Commit Graph

679 Commits

Author SHA1 Message Date
Andrea Bolognani
396ca36cb0 qemu: Enforce ACPI, UEFI requirements
Depending on the architecture, requirements for ACPI and UEFI can
be different; more specifically, while on x86 UEFI requires ACPI,
on aarch64 it's the other way around.

Enforce these requirements when validating the domain, and make
the error message more accurate by mentioning that they're not
necessarily applicable to all architectures.

Several aarch64 test cases had to be tweaked because they would
have failed the validation step otherwise.
2017-04-03 10:58:00 +02:00
Michal Privoznik
462c4b66fa Introduce and use virDomainDiskEmptySource
Currently, if we want to zero out disk source (e,g, due to
startupPolicy when starting up a domain) we use
virDomainDiskSetSource(disk, NULL). This works well for file
based storage (storage type file, dir, or block). But it doesn't
work at all for other types like volume and network.

So imagine that you have a domain that has a CDROM configured
which source is a volume from an inactive pool. Because it is
startupPolicy='optional', the CDROM is empty when the domain
starts. However, the source element is not cleared out in the
status XML and thus when the daemon restarts and tries to
reconnect to the domain it refreshes the disks (which fails - the
storage pool is still not running) and thus the domain is killed.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-04-03 08:35:57 +02:00
Peter Krempa
20ee78bf9b qemu: domain: Properly lookup top of chain in qemuDomainGetStorageSourceByDevstr
When idx is 0 virStorageFileChainLookup returns the base (bottom) of the
backing chain rather than the top. This is expected by the callers of
qemuDomainGetStorageSourceByDevstr.

Add a special case for idx == 0
2017-03-29 16:56:05 +02:00
Andrea Bolognani
7e667664d2 qemu: Fix memory locking limit calculation
For guests that use <memoryBacking><locked>, our only option
is to remove the memory locking limit altogether.

Partially-resolves: https://bugzilla.redhat.com/1431793
2017-03-28 10:54:49 +02:00
Andrea Bolognani
1f7661af8c qemu: Remove qemuDomainRequiresMemLock()
Instead of having a separate function, we can simply return
zero from the existing qemuDomainGetMemLockLimitBytes() to
signal the caller that the memory locking limit doesn't need
to be set for the guest.

Having a single function instead of two makes it less likely
that we will use the wrong value, which is exactly what
happened when we started applying the limit that was meant
for VFIO-using guests to <memoryBacking><locked>-using
guests.
2017-03-28 10:54:47 +02:00
Andrea Bolognani
4b67e7a377 Revert "qemu: Forbid <memoryBacking><locked> without <memtune><hard_limit>"
This reverts commit c2e60ad0e5.

Turns out this check is excessively strict: there are ways
other than <memtune><hard_limit> to raise the memory locking
limit for QEMU processes, one prominent example being
tweaking /etc/security/limits.conf.

Partially-resolves: https://bugzilla.redhat.com/1431793
2017-03-28 10:44:25 +02:00
Erik Skultety
c8e6775f30 qemu: Bump the memory locking limit for mdevs as well
Since mdevs are just another type of VFIO devices, we should increase
the memory locking limit the same way we do for VFIO PCI devices.

Signed-off-by: Erik Skultety <eskultet@redhat.com>
2017-03-27 15:39:35 +02:00
Erik Skultety
de4e8bdbc7 qemu: cgroup: Adjust cgroups' logic to allow mediated devices
As goes for all the other hostdev device types, grant the qemu process
access to /dev/vfio/<mediated_device_iommu_group>.

Signed-off-by: Erik Skultety <eskultet@redhat.com>
2017-03-27 15:39:35 +02:00
Erik Skultety
ec783d7c77 conf: Introduce new hostdev device type mdev
A mediated device will be identified by a UUID (with 'model' now being
a mandatory <hostdev> attribute to represent the mediated device API) of
the user pre-created mediated device. We also need to make sure that if
user explicitly provides a guest address for a mdev device, the address
type will be matching the device API supported on that specific mediated
device and error out with an incorrect XML message.

The resulting device XML:
<devices>
  <hostdev mode='subsystem' type='mdev' model='vfio-pci'>
    <source>
      <address uuid='c2177883-f1bb-47f0-914d-32a22e3a8804'>
    </source>
  </hostdev>
</devices>

Signed-off-by: Erik Skultety <eskultet@redhat.com>
2017-03-27 15:39:35 +02:00
Peter Krempa
9b93c4c264 qemu: domain: Add helper to look up disk soruce by the backing store string 2017-03-27 10:18:16 +02:00
Peter Krempa
4e1618ce72 qemu: domain: Add helper to generate indexed backing store names
The code is currently simple, but if we later add node names, it will be
necessary to generate the names based on the node name. Add a helper so
that there's a central point to fix once we add self-generated node
names.
2017-03-27 09:29:57 +02:00
Peter Krempa
1a5e2a8098 qemu: domain: Add helper to lookup disk by node name
Looks up a disk and its corresponding backing chain element by node
name.
2017-03-27 09:29:57 +02:00
John Ferlan
1a6b6d9a56 qemu: Set up the migration TLS objects for target
If the migration flags indicate this migration will be using TLS,
then set up the destination during the prepare phase once the target
domain has been started to add the TLS objects to perform the migration.

