Calling virDomainGetEmulatorPinInfo on a live VM with automatic NUMA
pinning and VIR_DOMAIN_AFFECT_CONFIG would return the automatic pinning
data in some cases which is bogus. Use the autoCpuset property only when
called on a live definition.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1365779
Calling virDomainGetVcpuPinInfo on a live VM with automatic NUMA pinning
and VIR_DOMAIN_AFFECT_CONFIG would return the automatic pinning data
in some cases which is bogus. Use the autoCpuset property only when
called on a live definition.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1365779
Sometimes adding a separate variable to access vm->privateData is not
necessary. Add a macro that will do the typecasting rather than having
to add a temp variable to force the compiler to typecast it.
Old libvirt represents
<graphics type='spice'>
<listen type='none'/>
</graphics>
as
<graphics type='spice' autoport='no'/>
In this mode, QEMU doesn't listen for SPICE connection anywhere and
clients have to use virDomainOpenGraphics* APIs to attach to the domain.
That is, the client has to run on the same host where the domains runs
and it's impossible to tell the client to reconnect to the destination
QEMU during migration (unless there is some kind of proxy on the host).
While current libvirt correctly ignores such graphics devices when
creating graphics migration cookie, old libvirt just sends
<graphics type='spice' port='0' listen='0.0.0.0' tlsPort='-1'/>
in the cookie. After seeing this cookie, we happily would call
client_migrate_info QMP command and wait for SPICE_MIGRATE_COMPLETED
event, which is quite pointless since the doesn't know where to connecti
anyway. We should just ignore such cookies.
https://bugzilla.redhat.com/show_bug.cgi?id=1376083
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Checking if a domain's definition or if it is active before we got a job
is pointless since the domain might have changed in the meantime.
Luckily libvirtd didn't crash when the API tried to talk to an inactive
domain:
debug : qemuDomainObjBeginJobInternal:2914 : Started job: modify
(async=none vm=0x7f8f340140c0 name=ble)
debug : qemuDomainObjEnterMonitorInternal:3137 : Entering monitor
(mon=(nil) vm=0x7f8f340140c0 name=ble)
warning : virObjectLock:319 : Object (nil) ((unknown)) is not a
virObjectLockable instance
debug : qemuMonitorOpenGraphics:3505 : protocol=spice fd=27
fdname=graphicsfd skipauth=1
error : qemuMonitorOpenGraphics:3508 : invalid argument: monitor must
not be NULL
debug : qemuDomainObjExitMonitorInternal:3160 : Exited monitor
(mon=(nil) vm=0x7f8f340140c0 name=ble)
debug : qemuDomainObjEndJob:3068 : Stopping job: modify (async=none
vm=0x7f8f340140c0 name=ble)
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
We can receive NULL as sync reply in two situations. First
is garbage sync reply and this situation is handled by
resending sync message. Second is different cases
of rebooting guest, destroing domain etc and we can
give more meaningful error message. Actually we have
this error message in qemuAgentCommand already which checks
for the same sitatuion. AFAIK case with mon->running
is just to be safe on adding some future(?) cases of
returning NULL reply.
We can easily handle receiving garbage on sync. We don't
have to make client deal with this situation. We just
need to resend sync command but this time garbage is
not be possible.
When we wait for sync reply we can receive delayed
reply to syncs or commands that were sent erlier. We can
safely skip them until we receive sync reply with correct id.
There is no much sense report this situation to client.
Actually with a bit of "luck" if we involve client into
this the play can go on forever: send sync 0, receive
sync reply -1, send sync 1, receive reply 0 ...
After sync is sent we can receive garbare and this is not error.
Consider next regular case:
1. libvirtd sends sync
2. qga sends partial sync reply and die
3. libvirtd sends sync
4. qga sends sync reply
5. libvirtd receives garbage
(half of first reply and second reply together)
We should handle this situation as it is recoverable.
Next sync can succeed. Let's report reply is NULL,
it will be converted to the VIR_ERR_AGENT_UNSYNCED
which signals client to retry.
Errors in qemuAgentIOProcessLine stop agent IO processing just
like any regular IO error, however some of current errors
that this functions spawns are false positives. Consider
next case for example:
1. send sync (unsynced state)
2. receive sync reply (sync established)
3. command send, but timeout occured (unsynced state)
4. receive command reply
Last IO triggers error because current code ignores
only delayed syncs when unsynced
We should not treat any delayed reply as error in unsynced
state. Until client and qga are not in sync delayed reply to any
command is possible. msg == NULL is the exact criterion
that we are not in sync.
Put it into qemuDomainPrepareShmemChardev() so it can be used later.
Also don't fill in the path unless the server option is enabled.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Some checks will need to be performed for newer device types as well, so
let's not duplicate them.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Commit 839a060 tied the lifecycle of virtlogd more
closely to that of libvirtd. Unfortunately, while starting
virtlogd when libvirtd is started is definitely a good idea,
restarting virtlogd or shutting it down at any time outside
of system poweroff is not.
Revert part of that commit by removing the PartOf= lines,
meaning that only startup requests will be propagated from
libvirtd to virtlogd.
Resolves: https://bugzilla.redhat.com/1372576
Now that we have two same implementations for getting path for
huge pages backed guest memory, lets merge them into one function.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When trying to migrate a huge page enabled guest, I've noticed
the following crash. Apparently, if no specific hugepages are
requested:
<memoryBacking>
<hugepages/>
</memoryBacking>
and there are no hugepages configured on the destination, we try
to dereference a NULL pointer.
Program received signal SIGSEGV, Segmentation fault.
