Commit Graph

3026 Commits

Author SHA1 Message Date
Peter Krempa
7183d7d2e8 qemu: snapshot: Use new APIs to detect presence of existing storage files
Use the new storage driver based "stat" api to detect exiting files just
as we did with local files.
2014-02-14 11:07:29 +01:00
Peter Krempa
8f4091d677 qemu: Switch snapshot deletion to the new API functions
Use the new storage driver APIs to delete snapshot backing files in case
of failure instead of directly relying on "unlink". This will help us in
the future when we will be adding network based storage without local
representation in the host.
2014-02-14 11:07:29 +01:00
Peter Krempa
6fb5a397bf conf: Move qemuSnapshotDiskGetActualType to virDomainSnapshotDiskGetActualType
All the data for getting the actual type is present in the snapshot
config. There is no need to have this function private to the qemu
driver and it will be re-used later in other parts of libvirt
2014-02-14 10:47:56 +01:00
Peter Krempa
f8f020da0a conf: Move qemuDiskGetActualType to virDomainDiskGetActualType
All the data for getting the actual type is present in the domain
config. There is no need to have this function private to the qemu
driver and it will be re-used later in other parts of libvirt
2014-02-14 10:47:56 +01:00
Pradipta Kr. Banerjee
cd921cf077 Handle non-sequential NUMA node numbers
On some platforms like IBM PowerNV the NUMA node numbers can be
non-sequential. For eg. numactl --hardware o/p from such a machine looks
as given below

node distances:
   node   0   1  16  17
     0:  10  40  40  40
     1:  40  10  40  40
    16:  40  40  10  40
    17:  40  40  40  10

The NUMA nodes are 0,1,16,17

Libvirt uses sequential index as NUMA node numbers and this can
result in crash or incorrect results.

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
Signed-off-by: Pradipta Kr. Banerjee <bpradip@in.ibm.com>
2014-02-11 14:44:20 +00:00
Martin Kletzander
d27e6bc40f qemu: introduce spiceport chardev backend
Add a new backend for any character device.  This backend uses channel
in spice connection.  This channel is similar to spicevmc, but
all-purpose in contrast to spicevmc.

Apart from spicevmc, spiceport-backed chardev will not be formatted
into the command-line if there is no spice to use (with test for that
as well).  For this I moved the def->graphics counting to the start
of the function so its results can be used in rest of the code even in
the future.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-02-11 13:43:55 +01:00
Martin Kletzander
296a4791eb qemu: remove pointless condition
This patch is here just to ease the code review and make related
changes look more sensible.  Apart from removing the condition this is
merely a whitespace (indentation) change.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-02-11 13:43:55 +01:00
Martin Kletzander
a53e504052 qemu: rework '-serial none'
Limiting ourselves to qemu without QEMU_CAPS_DEVICE capability, we
used '-serial none' only if there was no serial device defined in the
domain XML.  This means that if we want to have a possibility of the
device being defined in XML, but not used in the command-line
(e.g. when it's pointless), we'll fail to attach '-serial none' to the
command-line (when skipping the device's command-line building and the
device being the only one).

Since there is no such device, this patch doesn't actually do
anything, but enables easier future additions in this manner.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-02-11 13:43:55 +01:00
Martin Kletzander
5b189541ac conf: introduce spiceport chardev backend
Add a new character device backend called 'spiceport' that uses
spice's channel for communications and apart from spicevmc can be used
as a backend for any character device from libvirt's point of view.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-02-11 13:43:55 +01:00
Peter Krempa
9bf629ab60 qemu: Use correct permissions when determining the image chain
The code took into account only the global permissions. The domains now
support per-vm DAC labels and per-image DAC labels. Use the most
specific label available.
2014-02-10 15:49:59 +01:00
Peter Krempa
600bca592b qemu: hyperv: Add support for timer enlightenments
Add a new <timer> for the HyperV reference time counter enlightenment
and the iTSC reference page for Windows guests.

This feature provides a paravirtual approach to track timer events for
the guest (similar to kvmclock) with the option to use real hardware
clock on systems with a iTSC with compensation across various hosts.
2014-02-10 11:30:10 +01:00
Peter Krempa
8ffaa42d7b conf: Enforce supported options for certain timers
According to the documentation various timer options are only supported
by certain timer types. Add a post parse check to verify that the user
didn't specify invalid options.