This will create at least an "-object tls-creds-x509,endpoint=server,..."
for TLS credentials and potentially an "-object secret,..." to handle the
passphrase response to access the TLS credentials. The alias/id used for
the TLS objects will contain "libvirt_migrate".

Once the objects are created, the code will set the "tls-creds" and
"tls-hostname" migration parameters to signify usage of TLS.

During the Finish phase we'll be sure to attempt to clear the
migration parameters and delete those objects (whether or not they
were created). We'll also perform the same reset during recovery
if we've reached FINISH3.

If the migration isn't using TLS, then be sure to check if the
migration parameters exist and clear them if so.
2017-03-25 08:19:49 -04:00
Jiri Denemark
fcd56ce866 qemu: Set default values for CPU check attribute
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2017-03-17 11:50:48 +01:00
Michal Privoznik
7b89f857d9 qemu: Namespaces for NVDIMM
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-03-15 17:04:33 +01:00
Michal Privoznik
1bc173199e qemu: Implement NVDIMM
So, majority of the code is just ready as-is. Well, with one
slight change: differentiate between dimm and nvdimm in places
like device alias generation, generating the command line and so
on.

Speaking of the command line, we also need to append 'nvdimm=on'
to the '-machine' argument so that the nvdimm feature is
advertised in the ACPI tables properly.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-03-15 14:16:32 +01:00
Michal Privoznik
b4e8a49f8d Introduce NVDIMM memory model
NVDIMM is new type of memory introduced into QEMU 2.6. The idea
is that we have a Non-Volatile memory module that keeps the data
persistent across domain reboots.

At the domain XML level, we already have some representation of
'dimm' modules. Long story short, NVDIMM will utilize the
existing <memory/> element that lives under <devices/> by adding
a new attribute 'nvdimm' to the existing @model and introduce a
new <path/> element for <source/> while reusing other fields. The
resulting XML would appear as:

    <memory model='nvdimm'>
      <source>
        <path>/tmp/nvdimm</path>
      </source>
      <target>
        <size unit='KiB'>523264</size>
        <node>0</node>
      </target>
      <address type='dimm' slot='0'/>
    </memory>

So far, this is just a XML parser/formatter extension. QEMU
driver implementation is in the next commit.

For more info on NVDIMM visit the following web page:

    http://pmem.io/

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-03-15 13:30:58 +01:00
Michal Privoznik
290a00e41d qemuDomainBuildNamespace: Handle file mount points
https://bugzilla.redhat.com/show_bug.cgi?id=1431112

Yeah, that's right. A mount point doesn't have to be a directory.
It can be a file too. However, the code that tries to preserve
mount points under /dev for new namespace for qemu does not count
with that option.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-03-13 13:32:45 +01:00
Michal Privoznik
e915942b05 qemuProcessHandleMonitorEOF: Disable namespace for domain
https://bugzilla.redhat.com/show_bug.cgi?id=1430634

If a qemu process has died, we get EOF on its monitor. At this
point, since qemu process was the only one running in the
namespace kernel has already cleaned the namespace up. Any
attempt of ours to enter it has to fail.

This really happened in the bug linked above. We've tried to
attach a disk to qemu and while we were in the monitor talking to
qemu it just died. Therefore our code tried to do some roll back
(e.g. deny the device in cgroups again, restore labels, etc.).
However, during the roll back (esp. when restoring labels) we
still thought that domain has a namespace. So we used secdriver's
transactions. This failed as there is no namespace to enter.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-03-10 16:02:34 +01:00
Pavel Hrdina
cd4a8b9304 conf: store "autoGenerated" for graphics listen in status XML
When libvirtd is started we call qemuDomainRecheckInternalPaths
to detect whether a domain has VNC socket path generated by libvirt
based on option from qemu.conf.  However if we are parsing status XML
for running domain the existing socket path can be generated also if
the config XML uses the new <listen type='socket'/> element without
specifying any socket.

The current code doesn't make difference how the socket was generated
and always marks it as "fromConfig".  We need to store the
"autoGenerated" value in the status XML in order to preserve that
information.

The difference between "fromConfig" and "autoGenerated" is important
for migration, because if the socket is based on "fromConfig" we don't
print it into the migratable XML and we assume that user has properly
configured qemu.conf on both hosts.  However if the socket is based
on "autoGenerated" it means that a new feature was used and therefore
we need to leave the socket in migratable XML to make sure that if
this feature is not supported on destination the migration will fail.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2017-03-09 10:22:43 +01:00
John Ferlan
b2e5de96c7 qemu: Rename variable
Rename 'secretUsageType' to 'usageType' since it's superfluous in an
API qemu*Secret*
2017-03-08 14:37:05 -05:00
John Ferlan
7c2b7891cc qemu: Introduce qemuDomainSecretInfoTLSNew
Building upon the qemuDomainSecretInfoNew, create a helper which will
build the secret used for TLS.