0x00007fcc907fb20e in qemuGetHugepagePath (hugepage=0x0) at qemu/qemu_conf.c:1447
1447 if (virAsprintf(&ret, "%s/libvirt/qemu", hugepage->mnt_dir) < 0)
(gdb) bt
#0 0x00007fcc907fb20e in qemuGetHugepagePath (hugepage=0x0) at qemu/qemu_conf.c:1447
#1 0x00007fcc907fb2f5 in qemuGetDefaultHugepath (hugetlbfs=0x0, nhugetlbfs=0) at qemu/qemu_conf.c:1466
#2 0x00007fcc907b4afa in qemuBuildMemoryBackendStr (size=4194304, pagesize=0, guestNode=0, userNodeset=0x0, autoNodeset=0x0, def=0x7fcc70019070, qemuCaps=0x7fcc70004000, cfg=0x7fcc5c011800, backendType=0x7fcc95087228, backendProps=0x7fcc95087218,
force=false) at qemu/qemu_command.c:3297
#3 0x00007fcc907b4f91 in qemuBuildMemoryCellBackendStr (def=0x7fcc70019070, qemuCaps=0x7fcc70004000, cfg=0x7fcc5c011800, cell=0, auto_nodeset=0x0, backendStr=0x7fcc70020360) at qemu/qemu_command.c:3413
#4 0x00007fcc907c0406 in qemuBuildNumaArgStr (cfg=0x7fcc5c011800, def=0x7fcc70019070, cmd=0x7fcc700040c0, qemuCaps=0x7fcc70004000, auto_nodeset=0x0) at qemu/qemu_command.c:7470
#5 0x00007fcc907c5fdf in qemuBuildCommandLine (driver=0x7fcc5c07b8a0, logManager=0x7fcc70003c00, def=0x7fcc70019070, monitor_chr=0x7fcc70004bb0, monitor_json=true, qemuCaps=0x7fcc70004000, migrateURI=0x7fcc700199c0 "defer", snapshot=0x0,
vmop=VIR_NETDEV_VPORT_PROFILE_OP_MIGRATE_IN_START, standalone=false, enableFips=false, nodeset=0x0, nnicindexes=0x7fcc95087498, nicindexes=0x7fcc950874a0, domainLibDir=0x7fcc700047c0 "/var/lib/libvirt/qemu/domain-1-fedora") at qemu/qemu_command.c:9547
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Both qemu monitor and agent print the same
log on HUANGUP event, which would be confusing
when reading libvirtd log.
This patch will give a different log message to them.
Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Most of QEMU's PCI display device models, such as:
libvirt video/model/@type QEMU -device
------------------------- ------------
cirrus cirrus-vga
vga VGA
qxl qxl-vga
virtio virtio-vga
come with a linear framebuffer (sometimes called "VGA compatibility
framebuffer"). This linear framebuffer lives in one of the PCI device's
MMIO BARs, and allows guest code (primarily: firmware drivers, and
non-accelerated OS drivers) to display graphics with direct memory access.
Due to architectural reasons on aarch64/KVM hosts, this kind of
framebuffer doesn't / can't work in
qemu-system-(arm|aarch64) -M virt
machines. Cache coherency issues guarantee a corrupted / unusable display.
The problem has been researched by several people, including kvm-arm
maintainers, and it's been decided that the best way (practically the only
way) to have boot time graphics for such guests is to consolidate on
QEMU's "virtio-gpu-pci" device.
>From <https://bugzilla.redhat.com/show_bug.cgi?id=1195176>, libvirt
supports
<devices>
<video>
<model type='virtio'/>
</video>
</devices>
but libvirt unconditionally maps @type='virtio' to QEMU's "virtio-vga"
device model. (See the qemuBuildDeviceVideoStr() function and the
"qemuDeviceVideo" enum impl.)
According to the above, this is not right for the "virt" machine type; the
qemu-system-(arm|aarch64) binaries don't even recognize the "virtio-vga"
device model (justifiedly). Whereas "virtio-gpu-pci", which is a pure
virtio device without a compatibility framebuffer, is available, and works
fine.
(The ArmVirtQemu ("AAVMF") platform of edk2 -- that is, the UEFI firmware
for "virt" -- supports "virtio-gpu-pci", as of upstream commit
3ef3209d3028. See
<https://tianocore.acgmultimedia.com/show_bug.cgi?id=66>.)
Override the default mapping of "virtio", from "virtio-vga" to
"virtio-gpu-pci", if qemuDomainMachineIsVirt() evaluates to true.
Cc: Andrea Bolognani <abologna@redhat.com>
Cc: Drew Jones <drjones@redhat.com>
Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Martin Kletzander <mkletzan@redhat.com>
Suggested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1372901
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Martin Kletzander <mkletzan@redhat.com>
There is nothing Linux-specific in that function. Also since commit
8c3b5bf481 mingw build is broken due to
the fact that this function is not compiled in the library.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
In testOpenDefault we create a virtual computer that is later
presented to user. We also pretend to have NUMA cells and
initialize them somehow. But whilst doing so a magical constant
is used. Drop it.
Signed-off-by: Tomáš Ryšavý <tom.rysavy.0@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We will need this function shortly when implementing
nodeGetCPUStats in the test driver.
Signed-off-by: Tomáš Ryšavý <tom.rysavy.0@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Use the state information (online, hotpluggable) provided by the monitor
code rather than trying to infer it. This fixes an issue where on
architectures that require hotplug of multiple threads at once the
sub-cores would get updated as offline on daemon restart thus creating
an invalid configuration.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1375783
Return whether a vcpu entry is hotpluggable or online so that upper
layers don't have to infer the information from other data.
Advantage is that this code can be tested by unit tests.
The algorithm that matches data from query-cpus and
query-hotpluggable-cpus is quite complex. Start using descriptive
iterator names to avoid confusion.
https://bugzilla.redhat.com/show_bug.cgi?id=1372613
Apparently, some management applications use the following code
pattern when waiting for a block job to finish:
while (1) {
virDomainGetBlockJobInfo(dom, disk, info, flags);
if (info.cur == info.end)
break;
sleep(1);
}
Problem with this approach is in its corner cases. In case of
QEMU, libvirt merely pass what has been reported on the monitor.
However, if the block job hasn't started yet, qemu reports cur ==
end == 0 which tricks mgmt apps into thinking job is complete.
