On s390 machines host-passthrough and host-model CPUs result in the same
guest ABI (with QEMU new enough to be able to tell us what "host" CPU is
expanded to, which was implemented around 2.9.0). So instead of using
host-passthrough CPU when there's no CPU specified in a domain XML we
can safely use host-model and benefit from CPU compatibility checks
during migration, snapshot restore and similar operations.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

If a graphics device was added to XML that had no video device, libvirt
automatically added a video device which was always of type 'cirrus' on
x86_64, even if the underlying qemu didn't support cirrus.

This patch refines a bit the decision about the type of the video device.
Based on QEMU capabilities, cirrus is still preferred but only added if
QEMU supports it, otherwise VGA is used if supported by QEMU.  There is now
no fallback as libvirt only aspires to generate a basic working config and
leaves anything more specific up to higher-level management tools.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NPavel Mores <pmores@redhat.com>

The default video device type selection algorithm we're about to deploy will
increase the amount of code dedicated to the task by amount enough to warrant
factoring the whole thing into its own function so as not to pollute the
caller qemuDomainDeviceVideoDefPostParse().  Do it now so that the actual
algorithm change later on is in a clean commit by itself and easy to review.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NPavel Mores <pmores@redhat.com>

This previous commit introduced a simpler free callback for
hash data with only 1 arg, the value to free:

  commit 49288fac
  Author: Peter Krempa <pkrempa@redhat.com>
  Date:   Wed Oct 9 15:26:37 2019 +0200

    util: hash: Add possibility to use simpler data free function in virHash

It missed two functions in the hash table code which need
to call the alternate data free function, virHashRemoveEntry
and virHashRemoveSet.

After the previous patch though, there is no code that
makes functional use of the 2nd key arg in the data
free function. There is merely one log message that can
be dropped.

We can thus purge the current virHashDataFree callback
entirely, and rename virHashDataFreeSimple to replace
it.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Add a helper which will covert the PFLASH code file and variable file
into the virStorageSource objects stored in private data so that we can
use them with -blockdev while keeping the infrastructure to determine
the path to the loaders intact.

This is a temporary solution until we will want to do snapshots of the
pflash where we will be forced do track the full backing chain in the
XML.

In the meanwhile just convert it partially so that we can stop using
-drive.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

To allow converting the pflash drives to blockdev we will need a
virStorageSource to allow using our helpers. Temporarily prior to
coverting loader data to a virStorageSoruce add private data which will
house this.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

When starting a domain without a CPU model specified in the domain XML,
QEMU will choose a default one. Which is fine unless the domain gets
migrated to another host because libvirt doesn't perform any CPU ABI
checks and the virtual CPU provided by QEMU on the destination host can
differ from the one on the source host.

With QEMU 4.2.0 we can probe for the default CPU model used by QEMU for
a particular machine type and store it in the domain XML. This way the
chosen CPU model is more visible to users and libvirt will make sure
the guest will see the exact same CPU after migration.

Architecture specific notes
- aarch64: We only set the default CPU for TCG domains as KVM requires
  explicit "-cpu host" to work.

- ppc64: The default CPU for KVM is "host" thanks to some hacks in QEMU,
  we will translate the default model to the model corresponding to the
  host CPU ("POWER8" on a Power8 host, "POWER9" on Power9 host, etc.).
  This is not a problem as the corresponding CPU model is in fact an
  alias for "host". This is probably not ideal, but it's not wrong and
  the default virtual CPU configured by libvirt is the same QEMU would
  use. TCG uses various CPU models depending on machine type and its
  version.

- s390x: The default CPU for KVM is "host" while TCG defaults to "qemu".

- x86_64: The default CPU model (qemu64) is not runnable on any host
  with KVM, but QEMU just disables unavailable features and starts
  happily.

https://bugzilla.redhat.com/show_bug.cgi?id=1598151
https://bugzilla.redhat.com/show_bug.cgi?id=1598162Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Another weird bug appeared concerning qemu namespaces. Basically
the problem is as follows:

1) Issue an API that causes libvirt to create a node in domain's
   namespace, say /dev/nvme0n1 with 8:0 as major:minor (the API can
   be attach-disk for instance). Or simply create the node from a
   console by hand.