Signed-off-by: John Ferlan <jferlan@redhat.com>
2017-03-08 14:31:09 -05:00
John Ferlan
c9a7b7b6ea qemu: Introduce qemuDomainSecretInfoNew
Create a helper which will create the secinfo used for disks, hostdevs,
and chardevs.

Signed-off-by: John Ferlan <jferlan@redhat.com>
2017-03-08 14:31:07 -05:00
Pavel Hrdina
3ffea19acd qemu_domain: cleanup the controller post parse code
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2017-03-07 16:50:35 +01:00
Pavel Hrdina
57404ff7a7 qemu_domain: move controller post parse code into its own function
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2017-03-07 16:50:34 +01:00
Michal Privoznik
4da534c0b9 qemu: Enforce qemuSecurity wrappers
Now that we have some qemuSecurity wrappers over
virSecurityManager APIs, lets make sure everybody sticks with
them. We have them for a reason and calling virSecurityManager
API directly instead of wrapper may lead into accidentally
labelling a file on the host instead of namespace.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-03-06 08:54:28 +01:00
Marc Hartmayer
e22de286b1 qemu: Fix deadlock across fork() in QEMU driver
The functions in virCommand() after fork() must be careful with regard
to accessing any mutexes that may have been locked by other threads in
the parent process. It is possible that another thread in the parent
process holds the lock for the virQEMUDriver while fork() is called.
This leads to a deadlock in the child process when
'virQEMUDriverGetConfig(driver)' is called and therefore the handshake
never completes between the child and the parent process. Ultimately
the virDomainObjectPtr will never be unlocked.

It gets much worse if the other thread of the parent process, that
holds the lock for the virQEMUDriver, tries to lock the already locked
virDomainObject. This leads to a completely unresponsive libvirtd.

It's possible to reproduce this case with calling 'virsh start XXX'
and 'virsh managedsave XXX' in a tight loop for multiple domains.

This commit fixes the deadlock in the same way as it is described in
commit 61b52d2e38.

Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
2017-02-21 15:47:32 +01:00
Michal Privoznik
5c74cf1f44 qemu: Allow @rendernode for virgl domains
When enabling virgl, qemu opens /dev/dri/render*. So far, we are
not allowing that in devices CGroup nor creating the file in
domain's namespace and thus requiring users to set the paths in
qemu.conf. This, however, is suboptimal as it allows access to
ALL qemu processes even those which don't have virgl configured.
Now that we have a way to specify render node that qemu will use
we can be more cautious and enable just that.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-20 10:44:22 +01:00
Michal Privoznik
1bb787fdc9 qemuDomainGetHostdevPath: Report /dev/vfio/vfio less frequently
So far, qemuDomainGetHostdevPath has no knowledge of the reasong
it is called and thus reports /dev/vfio/vfio for every VFIO
backed device. This is suboptimal, as we want it to:

a) report /dev/vfio/vfio on every addition or domain startup
b) report /dev/vfio/vfio only on last VFIO device being unplugged

If a domain is being stopped then namespace and CGroup die with
it so no need to worry about that. I mean, even when a domain
that's exiting has more than one VFIO devices assigned to it,
this function does not clean /dev/vfio/vfio in CGroup nor in the
namespace. But that doesn't matter.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-02-20 07:21:59 +01:00
Michal Privoznik
b8e659aa98 qemuDomainGetHostdevPath: Create /dev/vfio/vfio iff needed
So far, we are allowing /dev/vfio/vfio in the devices cgroup
unconditionally (and creating it in the namespace too). Even if
domain has no hostdev assignment configured. This is potential
security hole. Therefore, when starting the domain (or
hotplugging a hostdev) create & allow /dev/vfio/vfio too (if
needed).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-02-20 07:21:58 +01:00
Michal Privoznik
9d92f533f8 qemuSetupHostdevCgroup: Use qemuDomainGetHostdevPath
Since these two functions are nearly identical (with
qemuSetupHostdevCgroup actually calling virCgroupAllowDevicePath)
we can have one function call the other and thus de-duplicate
some code.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-02-20 07:21:58 +01:00
Michal Privoznik
b57bd206b9 qemu_conf: Check for namespaces availability more wisely
The bare fact that mnt namespace is available is not enough for
us to allow/enable qemu namespaces feature. There are other
requirements: we must copy all the ACL & SELinux labels otherwise
we might grant access that is administratively forbidden or vice
versa.
At the same time, the check for namespace prerequisites is moved
from domain startup time to qemu.conf parser as it doesn't make
much sense to allow users to start misconfigured libvirt just to
find out they can't start a single domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-15 12:43:23 +01:00
Andrea Bolognani
ee6ec7824d qemu: Call chmod() after mknod()
mknod() is affected my the current umask, so we're not
guaranteed the newly-created device node will have the
right permissions.

