Commit Graph

2070 Commits

Author SHA1 Message Date
Peter Krempa
fb58f8e2a4 qemu: Don't corrupt pointer in qemuDomainSaveMemory()
The code that was split out into the qemuDomainSaveMemory expands the
pointer containing the XML description of the domain that it gets from
higher layers. If the pointer changes the old one is invalid and the
upper layer function tries to free it causing an abort.

This patch changes the expansion of the original string to a new
allocation and copy of the contents.
2012-11-06 14:45:27 +01:00
Michal Privoznik
0f720ab35a qemu: Add controllers in specified order
qemu is sensitive to the order of arguments passed. Hence, if a
device requires a controller, the controller cmd string must
precede device cmd string. The same apply for controllers, when
for instance ccid controller requires usb controller. So
controllers create partial ordering in which they should be added
to qemu cmd line.
2012-11-06 10:11:34 +01:00
Michal Privoznik
77b93dbc3e qemu: Wrap controllers code into dummy loop
which just re-indent code and prepare it for next patch.
2012-11-06 10:11:34 +01:00
Peter Krempa
0dac29d89f snapshot: qemu: Remove restrictions preventing external checkpoints
Some of the pre-snapshot check have restrictions wired in regarding
configuration options that influence taking of external checkpoints.

This patch removes restrictions that would inhibit taking of such a
snapshot.
2012-11-04 20:17:57 +01:00
Peter Krempa
f569b87f51 snapshot: qemu: Add support for external checkpoints
This patch adds support to take external system checkpoints.

The functionality is layered on top of the previous disk-only snapshot
code. When the checkpoint is requested the domain memory is saved to the
memory image file using migration to file. (The user may specify to
take the memory image while the guest is live with the
VIR_DOMAIN_SNAPSHOT_CREATE_LIVE flag.)

The memory save image shares format with the image created by
virDomainSave() API.
2012-11-04 16:53:32 +01:00
Peter Krempa
b5fd404471 snapshot: qemu: Rename qemuDomainSnapshotCreateActive
Before now, libvirt supported only internal snapshots for active guests.
This patch renames this function to qemuDomainSnapshotCreateActiveInternal
to prepare the grounds for external active snapshots.
2012-11-03 15:06:09 +01:00
Peter Krempa
2a59a3d597 snapshot: qemu: Add async job type for snapshots
The new external system checkpoints will require an async job while the
snapshot is taken. This patch adds QEMU_ASYNC_JOB_SNAPSHOT to track this
job type.
2012-11-03 14:57:43 +01:00
Peter Krempa
2771f8b74c qemu: Split out domain memory saving code to allow reuse
The code that saves domain memory by migration to file can be reused
while doing external checkpoints of a machine. This patch extracts the
common code and places it in a separate function.
2012-11-03 11:49:41 +01:00
Peter Krempa
ec69ca14f9 qemu: Clean up snapshot retrieval to use the new helper
Two other places were left with the old code to look up snapshots.
Change them to use the snapshot lookup helper.
2012-11-03 11:26:39 +01:00
Peter Krempa
d0fc6dc831 qemu: Fix possible race when pausing guest
When pausing the guest while migration is running (to speed up
convergence) the virDomainSuspend API checks if the migration job is
active before entering the job. This could cause a possible race if the
virDomainSuspend is called while the job is active but ends before the
Suspend API enters the job (this would require that the migration is
aborted). This would cause a incorrect event to be emitted.
2012-11-02 20:18:46 +01:00
Eric Blake
de76cae971 snapshot: merge pre-snapshot checks
Both system checkpoint snapshots and disk snapshots were iterating
over all disks, doing a final sanity check before doing any work.
But since future patches will allow offline snapshots to be either
external or internal, it makes sense to share the pass over all
disks, and then relax restrictions in that pass as new modes are
implemented.  Future patches can then handle external disks when
the domain is offline, then handle offline --disk-snapshot, and
finally, combine with migration to file to gain a complete external
system checkpoint snapshot of an active domain without using 'savevm'.

* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare)
(qemuDomainSnapshotIsAllowed): Merge...
(qemuDomainSnapshotPrepare): ...into one function.
(qemuDomainSnapshotCreateXML): Update caller.
2012-11-02 10:19:03 -06:00
Eric Blake
e260e401a5 snapshot: populate new XML info for qemu snapshots
Now that the XML supports listing internal snapshots, it is worth
always populating the <memory> and <disks> element to match.

* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Always
parse disk info and set memory info.
2012-11-02 10:11:50 -06:00
Daniel P. Berrange
1c04f99970 Remove spurious whitespace between function name & open brackets
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-11-02 13:36:49 +00:00
Guannan Ren
1851a0c864 qemu: use default machine type if missing it in qemu command line
BZ:https://bugzilla.redhat.com/show_bug.cgi?id=871273
when using virsh qemu-attach to attach an existing qemu process,
if it misses the -M option in qemu command line, libvirtd crashed
because the NULL value of def->os.machine in later use.

Example:
/usr/libexec/qemu-kvm -name foo \
                      -cdrom /var/lib/libvirt/images/boot.img \
                      -monitor unix:/tmp/demo,server,nowait \

error: End of file while reading data: Input/output error
error: Failed to reconnect to the hypervisor

This patch tries to set default machine type if the value of
def->os.machine is still NULL after qemu command line parsing.
2012-11-02 12:55:29 +08:00
Doug Goldstein
ba804d9fd1 qemu: QMP capabilities support starts with 1.2
Per the code comment in qemuCapsInitQMPBasic() and commit 43e23c7, we
should only use QMP for capabilities probing starting with 1.2 and
newer.  The old code had dead logic that probed on 1.0 and newer.

Signed-off-by: Eric Blake <eblake@redhat.com>
2012-11-01 17:50:02 -06:00
Stefan Hajnoczi
23d47b33a2 qemu: Fix name comparison in qemuMonitorJSONBlockIoThrottleInfo()
The string comparison logic was inverted and matched the first drive
that does *not* have the name we search for.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-01 13:23:27 -06:00
Stefan Hajnoczi
04ee70bfda qemu: Keep QEMU host drive prefix in BlkIoTune
The QEMU -drive id= begins with libvirt's QEMU host drive prefix
("drive-"), which is stripped off in several places two convert between
host ("-drive") and guest ("-device") device names.

In the case of BlkIoTune it is unnecessary to strip the QEMU host drive
prefix because we operate on "info block"/"query-block" output that uses
host drive names.

Stripping the prefix incorrectly caused string comparisons to fail since
we were comparing the guest device name against the host device name.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-01 13:03:26 -06:00
Daniel P. Berrange
6fea88a119 Fix arch detection for qemu-system-i386 with QMP
QEMU uses 'i386' for its 32-bit x86 architecture, but libvirt
wants that to be 'i686', so we must fix it up

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-11-01 09:16:37 +00:00
Eric Blake
4dbd6e9654 build: prefer mkostemp for multi-thread safety
https://bugzilla.redhat.com/show_bug.cgi?id=871756

Commit cd1e8d1 assumed that systems new enough to have journald
also have mkostemp; but this is not true for uclibc.

For that matter, use of mkstemp[s] is unsafe in a multi-threaded
program.  We should prefer mkostemp[s] in the first place.

* bootstrap.conf (gnulib_modules): Add mkostemp, mkostemps; drop
mkstemp and mkstemps.
* cfg.mk (sc_prohibit_mkstemp): New syntax check.
* tools/virsh.c (vshEditWriteToTempFile): Adjust caller.
* src/qemu/qemu_driver.c (qemuDomainScreenshot)
(qemudDomainMemoryPeek): Likewise.
* src/secret/secret_driver.c (replaceFile): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainScreenshot): Likewise.
2012-10-31 10:06:10 -06:00
Martin Kletzander
10c5212b10 qemu: Fix EmulatorPinInfo without emulatorpin
https://bugzilla.redhat.com/show_bug.cgi?id=871312

Recent fixes made almost all the right steps to make emulator pinned
to the cpuset of the whole domain in case <emulatorpin> isn't
specified, but qemudDomainGetEmulatorPinInfo still reports all the
CPUs even when cpuset is specified.  This patch fixes that.
2012-10-31 16:27:02 +01:00
Martin Kletzander
037a49dc66 Make non-KVM machines work with QMP probing
When there is no 'qemu-kvm' binary and the emulator used for a machine
is, for example, 'qemu-system-x86_64' that, by default, runs without
kvm enabled, libvirt still supplies '-no-kvm' option to this process,
even though it does not recognize such option (making the start of a
domain fail in that case).