The solution is to mangle cur/end values as described here [1].
1: https://www.redhat.com/archives/libvir-list/2016-September/msg00017.html
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Even though we merely just pass to users whatever qemu provided
on the monitor, we still do some translation. For instance we
turn bytes into mebibytes, or fix job type if needed. However, in
the future there is more fixing to be done so this code deserves
its own function.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Name it virNumaGetHostMemoryNodeset and return only NUMA nodes which
have memory installed. This is necessary as the kernel is not very happy
to set the memory cgroup setting for nodes which do not have any memory.
This would break vcpu hotplug with following message on such
configruation:
Invalid value '0,8' for 'cpuset.mems': Invalid argument
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1375268
In a full domain config, libvirt allows overriding the normal PCI
vs. PCI Express rules when a device address is explicitly provided
(so, e.g., you can force a legacy PCI device to plug into a PCIe port,
although libvirt would never do that on its own). However, due to a
bug libvirt doesn't give this same leeway when hotplugging devices. On
top of that, current libvirt assumes that *all* devices are legacy
PCI. The result of all this is that it's impossible to hotplug a
device into a PCIe port, even if you manually add the PCI address.
This can all be traced to the function
virDomainPCIAddressEnsureAddr(), and the fact that it calls
virDomainPCIaddressReserveSlot() for manually set addresses, and that
function hardcodes the argument "fromConfig" to false (meaning "this
address was auto-assigned, so it should be subject to stricter
validation").
Since virDomainPCIAddressReserveSlot() is just a one line simple
wrapper around virDomainPCIAddressReserveAddr() (adding in a hardcoded
reserveEntireSlot = true and fromConfig = false), all that's needed to
solve the problem with no unwanted side effects is to replace that
call for virDomainPCIAddressReserveSlot() with a direct call to
virDomainPCIAddressReserveAddr(), but with reserveEntireSlot = true,
fromConfig = true. That's what this patch does.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1337490
virQEMUDriverConfigNew() always initializes the bitmap in its
cgroupControllers member to -1 (i.e. all 1's).
Prior to commit a9331394, if qemu.conf had a line with
"cgroup_controllers", cgroupControllers would get reset to 0 before
going through a loop setting a bit for each named cgroup controller.
commit a9331394 left out the "reset to 0" part, so cgroupControllers
would always be -1; if you didn't want a controller included, there
was no longer a way to make that happen.
This was discovered by users who were using qemu commandline
passthrough to use the "input-linux" method of directing
keyboard/mouse input to a virtual machine:
https://www.redhat.com/archives/vfio-users/2016-April/msg00105.html
Here's the first report I found of the problem encountered after
upgrading libvirt beyond v2.0.0:
https://www.redhat.com/archives/vfio-users/2016-August/msg00053.html
Thanks to sL1pKn07 SpinFlo <sl1pkn07@gmail.com> for bringing the
problem up in IRC, and then taking the time to do a git bisect and
find the patch that started the problem.
previous commit:
commit 2c3223785c
Author: John Ferlan <jferlan@redhat.com>
Date: Mon Jun 13 12:30:34 2016 -0400
qemu: Add the ability to hotplug the TLS X.509 environment
added a parameter "bool listen" in some methods. This
unfortunately clashes with the listen() method, causing
compile failures on certain platforms (RHEL-6 for example)
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit id 'a48c7141' altered how to determine if a volume was encrypted
by adding a peek at an offset into the file at a specific buffer location.
Unfortunately, all that was compared was the first "char" of the buffer
against the expect "int" value.
Restore the virReadBufInt32BE to get the complete field in order to
compare against the expected value from the qcow2EncryptionInfo or
qcow1EncryptionInfo "modeValue" field.
This restores the capability to create a volume with encryption, then
refresh the pool, and still find the encryption for the volume.
A LUKS volume uses the volume secret type just like the QCOW2 secret, so
adjust the loading of the default secrets to handle any volume that the
virStorageFileGetMetadataFromBuf code has deemed to be an encrypted volume
to search for the volume's secret. This lookup is done by volume usage
where the usage is expected to be the path to volume.
When a new filter is being defined, the return code is not handled properly,
thus triggering OOM error reporting routine (bug introduced by 51b2606f).
Signed-off-by: Erik Skultety <eskultet@redhat.com>
When migration fails, we need to poke QEMU monitor to check for a reason
of the failure. We did this using query-migrate QMP command, which is
not supposed to return any meaningful result on the destination side.
Thus if the monitor was still functional when we detected the migration
failure, parsing the answer from query-migrate always failed with the
following error message:
"info migration reply was missing return status"
This irrelevant message was then used as the reason for the migration
failure replacing any message we might have had.
Let's use harmless query-status for poking the monitor to make sure we
only get an error if the monitor connection is broken.
https://bugzilla.redhat.com/show_bug.cgi?id=1374613
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Commit id 'b00d7f29' shifted the opening of the /sys/devices/intel_cqm/type
file from event enable to perf event initialization. If the file did not
exist, then an error would be written to the domain log:
2016-09-06 20:51:21.677+0000: 7310: error : virFileReadAll:1360 : Failed to open file '/sys/devices/intel_cqm/type': No such file or directory
Since the error is now handled in virPerfEventEnable by checking if the
event_attr->attrType == 0 for CMT, MBML, and MBMT events - we can just
use the Quiet API in order to not log the error we're going to throw away.
Additionally, rather than using virReportSystemError, use virReportError
and VIR_ERR_ARGUMENT_UNSUPPORTED in order to signify that support isn't there
for that type of perf event - adjust the error message as well.
Akin to previous commit but for "virsh cpu-baseline" which
computes a baseline CPU for a set of host cpu elements.
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Implement support for "virsh cpu-compare" so that we can calculate
common cpu element between a pool of hosts, which had a requirement
of providing host cpu description.
