Commit Graph

7622 Commits

Author SHA1 Message Date
Ján Tomko
b4418464e1 qemu: fix uninitialized variable in qemuParseCommandLine
Newly added if branch for kvm_pv_eoi did not set the ret variable.
2012-09-14 21:15:16 +08:00
Daniel P. Berrange
6b07dff012 Introduce a API for creating QEMU capabilities for a binary
Introduce a qemuCapsNewForBinary() API which creates a new
QEMU capabilities object, populated with data relating to
a specific QEMU binary. The qemuCaps object is also given
a timestamp, which makes it possible to detect when the
cached capabilities for a binary are out of date

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-14 12:59:29 +01:00
Daniel P. Berrange
97a1f07681 Remove upfront check for hmp - just try it cope with failure
Don't bother checking for the existance of the HMP passthrough
command. Just try to execute it, and propagate the failure.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-14 12:59:25 +01:00
Daniel P. Berrange
5505cf96b0 Don't overwrite errors raised by qemuMonitorHMPCommand
The qemuMonitorHMPCommand() API and things it calls will report
a wide variety of errors. The QEMU text monitor should not be
overwriting these errors

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-14 12:59:20 +01:00
Martin Kletzander
fbf9aa12c7 qemu: Add support for EOI with APIC
This patch adds full support for EOI setting for domains. Because this
is CPU feature (flag), the model needs to be added even when it's not
specified. Fortunately this problem was already solved with kvmclock,
so this patch simply abuses that.

And due to the size of the patch (17 lines) I dared to include the tests.
2012-09-14 08:32:56 +02:00
Martin Kletzander
4a8b7cba80 Add support for EOI with APIC
New options is added to support EOI (End of Interrupt) exposure for
guests. As it makes sense only when APIC is enabled, I added this into
the <apic> element in <features> because this should be tri-state
option (cannot be handled as standalone feature).
2012-09-14 08:18:11 +02:00
Martin Kletzander
b7ff9e6960 security: Fix libvirtd crash possibility
Fix for CVE-2012-4423.

When generating RPC protocol messages, it's strictly needed to have a
continuous line of numbers or RPC messages. However in case anyone
tries backporting some functionality and will skip a number, there is
a possibility to make the daemon segfault with newer virsh (version of
the library, rpc call, etc.) even unintentionally.

The problem is that the skipped numbers will get func filled with
NULLs, but there is no check whether these are set before the daemon
tries to run them. This patch very simply enhances one check and fixes
that.
2012-09-14 08:13:19 +02:00
Guannan Ren
ac89a611d4 snapshot: fix rollback failure in transaction mode
BZ:https://bugzilla.redhat.com/show_bug.cgi?id=843372
when qemu supports the 'transaction' monitor command,
and libvirt's --reuse-ext flag was not specified, libvirt created
a stub file with zero size in first place. After the failure of
QEMU transaction command performing qcow2 snapshots on more than
one drives, the stub file is left behind with non-empty
by the QEMU transaction command.
In order to unlink the file, the patch removes the file size checking.

Steps to reproduce the issue:
Steps:
 1, Create a qemu instance with two drive images of qcow2 type (root user)
    /usr/libexec/qemu-kvm -m 1024 -smp 1 -name "rhel6u1" \
      -drive file=/var/lib/libvirt/images/firstqcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none
      -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \
      -drive file=/var/lib/libvirt/images/secondqcow2,if=none,id=drive-virtio-disk1,format=qcow2,cache=none \
      -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x7,drive=drive-virtio-disk1,id=virtio-disk1 -qmp stdio

 2, Initialize qemu qmp
    {"execute":"qmp_capabilities"}

 3, Remove the second drive image file
    rm -f /var/lib/libvirt/images/secondqcow2

 4, Run 'transaction' command with snapshot qemu commands in.
    {"execute":"transaction","arguments":
      {"actions":
        [{"type":"blockdev-snapshot-sync","data":
          {"device":"drive-virtio-disk0","snapshot-file":"/var/lib/libvirt/images/firstqcow2-snapshot.img","format":"qcow2"}
         },
         {"type":"blockdev-snapshot-sync","data":
          {"device":"drive-virtio-disk1","snapshot-file":"/var/lib/libvirt/images/secondqcow2-snapshot.img","format":"qcow2"}
         }]
      },
   "id":"libvirt-6"}