This patch fixes building a command-line for QEMU machines without KVM
acceleration and is based on following assumptions:

 - QEMU_CAPS_KVM flag means that QEMU is running KVM accelerated
   machines by default (without explicitly requesting that using a
   command-line option).  It is the closest to the truth according to
   the code with the only exception being the comment next to the
   flag, so it's fixed in this patch as well.

 - QEMU_CAPS_ENABLE_KVM flag means that QEMU is, by default, running
   without KVM acceleration and in case we need KVM acceleration it
   needs to be explicitly instructed to do so.  This is partially
   true for the past (this option essentially means that QEMU
   recognizes the '-enable-kvm' option, even though it's almost the
   same).
2012-10-31 08:31:49 +01:00
Vladislav Bogdanov
81af5336ac qemu: pass -usb and usb hubs earlier, so USB disks with static address are handled properly 2012-10-30 08:54:32 +01:00
Vladislav Bogdanov
8f708761c0 qemu: Do not ignore address for USB disks 2012-10-30 08:54:28 +01:00
Michal Privoznik
34e8f63a32 qemu: Report errors from iohelper
Currently, we use iohelper when saving/restoring a domain.
However, if there's some kind of error (like I/O) it is not
propagated to libvirt. Since it is not qemu who is doing
the actual write() it will not get error. The iohelper does.
Therefore we should check for iohelper errors as it makes
libvirt more user friendly.
2012-10-29 17:04:26 +01:00
Ján Tomko
0b121614a2 xml: print uuids in the warning
In the XML warning, we print a virsh command line that can be used to
edit that XML. This patch prints UUIDs if the entity name contains
special characters (like shell metacharacters, or "--" that would break
parsing of the XML comment). If the entity doesn't have a UUID, just
print the virsh command that can be used to edit it.
2012-10-29 14:38:43 +01:00
Jiri Denemark
23f5e74ed3 Revert "qemu: Do not require hostuuid in migration cookie"
This reverts commit 8d75e47ede.

Libvirt was never released with support for migration cookies without
hostuuid.
2012-10-29 09:04:27 +01:00
Cole Robinson
9a2975786b qemu: Fix domxml-to-native network model conversion
https://bugzilla.redhat.com/show_bug.cgi?id=636832
2012-10-27 12:20:49 -04:00
Eric Blake
dd0a7040f7 build: typo fix for qemu cpu affinity
Introduced in commit 0039a32f.

* src/qemu/qemu_process.c (qemuPrepareCpumap): s/covert/convert/
2012-10-27 08:09:51 -06:00
Eric Blake
5a3501be9e blockjob: relabel entire existing chain
When using block copy to pivot over to a new chain, the backing files
for the new chain might still need labeling (particularly if the user
passes --reuse-ext with a relative backing file name).  Relabeling a
file that is already labeled won't hurt, so this just labels the entire
chain at the point of the pivot.  Doing the relabel of the chain uses
the fact that we already safely probed the file type of an external
file at the start of the block copy.

* src/qemu/qemu_driver.c (qemuDomainBlockPivot): Relabel chain before
asking qemu to pivot.
2012-10-27 07:43:39 -06:00
Eric Blake
35c7701c64 blockjob: allow mirroring under SELinux and cgroup
Use the recent addition of qemuDomainPrepareDiskChainElement to
obtain locking manager lease, permit a block device through cgroups,
and set the SELinux label; then audit the fact that we hand a new
file over to qemu.  Alas, releasing the lease and label at the end
of the mirroring is a trickier prospect (we would have to trace the
backing chain of both source and destination, and be sure not to
revoke rights to any part of the chain that is shared), so for now,
virDomainBlockJobAbort still leaves things with additional access
granted (as block-pull and block-commit have the same problem of
not clamping access after completion, a future cleanup would cover
all three commands).