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Parse libxl_hwcap accounting for versions since Xen 4.4 - Xen 4.7.
libxl_hwcaps is a set of cpuid leaves output that is described in [0] or
[1] in Xen 4.7. This is a collection of CPUID leaves that we version
in libvirt whenever feature words are reordered or added. Thus we keep the
common ones in one struct and others for each version. Since
libxl_hwcaps doesn't appear to have a stable format across all supported
versions thus we need to keep track of changes as a compromise until it's
exported in xen libxl API. We don't fail in initializing the driver in case
parsing of hwcaps failed for that reason. In addition, change the notation
on PAE feature such that is easier to read which bit it corresponds.
[0] xen/include/asm-x86/cpufeature.h
[1] xen/include/public/arch-x86/cpufeatureset.h
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Add support for describing cpu topology in host cpu element. In doing
so, refactor hwcaps part to its own helper namely libxlCapsInitCPU to
handle all host cpu related operations, including topology.
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Qemu always opens the tray if forced to. Skip the waiting step in such
case.
This also helps if qemu does not report the tray change event when
opening the cdrom forcibly (the documentation says that the event will
not be sent although qemu in fact does trigger it even if @force is
selceted).
This is a workaround for a qemu issue where qemu does not send the tray
change event in some cases (after migration with empty closed locked
drive) and thus renders the cdrom useless from libvirt's point of view.
Partially resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1368368
When a source image is dropped when missing due to startup policy the
policy needs to be cleared since it was relevant only for the given
storage source. New sources need to update it if needed.
Just like in the previous commit, teach qemu driver to detect
whether qemu supports this configuration knob or not.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Add a new secret usage type known as "tls" - it will handle adding the
secret objects for various TLS objects that need to provide some sort
of passphrase in order to access the credentials.
The format is:
<secret ephemeral='no' private='no'>
<description>Sample TLS secret</description>
<usage type='tls'>
<name>mumblyfratz</name>
</usage>
</secret>
Once defined and a passphrase set, future patches will allow the UUID
to be set in the qemu.conf file and thus used as a secret for various
TLS options such as a chardev serial TCP connection, a NBD client/server
connection, and migration.
Signed-off-by: John Ferlan <jferlan@redhat.com>
If the incoming XML defined a path to a TLS X.509 certificate environment,
add the necessary 'tls-creds-x509' object to the VIR_DOMAIN_CHR_TYPE_TCP
character device.
Likewise, if the environment exists the hot unplug needs adjustment as
well. Note that all the return ret were changed to goto cleanup since
the cfg needs to be unref'd
Signed-off-by: John Ferlan <jferlan@redhat.com>
When building a chardev device string for tcp, add the necessary pieces to
access provide the TLS X.509 path to qemu. This includes generating the
'tls-creds-x509' object and then adding the 'tls-creds' parameter to the
VIR_DOMAIN_CHR_TYPE_TCP command line.
Finally add the tests for the qemu command line. This test will make use
of the "new(ish)" /etc/pki/qemu setting for a TLS certificate environment
by *not* "resetting" the chardevTLSx509certdir prior to running the test.
Also use the default "verify" option (which is "no").
Signed-off-by: John Ferlan <jferlan@redhat.com>
Add a new TLS X.509 certificate type - "chardev". This will handle the
creation of a TLS certificate capability (and possibly repository) for
properly configured character device TCP backends.
Unlike the vnc and spice there is no "listen" or "passwd" associated. The
credentials eventually will be handled via a libvirt secret provided to
a specific backend.
Make use of the default verify option as well.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Rather than specify perhaps multiple TLS X.509 certificate directories,
let's create a "default" directory which can then be used if the service
(e.g. for now vnc and spice) does not supply a default directory.
Since the default for vnc and spice may have existed before without being
supplied, the default check will first check if the service specific path
exists and if so, set the cfg entry to that; otherwise, the default will
be set to the (now) new defaultTLSx509certdir.
Additionally add a "default_tls_x509_verify" entry which can also be used
to force the peer verification option (for vnc it's a x509verify option).
Add/alter the macro for the option being found in the config file to accept
the default value.
Signed-off-by: John Ferlan <jferlan@redhat.com>
If a migration of a domain which is already defined on the destination
host failed early (before we tried to start QEMU), we would forget to
remove the incoming transient definition. Later on when someone starts
the domain on the destination host, we will use the stale incoming
definition and the persistent definition will just be ignored.
https://bugzilla.redhat.com/show_bug.cgi?id=1368774
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The code for replacing domain's transient definition with the persistent
one is repeated in several places and we'll need to add one more. Let's
make a nice helper for it.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
There is an issue with a wrong label inside vah_add_path().
The compilation fails with the error:
make[3]: Entering directory '/tmp/libvirt/src'
CC security/virt_aa_helper-virt-aa-helper.o
security/virt-aa-helper.c: In function 'vah_add_path':
security/virt-aa-helper.c:769:9: error: label 'clean' used but not defined
goto clean;
This patch moves 'clean' label to 'cleanup' label.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
This patch fixes a segfault in virt-aa-helper caused by attempting to
modify a static string literal. It is triggered when a domain has a
<filesystem> with type='mount' configured read-only and libvirt is
using the AppArmor security driver for sVirt confinement. An "R" is
passed into the function and converted to 'r'.
Similarly to vcpu hotplug the emulator thread cgroup numa mapping needs
to be relaxed while hot-adding vcpus so that the threads can allocate
data in the DMA zone.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1370084
When hot-adding vcpus qemu needs to allocate some structures in the DMA
zone which may be outside of the numa pinning. Extract the code doing
this in a set of helpers so that it can be reused.
There is a possibility that qemu driver frees by unreferencing its
closeCallbacks pointer as it has the only reference to the object,
while in fact not all users of CloseCallbacks called thier
virCloseCallbacksUnset.