 5, Got the error as follows:
    {"id": "libvirt-6",
      "error": {"class": "OpenFileFailed", "desc": "Could not open '/var/lib/libvirt/images/secondqcow2-snapshot.img'",
                "data": {"filename": "/var/lib/libvirt/images/secondqcow2-snapshot.img"}
               }
    }

 6, List first newly-created snapshot file:
    -rw-r--r--. 1 root root     262144 Sep 13 11:43 firstqcow2-snapshot.img
2012-09-14 11:18:19 +08:00
Osier Yang
1e2864c2cd Improve virTypedParameterValidateSet
Assume not only domain object will use it.
2012-09-14 11:06:00 +08:00
Alex Jia
9ed534f081 conf: avoid libvirt crash with empty address guestfwd channel
The 'def->target.addr' hasn't been initialized in virDomainChrDefNew() and
its value is always '0xffffffff', in addition, the following test scenario
hasn't also include 'address' element in channel XML block, so the branch
'if (addrStr == NULL)' is hit in virDomainChrDefParseTargetXML(), the
programming jumps to 'error' label to release relevant resources, and the
statement 'if (VIR_ALLOC(def->target.addr) < 0)' hasn't been executed then
the virDomainChrDefFree() will free 'def->target.addr'(0xffffffff) via
VIR_FREE(), which results in libvirt crash, to use valgrind can also
find a 'Invalid free() / delete / delete[]' error. This patch just adjusts
codes order to initialize 'def->target.addr' firstly.

With this patch, libvirt hasn't crash and can get a expected error message "
XML error: guestfwd channel does not define a target address".

How to reproduce?

1. define a guest with the following channel XML configuration

$ cat foo.xml
<snip>
    <channel type='pty'>
      <target type='guestfwd'/>
    </channel>
</snip>

$ virsh define foo.xml

2. actual result

error: Failed to define domain from /tmp/foo.xml
error: End of file while reading data: Input/output error
error: Failed to reconnect to the hypervisor

GDB debugger information:
<snip>
Breakpoint 1, virDomainChrDefFree (def=0x7f8ab000ec70) at conf/domain_conf.c:1264
...ignore
1264    {
(gdb) p def->target
$2 = {port = -1, addr = 0xffffffff, name = 0xffffffff <Address 0xffffffff out of bounds>}
</snip>

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=856489

Signed-off-by: Alex Jia <ajia@redhat.com>
2012-09-14 00:41:38 +08:00
Dmitry Guryanov
a62116de32 parallels: implement containers creation
Add separate function parallelsCreateCt, which creates container.
Also add example xml configuration domain-parallels-ct-simple.xml.

Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
2012-09-13 21:19:58 +08:00
Dmitry Guryanov
0f82f30612 parallels: fix parallelsDomainDefineXML for existing containers
Fix code, which checks what is changed in virDomainDef structure.
It looks slightly different for containers and VMs: containers haven't
boot devices, but have init path

Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
2012-09-13 21:19:57 +08:00
Dmitry Guryanov
4bc97d592f parallels: handle unlimited cpus on containers
User may set "unlimited" cpus for containers, which means to
take all available cpus on the node.

Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
2012-09-13 21:19:57 +08:00
Dmitry Guryanov
fb583a8f5b parallels: add support of containers to the driver
This patch makes parallelsLoadDomains to be able to load information
about containers. So functions, which return different information
and change state will work.

parallelsDomainDefineXML will be fixed in separate patch.

Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
2012-09-13 21:19:57 +08:00
Daniel P. Berrange
9b5c540096 Fix data types used for list sizes in QEMU capabilities
The QEMU capabilities APIs used a misc of 'int' and
'unsigned int' for variables relating to array sizes.
Change all these to use 'size_t'

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-13 12:30:23 +01:00
Daniel P. Berrange
4dced75e79 Add API for copying instances of the qemuCapsPtr object
To allow each VM instance to record additional capabilities
without affecting other VMs, there needs to be a way to do
a deep copy of the qemuCapsPtr object
2012-09-13 12:28:01 +01:00
Daniel P. Berrange
116e2facde Add ability to store other metadata in the qemu capabilities object
Add struct fields and APIs to allow the qemu capabilities object
to store version, arch, machines & cpu names, etc

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-13 12:26:41 +01:00
Daniel P. Berrange
c29ce35af6 Make qemuCapsProbeCommand static
The qemuCapsProbeCommand API is only used by the capabilities
code, so can be static