* src/qemu/qemu_driver.c (qemuDomainBlockCopy): Set up labeling.
2012-10-27 07:43:39 -06:00
Eric Blake
8ee5073c1e blockjob: allow for existing files in block-copy
Support the REUSE_EXT flag, in part by copying sanity checks from
snapshot code.  This code introduces a case of probing an external
file for its type; such an action would be a security risk if the
existing file is supposed to be raw but the contents resemble some
other format; however, since the virDomainBlockRebase API has a
flag to force treating the file as raw rather than probe, we can
assume that probing is safe in all other instances.  Besides, if
we don't probe or force raw, then qemu will.

* src/qemu/qemu_driver.c (qemuDomainBlockRebase): Allow REUSE_EXT
flag.
(qemuDomainBlockCopy): Wire up flag, and add some sanity checks.
2012-10-27 07:43:39 -06:00
Eric Blake
c1eb38053d blockjob: implement block copy for qemu
Minimal patch to wire up all the pieces in the previous patches
to actually enable a block copy job.  By minimal, I mean that
qemu creates the file (that is, no REUSE_EXT flag support yet),
SELinux must be disabled, a lock manager is not informed, and the
audit logs aren't updated.  But those will be added as
improvements in future patches.

This patch is designed so that if we ever add a future API
virDomainBlockCopy with more bells and whistles (such as letting
the user specify a destination image format different than the
source), where virDomainBlockRebase is a wrapper around the
simpler portions of the new functionality, then the new API can
just reuse the new qemuDomainBlockCopy function and already
support _SHALLOW and _REUSE_EXT flags.  Also note that libvirt.c
already filtered the new flags if _COPY is not present, so that
we are not impacting the case of BlockRebase being a wrapper
around BlockPull.

* src/qemu/qemu_driver.c (qemuDomainBlockCopy): New function.
(qemuDomainBlockRebase): Call it when appropriate.
2012-10-27 07:43:39 -06:00
Eric Blake
400ac797ef blockjob: make block pivot safer
Since libvirt drops locks between issuing a monitor command and
getting a response, it is possible for libvirtd to be restarted
before getting a response on a block-job-complete command; worse, it
is also possible for the guest to shut itself down during the window
while libvirtd is down, ending the qemu process.  A management app
needs to know if the pivot happened (and the destination file
contains guest contents not in the source) or failed (and the source
file contains guest contents not in the destination), but since
the job is finished, 'query-block-jobs' no longer tracks the
status of the job, and if the qemu process itself has disappeared,
even 'query-block' cannot be checked to ask qemu its current state.

At the time of this patch, the design for persistent bitmap has not
been clarified, so a followup patch will be needed once qemu
actually figures out how to expose it, and we figure out how to use
it.  In the meantime, we have a solution that avoids the worst of
the problem.  [This problem was first analyzed with the RHEL 6.3
__com.redhat_drive-reopen command; which partly explains why
upstream qemu 1.3 ditched the drive-reopen idea and went with
block-job-complete plus persistent bitmap instead.]

If we surround 'drive-reopen' with a pause/resume pair, then we can
guarantee that the guest cannot modify either source or destination
files in the window of libvirtd uncertainty, and the management app
is guaranteed that either libvirt knows the outcome and reported it
correctly; or that on libvirtd restart, the guest will still be
paused and that the qemu process cannot have disappeared due to
guest shutdown; and use that as a clue that the management app must
implement recovery protocol, with both source and destination files
still being in sync and with 'query-block' still being an option as
part of that recovery.  My testing shows that the pause window will
typically be only a fraction of a second.

* src/qemu/qemu_driver.c (qemuDomainBlockPivot): Pause around
drive-reopen.
(qemuDomainBlockJobImpl): Update caller.
2012-10-27 07:43:38 -06:00
Eric Blake
eaba79d22e blockjob: support pivot operation on cancel
This is the bare minimum to end a copy job (of course, until a
later patch adds the ability to start a copy job, this patch
doesn't do much in isolation; I've just split the patches to
ease the review).

