Add property for IPv6 address ('ip6'). Build default value similarly to
IPv4 - common prefix + QID or Disp ID (for DispVMs).
This all is disabled unless 'ipv6' feature is enabled. It is inherited
from netvm (not template).
Even when enabled, VM may decide to not use it - or simply not support
it.
QubesOS/qubes-issues#718
Allow using default feature value from netvm, not template. This makes
sense for network-related features like using tor, supporting ipv6 etc.
Similarly to check_with_template, expose it also on Admin API.
Having both default_netvm and default_fw_netvm cause a lot of confusion,
because it isn't clear for the user which one is used when. Additionally
changing provides_network property may also change netvm property, which
may be unintended effect. This as a whole make it hard to:
- cover all netvm-changing actions with policy for Admin API
- cover all netvm-changing events (for example to apply the change to
the running VM, or to check for netvm loops)
As suggested by @qubesuser, kill the default_fw_netvm property and
simplify the logic around it.
Since we're past rc1, implement also migration logic. And add tests for
said migration.
FixesQubesOS/qubes-issues#3247
* qubesos/pr/166:
create "lvm" pool using rootfs thin pool instead of hardcoding qubes_dom0-pool00
change default pool code to be fast
cache PropertyHolder.property_list and use O(1) property name lookups
remove unused netid code
cache isinstance(default, collections.Callable)
don't access netvm if it's None in visible_gateway/netmask
There were many cases were the check was missing:
- changing default_netvm
- resetting netvm to default value
- loading already broken qubes.xml
Since it was possible to create broken qubes.xml using legal calls, do
not reject loading such file, instead break the loop(s) by setting netvm
to None when loop is detected. This will be also useful if still not all
places are covered...
Place the check in default_netvm setter. Skip it during qubes.xml loading
(when events_enabled=False), but still keep it in setter, to _validate_ the
value before any property-* event got fired.
If HVM have PCI device, it can't use PoD, so need 'maxmem' memory to be
started. Request that much from qmemman.
Note that is is somehow independent of enabling or not dynamic memory
management for the VM (`service.meminfo-writer` feature). Even if VM
initially had assigned maxmem memory, it can be later ballooned down.
QubesOS/qubes-issues#3207
* 20171107-storage:
api/admin: add API for changing revisions_to_keep dynamically
storage/file: move revisions_to_keep restrictions to property setter
api/admin: hide dd statistics in admin.vm.volume.Import call
storage/lvm: fix importing different-sized volume from another pool
storage/file: fix preserving spareness on volume clone
api/admin: add pool size and usage to admin.pool.Info response
storage: add size and usage properties to pool object
* 20171107-tests-backup-api-misc:
test: make race condition on xterm close less likely
tests/backupcompatibility: fix handling 'internal' property
backup: fix handling target write error (like no disk space)
tests/backupcompatibility: drop R1 format tests
backup: use offline_mode for backup collection
qubespolicy: fix handling '$adminvm' target with ask action
app: drop reference to libvirt object after undefining it
vm: always log startup fail
api: do not log handled errors sent to a client
tests/backups: convert to new restore handling - using qubesadmin module
app: clarify error message on failed domain remove (used somewhere)
Fix qubes-core.service ordering
currently it takes 100ms+ to determine the default pool every time,
including subprocess spawning (!), which is unacceptable since
finding out the default value of properties should be instantaneous
instead of checking every thin pool to see if the root device is in
it, find and cache the name of the root device thin pool and see if
there is a configured pool with that name
xterm is very fast on closing when application inside terminates. It is
so fast with closing on keydown event that xdotool do not manage to send
keyup event, resulting in xdotool crash. Add a little more time for
that.
When writing process returns an error, prefer reporting that one,
instead of other process (which in most cases will be canceled, so
the error will be meaningless CancelledError).
Then, include sanitized stderr from VM process in the error message.
This object is used solely for manipulating qubes.xml for the backup. Do
not open any connection to hypervisor/QubesDB/libvirt etc. This will
help avoiding various leaks (memory, FD).
Do not try to access that particular object (wrapper) when it got
undefined. If anyone want to access it, appropriate code should do a new
lookup, and probably re-define the object.
Those "errors" are already properly handled, and if necessary logged
independently by appropriate function. In some cases, such logs are
misleading (for example QubesNoSuchPropertyError is a normal thing
happening during qvm-ls).
FixesQubesOS/qubes-issues#3238
Besides converting itself, change how the test verify restore
correctness: first collect VM metadata (and hashes of data) into plain
dict, then compare against it. This allow to destroy old VMs objects
before restoring the backup, so avoid having duplicate objects of the
same VM - which results in weird effects like trying to undefine libvirt
object twice.
Point to system logs for more details. Do not include them directly in
the message for privacy reasons (Admin API client may not be given
permission to it).
QubesOS/qubes-issues#3273QubesOS/qubes-issues#3193
This one pool/volume property makes sense to change dynamically. There
may be more such properties, but lets be on the safe side and take
whitelist approach - allow only selected (just one for now), instead of
blacklisting any harmful ones.
QubesOS/qubes-issues#3256
Do not check for accepted value only in constructor, do that in property
setter. This will allow enforcing the limit regardless of how the value
was set.
This is preparation for dynamic revisions_to_keep change.
QubesOS/qubes-issues#3256
The previous version did not ensure that the stopped/shutdown event was
handled before a new VM start. This can easily lead to problems like in
QubesOS/qubes-issues#3164.
This improved version now ensures that the stopped/shutdown events are
handled before a new VM start.
Additionally this version should be more robust against unreliable
events from libvirt. It handles missing, duplicated and delayed stopped
events.
