Commit Graph

11222 Commits

Author SHA1 Message Date
Peter Krempa
88cac66d92 conf: Make tri-state feature options more universal
The apic-eoi feature enum and implementation can be made more universal
to allow re-use of the enum for other features.
2012-10-18 12:22:49 +02:00
Michal Privoznik
998dc17da3 qemu: Correctly wait for spice to migrate
Currently we query-spice after the main migration has completed
before moving to next state. Qemu reports this as boolean (not
enclosed within quotes). Therefore it is not correct to use
virJSONValueObjectGetString but virJSONValueObjectGetBoolean instead.
2012-10-18 10:31:56 +02:00
Viktor Mihajlovski
1916679506 qemu: Fixed default machine detection in qemuCapsParseMachineTypesStr
The machine in the last output line of <qemu-binary> -M ?
was always reported as default machine even if this wasn't the
actual default. Trivial fix.

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
2012-10-17 17:24:41 -06:00
Martin Kletzander
ba63d8f7d8 qemu: Pin the emulator when only cpuset is specified
According to our recent changes (clarifications), we should be pinning
qemu's emulator processes using the <vcpu> 'cpuset' attribute in case
there is no <emulatorpin> specified.  This however doesn't work
entirely as expected and this patch should resolve all the remaining
issues.
2012-10-17 17:37:10 +02:00
Jiri Denemark
837993d845 qemu: Clear async job when p2p migration fails early
When p2p migration fails early because qemuMigrationIsAllowed or
qemuMigrationIsSafe say migration should be cancelled, we fail to clear
the migration-out async job. As a result of that, further APIs called
for the same domain may fail with Timed out during operation: cannot
acquire state change lock.

Reported by Guido Winkelmann.
2012-10-17 15:43:38 +02:00
Doug Goldstein
1e7ec88d9a interface: add virInterfaceGetXMLDesc() in udev
Added support for retrieving the XML defining a specific interface via
the udev based backend to virInterface. Implement the following APIs
for the udev based backend:
* virInterfaceGetXMLDesc()

Note: Does not support bond devices.
2012-10-17 13:59:16 +02:00
Michal Privoznik
740225a1cb AUTHORS: Remove double entry
I've accidentally added Li Zhang <zhlcindy@linux.vnet.ibm.com> to
AUTHORS, even if he already was there.
2012-10-17 11:53:13 +02:00
Li Zhang
40f58ca75d Doc-fix for PowerPC CPU model driver
There are some descriptions not right in PowerPC CPU model driver.
This patch is to fix them.

Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
2012-10-17 10:03:34 +02:00
Li Zhang
9943a7341c Implement CPU model driver for PowerPC
Currently, the CPU model driver is not implemented for PowerPC.
Host's CPU information is needed to exposed to guests' XML file some
time.

This patch is to implement the callback functions of CPU model driver.

Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
2012-10-17 10:03:34 +02:00
Li Zhang
309f03db40 Add one file cpu_ppc_data.h to define CPU data for PPC
CPU version can be got by PVR on PowerPC. So this PVR is defined in
the CPU data in cpuData structure.

Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
2012-10-17 10:03:34 +02:00
Guannan Ren
d37a3a1d6c selinux: remove unused variables in socket labelling 2012-10-17 13:13:17 +08:00
Guannan Ren
89b63f0ad4 selinux: fix wrong tapfd relablling
It should relabel tapfd of virtual network of type VIR_DOMAIN_NET_TYPE_DIRECT
rather than VIR_DOMAIN_NET_TYPE_NETWORK and VIR_DOMAIN_NET_TYPE_BRIDGE
(commit ae368ebfcc introduced this bug)

Caution: The context of the two hunks is identical other than indentation.
Please be extremely cautious of where the patch gets applied.
2012-10-17 13:13:14 +08:00
Cole Robinson
9f0e9cba27 storage: lvm: lvcreate fails with allocation=0, don't do that
On F17 at least, this command fails:

$ sudo /usr/sbin/lvcreate --name sparsetest -L 0K --virtualsize 16384K vgvirt
  Unable to create new logical volume with no extents

Which is unfortunate since allocation=0 is what virt-manager tries to use
by default.

