIDisk
function. The check for the existence of a PCI address assigned
to the SCSI controller was moved in order to be executed only
when needed. The PCI address of a controller is not necessary
if QEMU_CAPS_DEVICE is supported.
This fixes issues with the hotplug of SCSI disks on pseries guests.
This resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=1025397
When virPCIGetVirtualFunctions created the list of an SRIOV Physical
Function's (PF) Virtual Functions (VF), it had assumed that the order
of "virtfn*" links returned by readdir() from the PF's sysfs directory
was already in the correct order. Experience has shown that this is
not always the case - it can be in alphabetical order (which would
e.g. place virtfn11 before virtfn2) or even some seemingly random
order (see the example in the bugzilla report)
This results in 1) incorrect assumptions made by consumers of the
output of the virt_functions list of virsh nodedev-dumpxml, and 2)
setting MAC address and vlan tag on the wrong VF (since libvirt uses
netlink to set mac address and vlan tag, netlink requires the VF#, and
the function virPCIGetVirtualFunctionIndex() returns the wrong index
due to the improperly ordered VF list).
The solution provided by this patch is for virPCIGetVirtualFunctions
to no longer scan the entire device directory in its natural order,
but instead to check for links individually by name "virtfn%d" where
%d starts at 0 and increases with each success. Since VFs are created
contiguously by the kernel, this will guarantee that all VFs are
found, and placed in the arry in the correct order.
One note of use to the uninitiated is that VIR_APPEND_ELEMENT always
either increments *num_virtual_functions or fails, so no this isn't an
endless loop.
(NB: the SRIOV_* defines at the top of virpci.c were removed
because they are unnecessary and/or not used.)
When adding support for Q35 guests, the code to assign a PCI address
to the primary video card was moved into Q35 and i440fx(PIIX3)
specific functions, but no fallback was kept for other machine types
that might have a video card.
This patch remedies that by assigning a PCI address to the primary
video card if it does not have any kind of address. In particular,
this fixes issues with pseries guests.
Signed-off-by: Vitor de Lima <vitor.lima@eldorado.org.br>
Signed-off-by: Laine Stump <laine@laine.org>
When starting a VM the qemu process may filter out some requested
features of a domain as it's not supported either by the host or by
qemu. Libvirt didn't check if this happened which might end up in
changing of the guest ABI when migrating.
The proof of concept implementation adds the check for the recently
introduced kvm_pv_unhalt cpuid feature bit. This feature depends on both
qemu and host kernel support and thus increase the possibility of guest
ABI breakage.
The linux kernel recently added support for paravirtual spinlock
handling to avoid performance regressions on overcomitted hosts. This
feature needs to be turned in the hypervisor so that the guest OS is
notified about the possible support.
This patch adds a new feature "paravirt-spinlock" to the XML and
supporting code to enable the "kvm_pv_unhalt" pseudo CPU feature in
qemu.
https://bugzilla.redhat.com/show_bug.cgi?id=1008989
Currently we were storing domain feature flags in a bit field as the
they were either enabled or disabled. New features such as paravirtual
spinlocks however can be tri-state as the default option may depend on
hypervisor version.
To allow storing tri-state feature state in the same place instead of
having to declare dedicated variables for each feature this patch
refactors the bit field to an array.
Some of the emulator features are presented in the <features> element in
the domain XML although they are virtual CPUID feature bits when
presented to the guest. To avoid confusing the users with these
features, as they are not configurable via the <cpu> element, this patch
adds an internal array where those can be stored privately instead of
exposing them in the XML.
Additionaly KVM feature bits are added as example usage of this code.
The qemu monitor supports retrieval of actual CPUID bits presented to
the guest using QMP monitor. Add APIs to extract these information and
tests for them.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
The CPUID functions were stored in multiple arrays according to a
specified prefix of those. This made it very hard to add another prefix
to store KVM CPUID features (0x40000000). Instead of hardcoding a third
array this patch changes the approach used:
The code is refactored to use a single array where the CPUID functions
are stored ordered by the cpuid function so that they don't depend on
the specific prefix and don't waste memory. The code is also less
complex using this approach. A trateoff to this is the change from O(N)
complexity to O(N^2) in x86DataAdd and x86DataSubtract. The rest of the
functions were already using O(N^2) algorithms.
vol-clone reports out of memory error with disk type on ppc64.