Instead of one 'domain-shutdown' event there are now 'domain-stopped'
and 'domain-shutdown'. The later is generated after the former. This way
it's easy to run code after the VM is shutdown including the stop of
it's storage.
If domain got removed during the tests (for example DispVM), vm.close()
wouldn't be called in cleanup and some file descriptors will be
leaked. Add event handler for cleaning this up. Do not use close()
method here, because it is destructive, but the object may still be used
by the test.
1. Fire both property-pre-del:netvm and property-del:netvm - those
events should be fired in pairs - especially one may assume the other
will be called too. This is the case here - one disconnect old netvm,
the other connect the new one.
2. Remove spurious 'newvalue' argument for property-del:netvm event.
3. Fix logic for default_fw_netvm/default_netvm usage. The former is
used if vm.provides_network=True.
If there was some netvm set, unset it first (same as with ordinary set).
Otherwise it will try to attach new netvm without detaching the old one
first.
oldvalue should contain the old value, even if it was default one. Same
as in property-(pre-)set events. If event want to check if that is
default value, it is always possible (in pre- event), but in practice
actual value is most useful.
This bug prevented netvm changing events from working when reseting
netvm.
Allow to get default value even it isn't set currently. This will allow
(G)UI to present better view, without duplicating logic for default
value.
FixesQubesOS/qubes-issues#3197
Check resize on each template separately, because it involves VM's
scripts (either qubes.ResizeDisk service, or some startup script).
QubesOS/qubes-issues#3173
- clone all features, not just qrexec (especially include 'gui')
- do not leak VM reference on failed test
- add test for online root volume resize
QubesOS/qubes-issues#3173
- make it clear that failed qubes.ResizeDisk service call means the need
to resize filesystem manually (but not necessarily the volume itself)
- propagate exceptions raised by async storage pool implementations
Related QubesOS/qubes-issues#3173
Expired rules are skipped while loading the firewall. Do that also when
such rules expired after loading the firewall. This applies to both
Admin API and actually applying the rules (sending them to appropriate
VM).
Related QubesOS/qubes-issues#3020
* bug3164:
tests: add regression test for #3164
storage/lvm: make sure volume cache is refreshed after changes
storage/lvm: fix Volume.verify()
storage/lvm: remove old volume only after successfully cloning new one
This is a race condition, so to make it more likely to fail (if it's
broken), make some things manually. In normal circumstances this order
of actions is also possible, just less likely to happen. But as seen in
the bug report, happens from time to time.
QubesOS/qubes-issues#3164
In some cases, it may happen that new volume (`self._vid_snap`) does not
exists. This is normally an error, but even in such a case, do not
remove the only remaining instance of volume (`self.vid`). Instead,
rename it temporarily and remove only after new volume is successfully
cloned.
FixesQubesOS/qubes-issues#3164
This applies to qvm-template-postprocess, which at the beginning try to
resize root volume to appropriate size. It makes more sense to silently
succeed here, instead of forcing every client-side utility to check if
the volume have already desired size.
- Use proper features/services names (updates proxy test).
- Fix logic error in wait_for_window.
- Fix test for qvm-sync-clock (first sync clockvm, then dom0), also fix
cleanup (unset clockvm before removing it)
- More fixes for asyncio usage
* fixes-20170929:
vm: do not start QubesDB watch instance multiple times
vm: report storage.stop() errors to log
vm: move comment
storage: fix method name in LinuxModules volume
Prevent removing domain that is referenced from anywhere
vm: add vm.klass property
Move QubesVM.{name,qid,uuid,label} to BaseVM
vm: do not allow deleting template property from AppVM and DispVM
vm/qubesvm: emit event on failed startup
vm/qubesvm: remove duplicated qmemman_client.close()
vm/dispvm: cleanup DispVM also on failed startup
vm/dispvm: fix error message
ext/block: properly list devtype=cdrom option
block: fix handling non-existing devices
block: improve handling device name and description
vm.create_qdb_entries can be called multiple times - for example when
changing VM IP. Move starting qdb watcher to start(). And just in case,
cleanup old watcher (if still exists) before starting new one.
This fixes one FD leak.
Do not use self.fail when handling exception - this will keep exception
object referenced, which in turn have reference to domain object (via
traceback).
- Prefer instance attributes over local variables - the former ones do
not leak into traceback object and are cleaned up by tests framework.
- Use 'with' syntax for handling files.
- Use subprocess.DEVNULL instead of open('/dev/null') where applicable
- Delete local variables when not needed anymore.
- Fix str/bytes
- Call skipTest as early as possible - before doing any setup
- Fix networking tests - configuration commands needs to be called as
root (missing user= argument).
- Fix setting firewall - policy is no longer changeable
- Add missing loop.run_until_complete() calls.
- Convert subprocess.Popen to asyncio.create_subprocess_exec where
needed (when called process needs to communicate with qubesd).
- Cleanup processes (call .wait()).
There is no more significant difference between PV and HVM. VMs are HVM
by default anyway. More important for this test is difference between
Linux (with Qubes packages installed) and other OS-es. Rename tests
accordingly. The later one is still incomplete.
The most important change is doing vm.close() when removing domain -
this means it wouldn't be cleaned later by iterating over app.domains.
Other changes include removing VMs in the right order, regarding netvm
dependency (otherwise killing or removing may fail). And one more
missing coroutine handling (in shutdown_and_wait).
Catch exception there and log it. Otherwise asyncio complains about not
retrieved exception. There is no one else to handle this exception,
because shutdown event is triggered from libvirt, not any Admin API.