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-13 12:24:13 +01:00
Daniel P. Berrange
beac09fd68 Turn QEMU capabilities object into a full virObjectPtr
The current qemu capabilities are stored in a virBitmapPtr
object, whose type is exposed to callers. We want to store
more data besides just the flags, so we need to move to a
struct type. This object will also need to be reference
counted, since we'll be maintaining a cache of data per
binary. This change introduces a 'qemuCapsPtr' virObject
class. Most of the change is just renaming types and
variables in all the callers

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-13 12:24:12 +01:00
Daniel P. Berrange
f4780c12dc Allow caps to be NULL when creating virDomainObjPtr instances
If no private data needs to be maintained, it can be useful
to create virDomainObjPtr instances without having a virCapsPtr
instance around. Adapt the virDomainObjNew() function to allow
for a NULL caps

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-13 12:16:59 +01:00
Daniel P. Berrange
985a321ac0 Wait to receive QMP greeting before sending any monitor commands
Technically speaking we should wait until we receive the QMP
greeting message before attempting to send any QMP monitor
commands. Mostly we've got away with this, but there is a race
in some QEMU which cause it to SEGV if you sent it data too
soon after startup. Waiting for the QMP greeting avoids the
race

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-13 11:44:05 +01:00
Daniel P. Berrange
d2fdeb3b1e Add a virBitmapCopy API
Add an API allowing flags from one virBitmapPtr to be copied
into another instance.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-13 11:44:01 +01:00
Guannan Ren
2d46f88d53 qemu: build USB redirection filter qemu command line
Input XML snip:
<redirdev bus='usb' type='spicevmc'>
   <address type='usb' bus='0' port='4'/>
 </redirdev>
<redirfilter>
  <usbdev class='0x08' vendor='0x1234' product='0xbeef' \
          version='2.00' allow='yes'/>
  <usbdev class='-1' vendor='-1' product='-1' version='-1' allow='no'/>
</redirfilter>

will be converted to:
-device usb-redir,chardev=charredir0,id=redir0,\
filter=0x08:0x1234:0xBEEF:0x2000:1|-1👎-1👎0,bus=usb.0,port=4
2012-09-13 17:22:32 +08:00
Guannan Ren
5b35cc532b qemu: define and parse USB redirection filter XML
https://bugzilla.redhat.com/show_bug.cgi?id=795929
http://git.qemu.org/?p=qemu.git;a=commitdiff;h=6af165892cf900291046f1d25f95416f379504c2

This patch define and parse the input XML of USB redirection filter.
<devices>
...
  <redirdev bus='usb' type='spicevmc'>
    <address type='usb' bus='0' port='4'/>
  </redirdev>
  <redirfilter>
    <usbdev class='0x08' vendor='0x1234' product='0xbeef' \
            version='2.00' allow='yes'/>
    <usbdev allow='no'/>
  </redirfilter>
...
</devices>

There is no 1:1 mapping between ports and redirected devices and
qemu and spicy client couldn't decide into which usbredir ports
the client can 'plug' redirected devices. So it make sense to apply
all of filter rules global to all existing usb redirection devices.
class attribute is USB Class codes. version is bcdDevice value
of USB device. vendor and product is USB vendorId and productId.
-1 can be used to allow any value for a field. Except allow attribute
the other four are optional, default value is -1.
2012-09-13 17:22:27 +08:00
Guannan Ren
16e41ab656 qemu: add usb-redir.filter qemu capability flag
Add a qemu flag for USB redirection filter support.

The output:
usb-redir.chardev=chr
usb-redir.debug=uint8
usb-redir.filter=string
usb-redir.port=string
2012-09-13 15:30:02 +08:00
Eric Blake
2387aa26c1 maint: fix missing spaces in message
I got an off-list report about a bad diagnostic:
Target network card mac 52:54:00:49:07:ccdoes not match source 52:54:00:49:07:b8

True to form, I've added a syntax check rule to prevent it
from recurring, and found several other offenders.