This patch intentionally avoids SELinux, lock manager, and audit
actions.  Also, if libvirtd restarts at the exact moment that a
'block-job-complete' is in flight, the proposed proper way to
detect the outcome of that would be with a persistent bitmap and
some additional query commands when libvirtd restarts.  This
patch is enough to test the common case of success when used
correctly, while saving the subtleties of proper cleanup for
worst-case errors for later.

When a mirror job is started, cancelling the job safely reverts back
to the source disk, regardless of whether the destination is in
phase 1 (streaming, in which case the destination is worthless) or
phase 2 (mirroring, in which case the destination is synced up to
the source at the time of the cancel).  Our existing code does just
fine in either phase, other than some bookkeeping cleanup; this
implements live block copy.

Ideas for future enhancements via new flags:

Depending on when persistent bitmap support is added, it may be
worth adding a VIR_DOMAIN_REBASE_COPY_ATOMIC flag that fails up
front if we detect an older qemu with risky pivot operation.

Interesting side note: while snapshot-create --disk-only creates a
copy of the disk at a point in time by moving the domain on to a
new file (the copy is the file now in the just-extended backing
chain), blockjob --abort of a copy job creates a copy of the disk
while keeping the domain on the original file.  There may be
potential improvements to the snapshot code to exploit block copy
over multiple disks all at one point in time.  And, if
'block-job-cancel' were made part of 'transaction', you could
copy multiple disks at the same point in time without pausing
the domain.  This also implies we may want to add a --quiesce flag
to virDomainBlockJobAbort, so that when breaking a mirror (whether
by cancel or pivot), the side of the mirror that we are abandoning
is at least in a stable state with regards to guest I/O.

* src/qemu/qemu_driver.c (qemuDomainBlockJobAbort): Accept new flag.
(qemuDomainBlockPivot): New helper function.
(qemuDomainBlockJobImpl): Implement it.
2012-10-27 07:43:38 -06:00
Eric Blake
edecd45c78 blockjob: return appropriate event and info
Handle the new type of block copy event and info.  Of course,
this patch does nothing until a later patch actually allows the
creation/abort of a block copy job.

* include/libvirt/libvirt.h.in (VIR_DOMAIN_BLOCK_JOB_READY): New
block job status.
* src/libvirt.c (virDomainBlockRebase): Document the event.
* src/qemu/qemu_monitor_json.c (eventHandlers): New event.
(qemuMonitorJSONHandleBlockJobReady): New function.
(qemuMonitorJSONGetBlockJobInfoOne): Translate new job type.
(qemuMonitorJSONHandleBlockJobImpl): Handle new event and job type.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Recognize
the event to minimize snooping.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Snoop a successful
info query to save effort on a pivot request.
2012-10-27 07:43:38 -06:00
Eric Blake
b3822ed04a blockjob: react to active block copy
For now, disk migration via block copy job is not implemented in
libvirt.  But when we do implement it, we have to deal with the
fact that qemu does not yet provide an easy way to re-start a qemu
process with mirroring still intact.  Paolo has proposed an idea
for a persistent dirty bitmap that might make this possible, but
until that design is complete, it's hard to say what changes
libvirt would need.  Even something like 'virDomainSave' becomes
hairy, if you realize the implications that 'virDomainRestore'
would be stuck with recreating the same mirror layout.

But if we step back and look at the bigger picture, we realize that
the initial client of live storage migration via disk mirroring is
oVirt, which always uses transient domains, and that if a transient
domain is destroyed while a mirror exists, oVirt can easily restart
the storage migration by creating a new domain that visits just the
source storage, with no loss in data.

We can make life a lot easier by being cowards for now, forbidding
certain operations on a domain.  This patch guarantees that we
never get in a state where we would have to restart a domain with
a mirroring block copy, by preventing saves, snapshots, migration,
hot unplug of a disk in use, and conversion to a persistent domain
(thankfully, it is still relatively easy to 'virsh undefine' a
running domain to temporarily make it transient, run tests on
'virsh blockcopy', then 'virsh define' to restore the persistence).
Later, if the qemu design is enhanced, we can relax our code.

The change to qemudDomainDefine looks a bit odd for undoing an
assignment, rather than probing up front to avoid the assignment,
but this is because of how virDomainAssignDef combines both a
lookup and assignment into a single function call.