Allow to get domain class as a property, not using admin.vm.List call.
This makes it unnecessary to call admin.vm.List on the client side to
construct wrapper object.
There is intentionally no default template in terms of qubes.property
definition, to not cause problems when switching global default_template
property - like breaking some VMs, or forcing the user to shutdown all
of them for this. But this also means it shouldn't be allowed to reset
template to "default" value, because it will result in a VM without
template at all.
FixesQubesOS/qubes-issues#3115
If VM startup failed before starting anything (even in paused state),
there will be no further event, not even domain-shutdown. This makes it
hard for event-listening applications (like domains tray) to account
domain state. Fix this by emiting domain-start-failed event in every
case of failed startup after emiting domain-pre-start.
Related QubesOS/qubes-issues#3100
* qubesos/pr/150:
qubes/tests: moar fixes
test-packages: add missing libvirt classes
qubes/tests: do not deadlock on .drain()
qubes/vm: put name= first in __repr__
tests: fix some memory leaks
tests: complain about memory leaks
tests: use one event loop and one libvirtaio impl
Recently libvirt removed support for changing event implementation.
Therefore we have to use a single, global one and we check if it is
empty between tests.
On certain locales (e.g. danish) `usage_percent` will output a comma-separated number, which will make `attr` point the last two decimal points, s.t. `return vol_info['attr'][4] == 'a'` (in the `verify` func) will fail and `qubesd` wont run.
* cdrom-boot:
devices: fix error reporting
api/admin: implement admin.vm.device....Set.persistent
devices: implement DeviceCollection.update_persistent()
devices: move DeviceInfo definition earlier
api: do not fail events when listener is cancelled in the meantime
'dispvm_allowed' name was confusing, because it suggested being able to
spawn new DispVMs, not being a template for DispVM.
FixesQubesOS/qubes-issues#3047
Clone properties from DispVM template after setting base properties
(qid, name, uuid). This means we can use standard clone_properties()
function. Otherwise various setters may fail - for example
netvm setter require uuid property initialized (for VM lookup in VM
collection).
Also, make dispvm_allowed check more robust - include direct creation of
DispVM, and also check just before VM startup (if property was changed
in the meantime).
FixesQubesOS/qubes-issues#3057
qvm-sync-clock in dom0 now synchronize only dom0 time. For VM time,
qvm-sync-clock needs to be called in VM. Also, both will communicate
with qubesd, so must be called asynchronously from tests.
Allow attached device to be converted from persistent to non-persistent
and the other way around.
This is to allow starting a VM with some device attached temporarily.
When VM is not running, it is possible to attach device only
persistently, so this change will allow to do that, then, after starting
the VM, change it to non-persistent - so it will not be attached again
at further startups.
QubesOS/qubes-issues#3055
This is because .tearDown() is not executed if the exception occurs in
setUp() [for example self.skipTest() raises an exception]. The lower
levels of .tearDown() being executed are critical to not leaking file
descriptors.
First, cache objects created with init_volume - this is the only place
where we have full volume configuration (including snap_on_start and
save_on_stop properties).
But also implement get_volume method, to get a volume instance for given
volume id. Such volume instance may be incomplete (other attributes are
available only in owning domain configuration), but it will be enough
for basic operations - like cheching and changing its size, cloning
etc.
Listing volumes still use list of physically present volumes.
This makes it possible to start qubesd service, without physical
presence of some storage devices. Starting VMs using such storage would
still fail, of course.
FixesQubesOS/qubes-issues#2960
This is useful to select default DispVM template for VMs started
directly by the user. This makes sense as long as AdminVM == GUIVM.
QubesOS/qubes-issues#2974
Add public Admin API call to create Disposable VM that would be
automatically destroyed after shutdown. Do not keep this functionality
for qrexec-policy tool only.
Also, use admin.vm.Start there, instead of internal.vm.Start and
admin.vm.Kill instead of internal.vm.CleanupDispVM (this is enough,
because DispVM now have auto_cleanup property).
QubesOS/qubes-issues#2974
Add auto_cleanup property, which remove DispVM after its shutdown
- this is to unify DispVM handling - less places needing special
handling after DispVM shutdown.
New DispVM inherit all settings from respective AppVM. Move this from
classmethod `DispVM.from_appvm()`, to DispVM constructor. This unify
creating new DispVM with any other VM class.
Notable exception are attached devices - because only one running VM can
have a device attached, this would prevent second DispVM started from
the same AppVM. If one need DispVM with some device attached, one can
create DispVM with auto_cleanup=False. Such DispVM will still not have
persistent storage (as any other DispVM).
Tests included.
QubesOS/qubes-issues#2974
* services:
tests: check clockvm-related handlers
doc: include list of extensions
qubesvm: fix docstring
ext/services: move exporting 'service.*' features to extensions
app: update handling features/service os ClockVM
* tests-storage:
tests: register libvirt events
tests: even more agressive cleanup in tearDown
app: do not wrap libvirt_conn.close() in auto-reconnect wrapper
api: keep track of established connections
tests: drop VM cleanup from tearDownClass, fix asyncio usage in tearDown
storage: fix Storage.clone and Storage.clone_volume
tests: more tests fixes
firewall: raise ValueError on invalid hostname in dsthost=
qmemman: don't load qubes.xml
tests: fix AdminVM test
tests: create temporary files in /tmp
tests: remove renaming test - it isn't supported anymore
tests: various fixes for storage tests
tests: fix removing LVM volumes
tests: fix asyncio usage in some tests
tests: minor fixes to api/admin tests
storage/file: create -cow.img only when needed
storage: move volume_config['source'] filling to one place
app: do not create 'default' storage pool
app: add missing setters for default_pool* global properties
* qdb-watch:
tests: add qdb_watch test
ext/block: make use of QubesDB watch
vm: add API for watching changes in QubesDB
vm: optimize imports
api/admin: don't send internal events in admin.Events
Add explanation why admin.vm.volume.Import is a custom script
Follow change of qubesdb path return type
Rename vm.qdb to vm.untrusted_qdb
Threis no more ntpd service used - new approach do not conflict with
ntpd. Because of this, new feature is named 'service.clocksync', and
should be _enabled_ in ClockVM ('ntpd' was disabled there).