Backtrace is the following:
Thread #1:
0 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
1 in virCondWait (c=<optimized out>, m=<optimized out>)
at util/virthread.c:154
2 in virThreadPoolFree (pool=0x7f0810110b50)
at util/virthreadpool.c:266
3 in qemuStateCleanup () at qemu/qemu_driver.c:1116
4 in virStateCleanup () at libvirt.c:808
5 in main (argc=<optimized out>, argv=<optimized out>)
at libvirtd.c:1660
Thread #2:
0 in virClassIsDerivedFrom (klass=0xdeadbeef, parent=0x7f0837c694d0) at util/virobject.c:169
1 in virObjectIsClass (anyobj=anyobj@entry=0x7f08101d4760, klass=<optimized out>) at util/virobject.c:365
2 in virObjectLock (anyobj=0x7f08101d4760) at util/virobject.c:317
3 in virCloseCallbacksUnset (closeCallbacks=0x7f08101d4760, vm=vm@entry=0x7f08101d47b0, cb=cb@entry=0x7f081d078fc0 <qemuProcessAutoDestroy>) at util/virclosecallbacks.c:163
4 in qemuProcessAutoDestroyRemove (driver=driver@entry=0x7f081018be50, vm=vm@entry=0x7f08101d47b0) at qemu/qemu_process.c:6368
5 in qemuProcessStop (driver=driver@entry=0x7f081018be50, vm=vm@entry=0x7f08101d47b0, reason=reason@entry=VIR_DOMAIN_SHUTOFF_SHUTDOWN, asyncJob=asyncJob@entry=QEMU_ASYNC_JOB_NONE, flags=flags@entry=0) at qemu/qemu_process.c:5854
6 in processMonitorEOFEvent (vm=0x7f08101d47b0, driver=0x7f081018be50) at qemu/qemu_driver.c:4585
7 qemuProcessEventHandler (data=<optimized out>, opaque=0x7f081018be50) at qemu/qemu_driver.c:4629
8 in virThreadPoolWorker (opaque=opaque@entry=0x7f0837c4f820) at util/virthreadpool.c:145
9 in virThreadHelper (data=<optimized out>) at util/virthread.c:206
10 in start_thread () from /lib64/libpthread.so.0
Let's reference CloseCallbacks object in virCloseCallbacksSet and
unreference in virCloseCallbacksUnset.
Signed-off-by: Maxim Nestratov <mnestratov@virtuozzo.com>
In the latest glibc, major() and minor() functions are marked as
deprecated (glibc commit dbab6577):
CC util/libvirt_util_la-vircgroup.lo
util/vircgroup.c: In function 'virCgroupGetBlockDevString':
util/vircgroup.c:768:5: error: '__major_from_sys_types' is deprecated:
In the GNU C Library, `major' is defined by <sys/sysmacros.h>.
For historical compatibility, it is currently defined by
<sys/types.h> as well, but we plan to remove this soon.
To use `major', include <sys/sysmacros.h> directly.
If you did not intend to use a system-defined macro `major',
you should #undef it after including <sys/types.h>.
[-Werror=deprecated-declarations]
if (virAsprintf(&ret, "%d:%d ", major(sb.st_rdev), minor(sb.st_rdev)) < 0)
^~
In file included from /usr/include/features.h:397:0,
from /usr/include/bits/libc-header-start.h:33,
from /usr/include/stdio.h:28,
from ../gnulib/lib/stdio.h:43,
from util/vircgroup.c:26:
/usr/include/sys/sysmacros.h:87:1: note: declared here
__SYSMACROS_DEFINE_MAJOR (__SYSMACROS_FST_IMPL_TEMPL)
^
Moreover, in the glibc commit, there's suggestion to keep
ordering of including of header files as implemented here.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Current implementation uses the dev.cpu.0.freq sysctl that is
provided by the cpufreq(4) framework and returns the actual
CPU frequency. However, there are environments where it's not available,
e.g. when running nested in KVM. In this case fall back to hw.clockrate
that reports CPU frequency at the boot time.
Resolves (hopefully):
https://bugzilla.redhat.com/show_bug.cgi?id=1369964
We already guarantee that virtlogd.socket is enabled/disabled
along with libvirtd.service, but if libvirtd.service has just
been installed and is started before rebooting, then
virtlogd.socket will not be running and guest startup will
fail.
Add Requires=virtlogd.socket to libvirtd.service to make sure
virtlogd.socket is always started along with libvirtd.service,
and add Before=libvirtd.service to both virtlogd.socket and
virtlogd.service so that virtlogd never disappears before
libvirtd has exited.
Also add PartOf=libvirtd.service to both virtlogd.socket and
virtlogd.service, so that virtlogd can be shut down when not
needed.
Resolves: https://bugzilla.redhat.com/1372576
We already have the ability to turn off dumping of guest
RAM via the domain XML. This is not particularly useful
though, as it is under control of the management application.
What is needed is a way for the sysadmin to turn off guest
RAM defaults globally, regardless of whether the mgmt app
provides its own way to set this in the domain XML.
So this adds a 'dump_guest_core' option in /etc/libvirt/qemu.conf
which defaults to false. ie guest RAM will never be included in
the QEMU core dumps by default. This default is different from
historical practice, but is considered to be more suitable as
a default because
a) guest RAM can be huge and so inflicts a DOS on the host
I/O subsystem when dumping core for QEMU crashes
b) guest RAM can contain alot of sensitive data belonging
to the VM owner. This should not generally be copied
around inside QEMU core dumps submitted to vendors for
debugging
c) guest RAM contents are rarely useful in diagnosing
QEMU crashes
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the QEMU processes inherit their core dump rlimit
from libvirtd, which is really suboptimal. This change allows
their limit to be directly controlled from qemu.conf instead.
With current perf framework, this patch adds support and documentation
for more perf events, including cache misses, cache references, cpu cycles,
and instructions.
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Introduce a static attr table and refactor virPerfEventEnable() for
general purpose usage.
This patch creates a static table/matrix that converts the VIR_PERF_EVENT_*
events into their respective "attr.type" and "attr.config" so that
virPerfEventEnable doesn't have the switch the calling function passes
by value the 'type'.
