The libxl driver reports different values of maximum memory depending
on state of a domain. If inactive, maximum memory value is reported
correctly. When active, maximum memory is derived from max_pages value
returned by the XEN_SYSCTL_getdomaininfolist sysctl operation. But
max_pages can be changed by toolstacks and does not necessarily
represent the maximum memory a domain can use during its active
lifetime.

A better location for determining a domain's maximum memory is the
/local/domain/<id>/memory/static-max node in xenstore. This value
is set from the libxl_domain_build_info.max_memkb field when creating
the domain. Currently it cannot be changed nor can its value be
exceeded by a balloon operation. From libvirt's perspective, always
reporting maximum memory with virDomainDefGetMemoryTotal() will produce
the same results as reading the static-max node in xenstore.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

When a user does not explicitly set a <driver> in the disk config,
libvirt defers selection of a default to libxl. This approach works
fine when starting a domain with such configuration or attaching a
disk to a running domain. But when detaching such a disk, libxl
will fail with "unrecognized disk backend type: 0". libxl makes no
attempt to recalculate a default backend (driver) on detach and
simply fails when uninitialized.

This patch updates the libvirt disk config with the backend selected
by libxl when starting a domain or attaching a disk to a running
domain. Another benefit of this approach is that the live XML is
also updated with the backend driver selected by libxl.

When starting a domian, a libxl_domain_config object is created from
virDomainDef. Any virDomainDiskDef devices with a format of
VIR_STORAGE_FILE_NONE are mapped to LIBXL_DISK_FORMAT_RAW in the
corresponding libxl_disk_device, but the virDomainDiskDef format is
never updated to reflect the change.

A better place to set a default format for disk devices is the
device post-parse callback, ensuring the virDomainDiskDef object
reflects the default format.

The typical pattern when calling libxl functions that populate a
structure is

  libxl_foo foo;
  libxl_foo_init(&foo);
  libxl_get_foo(ctx, &foo);
  ...
  libxl_foo_dispose(&foo);

Fix several instances of libxl_physinfo missing the init and
dispose calls.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

libxlGetAutoballoonConf is supposed to honor user-specified
autoballoon setting in libxl.conf. As written, the user-specified
setting could be overwritten by the subsequent logic to check
dom0_mem parameter. If user-specified setting is present and
correct, accept it. Only fallback to checking Xen dom0_mem
command line parameter if user-specfied setting is not present.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

xen.git commit 57f8b13c changed several of the libxl memory
get/set functions to take 64 bit parameters. The libvirt
libxl driver still uses uint32_t variables for these various
parameters, which is particularly problematic for the
libxl_set_memory_target() function.

When dom0 autoballooning is enabled, libvirt (like xl) determines
the memory needed to start a domain and the memory available. If
memory available is less than memory needed, dom0 is ballooned
down by passing a negative value to libxl_set_memory_target()
'target_memkb' parameter. Prior to xen.git commit 57f8b13c,
'target_memkb' was an int32_t. Subtracting a larger uint32 from
a smaller uint32 and assigning it to int32 resulted in a negative
number. After commit 57f8b13c, the same subtraction is widened
to a int64, resulting in a large positive number. The simple
fix taken by this patch is to assign the difference of the
uint32 values to a temporary int32 variable, which is then
passed to 'target_memkb' parameter of libxl_set_memory_target().

Note that it is undesirable to change libvirt to use 64 bit
variables since it requires setting LIBXL_API_VERSION to 0x040800.
Currently libvirt supports LIBXL_API_VERSION >= 0x040400,
essentially Xen >= 4.4.

While at it, use members of libxl_tsc_mode enum instead of literal
int values.

The current logic around configuring timers in libxl based on
virDomainDef object is a bit brain dead. Unsupported timers are
silently ignored and tsc is only recognized if it is the first
timer specified.

Change the logic to reject unsupported timers and honor the tsc
timer regardless of its order when multiple timers are specified.