Call chmod(), which is not affected by the current umask,
immediately afterwards to solve the issue.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1421036
2017-02-14 19:23:05 +01:00
Ján Tomko
723fef99c0 qemu: enforce maximum ports value for nec-xhci
This controller only allows up to 15 ports.

https://bugzilla.redhat.com/show_bug.cgi?id=1375417
2017-02-13 16:34:09 +01:00
Michal Privoznik
c2130c0d47 qemu_security: Introduce ImageLabel APIs
Just like we need wrappers over other virSecurityManager APIs, we
need one for virSecurityManagerSetImageLabel and
virSecurityManagerRestoreImageLabel. Otherwise we might end up
relabelling device in wrong namespace.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-09 08:04:57 +01:00
Michal Privoznik
b7feabbfdc qemuDomainNamespaceSetupDisk: Simplify disk check
Firstly, instead of checking for next->path the
virStorageSourceIsEmpty() function should be used which also
takes disk type into account.
Secondly, not every disk source passed has the correct type set
(due to our laziness). Therefore, instead of checking for
virStorageSourceIsBlockLocal() and also S_ISBLK() the former can
be refined to just virStorageSourceIsLocalStorage().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-08 15:56:21 +01:00
Michal Privoznik
786d8d91b4 qemuDomainDiskChainElement{Prepare,Revoke}: manage /dev entry
Again, one missed bit. This time without this commit there is no
/dev entry  in the namespace of the qemu process when doing disk
snapshots or block-copy.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-08 15:56:13 +01:00
Michal Privoznik
18ce9d139d qemuDomainNamespace{Setup,Teardown}Disk: Don't pass pointer to full disk
These functions do not need to see the whole virDomainDiskDef.
Moreover, they are going to be called from places where we don't
have access to the full disk definition. Sticking with
virStorageSource is more than enough.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-08 15:56:05 +01:00
Michal Privoznik
76d491ef14 qemuDomainNamespaceSetupDisk: Drop useless @src variable
Since its introduction in 81df21507b this variable was never
used.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-08 15:55:56 +01:00
Michal Privoznik
8dc867e978 qemu_domain: Don't pass virDomainDeviceDefPtr to ns helpers
There is no need for this. None of the namespace helpers uses it.
Historically it was used when calling secdriver APIs, but we
don't to that anymore.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-08 15:55:52 +01:00
Andrea Bolognani
c2e60ad0e5 qemu: Forbid <memoryBacking><locked> without <memtune><hard_limit>
In order for memory locking to work, the hard limit on memory
locking (and usage) has to be set appropriately by the user.

The documentation mentions the requirement already: with this
patch, it's going to be enforced by runtime checks as well,
by forbidding a non-compliant guest from being defined as well
as edited and started.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1316774
2017-02-07 18:43:10 +01:00
Michal Privoznik
7f0b382522 qemuDomainAttachDeviceMknod: Don't loop endlessly
When working with symlinks it is fairly easy to get into a loop.
Don't.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-07 13:20:19 +01:00
Michal Privoznik
3f5fcacf89 qemuDomainAttachDeviceMknod: Deal with symlinks
Similarly to one of the previous commits, we need to deal
properly with symlinks in hotplug case too.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-07 13:20:17 +01:00
Michal Privoznik
4ac847f93b qemuDomainCreateDevice: Don't loop endlessly
When working with symlinks it is fairly easy to get into a loop.
Don't.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-07 13:18:32 +01:00
Michal Privoznik
54ed672214 qemuDomainCreateDevice: Properly deal with symlinks
Imagine you have a disk with the following source set up:

/dev/disk/by-uuid/$uuid (symlink to) -> /dev/sda

After cbc45525cb the transitive end of the symlink chain is
created (/dev/sda), but we need to create any item in chain too.
Others might rely on that.
In this case, /dev/disk/by-uuid/$uuid comes from domain XML thus
it is this path that secdriver tries to relabel. Not the resolved
one.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-07 13:18:10 +01:00
Michal Privoznik
b621291f5c qemuDomain{Attach,Detach}Device NS helpers: Don't relabel devices
After previous commit this has become redundant step.
Also setting up devices in namespace and setting their label
later on are two different steps and should be not done at once.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-02-07 10:40:53 +01:00
Michal Privoznik
572eda12ad qemu: Implement mtu on interface
Not only we should set the MTU on the host end of the device but
also let qemu know what MTU did we set.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-26 10:00:01 +01:00
Michal Privoznik
b020cf73fe domain_conf: Introduce <mtu/> to <interface/>
So far we allow to set MTU for libvirt networks. However, not all
domain interfaces have to be plugged into a libvirt network and
even if they are, they might want to have a different MTU (e.g.
for testing purposes).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-26 09:59:56 +01:00
Chen Hanxiao
980f2a35c7 qemu_domain: add timestamp in tainting of guests log
We lacked of timestamp in tainting of guests log,
which bring troubles for finding guest issues:
such as whether a guest powerdown caused by qemu-monitor-command
or others issues inside guests.
If we had timestamp in tainting of guests log,
it would be helpful when checking guest's /var/log/messages.

Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
2017-01-21 12:34:19 -05:00
Michal Privoznik
57b5e27d3d qemu: set default vhost-user ifname
Based on work of Mehdi Abaakouk <sileht@sileht.net>.

When parsing vhost-user interface XML and no ifname is found we
can try to fill it in in post parse callback. The way this works
is we try to make up interface name from given socket path and
then ask openvswitch whether it knows the interface.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-20 15:42:12 +01:00
Michal Privoznik
d0baf54e53 qemu: Actually unshare() iff running as root
https://bugzilla.redhat.com/show_bug.cgi?id=1413922

While all the code that deals with qemu namespaces correctly
detects whether we are running as root (and turn into NO-OP for
qemu:///session) the actual unshare() call is not guarded with
such check. Therefore any attempt to start a domain under
qemu:///session shall fail as unshare() is reserved for root.

The fix consists of moving unshare() call (for which we have a
wrapper called virProcessSetupPrivateMountNS) into
qemuDomainBuildNamespace() where the proper check is performed.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
2017-01-17 13:23:56 +01:00
Michal Privoznik
93a062c3b2 qemu: Copy SELinux labels for namespace too
When creating new /dev/* for qemu, we do chown() and copy ACLs to
create the exact copy from the original /dev. I though that
copying SELinux labels is not necessary as SELinux will chose the
sane defaults. Surprisingly, it does not leaving namespace with
the following labels:

crw-rw-rw-. root root system_u:object_r:tmpfs_t:s0     random
crw-------. root root system_u:object_r:tmpfs_t:s0     rtc0
drwxrwxrwt. root root system_u:object_r:tmpfs_t:s0     shm
crw-rw-rw-. root root system_u:object_r:tmpfs_t:s0     urandom

As a result, domain is unable to start:

error: internal error: process exited while connecting to monitor: Error in GnuTLS initialization: Failed to acquire random data.
qemu-kvm: cannot initialize crypto: Unable to initialize GNUTLS library: Failed to acquire random data.

The solution is to copy the SELinux labels as well.

Reported-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-13 14:45:52 +01:00
Michal Privoznik
cbc45525cb qemuDomainCreateDevice: Canonicalize paths
So far the decision whether /dev/* entry is created in the qemu
namespace is really simple: does the path starts with "/dev/"?
This can be easily fooled by providing path like the following
(for any considered device like disk, rng, chardev, ..):

  /dev/../var/lib/libvirt/images/disk.qcow2

Therefore, before making the decision the path should be
canonicalized.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 18:08:13 +01:00
Michal Privoznik
49f326edc0 qemu: Use namespaces iff available on the host kernel
So far the namespaces were turned on by default unconditionally.
For all non-Linux platforms we provided stub functions that just
ignored whatever namespaces setting there was in qemu.conf and
returned 0 to indicate success. Moreover, we didn't really check
if namespaces are available on the host kernel.

This is suboptimal as we might have ignored user setting.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 18:07:43 +01:00
Michal Privoznik
41816751a7 util: Introduce virFileMoveMount
This is a simple wrapper over mount(). However, not every system
out there is capable of moving a mount point. Therefore, instead
of having to deal with this fact in all the places of our code we
can have a simple wrapper and deal with this fact at just one
place.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 18:06:30 +01:00
Michal Privoznik
2ff8c30548 qemuDomainSetupAllInputs: Update debug message
Due to a copy-paste error, the debug message reads:

  Setting up disks

It should have been:

  Setting up inputs.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 17:39:24 +01:00
Michal Privoznik
269589146c qemu_domain: Move qemuDomainGetPreservedMounts
This function is used only from code compiled on Linux. Therefore
on non-Linux platforms it triggers compilation error:

../../src/qemu/qemu_domain.c:209:1: error: unused function 'qemuDomainGetPreservedMounts' [-Werror,-Wunused-function]

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 19:23:49 +01:00
Michal Privoznik
406e390962 qemu: Drop qemuDomainDeleteNamespace
After previous commits, this function is no longer needed.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:57 +01:00
Michal Privoznik
5d198c2b2c qemuDomainCreateNamespace: move mkdir to qemuDomainBuildNamespace
Again, there is no need to create /var/lib/libvirt/$domain.*
directories in CreateNamespace(). It is sufficient to create them
as soon as we need them which is in BuildNamespace. This way we
don't leave them around for the whole lifetime of domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:57 +01:00
Michal Privoznik
5d30057695 qemuDomainGetPreservedMounts: Do not special case /dev
The c1140eb9e got me thinking. We don't want to special case /dev
in qemuDomainGetPreservedMounts(), but in all other places in the
code we special case it anyway. I mean,
/var/run/libvirt/$domain.dev path is constructed separately just
so that it is not constructed here. It makes only a little sense
(if any at all).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:57 +01:00
Michal Privoznik
40ebbf72d5 qemuDomainCreateNamespace: s/unlink/rmdir/
If something goes wrong in this function we try a rollback. That
is unlink all the directories we created earlier. For some weird
reason unlink() was called instead of rmdir().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:57 +01:00
Martin Kletzander
c1140eb9ed qemu: Remove /dev mount info properly
Just so it doesn't bite us in the future, even though it's unlikely.