Rather than telling the user 'don't do that', let's just give them the
smallest allocation possible if alloc=0 is requested.

https://bugzilla.redhat.com/show_bug.cgi?id=866481
2012-10-16 21:16:44 -04:00
Cole Robinson
01df6f2bff storage: lvm: Don't overwrite lvcreate errors
Before:
$ sudo virsh vol-create-as --pool vgvirt sparsetest --capacity 16M --allocation 0
error: Failed to create vol sparsetest
error: internal error Child process (/usr/sbin/lvchange -aln vgvirt/sparsetest) unexpected exit status 5:   One or more specified logical volume(s) not found.

After:
$ sudo virsh vol-create-as --pool vgvirt sparsetest --capacity 16M --allocation 0
error: Failed to create vol sparsetest
error: internal error Child process (/usr/sbin/lvcreate --name sparsetest -L 0K --virtualsize 16384K vgvirt) unexpected exit status 5:   Unable to create new logical volume with no extents
2012-10-16 21:16:44 -04:00
Jiri Denemark
3143c81ca1 spec: Require newer sanlock on recent distros 2
The previous commit was incomplete. We need to also add explicit
Requires for the newer version since RPM's automatic dependencies won't
work with sanlock.
2012-10-17 00:00:47 +02:00
Peter Krempa
cb4f41b8d0 spec: Add runtime requirement for libssh2
libssh2 unfortunately doesn't support symbol versioning so RPM can't
figure out what version is needed for the currently installed libvirt
package. This patch adds a runtime requirement, so that the correct
version of libssh2 can be installed along with libvirt.
2012-10-16 22:47:04 +02:00
Jiri Denemark
48bf62fde1 spec: Require newer sanlock on recent distros
Make sure libvirt is build with sanlock >= 2.4 on distros that are new
enough to provide it.
2012-10-16 21:32:07 +02:00
Jiri Denemark
5ce6d95eed locking: Fix build with sanlock < 2.4
libvirt started using sanlock_killpath to implement on_lockfailure
action. Since sanlock_killpath was introduced in sanlock 2.4, libvirt
fails to build with older sanlock.
2012-10-16 21:32:05 +02:00
Daniel P. Berrange
7bd744c401 Fix typo in previous commit s/lik/like/
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 16:37:50 +01:00
Daniel P. Berrange
d507f8f9b9 Make virInitialize thread safe
Currently there is a restriction that multi-threaded applications
must manually call virInitialize, before threads start using
libvirt, because it is not thread-safe. By switching it to use
a virOnceControl initializer we gain thread safety, and thus
applications no longer need to manually call it. They can rely
on virConnectOpen invoking it for them.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 16:33:38 +01:00
Daniel P. Berrange
84912e9c91 Fix virProcessKillPainfully on Win32
Win32 platforms don't have SIGKILL defined, but they do have
SIGABRT. Since our virProcess wrapper treats anything which
isn't SIGTERM/SIGINT as equivalent to SIGKILL, just use
SIGABRT on Win32.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 15:47:14 +01:00
Daniel P. Berrange
381a339e98 Add JSON serialization of virNetServerPtr objects for process re-exec()
Add two new APIs virNetServerNewPostExecRestart and
virNetServerPreExecRestart which allow a virNetServerPtr
object to be created from a JSON object and saved to a
JSON object, for the purpose of re-exec'ing a process.

This includes serialization of all registered services
and clients

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 15:45:55 +01:00
Daniel P. Berrange
3cfc3d7d2c Add JSON serialization of virNetServerClientPtr objects for process re-exec()
Add two new APIs virNetServerClientNewPostExecRestart and
virNetServerClientPreExecRestart which allow a virNetServerClientPtr
object to be created from a JSON object and saved to a
JSON object, for the purpose of re-exec'ing a process.