Also fix the qemu command line parsing function to set correct default
values for the kvmclock timer so that it passes the new check.
2014-02-10 11:17:32 +01:00
Martin Kletzander
440a1aa508 qemu: keep pre-migration domain state after failed migration
Couple of codepaths shared the same code which can be moved out to a
function and on one of such places, qemuMigrationConfirmPhase(), the
domain was resumed even if it wasn't running before the migration
started.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1057407

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-02-07 10:07:38 +01:00
Matthieu Coudron
0778fc1ab9 qemu_driver: Introduce <filesystem/> support in device attach/detach
This commit allows to attach/detach a <filesystem> device in qemu. For
this purpose I'm introducing two new functions: virDomainFSInsert() and
virDomainFSRemove() and adding necessary code in the qemu driver.  It
compares filesystems based on their "destination" folder. So if two
filesystems share the same destination, they are considered equal and
the qemu driver would reject the insertion.

Signed-off-by: Matthieu Coudron <mattator@gmail.com>
2014-02-06 17:20:03 +01:00
Jiri Denemark
05bf937572 qemu: Fix crash in virDomainMemoryStats with old qemu
If virDomainMemoryStats was run on a domain with virtio balloon driver
running on an old qemu which supports QMP but does not support qom-list
QMP command, libvirtd would crash. The reason is we did not check if
qemuMonitorJSONGetObjectListPaths failed and moreover we even stored its
result in an unsigned integer type.
2014-02-06 11:29:29 +01:00
Peter Krempa
5d2691cc4c qemu: blockjob: Print correct file name in error message
When attempting a blockcommit from the top layer, the base argument
passed is NULL. This will be dereferenced when attempting a commit with
an empty image chain. Output the real volume path instead:

virsh blockcommit --verbose --path vda --domain DOMNAME --wait
error: invalid argument: top '/path/somefile' in chain for 'vda' has no backing file

instead of:

error: invalid argument: top '(null)' in chain for 'vda' has no backing file
2014-02-06 10:43:57 +01:00
Michal Privoznik
51bea5df5d qemuBuildClockArgStr: Allow localtime clock basis
https://bugzilla.redhat.com/show_bug.cgi?id=1046192

Commit b8bf79a, which adds clock='variable', forgets to check
localtime basis in qemuBuildClockArgStr(). So that localtime
basis could not be used.

Reported-by: Jincheng Miao <jmiao@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2014-02-06 07:51:07 +01:00
Eric Blake
f34ea654de maint: fix grammar in conf file
Noticed a misuse of 'to' while testing my event regression under
polkit ACLs, and decided to review the entire conf files for
other legibility bugs.

* daemon/libvirtd.conf: Use correct grammar.
* src/qemu/qemu.conf: Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-02-05 10:40:14 -07:00
Eric Blake
11f20e43f1 event: move event filtering to daemon (regression fix)
https://bugzilla.redhat.com/show_bug.cgi?id=1058839

Commit f9f56340 for CVE-2014-0028 almost had the right idea - we
need to check the ACL rules to filter which events to send.  But
it overlooked one thing: the event dispatch queue is running in
the main loop thread, and therefore does not normally have a
current virIdentityPtr.  But filter checks can be based on current
identity, so when libvirtd.conf contains access_drivers=["polkit"],
we ended up rejecting access for EVERY event due to failure to
look up the current identity, even if it should have been allowed.

Furthermore, even for events that are triggered by API calls, it
is important to remember that the point of events is that they can
be copied across multiple connections, which may have separate
identities and permissions.  So even if events were dispatched
from a context where we have an identity, we must change to the
correct identity of the connection that will be receiving the
event, rather than basing a decision on the context that triggered
the event, when deciding whether to filter an event to a
particular connection.