Currently, wbytes is defined as size_t type (8 bytes), but
args's value in ioctl(fd, args..) in kernel is int (4 bytes).
This makes wbytes 2^32 times larger, causing an out of memory error.
This patch changes size_t to int to synchronize with kernel.
[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/block/ioctl.c?id=5e01dc7b#n363
[2] https://lkml.org/lkml/2013/11/1/620
Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Since 86d90b3a (yes, my patch; again) we are supporting NBD storage
migration. However, on error recovery path we got the steps reversed.
The correct order is: return NBD port to the virPortAllocator and then
either unlock the vm or remove it from the driver. Not vice versa.
==11192== Invalid write of size 4
==11192== at 0x11488559: qemuMigrationPrepareAny (qemu_migration.c:2459)
==11192== by 0x11488EA6: qemuMigrationPrepareDirect (qemu_migration.c:2652)
==11192== by 0x114D1509: qemuDomainMigratePrepare3Params (qemu_driver.c:10332)
==11192== by 0x519075D: virDomainMigratePrepare3Params (libvirt.c:7290)
==11192== by 0x1502DA: remoteDispatchDomainMigratePrepare3Params (remote.c:4798)
==11192== by 0x12DECA: remoteDispatchDomainMigratePrepare3ParamsHelper (remote_dispatch.h:5741)
==11192== by 0x5212127: virNetServerProgramDispatchCall (virnetserverprogram.c:435)
==11192== by 0x5211C86: virNetServerProgramDispatch (virnetserverprogram.c:305)
==11192== by 0x520A8FD: virNetServerProcessMsg (virnetserver.c:165)
==11192== by 0x520A9E1: virNetServerHandleJob (virnetserver.c:186)
==11192== by 0x50DA78F: virThreadPoolWorker (virthreadpool.c:144)
==11192== by 0x50DA11C: virThreadHelper (virthreadpthread.c:161)
==11192== Address 0x1368baa0 is 576 bytes inside a block of size 688 free'd
==11192== at 0x4A07F5C: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==11192== by 0x5079A2F: virFree (viralloc.c:580)
==11192== by 0x11456C34: qemuDomainObjPrivateFree (qemu_domain.c:267)
==11192== by 0x50F41B4: virDomainObjDispose (domain_conf.c:2034)
==11192== by 0x50C2991: virObjectUnref (virobject.c:262)
==11192== by 0x50F4CFC: virDomainObjListRemove (domain_conf.c:2361)
==11192== by 0x1145C125: qemuDomainRemoveInactive (qemu_domain.c:2087)
==11192== by 0x11488520: qemuMigrationPrepareAny (qemu_migration.c:2456)
==11192== by 0x11488EA6: qemuMigrationPrepareDirect (qemu_migration.c:2652)
==11192== by 0x114D1509: qemuDomainMigratePrepare3Params (qemu_driver.c:10332)
==11192== by 0x519075D: virDomainMigratePrepare3Params (libvirt.c:7290)
==11192== by 0x1502DA: remoteDispatchDomainMigratePrepare3Params (remote.c:4798)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
One of my previous patches (c7ac2519b7) did try to fix the issue when
domain dies too soon during migration. However, this clumsy approach was
missing removal of qemuProcessHandleMonitorDestroy resulting in double
unrefing of mon->vm and hence producing the daemon crash:
==11843== Invalid read of size 4
==11843== at 0x50C28C5: virObjectUnref (virobject.c:255)
==11843== by 0x1148F7DB: qemuMonitorDispose (qemu_monitor.c:258)
==11843== by 0x50C2991: virObjectUnref (virobject.c:262)
==11843== by 0x50C2D13: virObjectFreeCallback (virobject.c:388)
==11843== by 0x509C37B: virEventPollCleanupHandles (vireventpoll.c:583)
==11843== by 0x509C711: virEventPollRunOnce (vireventpoll.c:652)
==11843== by 0x509A620: virEventRunDefaultImpl (virevent.c:274)
==11843== by 0x520D21C: virNetServerRun (virnetserver.c:1112)
==11843== by 0x11F368: main (libvirtd.c:1513)