This includes serialization of the connected socket associated
with the client

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 15:45:55 +01:00
Daniel P. Berrange
0cc7925520 Add JSON serialization of virNetServerServicePtr objects for process re-exec()
Add two new APIs virNetServerServiceNewPostExecRestart and
virNetServerServicePreExecRestart which allow a virNetServerServicePtr
object to be created from a JSON object and saved to a
JSON object, for the purpose of re-exec'ing a process.

This includes serialization of the listening sockets associated
with the service

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 15:45:55 +01:00
Daniel P. Berrange
c298145344 Add JSON serialization of virNetSocketPtr objects for process re-exec()
Add two new APIs virNetSocketNewPostExecRestart and
virNetSocketPreExecRestart which allow a virNetSocketPtr
object to be created from a JSON object and saved to a
JSON object, for the purpose of re-exec'ing a process.

As well as saving the state in JSON format, the second
method will disable the O_CLOEXEC flag so that the open
file descriptors are preserved across the process re-exec()

Since it is not possible to serialize SASL or TLS encryption
state, an error will be raised if attempting to perform
serialization on non-raw sockets

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 15:45:55 +01:00
Daniel P. Berrange
8057c04e8d Add JSON serialization of virLockSpacePtr objects for process re-exec()
Add two new APIs virLockSpaceNewPostExecRestart and
virLockSpacePreExecRestart which allow a virLockSpacePtr
object to be created from a JSON object and saved to a
JSON object, for the purposes of re-exec'ing a process.

As well as saving the state in JSON format, the second
method will disable the O_CLOEXEC flag so that the open
file descriptors are preserved across the process re-exec()

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 15:45:55 +01:00
Daniel P. Berrange
eca72d4759 Introduce an internal API for handling file based lockspaces
The previously introduced virFile{Lock,Unlock} APIs provide a
way to acquire/release fcntl() locks on individual files. For
unknown reason though, the POSIX spec says that fcntl() locks
are released when *any* file handle referring to the same path
is closed. In the following sequence

  threadA: fd1 = open("foo")
  threadB: fd2 = open("foo")
  threadA: virFileLock(fd1)
  threadB: virFileLock(fd2)
  threadB: close(fd2)

you'd expect threadA to come out holding a lock on 'foo', and
indeed it does hold a lock for a very short time. Unfortunately
when threadB does close(fd2) this releases the lock associated
with fd1. For the current libvirt use case for virFileLock -
pidfiles - this doesn't matter since the lock is acquired
at startup while single threaded an never released until
exit.

To provide a more generally useful API though, it is necessary
to introduce a slightly higher level abstraction, which is to
be referred to as a "lockspace".  This is to be provided by
a virLockSpacePtr object in src/util/virlockspace.{c,h}. The
core idea is that the lockspace keeps track of what files are
already open+locked. This means that when a 2nd thread comes
along and tries to acquire a lock, it doesn't end up opening
and closing a new FD. The lockspace just checks the current
list of held locks and immediately returns VIR_ERR_RESOURCE_BUSY.

NB, the API as it stands is designed on the basis that the
files being locked are not being otherwise opened and used
by the application code. One approach to using this API is to
acquire locks based on a hash of the filepath.

eg to lock /var/lib/libvirt/images/foo.img the application
might do

   virLockSpacePtr lockspace = virLockSpaceNew("/var/lib/libvirt/imagelocks");
   lockname = md5sum("/var/lib/libvirt/images/foo.img");
   virLockSpaceAcquireLock(lockspace, lockname);

NB, in this example, the caller should ensure that the path
is canonicalized before calculating the checksum.

It is also possible to do locks directly on resources by
using a NULL lockspace directory and then using the file
path as the lock name eg

   virLockSpacePtr lockspace = virLockSpaceNew(NULL);
   virLockSpaceAcquireLock(lockspace, "/var/lib/libvirt/images/foo.img");

This is only safe to do though if no other part of the process
will be opening the files. This will be the case when this
code is used inside the soon-to-be-reposted virlockd daemon