* src/conf/domain_conf.h (virDomainHasDiskMirror): New prototype.
* src/conf/domain_conf.c (virDomainHasDiskMirror): New function.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/qemu/qemu_driver.c (qemuDomainSaveInternal)
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainBlockJobImpl, qemudDomainDefine): Prevent dangerous
actions while block copy is already in action.
* src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Likewise.
2012-10-27 07:43:38 -06:00
Eric Blake
6d264c9182 blockjob: add qemu capabilities related to block jobs
Upstream qemu 1.3 is adding two new monitor commands, 'drive-mirror'
and 'block-job-complete'[1], which can drive live block copy and
storage migration.  [Additionally, RHEL 6.3 had backported an earlier
version of most of the same functionality, but under the names
'__com.redhat_drive-mirror' and '__com.redhat_drive-reopen' and with
slightly different JSON arguments, and has been using patches similar
to these upstream patches for several months now.]

The libvirt API virDomainBlockRebase as already committed for 0.9.12
is flexible enough to expose the basics of block copy, but some
additional features in the 'drive-mirror' qemu command, such as
setting error policy, setting granularity, or using a persistent
bitmap, may later require a new libvirt API virDomainBlockCopy.  I
will wait to add that API until we know more about what qemu 1.3
will finally provide.

This patch caters only to the upstream qemu 1.3 interface, although
I have proven that the changes for RHEL 6.3 can be isolated to
just qemu_monitor_json.c, and the rest of this series will
gracefully handle either interface once the JSON differences are
papered over in a downstream patch.

For consistency with other block job commands, libvirt must handle
the bandwidth argument as MiB/sec from the user, even though qemu
exposes the speed argument as bytes/sec; then again, qemu rounds
up to cluster size internally, so using MiB hides the worst effects
of that rounding if you pass small numbers.

[1]https://lists.gnu.org/archive/html/qemu-devel/2012-10/msg04123.html

* src/qemu/qemu_capabilities.h (QEMU_CAPS_DRIVE_MIRROR)
(QEMU_CAPS_DRIVE_REOPEN): New bits.
* src/qemu/qemu_capabilities.c (qemuCaps): Name them.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCheckCommands): Set
them.
(qemuMonitorJSONDriveMirror, qemuMonitorDrivePivot): New functions.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDriveMirror)
(qemuMonitorDrivePivot): Declare them.
* src/qemu/qemu_monitor.c (qemuMonitorDriveMirror)
(qemuMonitorDrivePivot): New passthroughs.
* src/qemu/qemu_monitor.h (qemuMonitorDriveMirror)
(qemuMonitorDrivePivot): Declare them.
2012-10-27 07:43:37 -06:00
Laine Stump
def31e4c58 qemu: fix attach/detach of netdevs with matching mac addrs
This resolves:

   https://bugzilla.redhat.com/show_bug.cgi?id=862515

which describes inconsistencies in dealing with duplicate mac
addresses on network devices in a domain.

(at any rate, it resolves *almost* everything, and prints out an
informative error message for the one problem that isn't solved, but
has a workaround.)

A synopsis of the problems:

1) you can't do a persistent attach-interface of a device with a mac
address that matches an existing device.

2) you *can* do a live attach-interface of such a device.

3) you *can* directly edit a domain and put in two devices with
matching mac addresses.

4) When running virsh detach-device (live or config), only MAC address
is checked when matching the device to remove, so the first device
with the desired mac address will be removed. This isn't always the
one that's wanted.

5) when running virsh detach-interface (live or config), the only two
items that can be specified to match against are mac address and model
type (virtio, etc) - if multiple netdevs match both of those
attributes, it again just finds the first one added and assumes that
is the only match.

Since it is completely valid to have multiple network devices with the
same MAC address (although it can cause problems in many cases, there
*are* valid use cases), what is needed is:

1) remove the restriction that prohibits doing a persistent add of a
netdev with a duplicate mac address.

2) enhance the backend of virDomainDetachDeviceFlags to check for
something that *is* guaranteed unique (but still work with just mac
address, as long as it yields only a single results.