For HVM domains, pae is only set in libxl_domain_build_info when
explicitly specified in the hypervisor <features> config. This is
fine for i686 machines, but is incorrect behavior for x86_64 machines
where pae must always be enabled. See the following discussion for
additional details

https://www.redhat.com/archives/libvir-list/2017-January/msg00254.html

List indexes where mixed up in the code looping over the USB
input devices.

libxl doesn't provide a way to write one log for each domain. Thus
we need to demux the messages. If our logger doesn't know to which
domain to attribute a message, then it will write it to the default
log file.

Starting with Xen 4.9 (commit f9858025 and following), libxl will
write the domain ID in an easy to grab manner. The logger introduced
by this commit will use it to demux the libxl log messages.

Thanks to the default log file, this logger will also work with older
versions of Xen.

The libxl driver already supports getting maximum vcpu count via
libxlDomainGetVcpusFlags, allowing to trivially implement
virDomainGetMaxVcpus.

libvirt libxl picks its own default with respect to the default NIC
to use. libxlMakeNic is the one responsible for this and on boot it
picks LIBXL_NIC_TYPE_VIF_IOEMU for HVM domains such that it accomodates
both PV and emulated one. The good behaving guest at boot will then
select the pv and unplug the emulated device.

Now, on HVM when attaching an interface it will pick the same default
that is LIBXL_NIC_TYPE_VIF_IOEMU which as a result will fail the attach
(see xen commit 32e9d0f ("libxl: nic type defaults to vif in hotplug for
hvm guest"). Xen doesn't yet support the hotplug of emulated devices,
but we don't want to rule out that case either, which might get support
in the future. Hence we simply reverse the defaults when we are
attaching the interface which allows libvirt to prefer the PV nic first
without adding "model='netfront'" following the same pattern as above
commit. Also to avoid ruling out the emulated one we set to
LIBXL_NIC_TYPE_IOEMU when setting a model type that is not 'netfront'.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

If libxl has QED disk format support, then pass the feature
over to the user.

This is just a code move of virstat.c to virnetdevtap.c

In preparation to the code move to virnetdevtap.c, this change:

* renames virNetInterfaceStats to virNetDevTapInterfaceStats
* changes 'path' to 'ifname', to use the same vocable as other
  method in virnetdevtap.c.
* Add the attributes checker

New line character in name of domain is now forbidden because it
mess virsh output and can be confusing for users.
Validation of name is done in drivers, after parsing XML to avoid
problems with dissappeared domains which was already created with
new-line char in name.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Although the migration port is immediately released in the
finish phase of migration, it was never set in the domain
private object when allocated in the prepare phase. So
libxlDomainMigrationFinish() always released a 0-initialized
migrationPort, leaking any allocated port. After enough
migrations to exhaust the migration port pool, migration would
fail with

error: internal error: Unable to find an unused port in range
       'migration' (49152-49216)

Fix it by setting libxlDomainObjPrivate->migrationPort to the
port allocated in the prepare phase. While at it, also fix
leaking an allocated port if the prepare phase fails.

Change the virDomainChrDef to use a pointer to 'source' and allocate
that pointer during virDomainChrDefNew.

This has tremendous "fallout" in the rest of the code which mainly
has to change source.$field to source->$field.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Modeled after the qemuDomainHostdevPrivatePtr (commit id '27726d8c'),
create a privateData pointer in the _virDomainChardevDef to allow storage
of private data for a hypervisor in order to at least temporarily store
secret data for usage during qemuBuildCommandLine.