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 15:45:55 +01:00
Martin Kletzander
60f96bfc88 tests: Fix domain-events python test
There was a missing method in python implementation of domain-events
test and this patch adds that.
2012-10-16 16:37:29 +02:00
Eric Blake
819c8ce043 maint: prepare for next release number
Given Daniel's announcement[1], code targetting the next release will
be in 1.0.0, not 0.10.3.  Changed mechanically with:

for f in $(git grep -l '0\(.\)10\13\b') ; do
   sed -i -e 's/0\(.\)10\13/1\10\10/g' $f
done

[1]https://www.redhat.com/archives/libvir-list/2012-October/msg00403.html

* docs/formatdomain.html.in: Use 1.0.0 for next release.
* src/interface/interface_backend_udev.c: Likewise.
2012-10-16 08:09:01 -06:00
Eric Blake
1c3fee6abc maint: fix license on polkit script
As approved here:
https://www.redhat.com/archives/libvir-list/2012-October/msg00701.html

* daemon/libvirtd.policy.in: Use LGPLv2+ license.
2012-10-16 08:09:01 -06:00
Martin Kletzander
59952932f5 conf: add test for boot dev and order
Add test for 280b8c9e7c.
2012-10-16 12:25:32 +02:00
Martin Kletzander
280b8c9e7c conf: Fix crash with cleanup
There was a crash possible when both <boot dev... and <boot
order... were specified due to virDomainDefParseBootXML() erroring out
before setting *tmp (which was free'd in cleanup).  As a fix, I
created this cleanup that uses one pointer for all the temporary
stored XPath strings and values, plus this pointer is correctly
initialized to NULL.
2012-10-16 11:15:04 +02:00
Martin Kletzander
6676c1fc8f selinux: Use raw contexts 2
In commit 9674f2c637, I forgot to change
selabel_lookup with the other functions, so this one-liner does exactly
that.
2012-10-16 10:30:18 +02:00
Eric Blake
2cfa14bc8a maint: drop spurious semicolons
Detected with:
git grep ';;$' -- '**/*.[ch]'

* src/network/bridge_driver.c (networkRadvdConfContents): Fix
harmless typo.
* src/phyp/phyp_driver.c (phypUUIDTable_Pull): Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDriveDel):
Likewise.
2012-10-15 09:08:19 -06:00
Guannan Ren
ae368ebfcc selinux: add security selinux function to label tapfd
BZ:https://bugzilla.redhat.com/show_bug.cgi?id=851981
When using macvtap, a character device gets first created by
kernel with name /dev/tapN, its selinux context is:
system_u:object_r:device_t:s0

Shortly, when udev gets notification when new file is created
in /dev, it will then jump in and relabel this file back to the
expected default context:
system_u:object_r:tun_tap_device_t:s0

There is a time gap happened.
Sometimes, it will have migration failed, AVC error message:
type=AVC msg=audit(1349858424.233:42507): avc:  denied  { read write } for
pid=19926 comm="qemu-kvm" path="/dev/tap33" dev=devtmpfs ino=131524
scontext=unconfined_u:system_r:svirt_t:s0:c598,c908
tcontext=system_u:object_r:device_t:s0 tclass=chr_file

This patch will label the tapfd device before qemu process starts:
system_u:object_r:tun_tap_device_t:MCS(MCS from seclabel->label)
2012-10-15 21:01:07 +08:00
Martin Kletzander
7ba5defb5a Add support for SUSPEND_DISK event
This patch adds support for SUSPEND_DISK event; both lifecycle and
separated.  The support is added for QEMU, machines are changed to
PMSUSPENDED, but as QEMU sends SHUTDOWN afterwards, the state changes
to shut-off.  This and much more needs to be done in order for libvirt
to work with transient devices, wake-ups etc.  This patch is not
aiming for that functionality.
2012-10-15 12:09:10 +02:00
Ján Tomko
a9e3b4f78e util: switch virLogEatParams to virLogSource
Commit e8fd8757c8 changed 'const char *'
category to virLogSource enum. This changes it in virLogEatParams as
well, thus fixing the build with --disable-debug.
--
Hopefully moving the enum declarations is less ugly than using int.
2012-10-15 11:13:43 +02:00
Osier Yang
f81f0f2f1d node_memory: Add new parameter field to tune the new sysfs knob
Upstream kernel introduced new sysfs knob "merge_across_nodes" to
specify if pages from different numa nodes can be merged. When set
to 0, only pages which physically reside in the memory area of
same NUMA node can be merged. When set to 1, pages from all nodes
can be merged.