==11843== Address 0x13b88864 is 4 bytes inside a block of size 136 free'd
==11843== at 0x4A07F5C: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==11843== by 0x5079A2F: virFree (viralloc.c:580)
==11843== by 0x50C29E3: virObjectUnref (virobject.c:270)
==11843== by 0x114770E4: qemuProcessHandleMonitorDestroy (qemu_process.c:1103)
==11843== by 0x1148F7CB: qemuMonitorDispose (qemu_monitor.c:257)
==11843== by 0x50C2991: virObjectUnref (virobject.c:262)
==11843== by 0x50C2D13: virObjectFreeCallback (virobject.c:388)
==11843== by 0x509C37B: virEventPollCleanupHandles (vireventpoll.c:583)
==11843== by 0x509C711: virEventPollRunOnce (vireventpoll.c:652)
==11843== by 0x509A620: virEventRunDefaultImpl (virevent.c:274)
==11843== by 0x520D21C: virNetServerRun (virnetserver.c:1112)
==11843== by 0x11F368: main (libvirtd.c:1513)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
So far we are checking if qemu supports 'nbd-server-start'. This,
however, makes no sense on the source as nbd-server-* is used on the
destination. On the source the 'drive-mirror' is used instead.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Since 21685c955e we have tests/virpcitestdata dir containing the PCI
config files for some dummy PCI devices that are used int virpcitest.
However, the directory containing the config files is not distributed
making 'make rpm' fail.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
For some strange reason virDomainDiskSourcePoolDefParse accessed def of
the disk and allocated the pool object in it. To avoid the need to carry
over the disk definition object, refactor this function to return the
allocated object instead.
Commit b0f8546 broke the build on mingw, by exposing code that
had Linux-specific dependencies but which was previously protected
by libnuma ifdef guards:
make[3]: Entering directory `/home/eblake/libvirt-tmp/build/src'
CC libvirt_driver_la-nodeinfo.lo
../../src/nodeinfo.c: In function 'virNodeGetSiblingsList':
../../src/nodeinfo.c:1543:30: error: 'SYSFS_THREAD_SIBLINGS_LIST_LENGTH_MAX' undeclared (first use in this function)
if (virFileReadAll(path, SYSFS_THREAD_SIBLINGS_LIST_LENGTH_MAX, &buf) < 0)
^
../../src/nodeinfo.c:1543:30: note: each undeclared identifier is reported only once for each function it appears in
../../src/nodeinfo.c: In function 'virNodeCapsFillCPUInfo':
../../src/nodeinfo.c:1562:5: error: implicit declaration of function 'virNodeGetCpuValue' [-Werror=implicit-function-declaration]
if ((tmp = virNodeGetCpuValue(SYSFS_CPU_PATH, cpu_id,
^
../../src/nodeinfo.c:1562:5: error: nested extern declaration of 'virNodeGetCpuValue' [-Werror=nested-externs]
../../src/nodeinfo.c:1562:35: error: 'SYSFS_CPU_PATH' undeclared (first use in this function)
if ((tmp = virNodeGetCpuValue(SYSFS_CPU_PATH, cpu_id,
^
cc1: all warnings being treated as errors
* src/nodeinfo.c (virNodeCapsFillCPUInfo): Make conditional.
(virNodeGetSiblingsList): Move into #ifdef linux block.
Signed-off-by: Eric Blake <eblake@redhat.com>
This gets rid of another stat() per volume, as well as cutting
bytes read in half, when populating the volumes of a directory
pool during a pool refresh. Not to mention that it provides an
interface that can let gluster pools also probe file types.
* src/util/virstoragefile.h (virStorageFileProbeFormatFromFD):
Delete.
(virStorageFileProbeFormatFromBuf): New prototype.
(VIR_STORAGE_MAX_HEADER): New constant, based on...
* src/util/virstoragefile.c (STORAGE_MAX_HEAD): ...old name.
