Since v4.2-rc0, QEMU introduced a builtin rng backend that uses
getrandom() syscall to generate random. Add it to libvirt with the
backend model 'builtin'.

https://bugzilla.redhat.com/show_bug.cgi?id=1785091Signed-off-by: NHan Han <hhan@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

It is used to check if qemu is capable of rng-builtin object.

This object is added since qemu-4.2.0-rc0, commit 6c4e9d48.
Signed-off-by: NHan Han <hhan@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Since v5.6.0-48-g270583ed we try to cache domain capabilities,
i.e. store filled virDomainCaps in a hash table in virQEMUCaps
for future use. However, there's a race condition in the way it's
implemented. We use virQEMUCapsGetDomainCapsCache() to obtain the
pointer to the hash table, then we search the hash table for
cached data and if none is found the domcaps is constructed and
put into the table. Problem is that this is all done without any
locking, so if there are two threads trying to do the same, one
will succeed and the other will fail inserting the data into the
table.

Also, the API looks a bit fishy - obtaining pointer to the hash
table is dangerous.

The solution is to use a mutex that guards the whole operation
with the hash table. Then, the API can be changes to return
virDomainCapsPtr directly.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1791790Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>

The virConnectGetDomainCapabilities API accepts either a binary path
to the emulator, or desired guest arch. If guest arch is not given,
then the host arch is assumed.

In the case where the binary is not given, the code tried to find the
emulator binary in the existing list of cached emulator capabilities.
This is not valid since we switched to lazy population of the cache in:

  commit 3dd91af0
  Author: Daniel P. Berrangé <berrange@redhat.com>
  Date:   Mon Dec 2 13:04:26 2019 +0000

    qemu: stop creating capabilities at driver startup

As a result of this change, if there are no persistent guests defined
using the requested guest architecture, virConnectGetDomainCapabilities
will fail to find an emulator binary.

The solution is to stop relying on the cached capabilities to find the
binary and instead use the same logic we use to pick default a binary
per arch when populating capabilities.
Tested-by: NBoris Fiuczynski <fiuczy@linux.ibm.com>
Tested-by: NRichard W.M. Jones <rjones@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The "ps2" bus is only available on certain machines like x86. On
machines like s390x, we should refuse to add a device to this bus
instead of silently ignoring it.

Looking at the QEMU sources, PS/2 is only available if the QEMU binary
has the "i8042" device, so let's check for that and only allow "ps2"
devices if this QEMU device is available, or if we're on x86 anyway
(so we don't have to fake the QEMU_CAPS_DEVICE_I8042 capability in
all the tests that use <input ... bus='ps2'/> in their xml data).
Reported-by: NSebastian Mitterle <smitterl@redhat.com>
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1763191Signed-off-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

G_STATIC_ASSERT() is a drop-in functional equivalent of
the GNULIB verify() macro.
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

QEMU since 4.1.0 supports the "dies" parameter for -smp
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

libvirt currently always reports that USB is available as a bus subsystem
type when running "virsh domcapabilities". However, this is not always
true, for example the qemu-system-s390x binary normally never has support
for USB. Thus we should only report that USB is available if there is
also a USB host controller available where we can attach USB devices.
Reported-by: NSebastian Mitterle <smitterl@redhat.com>
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1759849Signed-off-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Remove unneeded, easy to remove goto labels (cleanup|error|done|...).
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

We don't need this for any functional purpose, but when debugging hosts
it is useful to know what binary a given capabilities XML document is
associated with.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Simplify repeated code patterns by providing a new constructor taking
the QEMU binary name.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Currently if the binary path is NULL in the qemu capabilities object,
cache invalidation is skipped. A future patch will ensure that the
binary path is always non-NULL, so a way to explicitly skip invalidation
is required.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

This capability tracks if qemu is capable of:

  -drive file.driver=nvme

The feature was added in QEMU's commit of v2.12.0-rc0~104^2~2.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Avoid grabbing the whole virCapsPtr object when we only need the
host CPU information.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Annoyingly there was no existing constructor, and identifying all the
places which do a VIR_ALLOC(cpu) is a bit error prone. Hopefully this
has found & converted them all.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Avoid grabbing the whole virCapsPtr object when we only need the
NUMA information.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The NUMA cells are stored directly in the virCapsHostPtr
struct. This moves them into their own struct allowing
them to be stored independantly of the rest of the host
capabilities. The change is used as an excuse to switch
the representation to use a GPtrArray too.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The QEMU impl of the callback can directly use the QEMU capabilities
cache to resolve the emulator binary name, allowing virCapsPtr to be
dropped.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

To enable the virCapsPtr parameter to the post parse method to be
eliminated, the drivers must fetch the virCapsPtr from their own
driver via the opaque parameter, or use an alternative approach
to validate the parsed data.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Currently the virQEMUCapsPtr objects are just empty. Future patches are
going to expect them to contain real data. Start off by populating the
machine types and arch information.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

As part of a goal to eliminate the need to use virCapsPtr for anything
other than the virConnectGetCapabilies() API impl, cache the host arch
against the QEMU driver struct and use that field directly.

