Some layered products such as oVirt have requested a way to avoid being
blocked by guest agent commands when querying a loaded vm. For example,
many guest agent commands are polled periodically to monitor changes,
and rather than blocking the calling process, they'd prefer to simply
time out when an agent query is taking too long.

This patch adds a way for the user to specify a custom agent timeout
that is applied to all agent commands.

One special case to note here is the 'guest-sync' command. 'guest-sync'
is issued internally prior to calling any other command. (For example,
when libvirt wants to call 'guest-get-fsinfo', we first call
'guest-sync' and then call 'guest-get-fsinfo').

Previously, the 'guest-sync' command used a 5-second timeout
(VIR_DOMAIN_QEMU_AGENT_COMMAND_DEFAULT), whereas the actual command that
followed always blocked indefinitely
(VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK). As part of this patch, if a
custom timeout is specified that is shorter than
5 seconds,  this new timeout is also used for 'guest-sync'. If there is
no custom timeout or if the custom timeout is longer than 5 seconds, we
will continue to use the 5-second timeout.
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

The pconfig feature was enabled in QEMU by accident in 3.1.0. All other
newer versions do not support it and it was removed from the
Icelake-Server CPU model in QEMU.

We don't normally change our CPU models even when QEMU does so to avoid
breaking migrations between different versions of libvirt. But we can
safely do so in this specific case. QEMU never supported enabling
pconfig so any domain which was able to start has pconfig disabled.

With a small compatibility hack which explicitly disables pconfig when
CPU model equals Icelake-Server in migratable domain definition, only
one migration scenario stays broken (and there's nothing we can do about
it): from any host to a host with libvirt < 5.10.0 and QEMU > 3.1.0.

https://bugzilla.redhat.com/show_bug.cgi?id=1749672Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

The function does not do anything that could fail. Remove the return
value.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

qemuDomainPrepareDiskSourceData historically prepared everything but
we've split out the majority of the functionality so that it sets up
predominately only according to the configuration of the disk. There
was one leftover bit of setting the gluster debug level from the config.

Split this out into a separate function so that
qemuDomainPrepareDiskSourceData only prepares based on the disk.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
ACKed-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

When undefining a UEFI domain its nvram file has to be properly handled as
well.  It's mandatory to use one of --nvram and --keep-nvram options when
'virsh undefine <domain>' is issued for a UEFI domain.  To fix the bug as
reported, virsh should return an error message if neither option is used
and the nvram file should be removed when --nvram is given.

The cause of the problem is that when qemuDomainUndefineFlags() is invoked
on an inactive domain the path to its nvram file is empty.  This commit
aims to fix this by formatting and filling in the path in time for the
nvram removal code to run properly.

https://bugzilla.redhat.com/show_bug.cgi?id=1751596Signed-off-by: NPavel Mores <pmores@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Introduced in GLib 2.10.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Rather than having to fix 5 places once we support the combination, add
a function called by all the blockjob/snapshot APIs.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Finish the refactor by moving and renaming functions from qemu_domain.c
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Move it to qemu_domain.c and rename it to qemuDomainObjFromDomain. This
will allow reusing it after splitting out checkpoint code from
qemu_driver.c.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Similar to the qemu_tpm.c, add a unit with a few functions to
start/stop and setup the cgroup of the external vhost-user-gpu
process. See function documentation.

The vhost-user connection fd is set on qemuDomainVideoPrivate struct.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

The same validation should be done for both static network devices and
hotplugged devices, but they are currently inconsistent. Move all the
relevant validation from qemuBuildInterfaceCommandLine() into the new
function qemuDomainValidateActualNetDef() and call the latter from
the former.
Signed-off-by: NLaine Stump <laine@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Let's pull this hunk out into a function, so it can be reused
in another codepath that needs to do the same thing.
Signed-off-by: NEric Farman <farman@linux.ibm.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

For VM started and migrated/saved without slirp-helpers, let's prevent
the automatic setup (as it would fail to migrate otherwise).
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Save & restore the slirp helper PID associated with a network
interface & the probed features.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

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

Add dbusVMStates to keep a list of dbus-vmstate objects needed for
migration. They are populated on the command line during start or
qemuDBusVMStateAdd/Remove() will hotplug them as needed.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Since libvirt stores the backing chain into the XML in a nested way it
is the prime possibility to hit libxml2's parsing limit of 256 layers.

Introduce code which will crawl the backing chain and verify that it's
not too deep. The maximum nesting is set to 200 layers so that there's
still some space left for additional properties or nesting into snapshot
XMLs.

The check is applied to all disk use cases (starting, hotplug, media
change) as well as block copy which changes image and snapshots.