QubesOS/qubes-issues#1230
When an API call is interrupted, the relevant coroutine is cancelled -
which means it may throw CancelledError. At the same time, cancelled
call have related socket already closed (and transport set to None). But
QubesDaemonProtocol.respond try to close the transport again, which
fails. Fix handling this case.
Get a VM statistics once. If previous measurements are provided,
calculate difference too. This is backend part of upcoming
admin.vm.Stats service.
QubesOS/qubes-issues#853
Remove some more references to objects holding (possibly indirectly)
reference to libvirt connection:
- local variables in tearDown function
- running Admin API calls (especially admin.Events)
- vmm._libvirt_conn directly, in case some reference to Qubes()
is still there
- any instance attribute that is an object from 'qubes' python package
(instead of just those descending from BaseVM)
- do not create new Qubes() instance for removing VMs - if we already
have one in self.app
Then trigger garbage collector to really cleanup those objects (and
close relevant file descriptors). It's important do do this before
closing event loop, because some of descructors may try to use it (for
example remove registered handlers).
When tearDownClass is executed, event loop is already closed. Since no
test really need it right now, drop support for test class-wide VMs and
convert those methods back to instance methods.
Also put coroutines (vm.remove_from_disk, vm.kill) onto event loop.
Only qubesd should load qubes.xml directly. Put a TODO comments for now
in place of slow VM reporting, invent some better mechanism later.
This loading of qubes.xml caused deadlocks, because qmemnan kept open
file descriptor (in locked state).
Since it is no longer child of QubesVM, constructor do not take 'qid'
and 'name' arguments.
Also:
- remove other dropped properties tests (netvm, storage related)
- make the test working in non-dom0
- improve TestPool mock - init_volume now return appropriate mock type,
instead of TestPool
- improve patching base directory (/var/lib/qubes) - it is stored in
more than one place...
- fix inheritance in TC_01_ThinPool class
- fix expected LVM volume names ('vm-' prefix)
- fix cleanup after FilePool tests - remove temporary qubes.xml
- asyncio usage
- better reporting in integ.storage - include error message in the
report, not only as a comment in code
Don't set 'source' volume in various places (each VM class constructor
etc), do it as part of volume initialization. And when it needs to be
re-calculated, call storage.init_volume again.
This code was duplicated, and as usual in such a case, those copies
were different - one have set 'size', the other one not.
QubesOS/qubes-issues#2256
Since we have app.default_pool* properties, create appropriately named
pool and let those properties choose the right pool. This also means we
don't need to specify pool name in default volume config anymore
QubesOS/qubes-issues#2256
Some events are internal for a sole purpose of getting some data from
extension. Since listeners of admin.Events cannot return anything, there
is no sense in sending those events there.
The old format have many issues and is discouraged by tar developers. In
this case the most important one is header with possible non-ASCII
characters, which will result in UnicodeDecodeError (tarfile module
require header parts in utf-8).
PAX format is much cleaner, as it use standard mechanism for extended
headers.
Since we have LVM by default, it is possible to backup VMs while they
are running. For now it will include its state from before startup, but
later we may implement some other logic (a snapshot of running VM).
Do not assume static list of volume (although it is true for now), and
also use proper API for getting volume size, instead of assuming it's a
normal file.
Changed the inheritance hierarchy:
1. Renamed `SystemTestsMixin` to `SystemTestCase`
2. `SystemTestCase` is a child of `QubesTestCase`
3. All classes extending the prior `SystemTestsMixin` now just extend `object`
* tests-fixes-1:
api: extract function to make pylint happy
tests/vm: simplify AppVM storage test
storage: do not use deepcopy on volume configs
api: cleanup already started servers when some later failed
tests: fix block devices tests when running on real system
tests: fix some FD leaks
Use minimal TestPool(), instead of Mock().
This allow effectively compare Volume instances (init_volume with the
same parameters return equal Volume instance).
Specify empty 'source' field, so it gets filled with appropriate
template's images. Then also fix recursive 'source' handling - DispVM
root volume should point at TemplateVM's root volume as a source, not a
AppVM's one - which is also only a snapshot.
FixesQubesOS/qubes-issues#2896
This code is unused now. Theoretically this is_outdated implementation
should be moved to FileVolume, but since we don't have VM reference
there, it isn't possible to read appropriate xenstore entry. As we're
phasing out file pool, simply ignore it for now.
QubesOS/qubes-issues#2256
LinuxKernel pool support only read-only volumes, so save_on_stop=True
doesn't make sense. Make it more explicit - raise NotImplementedError
otherwise.
Also, migrate old configs where snap_on_start=True, but no source was
given.
QubesOS/qubes-issues#2256
This driver isn't used in default Qubes 4.0 installation, but if we do
have it, let it follow defined API and its own documentation. And also
explicitly reject not supported operations:
- support only revisions_to_keep<=1, but do not support revert() anyway
(implemented version were wrong on so many levels...)