If there were an easy way to get from virConnectPtr to the
appropriate virIdentityPtr, then object_event.c could adjust the
identity prior to checking whether to dispatch an event.  But
setting up that back-reference is a bit invasive.  Instead, it
is easier to delay the filtering check until lower down the
stack, at the point where we have direct access to the RPC
client object that owns an identity.  As such, this patch ends
up reverting a large portion of the framework of commit f9f56340.
We also have to teach 'make check' to special-case the fact that
the event registration filtering is done at the point of dispatch,
rather than the point of registration.  Note that even though we
don't actually use virConnectDomainEventRegisterCheckACL (because
the RegisterAny variant is sufficient), we still generate the
function for the purposes of documenting that the filtering
takes place.

Also note that I did not entirely delete the notion of a filter
from object_event.c; I still plan on using that for my upcoming
patch series for qemu monitor events in libvirt-qemu.so.  In
other words, while this patch changes ACL filtering to live in
remote.c and therefore we have no current client of the filtering
in object_event.c, the notion of filtering in object_event.c is
still useful down the road.

* src/check-aclrules.pl: Exempt event registration from having to
pass checkACL filter down call stack.
* daemon/remote.c (remoteRelayDomainEventCheckACL)
(remoteRelayNetworkEventCheckACL): New functions.
(remoteRelay*Event*): Use new functions.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Drop unused parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/domain_event.c (virDomainEventFilter): Delete unused
function.
* src/conf/network_event.c (virNetworkEventFilter): Likewise.
* src/libxl/libxl_driver.c: Adjust caller.
* src/lxc/lxc_driver.c: Likewise.
* src/network/bridge_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/remote/remote_driver.c: Likewise.
* src/test/test_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/vbox/vbox_tmpl.c: Likewise.
* src/xen/xen_driver.c: Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-02-05 08:03:31 -07:00
Laine Stump
0d0a7bf45a qemu: be sure we're using the updated value of backend during hotplug
commit f094aaac changed qemuPrepareHostdevPCIDevices() such that it
may modify the "backend" (vfio vs. legacy kvm) setting in the
virHostdevDef. However, qemuDomainAttachHostPciDevice() (used by
hotplug) copies the backend setting into a local *before* calling
qemuPrepareHostdevPCIDevices(), and then later makes a decision based
on that pre-change value.

The result is that, if the backend had been set to "default" (i.e. not
specified in the config) and was later updated to "VFIO" by
qemuPrepareHostdevPCIDevices(), the qemu process' MacMemLock is not
increased (as is required for VFIO device assignment).

This patch delays making the local copy of backend until after its
potential modification.
2014-02-04 14:05:09 +02:00
Martin Kletzander
b44f9e7ec9 spice: don't force user to specify spicevmc channel
We support only one spicevmc channel name anyway and the code is
prepared to use the default one, there's only one check missing.  It
is also mentioned in the documentation already and helps defining
domains with spice vdagent for people using virsh.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-02-03 09:46:47 +01:00
Daniel P. Berrange
6e5c79a1b5 Push nwfilter update locking up to top level
The NWFilter code has as a deadlock race condition between
the virNWFilter{Define,Undefine} APIs and starting of guest
VMs due to mis-matched lock ordering.

In the virNWFilter{Define,Undefine} codepaths the lock ordering
is

  1. nwfilter driver lock
  2. virt driver lock
  3. nwfilter update lock
  4. domain object lock

In the VM guest startup paths the lock ordering is

  1. virt driver lock
  2. domain object lock
  3. nwfilter update lock

As can be seen the domain object and nwfilter update locks are
not acquired in a consistent order.

The fix used is to push the nwfilter update lock upto the top
level resulting in a lock ordering for virNWFilter{Define,Undefine}
of

  1. nwfilter driver lock
  2. nwfilter update lock
  3. virt driver lock
  4. domain object lock

and VM start using

  1. nwfilter update lock
  2. virt driver lock
  3. domain object lock

This has the effect of serializing VM startup once again, even if
no nwfilters are applied to the guest. There is also the possibility
of deadlock due to a call graph loop via virNWFilterInstantiate
and virNWFilterInstantiateFilterLate.

These two problems mean the lock must be turned into a read/write
lock instead of a plain mutex at the same time. The lock is used to
serialize changes to the "driver->nwfilters" hash, so the write lock
only needs to be held by the define/undefine methods. All other
methods can rely on a read lock which allows good concurrency.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-01-30 18:00:20 +00:00
Osier Yang
f406aa25f2 qemu: Fix the error message for scsi host device's shareable checking
This fixes the wrong argument order.
2014-01-30 16:50:10 +08:00
Osier Yang
10c9ceff6d util: Add one argument for several scsi utils
To support passing the path of the test data to the utils, one
more argument is added to virSCSIDeviceGetSgName,
virSCSIDeviceGetDevName, and virSCSIDeviceNew, and the related
code is changed accordingly.