We simply report an error and refuse the operation.

Without this check a restart of libvirtd would result in the status XML
failing to be parsed and thus losing the VM.

https://bugzilla.redhat.com/show_bug.cgi?id=1524278Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

In addition to the data that libvirt needs and extracts internally,
copy and store the whole 'props' JSON sub-object of the data returned by
query-hotpluggable-cpus for future use.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>

Now that virDomainXMLNamespace matches virXMLNamespace,
we no longer need to keep both around.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>

Since qemuDomainDefPostParse callback requires qemuCaps, we need to make
sure it gets the capabilities stored in the domain's private data if the
domain is running. Passing NULL may cause QEMU capabilities probing to
be triggered in case QEMU binary changed in the meantime. When this
happens while a running domain object is locked, QMP event delivered to
the domain before QEMU capabilities probing finishes will deadlock the
event loop.

This patch fixes all paths leading to qemuDomainDefFormatBufInternal.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Since qemuDomainDefPostParse callback requires qemuCaps, we need to make
sure it gets the capabilities stored in the domain's private data if the
domain is running. Passing NULL may cause QEMU capabilities probing to
be triggered in case QEMU binary changed in the meantime. When this
happens while a running domain object is locked, QMP event delivered to
the domain before QEMU capabilities probing finishes will deadlock the
event loop.

This patch fixes all paths leading to qemuDomainDefCopy.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Qemu bitmap operations require knowing the node name associated with
the format layer (the qcow2 file); as upcoming patches will be
grabbing that information frequently, make a helper function to access
it.

Another potential benefit of this function is that we have a single
place where we could insert a QMP node-name scraping call if we don't
currently know the node name, when -blockdev is not supported;
however, the goal is that we hopefully don't ever have to do that
because we instead scrape node names only at the point where they
change.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

A lot of this work heavily copies from the existing snapshot APIs.
What's more, this patch is (intentionally) very similar to the
checkpoint code just added in the test driver, to the point that qemu
checkpoints are not fully usable in this patch, but it at least
bisects and builds cleanly.  The separation between patches is done
because the grunt work of saving and restoring XML and tracking
relations between checkpoints is common to the test driver, while the
later patch adding integration with QMP is specific to qemu.

Also note that the interlocking to prevent checkpoints and snapshots
from existing at the same time will be a separate patch, to make it
easier to revert that restriction when we finally round out the design
for supporting interaction between the two concepts.
Signed-off-by: NEric Blake <eblake@redhat.com>

The PR manager is a property of the format layer in qemu so we need to
be able to track it also in the chains of orphaned block jobs.

Add a helper for qemu to look also into the blockjob state.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Add support for handling the event either synchronously or
asynchronously using the event thread.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Block jobs currently belong to disks only so we can look up the block
job data for them in the corresponding disks. This won't be the case
when using blockdev as certain jobs don't even correspond to a disk and
most of them can run on a part of the backing chain.

Add a global table of blockjobs which can be used to look up the data
for the blockjobs when the job events need to be processed.

The table is a hash table organized by job name and has a reference to
the job. New and running jobs will later be added to this table.
Reference counting will allow to reap job state for synchronous callers.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Similarly to qemuDomainSaveStatus add a helper to save the config XML
named qemuDomainSaveConfig.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Rename qemuDomainObjSaveJob and create a wrapper for it which does not
require 'driver' to be passed and export it so that other palces can
easily save the status XML without having to invoke virDomainSaveStatus
which has unpleasing parameters.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

There are some paths (e.g. /dev/vfio/vfio or /dev/mapper/control)
which are defined in qemu_domain.c and then in qemu_cgroup.c
again. This is suboptimal. Let's move paths into qemu_domain.h and
drop duplicate definitions.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

Similarly how we allow adding arbitrary command line arguments and
environment variables this patch introduces the ability to control
libvirt's perception of the qemu process by tweaking the capability bits
for testing purposes.

The idea is to allow developers and users either test a new feature by
enabling it early or disabling it to see whether it introduced
regressions.

This feature is not meant for production use though, so users should
handle it with care.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

qemu_conf.c deals with the configuration file. Better fit for the
structure and freeing function will be qemu_domain.c where the rest of
the namespace parsing/formatting stuff resides.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

If we have a monitor, it is a JSON monitor.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Acked-by: NPeter Krempa <pkrempa@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Introduce qemuDomainStorageSourceChainAccess(Allow|Revoke) as entry
points to qemuDomainStorageSourceChainAccessPrepare for symmetry with
the functions for single backing chain elements.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Move it to qemu_domain.c and call it
qemuDomainStorageSourceChainAccessPrepare.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>