- use 'save_on_stop'/'snap_on_start' properties directly instead of
obsolete volume types
- don't call sudo - qubesd is running as root
- consistently use path, path_cow, path_source, path_source_cow
Also, add tests for BlockDevice instance returned by
FileVolume.block_device().
QubesOS/qubes-issues#2256
Do not always use pool named 'default'. Instead, have global
`default_pool` property to specify default storage pools.
Additionally add `default_pool_*` properties for each VM property, so
those can be set separately.
QubesOS/qubes-issues#2256
Those functions are coroutines anyway, so allow event handlers to be
too.
Some of this (`domain-create-on-disk`, `domain-remove-from-disk`) will
be useful for appmenus handling.
This will allow starting processes and calling RPC services in those
events. This if required for usb devices, which are attached using RPC
services.
Intentionally keep device listing events synchronous only - to
discourage putting long-running actions there.
This change also require some not-async attach method version for
loading devices from qubes.xml - have `load_persistent` for this.
commit/recover/reset should really be handled in start/stop. Nothing
stops specific pool implementation to define such functions privately.
QubesOS/qubes-issues#2256
Always define those properties, always include them in volume config.
Also simplify overriding pool based on volume type defined by those:
override pool unless snap_on_start=True.
QubesOS/qubes-issues#2256
Since libvirt do provide object for dom0 too, return it here.
It's much easier than special-casing AdminVM everywhere. And in fact
sometimes it is actually useful (for example attaching devices from/to
dom0, adjusting memory).
The first operation returns a token, which can be passed to the second
one to actually perform clone operation. This way the caller needs have
power over both source and destination VMs (or at least appropriate
volumes), so it's easier to enforce appropriate qrexec policy.
The pending tokens are stored on Qubes() instance (as QubesAdminAPI is
not persistent). It is design choice to keep them in RAM only - those
are one time use and this way restarting qubesd is a simple way to
invalidate all of them. Otherwise we'd need some additional calls like
CloneCancel or such.
QubesOS/qubes-issues#2622
Add convenient collection wrapper for easier getting selected volume.
Storage pool implementation may still provide only volume listing
function (pool.list_volumes), or, additionally, optimized
pool.get_volume.
This means it is both possible to iterate over volumes:
```python
for volume in pool.volumes:
...
```
And get a single volume:
```python
volume = pool.volumes[vid]
```
QubesOS/qubes-issues#2256
In the end firewall is implemented as .Get and .Set rules, with policy
statically set to 'drop'. This way allow atomic firewall updates.
Since we already have appropriate firewall format handling in
qubes.firewall module - reuse it from there, but adjust the code to be
prepared for potentially malicious input. And also mark such variables
with untrusted_ prefix.
There is also third method: .Reload - which cause firewall reload
without making any change.
QubesOS/qubes-issues#2622FixesQubesOS/qubes-issues#2869
There is a problem with having separate default action ("policy") and
rules because it isn't possible to set both of them atomically at the
same time.
To solve this problem, always have policy 'drop' (as a safe default),
but by default have a single rule with action 'accept'
FixesQubesOS/qubes-issues#2869
Do this for all standard property types - even if other types do
additional validation, do not expose them to non-ASCII characters.
QubesOS/qubes-issues#2622
We've decided to make VM name immutable. This is especially important
for Admin API, where some parts (especially policy) are sticked to the
VM name.
Now, to rename the VM, one need to clone it under new name (thanks to
LVM, this is very quick action), then remove the old one.
FixesQubesOS/qubes-issues#2868
meminfo (written by VM) is expected report KiB, but qmemman internally
use bytes. Convert units.
And also move obscure unit conversion in is_meminfo_suspicious to more
logical place in sanitize_and_parse_meminfo.
Check if exit code retrieved from dom0 is really the one expected.
Fix typo in test_065_qrexec_exit_code_vm (testvm1/testvm2), adjust for
reporing remote exit code and remove expectedFailure.
QubesOS/qubes-issues#2861
Since tests expose qubesd socket, qvm-start-gui should handle starting
GUI daemons (so, GUI session inside VM). Add synchronization with it
using qubes.WaitForSession service.
When test expect to wait for remote process, use vm.run_for_stdio.
Additionally, when the call fail, (stdout, stderr) is not assigned - use
the one attached to exception object instead.
Since run_for_stdio raise an exception for non-zero exit code, it isn't
ignored anymore. So, check if qrexec-client-vm return expected value,
instead of keep ignoring it.
QubesOS/qubes-issues#2861
Test suite creates some VMs and needs to pass the knowledge about them
to qrexec policy checker. This is done using Admin API, so we need to
substitute qubesd with our own API server.
register_event_handlers is called early, when libvirt connection may not
be yet established - especially on empty qubes.xml. Do not skip
automatic connection logic.
* qubesos/pr/111:
vm: drop 'internal' property
qmemman: make sure to release lock
qmemman: fix meminfo parsing for python 3
devices: drop 'data' and 'frontend_domain' fields, rename 'devclass' to 'bus'
* qubesos/pr/110:
storage: use direct object references, not only identifiers
vm: fix volume_config
storage/lvm: prefix VM LVM volumes with 'vm-'
storage: fix VM rename
Make qubes.NotifyTools reuse logic of qubes.FeaturesRequest, then move
actual request processing to 'features-request' event handler. At the
same time implement handling 'qrexec' and 'gui' features request -
allowing to set template features when wasn't already there.
Behavior change: template is no longer allowed to change feature value
(regardless of being True or False). This means the user will always be
able to override what template have set.
Drop DeviceInfo.data - device extension should provide a subclass with
proper individual fields.