Later tests for the scsi utils will be based on this patch.

Signed-off-by: Osier Yang <jyang@redhat.com>
2014-01-30 15:48:28 +08:00
Osier Yang
fd243fc4ad qemu: Don't fail if the SCSI host device is shareable between domains
It doesn't make sense to fail if the SCSI host device is specified
as "shareable" explicitly between domains (NB, it works if and only
if the device is specified as "shareable" for *all* domains,
otherwise it fails).

To fix the problem, this patch introduces an array for virSCSIDevice
struct, which records all the names of domain which are using the
device (note that the recorded domains must specify the device as
shareable).  And the change on the data struct brings on many
subsequent changes in the code.

Prior to this patch, the "shareable" tag didn't work as expected,
it actually work like "non-shareable".  So this patch also added notes
in formatdomain.html to declare the fact.

* src/util/virscsi.h:
  - Remove virSCSIDeviceGetUsedBy
  - Change definition of virSCSIDeviceGetUsedBy and virSCSIDeviceListDel
  - Add virSCSIDeviceIsAvailable

* src/util/virscsi.c:
  - struct virSCSIDevice: Change "used_by" to be an array; Add
    "n_used_by" as the array count
  - virSCSIDeviceGetUsedBy: Removed
  - virSCSIDeviceFree: frees the "used_by" array
  - virSCSIDeviceSetUsedBy: Copy the domain name to avoid potential
    memory corruption
  - virSCSIDeviceIsAvailable: New
  - virSCSIDeviceListDel: Change the logic, for device which is already
    in the list, just remove the corresponding entry in "used_by". And
    since it's only used in one place, we can safely removing the code
    to find out the dev in the list first.
  - Copyright updating

* src/libvirt_private.sys:
  - virSCSIDeviceGetUsedBy: Remove
  - virSCSIDeviceIsAvailable: New

* src/qemu/qemu_hostdev.c:
  - qemuUpdateActiveScsiHostdevs: Check if the device existing before
    adding it to the list;
  - qemuPrepareHostdevSCSIDevices: Error out if the not all domains
    use the device as "shareable"; Also don't try to add the device
    to the activeScsiHostdevs list if it already there; And make
    more sensible error w.r.t the current "shareable" value in
    driver->activeScsiHostdevs.
  - qemuDomainReAttachHostScsiDevices: Change the logic according
    to the changes on helpers.

Signed-off-by: Osier Yang <jyang@redhat.com>
2014-01-30 15:46:24 +08:00
Peter Krempa
7076b4b72c snapshot: Add support for specifying snapshot disk backing type
Add support for specifying various types when doing snapshots. This will
later allow to do snapshots on network backed volumes. Disks of type
'volume' are not supported by snapshots (yet).

Also amend the test suite to check parsing of the various new disk
types that can now be specified.
2014-01-29 12:56:35 +01:00
Pradipta Kr. Banerjee
c6320d3463 Add hw random number generator (/dev/hwrng) to cgroup ACL
Creating a qemu VM with /dev/hwrng as backend RNG device throws the
following error - "Could not open '/dev/hwrng': Permission denied"
This patch fixes the issue

Signed-off-by: Pradipta Kr. Banerjee <bpradip@in.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2014-01-27 09:48:39 -07:00
John Ferlan
46a0737e13 Block info query: Add check for transient domain
Currently the qemuDomainGetBlockInfo will return allocation == physical
for most backing stores. For a qcow2 block backed device it's possible
to return the highest lv extent allocated from qemu for an active guest.
That is a value where allocation != physical and one would hope be less.
However, if the guest is not running, then the code falls back to returning
allocation == physical. This turns out to be problematic for rhev which
monitors the size of the backing store. During a migration, before the
VM has been started on the target and while it is deemed inactive on the
source, there's a small window of time where the allocation is returned
as physical triggering the code to extend the file unnecessarily.