* cfg.mk (sc_require_whitespace_in_translation): New rule.
* src/conf/domain_conf.c (virDomainNetDefCheckABIStability): Add
space.
* src/esx/esx_util.c (esxUtil_ParseUri): Likewise.
* src/qemu/qemu_command.c (qemuCollectPCIAddress): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSetMetadata)
(qemuDomainGetMetadata): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainChangeNetBridge): Likewise.
* src/rpc/virnettlscontext.c
(virNetTLSContextCheckCertDNWhitelist): Likewise.
* src/vmware/vmware_driver.c (vmwareDomainResume): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc, vboxAttachDrives):
Avoid false negatives.
* tools/virsh-domain.c (info_save_image_dumpxml): Reword.
Based on a report by Luwen Su.
2012-09-12 11:55:29 -06:00
Daniel P. Berrange
cf5491e5ba Add API for opening a QEMU monitor from a socket FD
Currently qemuMonitorOpen() requires an address of the QEMU
monitor. When doing QMP based capabilities detection it is
easier if a pre-opened FD can be provided, since then the
monitor can be run on the STDIO console. Add a new API
qemuMonitorOpenFD() for such usage

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-12 17:20:57 +01:00
Dmitry Guryanov
4cf4120b82 parallels: fix parallelsDomainDefineXML for domains with VNC and autoport
virDomainDefParseString assigns 0 to port if autoport enabled.
So fix code, which check different between old and new
configurations.
2012-09-12 17:52:49 +08:00
Dmitry Guryanov
748b6d8e90 parallels: fix parallelsDoCmdRun in case of command failure
Don't try to dereferece NULL pointer.
2012-09-12 17:38:35 +08:00
Li Zhang
babe7dada0 Backcompt for console devices in virDomainDeviceInfoIterate
Historically, the first <console> element is treated as the
alias of a <serial> device. In the virDomainDeviceInfoIterate,
This situation is not considered. It still handles the first <console>
element as another devices, which means that for console[0] with
serial targetType, it calls callback function another time.
It will cause the problem of address conflicts when assigning
spapr-vio address for serial device on pSeries guest.

For pSeries guest, the serial configuration in the xml file
is as the following:
         <serial type='pty'>
               <target port='0'/>
               <address type='spapr-vio'/>
          </serial>

Console configuration is default, the dumped xml file is as the following:
   <serial type='pty'>
      <source path='/dev/pts/5'/>
      <target port='0'/>
      <alias name='serial0'/>
      <address type='spapr-vio' reg='0x30000000'/>
    </serial>
    <console type='pty' tty='/dev/pts/5'>
      <source path='/dev/pts/5'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
      <address type='spapr-vio' reg='0x30000000'/>
    </console>

It shows that the <console> device is the alias of serial device.
So its address is the same as the serial device. When detecting
the conflicts in the qemuAssignSpaprVIOAddress the first console
and the serial device conflicts because virDomainDeviceInfoIterate()
still handle these as two different devices, and in the qemuAssignSpaprVIOAddress(),
it will compare these two devices' addressed. If they have same address,
it will report address conflict error.

So this patch is to handle the first console which targetType is serial
as the alias of serial device to avoid address conflicts error reported.

Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
2012-09-12 10:42:15 +02:00
Osier Yang
a3cf061c82 list: Implement listAllInterfaces
This is not that ideal as API for other objects, as it's still
O(n). Because interface driver uses netcf APIs to manage the
stuffs, instead of by itself. And netcf APIs don't return a object.
It provides APIs like old libvirt APIs:

   ncf_number_of_interfaces
   ncf_list_interfaces
   ncf_lookup_by_name
   ......

Perhaps we should further improve netcf to let it provide an API
to return the object, but it could be a later patch. And anyway,
we will still benefit from the new API for the simplification,
and no race like the old APIs.

src/interface/netcf_driver.c: Implement listAllInterfaces
2012-09-12 15:37:09 +08:00
Osier Yang
65741d84ed list: Implemente RPC calls for virConnectListAllInterfaces
The RPC generator doesn't support returning list of object yet, this patch
do the work manually.

  * daemon/remote.c:
    Implemente the server side handler remoteDispatchConnectListAllInterfaces.

  * src/remote/remote_driver.c:
    Add remote driver handler remoteConnectListAllInterfaces.

  * src/remote/remote_protocol.x:
    New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_INTERFACES and
    structs to represent the args and ret for it.