This patch supports the tuning by adding new param field
"shm_merge_across_nodes".
2012-10-15 17:35:54 +08:00
Laine Stump
6bde0a1a37 qemu: reorganize qemuDomainChangeNet and qemuDomainChangeNetBridge
This patch resolves:

  https://bugzilla.redhat.com/show_bug.cgi?id=805071

to the extent that it can be resolved with current qemu functionality.
It attempts to detect as many situations as possible when the simple
operation of disconnecting an existing tap device from one bridge and
attaching it to another will satisfy the change requested in
virDomainUpdateDeviceFlags() for a network device. Before this patch,
that situation could only be detected if the pre-change interface
*and* the post-change interface definition were both "type='bridge'".
After this patch, it can also be detected if the before or after
interfaces are any combination of type='bridge' and type='network'
(the networks can be <forward mode='nat|route|bridge'>, as long as
they use a Linux host bridge and not macvtap connections).

This extra effort is especially useful since the recent discovery that
a netdev_del+netdev_add combo (to reconnect the network device with
completely different hostside configuration) doesn't work properly
with current qemu (1.2) unless it is accompanied by the matching
device_del+device_add - see this mailing list message for details:

  http://lists.nongnu.org/archive/html/qemu-devel/2012-10/msg02355.html

(A slight modification of the patch referenced there has been prepared
to apply on top of this patch, but won't be pushed until qemu can be
made to work with it.)

* qemuDomainChangeNet needs access to the virDomainDeviceDef that
holds the new netdef (so that it can clear out the virDomainDeviceDef
if it ends up using the NetDef to replace the original), so the
virDomainNetDefPtr arg is replaced with a virDomainDeviceDefPtr.

* qemuDomainChangeNet previously checked for *some* changes to the
interface config, but this check was by no means complete. It was also
a bit disorganized.

This refactoring of the code is (I believe) complete in its check of
all NetDef attributes that might be changed, and either returns a
failure (for changes that are simply impossible), or sets one of three
flags:

  needLinkStateChange - if the device link state needs to go up/down
  needBridgeChange    - if everything else is the same, but it needs
                        to be connected to a difference linux host
                        bridge
  needReconnect       - if the entire host side of the device needs
                        to be torn down and reconstructed (currently
                        non-working, as mentioned above)

Note that this function will refuse to make any change that requires
the *guest* side of the device to be detached (e.g. changing the PCI
address or mac address). Those would be disruptive enough to the guest
that it's reasonable to require an explicit detach/attach sequence
from the management application.

* As mentioned above, qemuDomainChangeNet also does its best to
understand when a simple change in attached bridge for the existing
tap device will work vs. the need to completely tear down/reconstruct
the host side of the device (including tap device).

This patch *does not* implement the "reconnect" code anyway - there is
a placeholder that turns that into an error. Rather, the purpose of
this patch is to replicate existing behavior with code that is ready
to have that functionality plugged in in a later patch.

* The expanded uses for qemuDomainChangeNetBridge meant that it needed
to be enhanced as well - it no longer replaces the original brname
string in olddev with the new brname; instead, it relies on the
caller to replace the *entire* olddev with newdev (since we've gone
to great lengths to assure they are functionally identical other
than the name of the bridge, this is now not only safe, but more
correct). Additionally, qemuDomainNetChangeBridge can now set the
bridge for type='network' interfaces as well as plain type='bridge'
interfaces. (Note that I had to make this change simultaneous to the
reorganization of qemuDomainChangeNet because the two are too
closely intertwined to separate).
2012-10-15 04:36:39 -04:00
Guido Günther
dc9d7a171c Avoid straying </cpuset>
by using the same condition as for the <cpuset>.