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Since the domain lock is not held during preparation of an external XML
config, it is possible that the value can change resulting in unexpected
failures during ABI consistency checking for some save and migrate
operations.
This patch adds a new flag to skip the checking of the cur_balloon value
and then sets the destination value to the source value to ensure
subsequent checks without the skip flag will succeed.
This way it is protected from forges and is keeped up to date too.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Add support for multi serial devices, after this patch virsh can be used to
connect different serial devices of running domains. E.g.
vish # console <xxx> --devname serial<xxx>
Note:
This depends on a xen/libxl bug fix to have libxl_console_get_tty(...) correctly
returning the tty path (as opposed to always returning the first one).
[0] https://lists.xen.org/archives/html/xen-devel/2016-08/msg00438.html
Signed-off-by: Bob Liu <bob.liu@oracle.com>
libvirt uses the new_id PCI sysfs interface to bind a PCI stub driver
to a PCI device. The new_id interface is known to be buggy and racey,
hence a more deterministic interface was introduced in the 3.12 kernel:
driver_override. For more details see
https://www.redhat.com/archives/libvir-list/2016-June/msg02124.html
For more details about the driver_override interface and examples of
its usage, see
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/pci/pci-driver.c?h=v3.12&id=782a985d7af26db39e86070d28f987cad21313c0
This patch adds support for the driver_override interface by
- adding new virPCIDevice{BindTo,UnbindFrom}StubWithOverride functions
that use the driver_override interface
- renames the existing virPCIDevice{BindTo,UnbindFrom}Stub functions
to virPCIDevice{BindTo,UnbindFrom}StubWithNewid to perserve existing
behavior on new_id interface
- changes virPCIDevice{BindTo,UnbindFrom}Stub function to call one of
the above depending on availability of driver_override
The patch includes a bit of duplicate code, but allows for easily
dropping the new_id code once support for older kernels is no
longer desired.
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
libxl only has API to address the host USB devices by bus/device.
Find the bus/device if the user only provided the vendor/product
of the USB device.
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Finding an USB device from the vendor/device values will be needed
by libxl driver to convert from vendor/device to bus/dev addresses.
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
The 'multi' element in PCI address struct used as 'virTristateSwitch',
and its default value is 'VIR_TRISTATE_SWITCH_ABSENT'. Current PCI
process use 'false' to initialization 'multi', which is ambiguously
for assignment or comparison. This patch use '{0}' to initialize
the whole PCI address struct, which fix the 'multi' initialization
and makes code more simplify and explicitly.
Signed-off-by: Xian Han Yu <xhyubj@linux.vnet.ibm.com>
The libxl driver has long supported migration V3 but has never
indicated so in the connectSupportsFeature API. As a result, apps
such as virt-manager that use the more generic virDomainMigrate API
fail with
libvirtError: this function is not supported by the connection driver:
virDomainMigrate
Add VIR_DRV_FEATURE_MIGRATION_V3 to the list of features marked as
supported in the connectSupportsFeature API.
Test 12 from objecteventtest (createXML add event) segaults on FreeBSD
with bus error.
At some point it calls testNodeDeviceDestroy() from the test driver. And
it fails when it tries to unlock the device in the "out:" label of this
function.
Unlocking fails because the previous step was a call to
virNodeDeviceObjRemove from conf/node_device_conf.c. This function
removes the given device from the device list and cleans up the object,
including destroying of its mutex. However, it does not nullify the pointer
that was given to it.
As a result, we end up in testNodeDeviceDestroy() here:
out:
if (obj)
virNodeDeviceObjUnlock(obj);
And instead of skipping this, we try to do Unlock and fail because of
malformed mutex.
Change virNodeDeviceObjRemove to use double pointer and set pointer to
NULL.
As bhyve currently doesn't use controller addressing and simply
uses 1 implicit controller for 1 disk device, the scheme looks the
following:
pci addrees -> (implicit controller) -> disk device
So in fact we identify disk devices by pci address of implicit
controller and just pass it this way to bhyve in a form:
-s pci_addr,ahci-(cd|hd),/path/to/disk
Therefore, we cannot use virDeviceInfoPCIAddressWanted() because it
does not expect that disk devices might need PCI address assignment.
As a result, if a disk was specified without address, it will not be
generated and domain will to start.
Until proper controller addressing is implemented in the bhyve
driver, force each disk to have PCI address generated if it was not
specified by user.
Setting vcpu count when cpu topology is specified may result into an
invalid configuration. Since the topology can't be modified, reject the
setting if it doesn't match the requested topology. This will allow
fixing the topology in case it was broken.
Partially fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1370066
Validating the vcpu count is more intricate and doing it in the XML
parser will make previously valid configs (with older qemus) vanish.
Now that we have a very similar check in the qemu domain validation
callback we can do it in a more appropriate place.
This basically reverts commit b54de0830a.
Partially resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1370066
ce43cca0e refactored the helper to prepare it for sparse topologies but
forgot to fix the iterator used to fill the structures. This would
result into a weirdly sparse populated array and possible out of bounds
access and crash once sparse vcpu topologies were allowed.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1369988
While dettaching/attaching device in OpenStack, nova
calls vzDomainDettachDevice twice, because the update of the internal
configuration of the ct comes a bit latter than the update event.
As the result, we suffer from the second call to dettach the same device.
Signed-off-by: Olga Krishtal <okrishtal@virtuozzo.com>
libvirt-python passes parameter bandwidth = 0
by default. This means that bandwidth is unlimited.
VZ driver doesn't support bandwidth rate limiting,
but we still need to handle it and fail if bandwidth > 0.