NB: Since the qemu_parse_command (qemuParseCommandLine) code is not
expecting to restore the secret data, there's no need to add code
code to handle this new structure there.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

This function for some weird reason returns integer instead of
virDomainNetType type. It is important to return the correct type
so that we know what values we can expect.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This way we get reference counting and we can get rid of locking
function.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Due to a copy and paste error, the scheduler 'cap' parameter
was over-writing the 'weight' parameter when preparing the
return parameters in libxlDomainGetSchedulerParametersFlags.
As a result, the scheduler weight was never shown when getting
schedinfo and setting the weight failed as well

virsh  schedinfo testvm
Scheduler      : credit
cap            : 0

virsh  schedinfo testvm --cap 50 --weight 500
Scheduler      : credit
error: invalid scheduler option: weight

The obvious fix is to assign the 'caps' parameter to the correct
item in the parameter list.
Reported-by: NVolo M. <vm@vovs.net>

And allow libxl to handle channel element which creates a Xen
console visible to the guest as a low-bandwitdh communication
channel. If type is PTY we also fetch the tty after boot using
libxl_channel_getinfo to fetch the tty path. On socket case,
we autogenerate a path if not specified in the XML. Path autogenerated
is slightly different from qemu driver: qemu stores also on
"channels/target" but it creates then a directory per domain with
each channel target name. libxl doesn't appear to have a clear
definition of private files associated with each domain, so for
simplicity we do it slightly different. On qemu each autogenerated
channel goes like:

channels/target/<domain-name>/<target name>

Whereas for libxl:

channels/target/<domain-name>-<target name>

Should note that if path is not specified it won't persist,
existing only on live XML, unless user had initially specified it.
Since support for libxl channels only came on Xen >= 4.5 we therefore
need to conditionally compile it with LIBXL_HAVE_DEVICE_CHANNEL.

After this patch and having a qemu guest agent:
 $ cat domain.xml | grep -a1 channel | head -n 5 | tail -n 4
 <channel type='unix'>
   <source mode='bind' path='/tmp/channel'/>
   <target type='xen' name='org.qemu.guest_agent.0'/>
 </channel>

 $ virsh create domain.xml
 $ echo '{"execute":"guest-network-get-interfaces"}' | socat
 stdio,ignoreeof  unix-connect:/tmp/channel

 {"execute":"guest-network-get-interfaces"}
 {"return": [{"name": "lo", "ip-addresses": [{"ip-address-type": "ipv4",
 "ip-address": "127.0.0.1", "prefix": 8}, {"ip-address-type": "ipv6",
 "ip-address": "::1", "prefix": 128}], "hardware-address":
 "00:00:00:00:00:00"}, {"name": "eth0", "ip-addresses":
 [{"ip-address-type": "ipv4", "ip-address": "10.100.0.6", "prefix": 24},
 {"ip-address-type": "ipv6", "ip-address": "fe80::216:3eff:fe40:88eb",
 "prefix": 64}], "hardware-address": "00:16:3e:40:88:eb"}, {"name":
 "sit0"}]}
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

libxl events are delivered to libvirt via the libxlDomainEventHandler
callback registered with libxl. Documenation in
$xensrc/tools/libxl/libxl_event.h states that the callback "may occur
on any thread in which the application calls libxl". This can result
in deadlock since many of the libvirt callees of libxl hold a lock on
the virDomainObj they are working on. When the callback is invoked, it
attempts to find a virDomainObj corresponding to the domain ID provided
by libxl. Searching the domain obj list results in locking each obj
before checking if it is active, and its ID equals the requested ID.
Deadlock is possible when attempting to lock an obj that is already
locked further up the call stack. Indeed, Max Ustermann reported an
instance of this deadlock

https://www.redhat.com/archives/libvir-list/2015-November/msg00130.html

Guido Rossmueller also recently stumbled across it

https://www.redhat.com/archives/libvir-list/2016-September/msg00287.html

Fix the deadlock by moving the lookup of virDomainObj to the
libxlDomainShutdownThread. After this patch, libxl events are
enqueued on the libvirt side and processed by dedicated thread,
avoiding the described deadlock.
Reported-by: NMax Ustermann <ustermann78@web.de>
Reported-by: NGuido Rossmueller <Guido.Rossmueller@gdata.de>