Drop DeviceAssignment.frontend_domain - this information is redundant -
frontend domain is defined by where DeviceAssignment is attached.
Rename DeviceCollection.devclass to bus - devclass if confusing here,
because this term is also used for DeviceInfo subclass.
Reference objects, not their IDs - this way when object is modified, it
is visible everywhere where it is used. Main changes:
- volume.pool - Pool object
- volume.source - Volume object
Since volume have Pool object reference now, move volume related
functions into Volume class (from Pool class). This avoids horrible
`storage.get_pool(volume).something(volume)` construct.
One issue here is since volume.source reference a Volume object from a
different VM - VM's template, now VM load order is important. Since we
don't have control over it, initialize vm.storage when needed - possibly
while initializing storage of different VM. Since we don't have cycles
in AppVM-TemplateVM dependencies, it is safe.
Also, since this commit, volume.source (if defined) always points at
volume of the same name from VM's template. Using volumes with something
else as a source is no longer supported.
QubesOS/qubes-issues#2256
- kernel volume shouldn't have snap_on_start, it's read-only volume
anyway
- root volume of AppVM should have placeholder for 'source'
- private volume of AppVM should _not_ have placeholder for 'source'
(it's ignored anyway, because snap_on_start=False)
QubesOS/qubes-issues#2256
When VM is renamed only volume.vid get updated, but not other attributes
calculated from it. Convert them to dynamic properties to not worry
about it.
QubesOS/qubes-issues#2256
With libvirt in place, this isn't enough - libvirt also keep VM
configuration in its memory and adjusting xenstore doesn't change that.
In fact changing xenstore behind it back make it even worse in some
situations.
QubesOS/qubes-issues#1426
Re-init volume config of all 'snap_on_start' volumes at template
chanage. For this, save original volume config and re-use
config_volume_from_source function introduced in previous commit.
At the same time, forbid changing template of running AppVM or any
DispVM.
QubesOS/qubes-issues#2256
vm.kernel property have type 'str'. Putting None there makes a lot of
troubles: it gets encoded as 'None' in qubes.xml and then loaded back as
'None' string, not None value. Also it isn't possible to assign None
value to str property throgh Admin API.
kernel='' is equally good to specify "no kernel from dom0".
QubesOS/qubes-issues#2622
While libvirt handle locking itself, there is also Qubes-specific
startup part. Especially starting qrexec-daemon and waiting until
qrexec-agent connect to it. When someone will attempt to start VM the
second time (or simply assume it's already running) - qrexec will not be
connected yet and the operation will fail. Solve the problem by wrapping
the whole vm.start() function with a lock, including a check if VM is
running and waiting for qrexec.
Also, do not throw exception if VM is already running.
This way, after a call to vm.start(), VM will be started with qrexec
connected - regardless of who really started it.
Note that, it will not solve the situation when someone check if VM is
running manually, like:
if not vm.is_running():
yield from vm.start()
Such code should be changed to simply:
yield from vm.start()
FixesQubesOS/qubes-issues#2001FixesQubesOS/qubes-issues#2666
And place them in /qubes-service/ QubesDB directory. This allows
extensions to easily store some data not exposed to VM, but also have
control what VM will see. And at the same time, it make it compatible
with existing services framework
QubesOS/qubes-issues#1637
Setting VMProperty to None VM should be encoded as '' value (according
to VMProperty._none_value). But value validation rejected this value.
QubesOS/qubes-issues#2622
Implement this in two parts:
1. Permissions checks, getting a path from appropriate storage pool
2. Actual data import
The first part is done by qubesd in a standard way, but then, instead of
accepting all the data (which may be several GB), return a path to which
a shell script (in practice: `dd` command) will write the data.
Then the script call back to qubesd again to report success/failure and
qubesd response from that call is actually returned to the user.
This way we do not pass all the data through qubesd, but still can
control the process from there in a meaningful way. Note that the last
part (second call to qubesd) may perform all kind of verification (like
a signature check on the data, or so) and can also prevent VM from
starting (hooking also domain-pre-start event) from not verified image.
QubesOS/qubes-issues#2622
Allow importing not only from another volume, but also raw data. In
practice, for all currently implemented storage pools, this is the same
as Pool.export, because path returned there is read-write. But lets not
abuse this fact, some future implementation may need different methods.
QubesOS/qubes-issues#2622QubesOS/qubes-issues#2256
Remove debug prints, log full traceback (of handled exception) only when
debug mode enabled (--debug, introduce in this commit too).
--debug option also enables sending tracebacks to the API clients.
QubesOS/qubes-issues#853
Accessing non-existing property is a common action (for example
hasattr() do try to access the property). So, introduce specific
exception, inheriting from AttributeError. It will behave very similar
to standard (non-Admin-API) property access.
This exception is reported to the Admin API user, so it will be possible
to distinguish between non-existing property and access denied. But it
isn't any significant information leak, as list of valid properties is
publicly available in the source code.
QubesOS/qubes-issues#853
Use '<option name="option_name">option_value</option>' instead of
'<options option_name="option_value"/>'. It's more consistent with the
rest of qubes.xml - have one thing per element.
Also, add options deserialization test.
When libvirt domain is not defined, it isn't running for sure.
This commit fixes the case when vm.is_running() appears anywhere in the
code used during libvirt xml building. In this case, it's mostly about
PCI device description for libvirt.
Make it easy to retrieve DeviceInfo object out of DeviceAssignment
object. The only missing piece of information for that is device class,
so add it. Make it optional, as it can be filled on demand when passing
the object through DeviceCollection (either by listing devices, or
attaching/detaching).