2) Detach the disk from qemu.

3) Do something that makes /dev/nvme0n1 change it's minor number.

4) Try to attach the disk again.

The problem is, in a few cases - like disk-detach - we don't
remove the corresponding /dev node from the mount namespace
(because it may be used by some other disk's backing chain). But
this creates a problem, because if the node changes its MAJ:MIN
numbers we don't propagate the change into the domain's
namespace. We do plain mknod() and ignore EEXIST which obviously
is not enough because it doesn't guarantee that the node has
updated MAJ:MIN pair.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1752978Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

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

qemuDomainDefFormatBufInternal function wasn't testing whether the CPU
was actually defined in the XML and saving such a domain resulted in the
following backtrace:

0 in qemuDomainMakeCPUMigratable (cpu=0x0)
1 in qemuDomainDefFormatBufInternal()
2 in qemuDomainDefFormatXMLInternal()
3 in qemuDomainDefFormatLive()
4 in qemuDomainSaveInternal()
5 in qemuDomainSaveFlags()
6 in qemuDomainSave()
7 in virDomainSave()
Signed-off-by: NErik Skultety <eskultet@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

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>

As suggested by Cole, this patch uses the domain capabilities to
validate the supported video model types. This allows us to remove the
model type validation from qemu_process.c and qemu_domain.c and
consolidates it all in a single place that will automatically adjust
when new domain capabilities are added.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>

Continue consolidation of video device validation started in previous
patch.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>

The goal is to move all of the video device validation to a single place
and use domain caps to validate the supported video device models. Since
qemuDomainDeviceDefValidateVideo() is called from
qemuProcessStartValidate(), these changes should not change anny
behavior.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>

This allows us to simplify the function and avoid jumping to 'cleanup'.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>

When the virDomainCapsDeviceDefValidate() function returned an error
status (-1), we were aborting the function early, but returning the
default return value (0). This patch properly returns an error in that
case.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>

In an effort to remove as much gnulib usage as possible let's
reimplement virFileReadLink. Since it's used in two places only I opted
to open-code it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Fixes: 224d269fSigned-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

Use the new helper to initialize child XML element buffers.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@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>

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

The qemuDomainObjEnterMonitor() should not be called without a
job set. Catch this error and produce a warning message if such
call occurred.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJonathon Jongsma <jjongsma@redhat.com>

This introduces semantic validation for SVE-related features,
preventing the user from combining them in invalid ways; it also
automatically enables overall SVE support if any SVE vector
length has been enabled by the user to make sure QEMU behaves
correctly.
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>
Tested-by: NAndrew Jones <drjones@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Now that we don't have to deal with errors of virBuffer we can also make
this function void.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The function now does not return an error so we can drop it fully.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

All OSes that we support have libselinux >= 2.5 except for Ubuntu 16.04
where the version is 2.4.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

In many cases we used virDomainDiskByName to solely look up disk by
target. We have a new helper now so we can replace it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

In some cases we want to prepare a @src which is not meant to belong to
a disk and thus does not require us to copy the data. Allow passing in
NULL @disk into qemuDomainPrepareDiskSourceData.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

Note in the comment that this function prepares the storage source based
on the configuration of the disk.
Signed-off-by: NPeter Krempa <pkrempa@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>

The @freeTmpPath boolean is used to determine if @tmpPath holds
an allocated memory or is a pointer to a constant string and
therefore if it needs to be freed or not when returning from the
function. Well, we can unify the way we set @tmpPath so that it
always holds an allocated memory and thus always must be freed.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

There are three cases where vir*DeviceGetPath() returns a const
string. In these cases, the string is initialized in
corresponding vir*DeviceNew() calls which fail if string couldn't
be allocated. There's no point in checking the second time if the
string is NULL.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

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

In some places we need to check if a hostdev has VFIO backend.
Because of how complicated virDomainHostdevDef structure is, the
check consists of three lines. Move them to a function and
replace all checks with the function call.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

Replace all occurrences of
  if (VIR_STRDUP(a, b) < 0)
     /* effectively dead code */
with:
  a = g_strdup(b);
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Replace:
  if (!s && VIR_STRDUP(s, str) < 0)
    goto;
with:
  if (!s)
    s = g_strdup(str);
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>