The PMU feature is enabled by default in ppc64 guests and can't
be disabled via Libvirt or QEMU [1]. The current PMU feature
implementation does not allow PMU to enabled or disabled in the
ppc64 guest. Declaring the PMU feature will make the 'pmu'
property to be passed on to QEMU, but this property isn't
available for ppc64:

qemu-kvm: can't apply global host-powerpc64-cpu.pmu=on: Property '.pmu' not found

A similar error is thrown when trying to disable the PMU.

This patch standardizes the PMU handling for ppc64 guests by:

- throwing an error if the user attempts to set the feature to
'off', given that this feature can't be turned off at all;

- allowing the feature to be declared as 'on' in the domain XML.
This is done by skipping ppc64 guests when creating the command
line for this feature.

[1] https://www.redhat.com/archives/libvir-list/2020-March/msg00874.htmlSigned-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

Hyperv features are supported by both x86 and aarch64. The <hyperv/>
declaration in the XML by itself is benign to other architectures,
but any of its 14 current features will break QEMU with an error
like this (from ppc64):

qemu-kvm: Expected key=value format, found hv_relaxed

This is a more extreme case than the one for apic eoi because we
would need an extra 'switch' statement, with all current Hyperv
features in the body of qemuDomainDefValidateFeatures(), to
check if the user attempted to activate any of them. It's easier to
simply fail to launch with any 'hyperv' declaration in the XML for
every arch which is not x86 and aarch64.

A fair disclaimer about Windows and PowerPC: the last Windows version
that ran in the architecture is the hall of famer Windows NT 4.0,
launched in 1996 and with end of extended support for the Server
version in 2004 [1]. I am acknowledging that there might be Windows
NT 4.0 users running in PowerPC, but not enough people running it
under KVM/QEMU to justify Libvirt allowing 'hyperv' to exist in the
domain XML of ppc64 domains.

[1] https://en.wikipedia.org/wiki/Windows_NT_4.0Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

The 'pvspinlock' feature is x86 only. The "<pvspinlock/>" declaration
will always have a value 'on' or 'off', and both will break QEMU when
launching non-x86 guests. This is the error message for
"<pvspinlock state='on'/>" when running a ppc64 guest:

qemu-kvm: Expected key=value format, found +kvm_pv_unhalt

A similar error message is thrown for "<pvspinlock state='off'/>".

This patch prevents non-x86 guests from launching with any
pvspinlock setting with a more informative error message:

error: unsupported configuration: The 'pvspinlock' feature is not
supported for architecture 'ppc64' or machine type 'pseries'
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

The "<apic/>" feature, although it's available only for x86 guests,
can be declared in the domain XML of other archs without errors.
But setting its 'eoi' attribute will break QEMU. For "<apic eoi='on'/>",
in a ppc64 guest:

qemu-kvm: Expected key=value format, found +kvm_pv_eoi

A similar error happens with eoi='off'.

One can argue that it's better to simply forbid launching non-x86
guests with "<apic/>" declared in the XML - it is a feature that
the architecture doesn't support and this would make it clearer
about it. This is sensible, but there are non-x86 guests that are
running with "<apic/>" declared in the domain (and A LOT of guests
running with "<acpi/>" for that matter, probably reminiscent of x86
templates that were reused for other archs) that will stop working if we
go this route.

A more subtle approach is to detect if the 'eoi' element is being set
for non-x86 guests and warn the user about it with a better error
message than the one QEMU provides. This is the new error message
when any value is set for the 'eoi' element in a ppc64 XML:

error: unsupported configuration: The 'eoi' attribute of the 'apic'
feature is not supported for architecture 'ppc64' or machine type
'pseries'.

https://bugzilla.redhat.com/show_bug.cgi?id=1236440Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

Don't report cases when the guest information is not requested
explicitly and not present either.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Use qemuAgentCommandFull so that callers of qemuAgentGetFSInfo can
suppress error reports if the function is not supported by the guest
agent.

Since this patch removes the last use of
qemuAgentErrorCommandUnsupported the whole function is deleted as well.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Use qemuAgentCommandFull so that callers of qemuAgentGetTimezone can
suppress error reports if the function is not supported by the guest
agent.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Use qemuAgentCommandFull so that callers of qemuAgentGetOSInfo can
suppress error reports if the function is not supported by the guest
agent.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Use qemuAgentCommandFull so that callers of qemuAgentGetUsers can
suppress error reports if the function is not supported by the guest
agent.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Use qemuAgentCommandFull in qemuAgentGetHostname so that we can suppress
error reports if the caller will not require them. Callers for now
always require error reporting but will be fixed later.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

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

Return 0 on success to match the documentation. The callers only check
for negative values.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

In some cases we don't want to log errors if an agent command is
unsupported. Wire it up into qemuAgentCheckError via qemuAgentCommandFull
and provide a thin wrapper (qemuAgentCommand) to prevent having to fix
all callers.
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>

'qemuDomainGetGuestInfoCheckSupport' despite its name was not checking
whether the info types are supported. Convert the function to return
integers and include the check.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The logic has been moved to the individual drivers.
Signed-off-by: NRafael Fonseca <r4f4rfs@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