In the tests we move virArchFromHost() globally in testutils.c so that
every test runs with a fixed default architecture reported.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Blockdev is required to do incremental backups properly. Add a helper
function for locking out capabilities and export it to allow re-doing
the processing if a different code path modifies capabilities.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

Checking whether a qemu capability set right before clearing it without
any other logic doesn't make sense.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

The cpuModels member of _virQEMUCapsAccel struct is not a
virObject but regular struct with a free function defined:
qemuMonitorCPUDefsFree(). Use that when clearing parent structure
instead of virObjectUnref() to avoid a memleak:

==212322== 57,275 (48 direct, 57,227 indirect) bytes in 3 blocks are definitely lost in loss record 623 of 627
==212322==    at 0x4838B86: calloc (vg_replace_malloc.c:762)
==212322==    by 0x554A158: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.6000.6)
==212322==    by 0x17B14BF5: qemuMonitorCPUDefsNew (qemu_monitor.c:3587)
==212322==    by 0x17B27BA7: qemuMonitorJSONGetCPUDefinitions (qemu_monitor_json.c:5616)
==212322==    by 0x17B14B0B: qemuMonitorGetCPUDefinitions (qemu_monitor.c:3559)
==212322==    by 0x17A6AFBB: virQEMUCapsFetchCPUDefinitions (qemu_capabilities.c:2571)
==212322==    by 0x17A6B2CC: virQEMUCapsProbeQMPCPUDefinitions (qemu_capabilities.c:2629)
==212322==    by 0x17A70C00: virQEMUCapsInitQMPMonitorTCG (qemu_capabilities.c:4769)
==212322==    by 0x17A70DDF: virQEMUCapsInitQMPSingle (qemu_capabilities.c:4820)
==212322==    by 0x17A70E99: virQEMUCapsInitQMP (qemu_capabilities.c:4848)
==212322==    by 0x17A71044: virQEMUCapsNewForBinaryInternal (qemu_capabilities.c:4891)
==212322==    by 0x17A7119C: virQEMUCapsNewData (qemu_capabilities.c:4923)
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>

Now that all pieces are in place (hopefully) let's enable -blockdev.

We base the capability on presence of the fix for 'auto-read-only' on
files so that blockdev works properly, mandate that qemu supports
explicit SCSI id strings to avoid ABI regression and that the fix for
'savevm' is present so that internal snapshots work.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

The 'savevm' HMP command didn't work properly with blockdev as it tried
to do snapshot of everything including the protocol nodes accessing
files which are not snapshottable. Qemu fixed this bug so now we need to
detect it to allow enabling blockdev.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

Initial implementation of 'auto-read-only' didn't reopen the backing
files when needed. For '-blockdev' to work we need to be able to tel
qemu to open a file read-only and change it during blockjobs as we label
backing chains with a sVirt label which does not allow writing. The
dynamic auto-read-only supports this as it reopens files when writing
is demanded.

Add a capability to detect that the posix file based backends support
the dynamic part.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

The qemu driver will obey <backingStore> when we support blockdev.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

Commit 5751a0b6 added a helper function
called virDomainCapsFeaturesInitUnsupported which initialized all domain
capability features as unsupported.

When adding a new feature this would initialize it as unsupported also
for hypervisor drivers which the original author possibly didn't intend
to modify. To prevent accidental wrong value being reported in such case
revert back to initializing individual features in the hypervisor
drivers themselves.

This is not a straight revert as additonal patches modified how we store
the capabilities.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

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

QEMU 4.2.0 will report default CPU types used by each machine type and
we will want to start using it.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Almost all TCG query-machines replies match KVM. The only exceptions are
4.2.0 replies on s390x which differ in the reported default CPU type.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Some specifics of machine types may depend on the accelerator and thus
the data should be moved to virQEMUCapsAccel. The TCG machine types are
just copied from the ones probed for KVM to simplify the changes to
qemucapabilitiestest data files.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The function copies machine type data from one QEMU caps structure to
another.
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>

In preparation for making machine types dependent on the accelerator,
the <machine> elements are formatted between <cpu type='kvm'> and
<cpu type='tcg'>.
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>

All the code for formatting machine type data was moved to a standalone
virQEMUCapsFormatMachines function.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

All the code for loading machine type data was moved to a standalone
virQEMUCapsLoadMachines function.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>