Fixes "make check" found by
    http://honk.sigxcpu.org:8001/job/libvirt-check/160/
2012-10-15 17:14:25 +08:00
Laine Stump
11c47d979c conf: virDomainDeviceInfoCopy utility function
This does a shallow copy of all the bits, then strdups the two items
that are actually allocated separately.
2012-10-15 04:03:06 -04:00
Laine Stump
310945597c conf: fix virDevicePCIAddressEqual args
This function really should have been taking virDevicePCIAddress*
instead of the inefficient virDevicePCIAddress (results in copying two
entire structs onto the stack rather than just two pointers), and
returning a bool true/false (not matching is not necessarily a
"failure", as a -1 return would imply, and also using "if
(!virDevicePCIAddressEqual(x, y))" to mean "if x == y" is just a bit
counterintuitive).
2012-10-15 04:03:06 -04:00
Guido Günther
a2b80edbc6 Fix tab vs space
that broke "make syntax-check"

found by http://honk.sigxcpu.org:8001/job/libvirt-syntax-check/157/

Pushed under the build breaker rule.
2012-10-15 09:18:18 +02:00
Osier Yang
3635b41e15 qemu: Ignore def->cpumask if emulatorpin is specified
If the vcpu placement is "static", it's just fine to ignore the
def->cpumask if emulatorpin is specified.
2012-10-15 12:20:37 +08:00
Osier Yang
5378effd57 conf: Ignore emulatorpin if vcpu placement is auto
When vcpu placement is "auto", the domain process will be pinned
to advisory nodeset from querying numad, While emulatorpin will
override the pinning. That means both of them are to set the
pinning policy for domain process, but conflicts with each other.

This patch ingore emulatorpin if vcpu placement is "auto", because
<vcpu> placement can't be simply ignored for <numatune> placement
could default to it.
2012-10-15 12:19:54 +08:00
Osier Yang
0df1a79089 qemu: Initialize cpuset for hotplugged vcpu as def->cpuset
The onlined vcpu pinning policy should inherit def->cpuset if
it's not specified explicitly, and the affinity should be set
in this case. Oppositely, the offlined vcpu pinning policy should
be free()'ed.
2012-10-15 12:16:02 +08:00
Osier Yang
a9bfe887f9 qemu: Create or remove cgroup when doing vcpu hotpluging
Various APIs use cgroup to either set or get the statistics of
host or guest. Hotplug or hot unplug new vcpus without creating
or removing the cgroup for the vcpus could cause problems for
those APIs. E.g.

% virsh vcpucount dom
maximum      config        10
maximum      live          10
current      config         1
current      live           1

% virsh setvcpu dom 2

% virsh schedinfo dom --set vcpu_quota=1000
Scheduler      : posix
error: Unable to find vcpu cgroup for rhel6.2(vcpu: 1): No such file or
directory

This patch fixes the problem by creating cgroups for each of the
onlined vcpus, and destroying cgroups for each of the offlined
vcpus.
2012-10-15 12:15:32 +08:00
Osier Yang
10f8a45deb conf: Initialize the pinning policy for vcpus
Document for <vcpu>'s "cpuset" says:

Since 0.4.4, this element can contain an optional cpuset attribute,
which is a comma-separated list of physical CPU numbers that virtual
CPUs can be pinned to.

However, it's not the truth, libvirt actually pins the domain
process to the specified pCPUs by "cpuset" of <vcpu>. And the
vcpu thread are pinned to all available pCPUs if no <vcpupin>
is specified for it.

This patch is to implement the codes to inherit <vcpu>'s "cpuset" for
vcpu that doesn't have <vcpupin> specified, and <vcpupin>
for these vcpu will be ignored when formating. Underlying
driver implementation will make sure the vcpu thread pinned
to correct pCPUs.
2012-10-15 12:14:22 +08:00
Osier Yang
60b176c3d0 conf: Ignore vcpupin for not onlined vcpus when parsing
Setting pinning policy for vcpu which exceeds current vcpus number
just makes no sense, however, it could cause various problems, E.g.