And fix the comment above it as well.  Commit e08ee7cd34 took the
info from the function it's calling, but that was lie itself in the
first place.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2017-01-05 16:24:55 +01:00
Michal Privoznik
e08ee7cd34 qemuDomainGetPreservedMounts: Fetch list of /dev/* mounts dynamically
With my namespace patches, we are spawning qemu in its own
namespace so that we can manage /dev entries ourselves. However,
some filesystems mounted under /dev needs to be preserved in
order to be shared with the parent namespace (e.g. /dev/pts).
Currently, the list of mount points to preserve is hardcoded
which ain't right - on some systems there might be less or more
items under real /dev that on our list. The solution is to parse
/proc/mounts and fetch the list from there.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-05 16:00:20 +01:00
Michal Privoznik
dd78da09b0 qemuDomainCreateDevice: Be more careful about device path
Again, not something that I'd hit, but there is a chance in
theory that this might bite us. Currently the way we decide
whether or not to create /dev entry for a device is by marching
first four characters of path with "/dev". This might be not
enough. Just imagine somebody has a disk image stored under
"/devil/path/to/disk". We ought to be matching against "/dev/".

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-04 15:36:42 +01:00
Michal Privoznik
ce01a2b11c qemuDomainAttachDeviceMknodHelper: Don't unlink() so often
Not that I'd encounter any bug here, but the code doesn't look
100% correct. Imagine, somebody is trying to attach a device to a
domain, and the device's /dev entry already exists in the qemu
namespace. This is handled gracefully and the control continues
with setting up ACLs and calling security manager to set up
labels. Now, if any of these steps fail, control jump on the
'cleanup' label and unlink() the file straight away. Even when it
was not us who created the file in the first place. This can be
possibly dangerous.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-04 15:36:42 +01:00
Michal Privoznik
3aae99fe71 qemu: Handle EEXIST gracefully in qemuDomainCreateDevice
https://bugzilla.redhat.com/show_bug.cgi?id=1406837

Imagine you have a domain configured in such way that you are
assigning two PCI devices that fall into the same IOMMU group.
With mount namespace enabled what happens is that for the first
PCI device corresponding /dev/vfio/X entry is created and when
the code tries to do the same for the second mknod() fails as
/dev/vfio/X already exists:

2016-12-21 14:40:45.648+0000: 24681: error :
qemuProcessReportLogError:1792 : internal error: Process exited
prior to exec: libvirt: QEMU Driver error : Failed to make device
/var/run/libvirt/qemu/windoze.dev//vfio/22: File exists

Worse, by default there are some devices that are created in the
namespace regardless of domain configuration (e.g. /dev/null,
/dev/urandom, etc.). If one of them is set as backend for some
guest device (e.g. rng, chardev, etc.) it's the same story as
described above.

Weirdly, in attach code this is already handled.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-04 15:36:42 +01:00
John Ferlan
7f7d990483 qemu: Don't assume secret provided for LUKS encryption
https://bugzilla.redhat.com/show_bug.cgi?id=1405269

If a secret was not provided for what was determined to be a LUKS
encrypted disk (during virStorageFileGetMetadata processing when
called from qemuDomainDetermineDiskChain as a result of hotplug
attach qemuDomainAttachDeviceDiskLive), then do not attempt to
look it up (avoiding a libvirtd crash) and do not alter the format
to "luks" when adding the disk; otherwise, the device_add would
fail with a message such as:

   "unable to execute QEMU command 'device_add': Property 'scsi-hd.drive'
    can't find value 'drive-scsi0-0-0-0'"

because of assumptions that when the format=luks that libvirt would have
provided the secret to decrypt the volume.

Access to unlock the volume will thus be left to the application.
2017-01-03 12:59:18 -05:00
Marc Hartmayer
fb2cd32c9a qemu: qemuDomainDiskChangeSupported: Add missing 'address' check
Disk->info is not live updatable so add a check for this. Otherwise
libvirt reports success even though no data was updated.

Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
2016-12-20 11:22:44 +01:00
Michal Privoznik
ab41ce7f4e qemu: Mark more namespace code linux-only
Some of the functions are not called on non-linux platforms
which makes them useless there.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-16 11:51:06 +00:00
Michal Privoznik
f444faa94a qemu: Enable mount namespace
https://bugzilla.redhat.com/show_bug.cgi?id=1404952