This patch does three things:

1) removes the check for duplicate mac address during a persistent
netdev attach.

2) unifies the searching for both live and config detach of netdevices
in the subordinate functions of qemuDomainModifyDeviceFlags() to use the
new function virDomainNetFindIdx (which matches mac address and PCI
address if available, checking for duplicates if only mac address was
specified). This function returns -2 if multiple matches are found,
allowing the callers to print out an appropriate message.

Steps 1 & 2 are enough to fully fix the problem when using virsh
attach-device and detach-device (which require an XML description of
the device rather than a bunch of commandline args)

3) modifies the virsh detach-interface command to check for multiple
matches of mac address and show an error message suggesting use of the
detach-device command in cases where there are multiple matching mac
addresses.

Later we should decide how we want to input a PCI address on the virsh
commandline, and enhance detach-interface to take a --address option,
eliminating the need to use detach-device

* src/conf/domain_conf.c
* src/conf/domain_conf.h
* src/libvirt_private.syms
  * added new virDomainNetFindIdx function
  * removed now unused virDomainNetIndexByMac and
    virDomainNetRemoveByMac

* src/qemu/qemu_driver.c
  * remove check for duplicate max from qemuDomainAttachDeviceConfig
  * use virDomainNetFindIdx/virDomainNetRemove instead
    of virDomainNetRemoveByMac in qemuDomainDetachDeviceConfig
  * use virDomainNetFindIdx instead of virDomainIndexByMac
    in qemuDomainUpdateDeviceConfig

* src/qemu/qemu_hotplug.c
  * use virDomainNetFindIdx instead of a homespun loop in
    qemuDomainDetachNetDevice.

* tools/virsh-domain.c: modified detach-interface command as described
    above
2012-10-26 20:47:54 -04:00
Eric Blake
4fbf322fe9 cpustat: fix regression when cpus are offline
It turns out that the cpuacct results properly account for offline
cpus, and always returns results for every possible cpu, not just
the online ones.  So there is no need to check the map of online
cpus in the first place, merely only a need to know the maximum
possible cpu.  Meanwhile, virNodeGetCPUBitmap had a subtle change
from returning the maximum id to instead returning the width of
the bitmap (one larger than the maximum id) in commit 2f4c5338,
which made this code encounter some off-by-one logic leading to
bad error messages when a cpu was offline:

$ virsh cpu-stats dom
error: Failed to virDomainGetCPUStats()

error: An error occurred, but the cause is unknown

Cleaning this up unraveled a chain of other unused variables.

* src/qemu/qemu_driver.c (qemuDomainGetPercpuStats): Drop
pointless check for cpumap changes, and use correct number of
cpus.  Simplify signature.
(qemuDomainGetCPUStats): Adjust caller.
* src/nodeinfo.h (nodeGetCPUCount): New prototype.
(nodeGetCPUBitmap): Drop unused parameter.
* src/nodeinfo.c (nodeGetCPUBitmap): Likewise.
(nodeGetCPUMap): Adjust caller.
(nodeGetCPUCount): New function.
* src/libvirt_private.syms (nodeinfo.h): Export it.
2012-10-26 15:34:52 -06:00
Viktor Mihajlovski
e3ba67037b virNodeGetCPUMap: Implement driver support
Driver support added for:
- test: pretending 8 host CPUS, 3 being online
- qemu, lxc, openvz, uml: using nodeGetCPUMap

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
2012-10-25 11:20:15 -06:00
Eric Blake
2f4c5338a6 nodeinfo: improve probing node cpu bitmap
Callers should not need to know what the name of the file to
be read in the Linux-specific version of nodeGetCPUmap;
furthermore, qemu cares about online cpus, not present cpus,
when determining which cpus to skip.

While at it, I fixed the fact that we were computing the maximum
online cpu id by doing a slow iteration, when what we really want
to know is the max available cpu.