  * src/remote_protocol-structs: Likewise.
2012-09-12 15:36:56 +08:00
Osier Yang
f4af202f4e list: Define new API virConnectListAllInterfaces
This is to list the interface objects, supported filtering flags
are: active|inactive.

include/libvirt/libvirt.h.in: Declare enum virConnectListAllInterfaceFlags
                              and virConnectListAllInterfaces.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllInterfaces)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public
2012-09-12 15:19:46 +08:00
Hu Tao
f7e1a546f2 fix bug in qemuSetupCgroupForEmulator
Should not return 0 when failed to setup cgroup.
2012-09-11 16:08:41 -06:00
Osier Yang
819ea2084f Build: Fix typos which cause build failure
Pushed under trivial rule.
2012-09-11 20:15:15 +08:00
Daniel P. Berrange
d95606e3d8 Don't invoke the auth callback if all credentials were in config file
The remote driver first looks at the libvirt auth config file to
fill in any credentials. It then invokes the auth callback for
any remaining credentials. It was accidentally invoking the
auth callback even if there were not any more credentials
required.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-11 12:16:18 +01:00
Daniel P. Berrange
48fea23ba5 Call virResetLastError in all virConnectOpen* functions
All public API functions must call virResetLastError to clear
out any previous error. The virConnectOpen* functions forgot
to do this.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-11 12:16:17 +01:00
Osier Yang
4a27ac1de1 list: Implement listAllNetworks for test driver
src/test/test_driver.c: Implement listAllNetworks.
2012-09-11 17:01:25 +08:00
Osier Yang
f07034159e list: Implement listAllNetworks for network driver
src/network/bridge_driver.c: Implement listAllNetworks.
2012-09-11 17:00:46 +08:00
Osier Yang
d3c6cabbac list: Add helpers to list network objects
src/conf/network_conf.c: Add virNetworkMatch to filter the networks;
and virNetworkList to iterate over all the networks with the filter.

src/conf/network_conf.h: Declare virNetworkList and define the macros
for filters.

src/libvirt_private.syms: Export virNetworkList.
2012-09-11 16:59:51 +08:00
Osier Yang
eff8a8dbb1 list: Implement RPC calls for virConnectListAllNetworks
The RPC generator doesn't support returning list of object, this patch
do the work manually.

* daemon/remote.c:
  Implemente the server side handler remoteDispatchConnectListAllNetworks.

* src/remote/remote_driver.c:
  Add remote driver handler remoteConnectListAllNetworks.

* src/remote/remote_protocol.x:
  New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_NETWORKS and
  structs to represent the args and ret for it.

* src/remote_protocol-structs: Likewise.
2012-09-11 16:59:33 +08:00
Osier Yang
89a1df9b06 list: Define new API virConnectListAllNetworks
This is to list the network objects, supported filtering flags
are: active|inactive, persistent|transient, autostart|no-autostart.

include/libvirt/libvirt.h.in: Declare enum virConnectListAllNetworkFlags
                              and virConnectListAllNetworks.
python/generator.py: Skip auto-generating
src/driver.h: (virDrvConnectListAllNetworks)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public
2012-09-11 16:58:16 +08:00
Christophe Fergeau
164c03d33b Fix unwanted closing of libvirt client connection
e5a1bee07 introduced a regression in Boxes: when Boxes is left idle
(it's still doing some libvirt calls in the background), the
libvirt connection gets closed after a few minutes. What happens is
that this code in virNetClientIOHandleOutput gets triggered:

if (!thecall)
    return -1; /* Shouldn't happen, but you never know... */

and after the changes in e5a1bee07, this causes the libvirt connection
to be closed.

Upon further investigation, what happens is that
virNetClientIOHandleOutput is called from gvir_event_handle_dispatch
in libvirt-glib, which is triggered because the client fd became
writable. However, between the times gvir_event_handle_dispatch
is called, and the time the client lock is grabbed and
virNetClientIOHandleOutput is called, another thread runs and
completes the current call. 'thecall' is then NULL when the first
thread gets to run virNetClientIOHandleOutput.

After describing this situation on IRC, danpb suggested this:

11:37 < danpb> In that case I think the correct thing would be to change
               'return -1' above to 'return 0' since that's not actually an
               error - its a rare, but expected event

which is what this patch is doing. I've tested it against master
libvirt, and I didn't get disconnected in ~10 minutes while this
happens in less than 5 minutes without this patch.
2012-09-10 14:13:06 +02:00
Osier Yang
a4d7f4a0d9 list: Implement virStoragePoolListAllVolumes for test driver
src/test/test_driver.c: Implement poolListAllVolumes.
2012-09-10 10:39:58 +08:00
Osier Yang
7254a3670e list: Implement virStoragePoolListAllVolumes for storage driver
src/storage/storage_driver.c: Implement poolListAllVolumes.
2012-09-10 10:38:57 +08:00
Osier Yang
a8bac1c0f3 list: Implement RPC calls for virStoragePoolListAllVolumes
The RPC generator doesn't returning support list of object, this
patch do the work manually.