This is mostly to ease handling options in libvirt template - to get
them, you need to use `assignments()`, istead of `persistent()` or
`attached()`, but there were no _simple_ way of getting actual device
object.
This also makes DeviceCollection._device method not needed anymore.
Filter in python3 returns a generator, can be iterated only once.
This is about list of existing domains - store it as a list, otherwise
domains will "disappear" after being discovered.
qubesd do start other daemons - make sure they will not try to signal
systemd about it. In some cases such daemons (qubesdb-daemon) behave
differently based on this variable.
Do not initialize it only at qubes.xml load time, but re-read vm.kernel
property each time the path is constructed. While at it, add support for
vm.kernel set to 'None' - simply don't include modules.img (xvdd) then.
When device extension do not return some "persistent" device as
currently attached, still return it, as it will be attached at next
domain startup. User can distinguish such devices by having
frontend_domain=None (or other VM).
Also, return a set from DeviceCollection.assignments().
While at it, adjust implementation to specification: tags don't have
value, only one bit of information (present/not present).
FixesQubesOS/qubes-issues#2686
This requires creating LVM volume group, so create on based on loop dev
in /tmp.
This is rather rough, but if any of this fails, run the tests anyway -
it will simply skip LVM tests.
Device ident may contain only characters allowed in qrexec argument.
This will allow using it directly in qrexec argument in Attach/Detach
methods.
This also means PCI extension will need to be updated (it uses ':' in
ident).
QubesOS/qubes-issues#853
This is required to get shutdown notification, when it wasn't initiated
by qubesd (for example 'poweroff' command inside of VM).
Libvirt event loop implementation must be registered before making
connection to libvirt, so move it to the beginning of main().
For now, only 'domain-shutdown' event is emited.
User session may not be started at all (for example no qubes packages
installed there), so don't block it in all the cases. Also this would
prevent running 'qubes.WaitForSession' service...
In practice, default value for 'gui' argument is False, so in most cases
user session will be ignored. Which doesn't matter in most cases -
especially for services called by qubesd.
Keep it uniform - QubesVM() object is responsible for handling
vm.dir_path, Storage() is responsible for handling disk volumes (which
may live in that directory
QubesOS/qubes-issues#2256
Allow specific pool implementation to provide asynchronous
implementation. vm.storage.* methods will detect if given implementation
is synchronous or asynchronous and will act accordingly.
Then it's up to pool implementation how asynchronous should be achieved.
Do not force it using threads (`run_in_executor()`). But pool
implementation is free to use threads, if consider it safe in a
particular case.
This commit does not touch any pool implementation - all of them are
still synchronous.
QubesOS/qubes-issues#2256
Split actual filtering done by mgmt-permission: events into calling an
event and applying returned filters. This way filtering done in
mgmt.Events handler could reuse the same function.
...in core-mgmt-client repository. qubesd isn't the right place to start
GUI applications, which will be even more important when GUI domain will
be something different than Dom0.
QubesOS/qubes-issues#833
Some methods inherited from dict (pop and setdefault here) are covered
by placeholders raising NotImplementedError. Lets fix their signatures
(to match those of dict) to really get NotImplementedError, instead of
TypeError.
This allows avoid race condition between registering event handlers and
performing some action. The important thing is the event sent after
registering event handlers in qubesd. This means state changes (like
VM start/stop) after 'connection-established' event will be included in
event stream.
QubesOS/qubes-issues#2622
Management API gives access only to qubes.property. And this is
actually a good thing, so instead of extending it to access also
builtins.property, add a simple decorator to define read-only, stateless
qubes.property.
QubesOS/qubes-issues#2622
qvm-ls tool (as all other tools) will be accessing properties through
API, so no need (nor sense) for this tool-specific attributes in
qubes.property. The only somehow used was ls_width, and in fact it made
the output unnecessary wide.
The tool itself is already moved to core-mgmt-client repository.
QubesOS/qubes-issues#853
Standard methods return only one value, after operation is completed,
but events-related methods may return multiple values during the method
execution time. Provide a callback for such cases.
Also, according to specification, avoid sending both event and non-event
values.
QubesOS/qubes-issues#2622
Allow method handler to decide if operation could be cancelled. If yes,
when connection to the qubesd is terminated (and
protocol.connection_lost get called) the operation is cancelled using
standard asyncio method - in which case asyncio.CancelledError is thrown
inside method handler. This needs to be explicitly enabled, because
cancellable methods are much harder to write, to maintain consistent
system state.
Caveat: protocol.connection_lost is called only when trying to send some
data to it (and it's already terminated). Which makes this whole
mechanism useful only for events. Otherwise, when sending some data (and
possibly detecting that connection is broken), the operation is already
completed.
QubesOS/qubes-issues#2622
* kalkin/device-assignments: (21 commits)
PCI extension cache PCIDevice objects
Make pylint ♥
Fix pylint warning no-else-return
Fix pylint warning len-as-conditional
device-list-attached event returns a dev/options tupples list
DeviceAssignment options are now a dict
Remove WrongAssignment exception
Rename qubes.devices.BlockDevice to qubes.storage.BlockDevice
Update relaxng devices option element
Fix tests broken by the new assignment api
Fix qubes.tests.devices
Fix pci device integration tests
qvm-device add support for assignments
Update ext/pci to new api
BaseVM add DeviceAssignment xml serialization
Migrate DeviceCollection to new API
Add PersistentCollection helper to qubes.devices
Add DeviceAssignment
qvm-device validates device parameters
qvm-device fix handling of non block devices
...