(vmdk4GetBackingStore, virStorageFileGetMetadataInternal)
(virStorageFileProbeFormat): Adjust clients.
(virStorageFileProbeFormatFromFD): Delete.
(virStorageFileProbeFormatFromBuf): Export.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Adjust client.
* src/libvirt_private.syms (virstoragefile.h): Adjust exports.
Signed-off-by: Eric Blake <eblake@redhat.com>
Future patches will want to learn metadata about a file using
a buffer that was already parsed in order to probe the file's
format. Rather than reopening and re-reading the file, it makes
sense to separate getting file contents from actually parsing
those contents.
* src/util/virstoragefile.c (virStorageFileGetMetadataFromBuf)
(virStorageFileGetMetadataFromFDInternal): New functions.
(virStorageFileGetMetadataInternal): Hoist fstat() and read() into
callers.
(virStorageFileGetMetadataFromFD)
(virStorageFileGetMetadataRecurse): Rework clients.
* src/util/virstoragefile.h (virStorageFileGetMetadataFromBuf):
New prototype.
* src/libvirt_private.syms (virstoragefile.h): Export it.
Signed-off-by: Eric Blake <eblake@redhat.com>
We are calling fstat() at least twice per storage volume in
a directory storage pool; this is rather wasteful. Refactoring
this is also a step towards making code reusable for gluster,
where gluster can provide struct stat but cannot use fstat().
* src/storage/storage_backend.h
(virStorageBackendVolOpenCheckMode)
(virStorageBackendUpdateVolTargetInfoFD): Update signature.
* src/storage/storage_backend.c
(virStorageBackendVolOpenCheckMode): Pass stat results back.
(virStorageBackendUpdateVolTargetInfoFD): Use existing stats.
(virStorageBackendVolOpen, virStorageBackendUpdateVolTargetInfo):
Update callers.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
* src/storage/storage_backend_scsi.c
(virStorageBackendSCSIUpdateVolTargetInfo): Likewise.
* src/storage/storage_backend_mpath.c
(virStorageBackendMpathUpdateVolTargetInfo): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Our backing file chain code was not very robust to an ill-timed
EINTR, which could lead to a short read causing us to randomly
treat metadata differently than usual. But the existing
virFileReadLimFD forces an error if we don't read the entire
file, even though we only care about the header of the file.
So add a new virFile function that does what we want.
* src/util/virfile.h (virFileReadHeaderFD): New prototype.
* src/util/virfile.c (virFileReadHeaderFD): New function.
* src/libvirt_private.syms (virfile.h): Export it.
* src/util/virstoragefile.c (virStorageFileGetMetadataInternal)
(virStorageFileProbeFormatFromFD): Use it.
Signed-off-by: Eric Blake <eblake@redhat.com>
'unsigned char *' makes sense if you are doing math on bytes and
don't want to worry about wraparound from a signed 'char'; but
since all we are doing is memcmp() or virReadBufInt*[LB]E(), which
are both safe on either type of char, and since read() prefers to
operate on 'char *', it's simpler to avoid casts by just typing
things as 'char *' from the get-go. [Technically, read can
operate on an 'unsigned char *' thanks to the C rule that any
pointer can be implicitly converted to 'char *' for legacy K&R
compatibility; but where this patch saves us is if we try to use
virfile.h functions that take 'char **' in order to allocate the
buffer, where the compiler would barf on type mismatch.]
* src/util/virstoragefile.c (FileTypeInfo): Avoid unsigned char.
(cowGetBackingStore, qcow2GetBackingStoreFormat)
(qcowXGetBackingStore, qcow1GetBackingStore)
(qcow2GetBackingStore, vmdk4GetBackingStore, qedGetBackingStore)
(virStorageFileMatchesMagic, virStorageFileMatchesVersion)
(virStorageFileProbeFormatFromBuf, qcow2GetFeatures)
(virStorageFileGetMetadataInternal)
(virStorageFileProbeFormatFromFD): Simplify clients.
Signed-off-by: Eric Blake <eblake@redhat.com>
Starting from v2.4 (released today!), SystemTap can use libvirt to
execute scripts inside virtual machines.
Signed-off-by: Eric Blake <eblake@redhat.com>