It is more related to a domain as we might use it even when there is
no systemd and it does not use any dbus/systemd functions.  In order
not to use code from conf/ in util/ pass machineName in cgroups code
as a parameter.  That also fixes a leak of machineName in the lxc
driver and cleans up and de-duplicates some code.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

This way we can finally make it static and not use any externs anywhere.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

vcpu properties gathered from query-hotpluggable cpus need to be passed
back to qemu. As qemu did not use the node-id property until now and
libvirt forgot to pass it back properly (it was parsed but not passed
around) we did not honor this.

This patch adds node-id to the structures where it was missing and
passes it around as necessary.

The test data was generated with a VM with following config:
    <numa>
      <cell id='0' cpus='0,2,4,6' memory='512000' unit='KiB'/>
      <cell id='1' cpus='1,3,5,7' memory='512000' unit='KiB'/>
    </numa>

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1452053

In QEMU driver we can use virtlogd as stdio handler for source backend
of char devices if current QEMU is new enough and it's enabled in
qemu.conf.  We should store this information while starting a guest
because the config option may change while the guest is running.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

When making ABI stability checks for an active domain, we need to make
sure we use the same migratable definition which virDomainGetXMLDesc
with the MIGRATABLE flag provides, otherwise the ABI check will fail.
This is implemented in the new qemuDomainCheckABIStability which takes a
domain object and generates the right migratable definition from it.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

If QEMU is new enough and we have the live updated CPU definition in
either save or migration cookie, we can use it to enforce ABI. The
original guest CPU from domain XML will be stored in private data.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

Since the domain XML saved in a snapshot or saved image uses the
original guest CPU definition but we still want to enforce ABI when
restoring the domain if libvirt and QEMU are new enough, we save the
live updated CPU definition in a save cookie.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

The destination host may not be able to start a domain using the live
updated CPU definition because either libvirt or QEMU may not be new
enough. Thus we need to send the original guest CPU definition.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

When starting a domain we update the guest CPU definition to match what
QEMU actually provided (since it is allowed to add or removed some
features unless check='full' is specified). Let's store the original CPU
in domain private data so that we can use it to provide a backward
compatible domain XML.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

This patch implements a new save cookie object and callbacks for qemu
driver. The actual useful content will be added in the object later.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

This will be used later when a save cookie will become part of the
snapshot XML using new driver specific parser/formatter functions.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1450349

Problem is, qemu fails to load guest memory image if these
attribute change on migration/restore from an image.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Not all async jobs are visible via virDomainGetJobStats (either they are
too fast or getting the stats is not allowed during the job), but
forcing all of them to advertise the operation is easier than hunting
the jobs for which fetching statistics is allowed. And we won't need to
think about this when we add support for getting stats for more jobs.

https://bugzilla.redhat.com/show_bug.cgi?id=1441563Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Introduce new wrapper functions without *Machine* in the function
name that take the whole virDomainDef structure as argument and
call the existing functions with *Machine* in the function name.

Change the arguments of existing functions to *machine* and *arch*
because they don't need the whole virDomainDef structure and they
could be used in places where we don't have virDomainDef.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

This way qemuDomainLogContextRef() and qemuDomainLogContextFree() is
no longer needed. The naming qemuDomainLogContextFree() was also
somewhat misleading. Additionally, it's easier to turn
qemuDomainLogContext in a self-locking object.
Signed-off-by: NMarc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: NBjoern Walk <bwalk@linux.vnet.ibm.com>

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.

So far, the official support is for x86_64 arch guests so unless a
different device API than vfio-pci is available let's only turn on
support for PCI address assignment. Once a different device API is
introduced, we can enable another address type easily.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

To allow matching the node names gathered via 'query-named-block-nodes'
we need to query and then use the top level nodes from 'query-block'.
Add the data to the structure returned by qemuMonitorGetBlockInfo.

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.

Looks up a disk and its corresponding backing chain element by node
name.

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.

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>

QEMU should be written all upper or all lower case.

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 61b52d2e.
Signed-off-by: NMarc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>

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: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>

After previous commits, this function is no longer needed.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

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.

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: NMichal Privoznik <mprivozn@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>

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: NMichal Privoznik <mprivozn@redhat.com>