The logic setting a device default should be in the post parse function
of individual driver code.
Signed-off-by: NRafael Fonseca <r4f4rfs@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

The logic setting a device default should be in the post parse function
of individual driver code.
Signed-off-by: NRafael Fonseca <r4f4rfs@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

The logic setting a device default should be in the post parse function
of individual driver code.
Signed-off-by: NRafael Fonseca <r4f4rfs@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

The logic setting a device default should be in the post parse function
of individual driver code.
Signed-off-by: NRafael Fonseca <r4f4rfs@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

The logic setting a device default should be in the post parse function
of individual driver code.
Signed-off-by: NRafael Fonseca <r4f4rfs@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

The logic setting a device default should be in the post parse function
of individual driver code.
Signed-off-by: NRafael Fonseca <r4f4rfs@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Unfortunately, advisory record locking lose the lock if any fd refering
to the file is closed. There doesn't seem to be a way to preserve the
lock atomically. We could eventually retake the lock if low pidfilefd
is required.

This fixes processes being leaked, as they are not killed in
virPidFileForceCleanupPath() if the lock can be taken. Here also, we may
consider this is not good enough, as a process may leak by simply
closing the pidfilefd.

Fixes commit d146105f ("virCommand:
Actually acquire pidfile instead of just writing it")
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

s/ommited/omitted/
Signed-off-by: NJán Tomko <jtomko@redhat.com>

The WIP specification is hosted on slirp wiki at this point:
https://gitlab.freedesktop.org/slirp/libslirp/-/wikis/Slirp-Helper

We would need more feedback from various parties (including libvirt,
podman, and other developpers) before declaring a frozen version.

So for now, follow it, and feedback welcome!
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

When the helper supports DBus, connect it to the bus and set its ID.

If the helper supports migration, register its ID to the list of
dbus-vmstate ID to migrate, and specify --dbus-incoming when
restoring the VM.
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>

Helper processes may have their state migrated with QEMU data stream
thanks to the QEMU "dbus-vmstate".

libvirt maintains the list of helpers to be migrated. The
"dbus-vmstate" is added when required, and given the list of helper
Ids that must be migrated, on save & load sides.

See also:
https://git.qemu.org/?p=qemu.git;a=blob;f=docs/interop/dbus-vmstate.rstSigned-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>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

This avoids trying to start a dbus-daemon when its already running.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Add a unit to start & stop a private dbus-daemon.

The daemon is meant to be started on demand, and associated with a
QEMU process. It should be stopped when the QEMU process is stopped.

The current policy is permissive like a session bus. Stricter
policies can be added later, following recommendations from:
https://git.qemu.org/?p=qemu.git;a=blob;f=docs/interop/dbus.rstSigned-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Location of DBus daemon state configuration, socket, pid...
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

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

This code was based on a per-helper instance and peer-to-peer
connections. The code that landed in qemu master for v5.0 is relying
on a single instance and DBus bus.

Instead of trying to adapt the existing dbus-vmstate code, let's
remove it and resubmit. That should make reviewing easier.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

In the network driver code there's networkKillDaemon() which is
the same as virProcessKillPainfully(). Replace the former with
the later and drop what becomes unused function.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

Now, that we know that the virtiofsd will have the pidfile open
and locked we can use virPidFileForceCleanupPath() to kill it and
unlink the pidfile.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

Now, that we know that the slirp helper will have the pidfile
open and locked we can use virPidFileForceCleanupPath() to kill
it and unlink the pidfile.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

Now, that our virCommandSetPidFile() is more intelligent we don't
need to rely on the daemon to create and lock the pidfile and use
virCommandSetPidFile() at the same time.

NOTE that as advertised in the previous commit, this was
temporarily broken, because both virCommand and
qemuProcessStartManagedPRDaemon() would try to lock the pidfile.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

Our virCommand module allows us to set a pidfile for commands we
want to spawn. The caller constructs the string of pidfile path
and then uses virCommandSetPidFile() to tell the module to write
the pidfile once the command is ran. This usually works, but has
two flaws:

1) the child process does not hold the pidfile open & locked.
Therefore, the caller (or anybody else) can't use our fancy
virPidFileForceCleanupPath() function to kill the command
afterwards. Also, for everybody else on the system it's
needlessly harder to check if the pid from the pidfile is still
alive or not.

2) if the caller ever makes a mistake and passes the same pidfile
path for two different commands, the start of the second command
will overwrite the pidfile even though the first command might
still be running.

NOTE that this temporarily renders some command spawning
unusable, specifically those code patterns where both
virCommandSetPidFile() is used together with instructing spawned
command to acquire pidfile itself. Fortunately, there is only one
occurrence of such pattern and it is in
qemuProcessStartManagedPRDaemon(). This is fixed in next commit.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: NSeeteena Thoufeek <s1seetee@linux.vnet.ibm.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

As a part of c799d150 I've introduced a test case that
tests whether passing error object between processes works. The
test spawns a child which reports a system error, parent process
then reads the error and compares with expected output. Problem
with this approach is that error message contains stringified
errno which is not portable. FreeBSD has generally different
messages than Linux. Therefore, use g_strerror() to do the errno
to string translation for us.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>