  * daemon/remote.c:
    Implemente the server side handler remoteDispatchStoragePoolListAllVolumes

  * src/remote/remote_driver.c:
    Add remote driver handler remoteStoragePoolListAllVolumes

  * src/remote/remote_protocol.x:
    New RPC procedure REMOTE_PROC_STORAGE_POOL_LIST_ALL_VOLUMES and
    structs to represent the args and ret for it.

  * src/remote_protocol-structs: Likewise.
2012-09-10 10:37:43 +08:00
Osier Yang
a42eac601e list: Define new API virStoragePoolListAllVolumes
Simply returns the storage volume objects. No supported filter
flags.

include/libvirt/libvirt.h.in: Declare the API
python/generator.py: Skip the function for generating. virStoragePool.py
                     will be added in later patch.
src/driver.h: virDrvStoragePoolListVolumesFlags
src/libvirt.c: Implementation for the API.
src/libvirt_public.syms: Export the symbol to public
2012-09-10 10:37:22 +08:00
Matthias Bolte
aa7c4068a8 esx: Remove unused variable from esxDomainGetAutostart 2012-09-09 12:44:20 +02:00
Christophe Fergeau
defa8b8589 events: Fix domain event race on client disconnect
GNOME Boxes sometimes stops getting domain events from libvirtd, even
after restarting it. Further investigation in libvirtd shows that
events are properly queued with virDomainEventStateQueue, but the
timer virDomainEventTimer which flushes the events and sends them to
the clients never gets called. Looking at the event queue in gdb
shows that it's non-empty and that its size increases with each new
events.

virDomainEventTimer is set up in virDomainEventStateRegister[ID]
when going from 0 client connecte to 1 client connected, but is
initially disabled. The timer is removed in
virDomainEventStateRegister[ID] when the last client is disconnected
(going from 1 client connected to 0).

This timer (which handles sending the events to the clients) is
enabled in virDomainEventStateQueue when queueing an event on an
empty queue (queue containing 0 events). It's disabled in
virDomainEventStateFlush after flushing the queue (ie removing all
the elements from it). This way, no extra work is done when the queue
is empty, and when the next event comes up, the timer will get
reenabled because the queue will go from 0 event to 1 event, which
triggers enabling the timer.

However, with this Boxes bug, we have a client connected (Boxes), a
non-empty queue (there are events waiting to be sent), but a disabled
timer, so something went wrong.

When Boxes connects (it's the only client connecting to the libvirtd
instance I used for debugging), the event timer is not set as expected
(state->timer == -1 when virDomainEventStateRegisterID is called),
but at the same time the event queue is not empty. In other words,
we had no clients connected, but pending events. This also explains
why the timer never gets enabled as this is only done when an event
is queued on an empty queue.

I think this can happen if an event gets queued using
virDomainEventStateQueue and the client disconnection happens before
the event timer virDomainEventTimer gets a chance to run and flush
the event. In this situation, virDomainEventStateDeregister[ID] will
get called with a non-empty event queue, the timer will be destroyed
if this was the only client connected. Then, when other clients connect
at a later time, they will never get notified about domain events as
the event timer will never get enabled because the timer is only
enabled if the event queue is empty when virDomainEventStateRegister[ID]
gets called, which will is no longer the case.

To avoid this issue, this commit makes sure to remove all events from
the event queue when the last client in unregistered. As there is
no longer anyone interested in receiving these events, these events
are stale so there is no need to keep them around. A client connecting
later will have no interest in getting events that happened before it
got connected.
2012-09-07 14:45:00 +02:00
Daniel P. Berrange
a4fd740561 Don't assume use of /sys/fs/cgroup
The introduction of /sys/fs/cgroup came in fairly recent kernels.
Prior to that time distros would pick a custom directory like
/cgroup or /dev/cgroup. We need to auto-detect where this is,
rather than hardcoding it

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-09-07 13:30:20 +01:00