* src/nodeinfo.h (nodeGetCPUmap): Rename...
(nodeGetCPUBitmap): ...and simplify signature.
* src/nodeinfo.c (linuxParseCPUmax): New function.
(linuxParseCPUmap): Simplify and alter signature.
(nodeGetCPUBitmap): Change implementation.
* src/libvirt_private.syms (nodeinfo.h): Reflect rename.
* src/qemu/qemu_driver.c (qemuDomainGetPercpuStats): Update
caller.
2012-10-25 11:20:08 -06:00
Osier Yang
a6bd7c22ea qemu: Prohibit chaning affinity of domain process if placement is 'auto'
On one hand, numad probably will manage the affinity of domain process
dynamically in future. On the other hand, even numad won't manage it,
it still could confusion. Let's make things simpler enough to avoid
the lair for now.
2012-10-24 22:26:11 +08:00
Osier Yang
bb81021bfe qemu: Keep the affinity when creating cgroup for emulator thread
When the cpu placement model is "auto", it sets the affinity for
domain process with the advisory nodeset from numad, however,
creating cgroup for the domain process (called emulator thread
in some contexts) later overrides that with pinning it to all
available pCPUs.

How to reproduce:

  * Configure the domain with "auto" placement for <vcpu>, e.g.
    <vcpu placement='auto'>4</vcpu>
  * % virsh start dom
  * % cat /proc/$dompid/status

Though the emulator cgroup cause conflicts, but we can't simply
prohibit creating it, as other tunables are still useful, such
as "emulator_period", which is used by API
virDomainSetSchedulerParameter. So this patch doesn't prohibit
creating the emulator cgroup, but inherit the nodeset from numad,
and reset the affinity for domain process.

* src/qemu/qemu_cgroup.h: Modify definition of qemuSetupCgroupForEmulator
                          to accept the passed nodenet
* src/qemu/qemu_cgroup.c: Set the affinity with the passed nodeset
2012-10-24 21:46:24 +08:00
Osier Yang
0039a32fca qemu: Add helper to prepare cpumap for affinity setting
Abstract the codes to prepare cpumap into a helper a function,
which can be used later.

* src/qemu/qemu_process.h: Declare qemuPrepareCpumap
* src/qemu/qemu_process.c: Implement qemuPrepareCpumap, and use it.
2012-10-24 21:24:10 +08:00
Kyle Mestery
2f3e2c0c43 qemu_migration: Transport OVS per-port data during live migration
Transport Open vSwitch per-port data during live
migration by using the utility functions
virNetDevOpenvswitchGetMigrateData() and
virNetDevOpenvswitchSetMigrateData().

Signed-off-by: Kyle Mestery <kmestery@cisco.com>
2012-10-23 15:26:04 -04:00
Kyle Mestery
694d0c520b qemu_migration: Add hooks to transport network data during migration
Add the ability for the Qemu V3 migration protocol to
include transporting network configuration. A generic
framework is proposed with this patch to allow for the
transfer of opaque data.

Signed-off-by: Kyle Mestery <kmestery@cisco.com>
Signed-off-by: Laine Stump <laine@laine.org>
2012-10-23 15:26:04 -04:00
Eric Blake
33eaebe48e snapshot: sanity check when reusing file for snapshot
The snapshot code when reusing an existing file had hard-to-read
logic, as well as a missing sanity check: REUSE_EXT should require
the destination to already be present.

* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare): Require
destination on REUSE_EXT, rename variable for legibility.
2012-10-22 15:10:16 -06:00
Cole Robinson
e58dfad4a4 qemu: Don't use -enable-nesting with qemu 1.2.0+
Since the option doesn't exist. Fixes booting with
cpu mode='host-model' and qemu 1.2.0
2012-10-22 16:15:12 -04:00
Doug Goldstein
2da776b1d6 qemu: Don't blindly assume VNC is supported
Currently it's assumed that qemu always supports VNC, however it is
definitely possible to compile qemu without VNC support so we should at
the very least check for it and handle that correctly.
2012-10-22 23:16:17 +08:00
Eric Blake
d9d77bfa80 storage: let format probing work on root-squash NFS
Yet another instance of where using plain open() mishandles files
that live on root-squash NFS, and where improving the API can
improve the chance of a successful probe.

* src/util/storage_file.h (virStorageFileProbeFormat): Alter
signature.
* src/util/storage_file.c (virStorageFileProbeFormat): Use better
method for opening file.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Update caller.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
2012-10-22 09:04:57 -06:00