Since rhev uses transient domains and this is edge condition for a transient
domain, rather than returning good status and allocation == physical when
this "window of opportunity" exists, this patch will check for a transient
(or non persistent) domain and return a failure to the caller rather than
returning the defaults. For a persistent domain, the defaults will be
returned. The description for the virDomainGetBlockInfo has been updated
to describe the phenomena.
2014-01-24 11:37:18 -05:00
Gao feng
71f7d5840f qemu: remove memset params array to zero in qemuDomainGetPercpuStats
the array params is allocated by VIR_ALLOC_N in
remoteDispatchDomainGetCPUStats. it had been set
to zero. No need to reset it to zero again, and
this reset here is incorrect too, nparams * ncpus
is the array length not the size of params array.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
2014-01-24 16:31:53 +08:00
Osier Yang
2b66504ded util: Add "shareable" field for virSCSIDevice struct
Unlike the host devices of other types, SCSI host device XML supports
"shareable" tag. This patch introduces it for the virSCSIDevice struct
for a later patch use (to detect if the SCSI device is shareable when
preparing the SCSI host device in QEMU driver).
2014-01-23 17:52:33 +08:00
Eric Blake
7f2d27d1e3 api: require write permission for guest agent interaction
I noticed that we allow virDomainGetVcpusFlags even for read-only
connections, but that with a flag, it can require guest agent
interaction.  It is feasible that a malicious guest could
intentionally abuse the replies it sends over the guest agent
connection to possibly trigger a bug in libvirt's JSON parser,
or withhold an answer so as to prevent the use of the agent
in a later command such as a shutdown request.  Although we
don't know of any such exploits now (and therefore don't mind
posting this patch publicly without trying to get a CVE assigned),
it is better to err on the side of caution and explicitly require
full access to any domain where the API requires guest interaction
to operate correctly.

I audited all commands that are marked as conditionally using a
guest agent.  Note that at least virDomainFSTrim is documented
as needing a guest agent, but that such use is unconditional
depending on the hypervisor (so the existing domain:fs_trim ACL
should be sufficient there, rather than also requirng domain:write).
But when designing future APIs, such as the plans for obtaining
a domain's IP addresses, we should copy the approach of this patch
in making interaction with the guest be specified via a flag, and
use that flag to also require stricter access checks.

* src/libvirt.c (virDomainGetVcpusFlags): Forbid guest interaction
on read-only connection.
(virDomainShutdownFlags, virDomainReboot): Improve docs on agent
interaction.
* src/remote/remote_protocol.x
(REMOTE_PROC_DOMAIN_SNAPSHOT_CREATE_XML)
(REMOTE_PROC_DOMAIN_SET_VCPUS_FLAGS)
(REMOTE_PROC_DOMAIN_GET_VCPUS_FLAGS, REMOTE_PROC_DOMAIN_REBOOT)
(REMOTE_PROC_DOMAIN_SHUTDOWN_FLAGS): Require domain:write for any
conditional use of a guest agent.
* src/xen/xen_driver.c: Fix clients.
* src/libxl/libxl_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-01-22 16:52:41 -07:00
Peter Krempa
7f0fd42741 qemu: Avoid crash in qemuDiskGetActualType
Libvirtd would crash if a domain contained an empty cdrom drive of
type='volume' as the disk def->srcpool member would be dereferenced. Fix
it by checking if the source pool is present before dereferencing it.

Also alter tests to catch this issue in the future.

Reported by: Kevin Shanahan
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1056328
2014-01-22 11:33:31 +01:00
Peter Krempa
3d1e9e4779 qemu: snapshot: Forbid snapshots when backing is a scsi passthrough disk
https://bugzilla.redhat.com/show_bug.cgi?id=1034993

SCSI passthrough disks (<disk .. device="lun">) can't be used as backing
for snapshots. Currently with upstream qemu the vm crashes on such
attempt.