Signed-off-by: Pavel Glushchak <pglushchak@virtuozzo.com>
* Added VIR_MIGRATE_LIVE, VIR_MIGRATE_UNDEFINE_SOURCE and
VIR_MIGRATE_PERSIST_DEST to supported migration flags
Signed-off-by: Pavel Glushchak <pglushchak@virtuozzo.com>
When support for auto-creating tap devices was added to <interface
type='ethernet'> in commit 9c17d6, the code assumed that
virNetDevTapCreate() would honor the VIR_NETDEV_TAP__CREATE_IFUP flag
that is supported by virNetDevTapCreateInBridgePort(). That isn't the
case - the latter function performs several operations, and one of
them is setting the tap device online. But virNetDevTapCreate() *only*
creates the tap device, and relies on the caller to do everything
else, so qemuInterfaceEthernetConnect() needs to call
virNetDevSetOnline() after the device is successfully created.
The linkstate setting of an <interface> is only meant to change the
online status reported to the guest system by the emulated network
device driver in qemu, but when support for auto-creating tap devices
for <interface type='ethernet'> was added in commit 9717d6, a chunk of
code was also added to qemuDomainChangeNetLinkState() that sets the
online status of the tap device (i.e. the *host* side of the
interface) for type='ethernet'. This was never done for tap devices
used in type='bridge' or type='network' interfaces, nor was it done in
the past for tap devices created by external scripts for
type='ethernet', so we shouldn't be doing it now.
This patch removes the bit of code in qemuDomainChangeNetLinkState()
that modifies online status of the tap device.
The call to virNetDevIPInfoAddToDev() that sets up tap device IP
addresses and routes was somehow incorrectly placed in
qemuInterfaceStopDevice() instead of qemuInterfaceStartDevice() in
commit fe8567f6. This fixes that error by moving the call to
virNetDevIPInfoAddToDev() to qemuInterfaceStartDevice().
Signed-off-by: Vasiliy Tolstov <v.tolstov@selfip.ru>
This patch removes the old vcpu unplug code completely and replaces it
with the new code using device_del. The old hotplug code basically never
worked with any recent qemu and thus is useless.
As the new code is using device_del all the implications of using it
are present. Contrary to the device deletion code, the vcpu deletion
code fails if the unplug request is not executed in time.
To allow unplugging the vcpus, hotplugging of vcpus on platforms which
require to plug multiple logical vcpus at once or plugging them in an
arbitrary order it's necessary to use the new device_add interface for
vcpu hotplug.
This patch adds support for the device_add interface using the old
setvcpus API by implementing an algorithm to select the appropriate
entities to plug in.
Add support for using the new approach to hotplug vcpus using device_add
during startup of qemu to allow sparse vcpu topologies.
There are a few limitations imposed by qemu on the supported
configuration:
- vcpu0 needs to be always present and not hotpluggable
- non-hotpluggable cpus need to be ordered at the beginning
- order of the vcpus needs to be unique for every single hotpluggable
entity
Qemu also doesn't really allow to query the information necessary to
start a VM with the vcpus directly on the commandline. Fortunately they
can be hotplugged during startup.
The new hotplug code uses the following approach:
- non-hotpluggable vcpus are counted and put to the -smp option
- qemu is started
- qemu is queried for the necessary information
- the configuration is checked
- the hotpluggable vcpus are hotplugged
- vcpus are started
This patch adds a lot of checking code and enables the support to
specify the individual vcpu element with qemu.
The vcpu order information is extracted only for hotpluggable entities,
while vcpu definitions belonging to the same hotpluggable entity need
to all share the order information.
We also can't overwrite it right away in the vcpu info detection code as
the order is necessary to add the hotpluggable vcpus enabled on boot in
the correct order.
The helper will store the order information in places where we are
certain that it's necessary.
Introduce a new migration cookie flag that will be used for any
configurations that are not compatible with libvirt that would not
support the specific vcpu hotplug approach. This will make sure that old
libvirt does not fail to reproduce the configuration correctly.
Individual vCPU hotplug requires us to track the state of any vCPU. To
allow this add the following XML:
<domain>
...
<vcpu current='2'>3</vcpu>
<vcpus>
<vcpu id='0' enabled='yes' hotpluggable='no' order='1'/>
<vcpu id='1' enabled='yes' hotpluggable='yes' order='2'/>
<vcpu id='1' enabled='no' hotpluggable='yes'/>
</vcpus>
...
The 'enabled' attribute allows to control the state of the vcpu.
'hotpluggable' controls whether given vcpu can be hotplugged and 'order'
allows to specify the order to add the vcpus.
Similarly to devices the guest may allow unplug of the VCPU if libvirt
is down. To avoid problems, refresh the vcpu state on reconnect. Don't
mess with the vcpu state otherwise.
Now that the monitor code gathers all the data we can extract it to
relevant places either in the definition or the private data of a vcpu.
As only thread id is broken for TCG guests we may extract the rest of
the data and just skip assigning of the thread id. In case where qemu
would allow cpu hotplug in TCG mode this will make it work eventually.
For hotplug purposes it's necessary to retrieve data using
query-hotpluggable-cpus while the old query-cpus API report thread IDs
and order of hotplug.
This patch adds code that merges the data using a rather non-trivial
algorithm and fills the data to the qemuMonitorCPUInfo structure for
adding to appropriate place in the domain definition.
Add support for retrieving information regarding hotpluggable cpu units
supported by qemu. Data returned by the command carries information
needed to figure out the granularity of hotplug, the necessary cpu type
name and the topology information.
Note that qemu doesn't specify any particular order of the entries thus
it's necessary sort them by socket_id, core_id and thread_id to the
order libvirt expects.
To allow matching up the data returned by query-cpus to entries in the
query-hotpluggable-cpus reply for CPU hotplug it's necessary to extract
the QOM path as it's the only link between the two.
QEMU reports whether 'query-hotpluggable-cpus' is supported for a given
machine type. Extract and cache the information using the capability
cache.
When copying the capabilities for a new start of qemu, mask out the
presence of QEMU_CAPS_QUERY_HOTPLUGGABLE_CPUS if the machine type
doesn't support hotpluggable cpus.