Just like virDomainDefPostParseCallback has gained new
parseOpaque argument, we need to follow the logic with
virDomainDeviceDefPostParse.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

We want to pass the proper opaque pointer instead of NULL to
virDomainDefParseString.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

We want to pass the proper opaque pointer instead of NULL to
virDomainDefParse and subsequently virDomainDefParseNode too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Some callers might want to pass yet another pointer to opaque
data to post parse callbacks. The driver generic one is not
enough because two threads executing post parse callback might
want to see different data (e.g. domain object pointer that
domain def belongs to).
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

If passing an empty usbdevice_list to libxl, qemu will always get an
-usb parameter for HVM guests with only non-USB input devices. This
causes qemu to crash when passing pvusb device on HVM guests.

The solution is to allocate the list only when an item to put in it
is found.

Both cpuCompare* APIs are renamed to virCPUCompare*. And they should now
work for any guest CPU definition, i.e., even for host-passthrough
(trivial) and host-model CPUs. The implementation in x86 driver is
enhanced to provide a hint about -noTSX Broadwell and Haswell models
when appropriate.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

By default, virt-manager (and likely other libvirt-based apps) sets
the VIR_MIGRATE_PERSIST_DEST flag when invoking the migrate API, which
fails in a Xen setup since the libxl driver does not support the flag.

Persisting a domain is a trivial task in the grand scheme of migration,
so be nice to libvirt apps and add support for VIR_MIGRATE_PERSIST_DEST
in the libxl driver.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

Akin to previous commit but for "virsh cpu-baseline" which
computes a baseline CPU for a set of host cpu elements.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Implement support for "virsh cpu-compare" so that we can calculate
common cpu element between a pool of hosts, which had a requirement
of providing host cpu description.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Parse libxl_hwcap accounting for versions since Xen 4.4 - Xen 4.7.
libxl_hwcaps is a set of cpuid leaves output that is described in [0] or
[1] in Xen 4.7. This is a collection of CPUID leaves that we version
in libvirt whenever feature words are reordered or added. Thus we keep the
common ones in one struct and others for each version. Since
libxl_hwcaps doesn't appear to have a stable format across all supported
versions thus we need to keep track of changes as a compromise until it's
exported in xen libxl API. We don't fail in initializing the driver in case
parsing of hwcaps failed for that reason. In addition, change the notation
on PAE feature such that is easier to read which bit it corresponds.

[0] xen/include/asm-x86/cpufeature.h
[1] xen/include/public/arch-x86/cpufeatureset.h
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

Add support for describing cpu topology in host cpu element.  In doing
so, refactor hwcaps part to its own helper namely libxlCapsInitCPU to
handle all host cpu related operations, including topology.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

The code for replacing domain's transient definition with the persistent
one is repeated in several places and we'll need to add one more. Let's
make a nice helper for it.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Add support for multi serial devices, after this patch virsh can be used to
connect different serial devices of running domains. E.g.
vish # console <xxx> --devname serial<xxx>

Note:
This depends on a xen/libxl bug fix to have libxl_console_get_tty(...) correctly
returning the tty path (as opposed to always returning the first one).
[0] https://lists.xen.org/archives/html/xen-devel/2016-08/msg00438.htmlSigned-off-by: NBob Liu <bob.liu@oracle.com>

libxl only has API to address the host USB devices by bus/device.
Find the bus/device if the user only provided the vendor/product
of the USB device.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>

The libxl driver has long supported migration V3 but has never
indicated so in the connectSupportsFeature API. As a result, apps
such as virt-manager that use the more generic virDomainMigrate API
fail with

libvirtError: this function is not supported by the connection driver:
virDomainMigrate

Add VIR_DRV_FEATURE_MIGRATION_V3 to the list of features marked as
supported in the connectSupportsFeature API.