<vcpu current='1'>4</vcpu>
<cputune>
  <vcpupin vcpuid='3' cpuset='4'/>
</cputune>

% virsh start linux
error: Failed to start domain linux
error: cannot set CPU affinity on process 32534: No such process

We must have some odd codes underlying which produces the
"on process 32534", but the point is why we not to prevent
earlier when parsing? Note that this is only one of the
problem it could cause.

This patch is to ignore the <vcpupin> for not onlined vcpus.
2012-10-15 12:13:57 +08:00
Osier Yang
f108944ae0 doc: Sort out the relationship between <vcpu>, <vcpupin>, and <emulatorpin>
These 3 elements conflicts with each other in either the doc
or the underlying codes.

Current problems:

Problem 1:

The doc shouldn't simply say "These settings are superseded
by CPU tuning. " for element <vcpu>. As except the tuning, <vcpu>
allows to specify the current, maxmum vcpu number. Apart from that,
<vcpu> also allows to specify the placement as "auto", which binds
the domain process to the advisory nodeset from numad.

Problem 2:

Doc for <vcpu> says its "cpuset" specify the physical CPUs
that the vcpus can be pinned. But it's not the truth, as
actually it only pin domain process to the specified physical
CPUs. So either it's a document bug, or code bug.

Problem 3:

Doc for <vcpupin> says it supersed "cpuset" of <vcpu>, it's
not quite correct, as each <vcpupin> specify the pinning policy
only for one vcpu. How about the ones which doesn't have
<vcpupin> specified? it says the vcpu will be pinned to all
available physical CPUs, but what's the meaning of attribute
"cpuset" of <vcpu> then?

Problem 4:

Doc for <emulatorpin> says it pin the emulator threads (domain
process in other context, perhaps another follow up patch to
cleanup the inconsistency is needed) to the physical CPUs
specified its attribute "cpuset". Which conflicts with
<vcpu>'s "cpuset". And actually in the underlying codes,
it set the affinity for domain process twice if both
"cpuset" for <vcpu> and <emulatorpin> are specified,
and <emulatorpin>'s pinning will override <vcpu>'s.

Problem 5:

When "placement" of <vcpu> is "auto" (I.e. uses numad to
get the advisory nodeset to which the domain process is
pinned to), it will also be overridden by <emulatorpin>,

This patch is trying to sort out the conflicts or bugs by:

1) Don't say <vcpu> is superseded by <cputune>

2) Keep the semanteme for "cpuset" of <vcpu> (I.e. Still says it
   specify the physical CPUs the virtual CPUs). But modifying it
   to mention it also set the pinning policy for domain process,
   and the CPU placement of domain process specified by "cpuset"
   of <vcpu> will be ingored if <emulatorpin> specified, and
   similary, the CPU placement of vcpu thread will be ignored
   if it has <vcpupin> specified, for vcpu which doesn't have
   <vcpupin> specified, it inherits "cpuset" of <vcpu>.

3) Don't say <vcpu> is supersed by <vcpupin>. If neither <vcpupin>
   nor "cpuset" of <vcpu> is specified, the vcpu will be pinned
   to all available pCPUs.

4) If neither <emulatorpin> nor "cpuset" of <vcpu> is specified,
   the domain process (emulator threads in the context) will be
   pinned to all available pCPUs.

5) If "placement" of <vcpu> is "auto", <emulatorpin> is not allowed.

6) hotplugged vcpus will also inherit "cpuset" of <vcpu>

Codes changes according to above document changes:

1) Inherit def->cpumask for each vcpu which doesn't have <vcpupin>
   specified, during parsing.

2) ping the vcpu which doesn't have <vcpupin> specified to def->cpumask
   either by cgroup for sched_setaffinity(2), which is actually done
   by 1).

3) Error out if "placement" == "auto", and <emulatorpin> is specified.
   Otherwise, <emulatorpin> is honored, and "cpuset" of <cpuset> is
   ignored.

4) Setup cgroup for each hotplugged vcpu, and setup the pinning policy
   by either cgroup or sched_setaffinity(2).

5) Remove cgroup and <vcpupin> for each hot unplugged vcpu.

Patches are following (6 in total except this patch)
2012-10-15 12:13:34 +08:00