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
661887f558 qemu: Let users opt-out from containerization
Given how intrusive previous patches are, it might happen that
there's a bug or imperfection. Lets give users a way out: if they
set 'namespaces' to an empty array in qemu.conf the feature is
suppressed.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
f95c5c48d4 qemu: Manage /dev entry on RNG hotplug
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
f5fdf23a68 qemu: Manage /dev entry on chardev hotplug
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
6e57492839 qemu: Manage /dev entry on hostdev hotplug
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
81df21507b qemu: Manage /dev entry on disk hotplug
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
2160f338a7 qemu: Prepare RNGs when starting a domain
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
8ec8a8c5ff qemu: Prepare inputs when starting a domain
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
2c654490f3 qemu: Prepare TPM when starting a domain
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
4e4451019c qemu: Prepare chardevs when starting a domain
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
73267cec46 qemu: Prepare hostdevs when starting a domain
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
054202d020 qemu: Prepare disks when starting a domain
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
bb4e529664 qemu: Spawn qemu under mount namespace
Prime time. When it comes to spawning qemu process and
relabelling all the devices it's going to touch, there's inherent
race with other applications in the system (e.g. udev). Instead
of trying convincing udev to not touch libvirt managed devices,
we can create a separate mount namespace for the qemu, and mount
our own /dev there. Of course this puts more work onto us as we
have to maintain /dev files on each domain start and device
hot(un-)plug. On the other hand, this enhances security also.

From technical POV, on domain startup process the parent
(libvirtd) creates:

  /var/lib/libvirt/qemu/$domain.dev
  /var/lib/libvirt/qemu/$domain.devpts

The child (which is going to be qemu eventually) calls unshare()
to create new mount namespace. From now on anything that child
does is invisible to the parent. Child then mounts tmpfs on
$domain.dev (so that it still sees original /dev from the host)
and creates some devices (as explained in one of the previous
patches). The devices have to be created exactly as they are in
the host (including perms, seclabels, ACLs, ...). After that it
moves $domain.dev mount to /dev.

What's the $domain.devpts mount there for then you ask? QEMU can
create PTYs for some chardevs. And historically we exposed the
host ends in our domain XML allowing users to connect to them.
Therefore we must preserve devpts mount to be shared with the
host's one.

To make this patch as small as possible, creating of devices
configured for domain in question is implemented in next patches.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
7ed6934f3b virDomainObjGetShortName: take virDomainDef
So far this function takes virDomainObjPtr which:
1) is an overkill,
2) might be not available in all the places we will use it.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-08 15:45:52 +01:00
Laine Stump
9b0848d523 qemu: propagate virQEMUDriver object to qemuDomainDeviceCalculatePCIConnectFlags
If libvirtd is running unprivileged, it can open a device's PCI config
data in sysfs, but can only read the first 64 bytes. But as part of
determining whether a device is Express or legacy PCI,
qemuDomainDeviceCalculatePCIConnectFlags() will be updated in a future
patch to call virPCIDeviceIsPCIExpress(), which tries to read beyond
the first 64 bytes of the PCI config data and fails with an error log
if the read is unsuccessful.

In order to avoid creating a parallel "quiet" version of
virPCIDeviceIsPCIExpress(), this patch passes a virQEMUDriverPtr down
through all the call chains that initialize the
qemuDomainFillDevicePCIConnectFlagsIterData, and saves the driver
pointer with the rest of the iterdata so that it can be used by
qemuDomainDeviceCalculatePCIConnectFlags(). This pointer isn't used
yet, but will be used in an upcoming patch (that detects Express vs
legacy PCI for VFIO assigned devices) to examine driver->privileged.
2016-11-30 15:28:07 -05:00
Michal Privoznik
c2a5a4e7ea virstring: Unify string list function names
We have couple of functions that operate over NULL terminated
lits of strings. However, our naming sucks:

virStringJoin
virStringFreeList
virStringFreeListCount
virStringArrayHasString
virStringGetFirstWithPrefix

We can do better:

virStringListJoin
virStringListFree
virStringListFreeCount
virStringListHasString
virStringListGetFirstWithPrefix

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-11-25 13:54:05 +01:00
Nikolay Shirokovskiy
aaf2992d90 qemu: agent: fix unsafe agent access
qemuDomainObjExitAgent is unsafe.

First it accesses domain object without domain lock.
Second it uses outdated logic that goes back to commit 79533da1 of
year 2009 when code was quite different. (unref function
instead of unreferencing only unlocked and disposed object
in case of last reference and leaved unlocking to the caller otherwise).
Nowadays this logic may lead to disposing locked object
i guess.

Another problem is that the callers of qemuDomainObjEnterAgent
use domain object again (namely priv->agent) without domain lock.

This patch address these two problems.

qemuDomainGetAgent is dropped as unused.
2016-11-23 11:31:28 +03:00
Nikolay Shirokovskiy
3c1c56781d qemu: drop write-only agentStart 2016-11-23 11:31:14 +03:00
Marc Hartmayer
1c122e737e Refactoring: Use virHostdevIsSCSIDevice()
Use the util function virHostdevIsSCSIDevice() to simplify if
statements.

Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
2016-11-22 14:37:36 +01:00
Marc Hartmayer
505bc9b025 qemu: Fix improper union member access on hostdevs
Add missing checks if a hostdev is a subsystem/SCSI device before access
the union member 'subsys'/'scsi'.  Also fix indentation and simplify
qemuDomainObjCheckHostdevTaint().

Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
2016-11-22 14:37:36 +01:00
Peter Krempa
0df2524acb qemu: domain: Refresh vcpu halted state using qemuMonitorGetCpuHalted
Don't use qemuMonitorGetCPUInfo which does a lot of matching to get the
full picture which is not necessary and would be mostly discarded.

Refresh only the vcpu halted state using data from query-cpus.
2016-11-21 17:19:48 +01:00
Peter Krempa
3f71c79768 qemu: monitor: Extract qemu cpu id along with other data
Storing of the ID will allow simpler extraction of data present only in
query-cpus without the need to call qemuMonitorGetCPUInfo in statistics
paths.
2016-11-21 17:19:48 +01:00
Laine Stump
d8bd837669 qemu: add a USB3 controller to Q35 domains by default
Previously we added a set of EHCI+UHCI controllers to Q35 machines to
mimic real hardware as closely as possible, but recent discussions
have pointed out that the nec-usb-xhci (USB3) controller is much more
virtualization-friendly (uses less CPU), so this patch switches the
default for Q35 machinetypes to add an XHCI instead (if it's
supported, which it of course *will* be).

Since none of the existing test cases left out USB controllers in the
input XML, a new Q35 test case was added which has *no* devices, so
ends up with only the defaults always put in by qemu, plus those added
by libvirt.
2016-11-14 14:22:23 -05:00
Laine Stump
807232203a qemu: don't force-add a dmi-to-pci-bridge just on principle
Now the a dmi-to-pci-bridge is automatically added just as it's needed
(when a pci-bridge is being added), we no longer have any need to
force-add one to every single Q35 domain.
2016-11-14 14:21:43 -05:00
Laine Stump
50adb8a660 qemu: new functions qemuDomainMachineHasPCI[e]Root()
These functions provide a simple one line method of learning if the
current domain has a pci-root or pcie-root bus.
2016-11-14 14:03:09 -05:00
Martin Kletzander
acf0ec024a qemu: Save various defaults for shmem
We're keeping some things at default and that's not something we want to
do intentionally.  Let's save some sensible defaults upfront in order to
avoid having problems later.  The details for the defaults (of the newer
implementation) can be found in qemu's commit 5400c02b90bb:

  http://git.qemu.org/?p=qemu.git;a=commit;h=5400c02b90bb

Since we are merely saving the defaults it will not change the guest ABI
and thanks to the fact that we're doing it in the PostParse callback it
will not break the ABI stability checks.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2016-11-02 16:05:39 +01:00
John Ferlan
daf5c651f0 qemu: Add a secret object to/for a char source dev
Add the secret object so the 'passwordid=' can be added if the command line
if there's a secret defined in/on the host for TCP chardev TLS objects.

Preparation for the secret involves adding the secinfo to the char source
device prior to command line processing. There are multiple possibilities
for TCP chardev source backend usage.

Add test for at least a serial chardev as an example.
2016-10-26 07:18:25 -04:00
Viktor Mihajlovski
08f22976b1 qemu: Add domain support for VCPU halted state
Adding a field to the domain's private vcpu object to hold the halted
state information.
Adding two functions in support of the halted state:
- qemuDomainGetVcpuHalted: retrieve the halted state from a
  private vcpu object
- qemuDomainRefreshVcpuHalted: obtain the per-vcpu halted states
  via qemu monitor and store the results in the private vcpu objects

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Hao QingFeng <haoqf@linux.vnet.ibm.com>
Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
2016-10-24 18:52:36 -04:00
Pavel Hrdina
7c8df1e82f domain: fix migration to older libvirt
Since TLS was introduced hostwide for libvirt 2.3.0 and a domain
configurable haveTLS was implemented for libvirt 2.4.0, we have to
modify the migratable XML for specific case where the 'tls' attribute
is based on setting from qemu.conf.

The "tlsFromConfig" is libvirt internal attribute and is stored only in
status XML to ensure that when libvirtd is restarted this internal flag
is not lost by the restart.

That flag is used to decide whether we should put *tls* attribute to
migratable XML or not.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2016-10-24 16:29:26 +02:00
Pavel Hrdina
0298531b29 domain: Add optional 'tls' attribute for TCP chardev
Add an optional "tls='yes|no'" attribute for a TCP chardev.

For QEMU, this will allow for disabling the host config setting of the
'chardev_tls' for a domain chardev channel by setting the value to "no" or
to attempt to use a host TLS environment when setting the value to "yes"
when the host config 'chardev_tls' setting is disabled, but a TLS environment
is configured via either the host config 'chardev_tls_x509_cert_dir' or
'default_tls_x509_cert_dir'

Signed-off-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
2016-10-24 16:05:33 +02:00
John Ferlan
7bd8312e7f conf: Move the privateData from virDomainChrDef to virDomainChrSourceDef
Commit id '5f2a132786' should have placed the data in the host source
def structure since that's also used by smartcard, redirdev, and rng in
order to provide a backend tcp channel.  The data in the private structure
will be necessary in order to provide the secret properly.

This also renames the previous names from "Chardev" to "ChrSource" for
the private data structures and API's
2016-10-21 16:42:59 -04:00