As of qemu commit:
commit a32ef3bfc12c8d0588f43f74dcc5280885bbdb30
Author: Thomas Huth <thuth@redhat.com>
Date: Wed Jul 22 15:59:50 2015 +0200
vl: Add another sanity check to smp_parse() function
v2.4.0-952-ga32ef3b
configuration where the maximum CPU count doesn't match the topology is
rejected. Prior to that only configurations where the topology would
contain more cpus than the maximum count would be rejected.
Use QEMU_CAPS_QUERY_HOTPLUGGABLE_CPUS as a relevant recent enough
witness to avoid breaking old configs.
Prepare to extract more data by returning an array of structs rather than
just an array of thread ids. Additionally report fatal errors separately
from qemu not being able to produce data.
vzDomainMigrateConfirm3Params is whitelisted. Otherwise we need to
move removing domain from domain list from perform to confirm
step. This would further imply adding a flag and check that migration
is in progress to prohibit mistakenly (maliciously) removing domains
on confirm step. vz version of p2p also need to be fixed to include confirm step.
One would also need to add means to cleanup pending migration
on client disconnect as now is has state across several API
calls.
On the other hand current version of confirm step is totaly
harmless thus it is easier to whitelist it at the moment.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Maxim Nestratov <mnestratov@virtuozzo.com>
This way we make naming consistent to API calls and make subsequent
ACL checks possible (otherwise ACL check would discover name
discrepancies).
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
ACL check on perform step should be in API call itself to make ACL
checking script pass. Thus we need to reorganize code to obtain
domain object in perform API itself. Most of this is straight
forward, the only nuance is dropping locks on lengthy remote
operations.
The other motivation is to have only perform step ACL checks for
p2p migration instead of both begin in perform if we can leave
ACL check in vzDomainMigratePerformStep.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
We need it to prepare the calls for ACL checks otherwise ACL checking
script will fail.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
This action deserves its own function and makes main API call
structure much cleaner.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
The original motivation is to expand API calls like start/stop etc so that
the ACL checks could be added. But this patch has its own befenits.
1. functions like prlsdkStart/Stop use common routine to wait for
job without domain lock. They become more self contained and do
not return intermediate PRL_RESULT.
2. vzDomainManagedSave do not update cache twice.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Maxim Nestratov <mnestratov@virtuozzo.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1367259
Crash occurs because 'secrets' is being dereferenced in call:
if (qemuDomainSecretSetup(conn, priv, secinfo, disk->info.alias,
VIR_SECRET_USAGE_TYPE_VOLUME, NULL,
&src->encryption->secrets[0]->seclookupdef,
true) < 0)
(gdb) p *src->encryption
$1 = {format = 2, nsecrets = 0, secrets = 0x0, encinfo = {cipher_size = 0,
cipher_name = 0x0, cipher_mode = 0x0, cipher_hash = 0x0, ivgen_name = 0x0,
ivgen_hash = 0x0}}
(gdb) bt
priv=priv@entry=0x7fffc03be160, disk=disk@entry=0x7fffb4002ae0)
at qemu/qemu_domain.c:1087
disk=0x7fffb4002ae0, vm=0x7fffc03a2580, driver=0x7fffc02ca390,
conn=0x7fffb00009a0) at qemu/qemu_hotplug.c:355
Upon entry to qemuDomainAttachVirtioDiskDevice, src->encryption points
at a valid 'secret' buffer w/ nsecrets == 1; however, the call to
qemuDomainDetermineDiskChain will call virStorageFileGetMetadata
and eventually virStorageFileGetMetadataInternal where the src->encryption
was overwritten when probing the volume.
Commit id 'a48c7141' added code to virStorageFileGetMetadataInternal
to determine if the disk/volume would use/need encryption and allocated
a meta->encryption. This overwrote an existing encryption buffer
already provided by the XML
This patch adds a check for meta->encryption already present before
just allocating and overwriting an existing buffer. It then checks the
existing encryption data to ensure the XML provided format for the
disk matches the expected format read from the disk and errors if there
is a mismatch.
For some unknown reason the original implementation of the <forwarder>
element only took advantage of part of the functionality in the
dnsmasq feature it exposes - it allowed specifying the ip address of a
DNS server which *all* DNS requests would be forwarded to, like this:
<forwarder addr='192.168.123.25'/>
This is a frontend for dnsmasq's "server" option, which also allows
you to specify a domain that must be matched in order for a request to
be forwarded to a particular server. This patch adds support for
specifying the domain. For example:
<forwarder domain='example.com' addr='192.168.1.1'/>
<forwarder domain='www.example.com'/>
<forwarder domain='travesty.org' addr='10.0.0.1'/>
would forward requests for bob.example.com, ftp.example.com and
joe.corp.example.com all to the DNS server at 192.168.1.1, but would
forward requests for travesty.org and www.travesty.org to
10.0.0.1. And due to the second line, requests for www.example.com,
and odd.www.example.com would be resolved by the libvirt network's own
DNS server (i.e. thery wouldn't be immediately forwarded) even though
they also match 'example.com' - the match is given to the entry with
the longest matching domain. DNS requests not matching any of the
entries would be resolved by the libvirt network's own DNS server.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1331796
If you define a libvirt virtual network with one or more IP addresses,
it starts up an instance of dnsmasq. It's always been possible to
avoid dnsmasq's dhcp server (simply don't include a <dhcp> element),
but until now it wasn't possible to avoid having the DNS server
listening; even if the network has no <dns> element, it is started
using default settings.
This patch adds a new attribute to <dns>: enable='yes|no'. For
backward compatibility, it defaults to 'yes', but if you don't want a
DNS server created for the network, you can simply add:
<dns enable='no'/>
to the network configuration, and next time the network is started
there will be no dns server created (if there is dhcp configuration,
dnsmasq will be started with "port=0" which disables the DNS server;
if there is no dhcp configuration, dnsmasq won't be started at all).
The new forward mode 'open' is just like mode='route', except that no
firewall rules are added to assure that any traffic does or doesn't
pass. It is assumed that either they aren't necessary, or they will be
setup outside the scope of libvirt.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=846810