This patch adds a early check to catch an attempt to do such a snapshot
and rejects it right away. qemu will fix the issue but this will let us
control the error message.
2014-01-21 17:05:21 +01:00
Peter Krempa
55bbb011b9 qemu: snapshot: Avoid libvirtd crash when qemu crashes while snapshotting
We shouldn't access the domain definition while we are in the monitor
section as the domain is unlocked. Additionally after we exit from the
monitor we need to check if the VM is still alive. Not doing so resulted
in a crash if qemu exits while attempting to do an external VM snapshot.
2014-01-21 11:42:01 +01:00
Francesco Romani
08d07e5fd8 spice: expose the QEMU disable file transfer option
spice-server offers an API to disable file transfer messages
on the agent channel between the client and the guest.
This is supported in qemu through the disable-agent-file-xfer option.

This patch exposes this option to libvirt.
Adds a new element 'filetransfer', with one property,
'enable', which accepts a boolean.
Default is enabled, for backward compatibility.

Depends on the capability exported in the first patch of the series.

Signed-off-by: Francesco Romani <fromani@redhat.com>
2014-01-21 11:35:41 +01:00
Francesco Romani
19bbc81276 spice: detect if qemu can disable file transfer
spice-server offers an API to disable file transfer messages
on the agent channel between the client and the guest.
This is supported in qemu through the disable-agent-file-xfer option.

This patch detects if QEMU supports this option, and add
a capability if does.

Signed-off-by: Francesco Romani <fromani@redhat.com>
2014-01-21 11:35:40 +01:00
Jincheng Miao
df8022721e qemu: Don't detach devices if passthrough doesn't work
https://bugzilla.redhat.com/show_bug.cgi?id=1046919

If none (KVM, VFIO) of the supported PCI passthrough methods is known to
work on a host, it's better to fail right away with a nice error message
rather than letting attachment fail with a more cryptic message such as

    Failed to bind PCI device '0000:07:05.0' to vfio-pci: No such device

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2014-01-20 13:58:04 +01:00
Gao feng
0728d4721b qemu: allow to setup throttle blkio cgroup through virsh
With this patch, user can setup throttle blkio cgroup
through virsh for qemu domain.

Signed-off-by: Guan Qiang <hzguanqiang@corp.netease.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
2014-01-20 10:52:49 +08:00
Gao feng
3b431929a2 blkio: Setting throttle blkio cgroup for domain
This patch introduces virCgroupSetBlkioDeviceReadIops,
virCgroupSetBlkioDeviceWriteIops,
virCgroupSetBlkioDeviceReadBps and
virCgroupSetBlkioDeviceWriteBps,

we can use these interfaces to set up throttle
blkio cgroup for domain.

This patch also adds the new throttle blkio cgroup
elements to the test xml.

Signed-off-by: Guan Qiang <hzguanqiang@corp.netease.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
2014-01-20 10:52:44 +08:00
Eric Blake
c8ed177af4 maint: don't lose error on canceled migration
While auditing the error reporting, I noticed that migration
had some issues.  Some of the static helper functions tried
to call virDispatchError(), even though their caller will also
report the error.  Also, if a migration is cancelled early
because a uri was not set, we did not guarantee that the finish
stage would not overwrite the first error message.

* src/qemu/qemu_migration.c (doPeer2PeerMigrate2)
(doPeer2PeerMigrate3): Preserve first error when cancelling.
* src/libvirt.c (virDomainMigrateVersion3Full): Likewise.
(virDomainMigrateVersion1, virDomainMigrateVersion2)
(virDomainMigrateDirect): Avoid redundant error dispatch.
(virDomainMigrateFinish2, virDomainMigrateFinish3)
(virDomainMigrateFinish3Params): Don't report error on cleanup
path.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-01-16 12:26:54 -07:00
Eric Blake
25221a1b21 maint: avoid nested use of virConnect{Ref,Close}
The public virConnectRef and virConnectClose API are just thin
wrappers around virObjectRef/virObjectRef, with added object
validation and an error reset.  Within our backend drivers, use
of the object validation is just an inefficiency since we always
pass valid objects.  More important to think about is what
happens with the error reset; our uses of virConnectRef happened
to be safe (since we hadn't encountered any earlier errors), but
in several cases the use of virConnectClose could lose a real
error.

Ideally, we should also avoid calling virConnectOpen() from
within backend drivers - but that is a known situation that
needs much more design work.

* src/qemu/qemu_process.c (qemuProcessReconnectHelper)
(qemuProcessReconnect): Avoid nested public API call.
* src/qemu/qemu_driver.c (qemuAutostartDomains)
(qemuStateInitialize, qemuStateStop): Likewise.
* src/qemu/qemu_migration.c (doPeer2PeerMigrate): Likewise.
* src/storage/storage_driver.c (storageDriverAutostart):
Likewise.
* src/uml/uml_driver.c (umlAutostartConfigs): Likewise.
* src/lxc/lxc_process.c (virLXCProcessAutostartAll): Likewise.
(virLXCProcessReboot): Likewise, and avoid leaking conn on error.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-01-16 12:25:45 -07:00
Martin Kletzander
fe89b687a0 qemu: Change the default unix monitor timeout
There is a number of reported issues when we fail starting a domain.
Turns out that, in some scenarios like high load, 3 second timeout is
not enough for qemu to start up to the phase where the socket is
created.  Since there is no downside of waiting longer, raise the
timeout right to 30 seconds.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-01-16 17:20:08 +01:00
Eric Blake
f9f5634053 event: filter global events by domain:getattr ACL [CVE-2014-0028]
Ever since ACL filtering was added in commit 7639736 (v1.1.1), a
user could still use event registration to obtain access to a
domain that they could not normally access via virDomainLookup*
or virConnectListAllDomains and friends.  We already have the
framework in the RPC generator for creating the filter, and
previous cleanup patches got us to the point that we can now
wire the filter through the entire object event stack.

Furthermore, whether or not domain:getattr is honored, use of
global events is a form of obtaining a list of networks, which
is covered by connect:search_domains added in a93cd08 (v1.1.0).
Ideally, we'd have a way to enforce connect:search_domains when
doing global registrations while omitting that check on a
per-domain registration.  But this patch just unconditionally
requires connect:search_domains, even when no list could be
obtained, based on the following observations:
1. Administrators are unlikely to grant domain:getattr for one
or all domains while still denying connect:search_domains - a
user that is able to manage domains will want to be able to
manage them efficiently, but efficient management includes being
able to list the domains they can access.  The idea of denying
connect:search_domains while still granting access to individual
domains is therefore not adding any real security, but just
serves as a layer of obscurity to annoy the end user.
2. In the current implementation, domain events are filtered
on the client; the server has no idea if a domain filter was
requested, and must therefore assume that all domain event
requests are global.  Even if we fix the RPC protocol to
allow for server-side filtering for newer client/server combos,
making the connect:serach_domains ACL check conditional on
whether the domain argument was NULL won't benefit older clients.
Therefore, we choose to document that connect:search_domains
is a pre-requisite to any domain event management.

Network events need the same treatment, with the obvious
change of using connect:search_networks and network:getattr.

* src/access/viraccessperm.h
(VIR_ACCESS_PERM_CONNECT_SEARCH_DOMAINS)
(VIR_ACCESS_PERM_CONNECT_SEARCH_NETWORKS): Document additional
effect of the permission.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Add new parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/object_event_private.h (virObjectEventStateRegisterID):
Likewise.
* src/conf/object_event.c (_virObjectEventCallback): Track a filter.
(virObjectEventDispatchMatchCallback): Use filter.
(virObjectEventCallbackListAddID): Register filter.
* src/conf/domain_event.c (virDomainEventFilter): New function.
(virDomainEventStateRegister, virDomainEventStateRegisterID):
Adjust callers.
* src/conf/network_event.c (virNetworkEventFilter): New function.
(virNetworkEventStateRegisterID): Adjust caller.
* src/remote/remote_protocol.x
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER)
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER_ANY)
(REMOTE_PROC_CONNECT_NETWORK_EVENT_REGISTER_ANY): Generate a
filter, and require connect:search_domains instead of weaker
connect:read.
* src/test/test_driver.c (testConnectDomainEventRegister)
(testConnectDomainEventRegisterAny)
(testConnectNetworkEventRegisterAny): Update callers.
* src/remote/remote_driver.c (remoteConnectDomainEventRegister)
(remoteConnectDomainEventRegisterAny): Likewise.
* src/xen/xen_driver.c (xenUnifiedConnectDomainEventRegister)
(xenUnifiedConnectDomainEventRegisterAny): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc): Likewise.
* src/libxl/libxl_driver.c (libxlConnectDomainEventRegister)
(libxlConnectDomainEventRegisterAny): Likewise.
* src/qemu/qemu_driver.c (qemuConnectDomainEventRegister)
(qemuConnectDomainEventRegisterAny): Likewise.
* src/uml/uml_driver.c (umlConnectDomainEventRegister)
(umlConnectDomainEventRegisterAny): Likewise.
* src/network/bridge_driver.c
(networkConnectNetworkEventRegisterAny): Likewise.
* src/lxc/lxc_driver.c (lxcConnectDomainEventRegister)
(lxcConnectDomainEventRegisterAny): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-01-15 13:55:21 -07:00
Peter Krempa
b952cbbcca qemu: Avoid operations on NULL monitor if VM fails early
https://bugzilla.redhat.com/show_bug.cgi?id=1047659

If a VM dies very early during an attempted connect to the guest agent
while the locks are down the domain monitor object will be freed. The
object is then accessed later as any failure during guest agent startup
isn't considered fatal.

In the current upstream version this doesn't lead to a crash as
virObjectLock called when entering the monitor in
qemuProcessDetectVcpuPIDs checks the pointer before attempting to
dereference (lock) it. The NULL pointer is then caught in the monitor
helper code.

Before the introduction of virObjectLockable - observed on 0.10.2 - the
pointer is locked directly via virMutexLock leading to a crash.

To avoid this problem we need to differentiate between the guest agent
not being present and the VM quitting when the locks were down. The fix
reorganizes the code in qemuConnectAgent to add the check and then adds
special handling to the callers.
2014-01-15 18:04:25 +01:00
Michal Privoznik
4f588a1b46 qemuBuildNicDevStr: Set vectors= on Multiqueue
Yet another advice appeared on the Multiqueue wiki page:

http://www.linux-kvm.org/page/Multiqueue#Enable_MQ_feature

We should add vectors=N onto the qemu command line, where
N = 2 * (number of queues) + 1.
2014-01-09 15:23:57 +01:00
Jiri Denemark
3b56425938 qemu: Fix job usage in virDomainGetBlockIoTune
CVE-2013-6458

Every API that is going to begin a job should do that before fetching
data from vm->def.
2014-01-07 16:12:11 +01:00
Jiri Denemark
ff5f30b6bf qemu: Fix job usage in qemuDomainBlockCopy
Every API that is going to begin a job should do that before fetching
data from vm->def.
2014-01-07 16:12:01 +01:00
Jiri Denemark
f93d2caa07 qemu: Fix job usage in qemuDomainBlockJobImpl
CVE-2013-6458

Every API that is going to begin a job should do that before fetching
data from vm->def.
2014-01-07 16:10:42 +01:00
Jiri Denemark
b799259583 qemu: Avoid using stale data in virDomainGetBlockInfo
CVE-2013-6458

Generally, every API that is going to begin a job should do that before
fetching data from vm->def. However, qemuDomainGetBlockInfo does not
know whether it will have to start a job or not before checking vm->def.
To avoid using disk alias that might have been freed while we were
waiting for a job, we use its copy. In case the disk was removed in the
meantime, we will fail with "cannot find statistics for device '...'"
error message.
2014-01-07 16:10:02 +01:00
Jiri Denemark
db86da5ca2 qemu: Do not access stale data in virDomainBlockStats
CVE-2013-6458
https://bugzilla.redhat.com/show_bug.cgi?id=1043069

When virDomainDetachDeviceFlags is called concurrently to
virDomainBlockStats: libvirtd may crash because qemuDomainBlockStats
finds a disk in vm->def before getting a job on a domain and uses the
disk pointer after getting the job. However, the domain in unlocked
while waiting on a job condition and thus data behind the disk pointer
may disappear. This happens when thread 1 runs
virDomainDetachDeviceFlags and enters monitor to actually remove the
disk. Then another thread starts running virDomainBlockStats, finds the
disk in vm->def, and while it's waiting on the job condition (owned by
the first thread), the first thread finishes the disk removal. When the
second thread gets the job, the memory pointed to be the disk pointer is
already gone.

That said, every API that is going to begin a job should do that before
fetching data from vm->def.
2014-01-07 16:09:44 +01:00