* core3-policy:
Make pylint happy
tests: disable GTK tests on travis
qubespolicy: make pylint happy
qubespolicy: run GUI code inside user session and expose it as dbus object
tests: plug rpc-window tests into main test runner
qubespolicy: plug GUI code into qrexec-policy tool
rpm: add rpc-window related files to package
rpc-window: adjust for qubespolicy API
rpc-window: use pkg_resources for glade file
rpc-window: use 'edit-find' icon if no other is found
rpc-window: adjust for python3
rpc-window: code style adjustments
Import new rpc confirmation window code
qubesd: add second socket for in-dom0 internal calls
policy: qrexec-policy cli tool
tests: qubespolicy tests
qubespolicy: initial version for core3
vm/appvm: add dispvm_allowed property
dispvm: don't load separate Qubes() instance when handling DispVM
This socket (and commands) are not exposed to untrusted input, so no
need to extensive sanitization. Also, there is no need to provide a
stable API here, as those methods are used internally only.
QubesOS/qubes-issues#853
0) All those methods are now awaitable rather than synchronous.
1) The base method is run_service(). The method run() was rewritten
using run_service('qubes.VMShell', input=...). There is no provision
for running plain commands.
2) Get rid of passio*= arguments. If you'd like to get another return
value, use another method. It's as simple as that.
See:
- run_service_for_stdio()
- run_for_stdio()
Also gone are wait= and localcmd= arguments. They are of no use
inside qubesd.
3) The qvm-run tool and tests are left behind for now and will be fixed
later. This is because they also need event loop, which is not
implemented yet.
fixesQubesOS/qubes-issues#1900QubesOS/qubes-issues#2622
- Get rid of @not_in_api, exchange for explicit @api() decorator.
- Old @no_payload decorator becomes an argument (keyword-only).
- Factor out AbstractQubesMgmt class to be a base class for other mgmt
backends.
- Use async def instead of @asyncio.coroutine.
QubesOS/qubes-issues#2622
This also means we don't check if a VM with given name (in case of
VMProperty) exists in the system, at this stage. But this is ok, lets
not duplicate work of property setter.
QubesOS/qubes-issues#2622
If kwargs contains dict as one of values, it isn't hashable and can't be
used as value in frozenset/tuple. Convert such values into
frozenset(dict.items()). Only one (more) level is supported, but it
should be enough.
Solution from http://stackoverflow.com/a/13264725
In theory any call could modify config (through events), but lets keep
writes to qubes.xml low. In any case, qubes.xml will be eventually
written (either at next config-modifying call, or daemon exit).
Sanitization of input value is tricky here, and also very important at
the same time. If property define value type (and it's something more
specific than 'str'), use that. Otherwise allow only printable ASCII
characters, and let appropriate event and setter handle value.
At this point I've reviewed all QubesVM properties in this category and
added appropriate setters where needed.
QubesOS/qubes-issues#2622
Don't allow characters potentially interfering with qrexec. To be on the
safe side, allow only alphanumeric characters + very few selected
punctuations.
Split it into two functions: validate_name - context-less verification,
and actual _setter_name which perform additional verification in
context of actual VM.
Switch to qubes.exc.* exceptions where appropriate.
This reverts commit 0f1672dc63.
Bring it back. Lets not revert the whole feature just because required
package exists only in qubes-builder, not in some online repository.
Also, this revert didn't go as planned - there was a reference to a
'passphrase' local variable, but it wasn't assigned any value.
Cc: @woju
This will allow more flexible API usage, especially when using mgmt API
- we need to use VM type as string there.
We don't lose any flexibility here - VM class names needs to be uniquely
identified by a string (used in qubes.xml) anyway.
Use the right cow image and apply the second layer to provide read-write
access. The correct setup is:
- base image + base cow -> read-only snapshot (base changes "cached"
until committed)
- read-only snapshot + VM cow -> read-write snapshot (changes discarded
after VM shutdown)
This way, even VM without Qubes-specific startup scripts will can
benefit from Template VMs, while VMs with Qubes-specific startup scripts
may still see original root.img content (for possible signature
verification, when storage domain got implemented).
QubesOS/qubes-issues#2256
QubesDB daemon no longer remove socket created by new instance, so one
part of VM restart race condition is solved. The only remaining part is
to ensure that we really connect to the new instance, instead of talking
to the old one (soon to be terminated).
FixesQubesOS/qubes-issues#1694
None of properties set there do any "dangerous thing" for filesystem
permissions (at least for now), so do not require it. This is mostly to
keep compatibility with %post rpm scripts (kernel-qubes-vm at least).
QubesOS/qubes-issues#2412
This tool by design is called as root, so try to:
- switch to normal user if possible
- fix file permissions afterwards - if not
QubesOS/qubes-issues#2412
There was a comment '# Set later', but actually values were never set.
This break adding just installed template (qvm-template-postprocess).
QubesOS/qubes-issues#2412
When system is installed with LVM thin pool, it should be used by
default. But lets keep file-based on for /var/lib/qubes for some corner
cases, migration etc.
QubesOS/qubes-issues#2412
This is intended to call to finish template installation/removal.
Template RPM package is basically container for root.img, nothing more.
Other parts needs to be generated after root.img extraction. Previously
it was open coded in rpm post-install script, but lets keep it as qvm
tool to ease supporting multiple version in template builder
QubesOS/qubes-issues#2412
VM files may be already removed. Don't fail on this while removing a
VM, it's probably the reason why domain is being removed.
qvm-remove tool have its own guard for this, but it isn't enough - if
rmtree(dir_path) fails, storage.remove() would not be called, so
non-file storages would not be cleaned up.
This is also needed to correctly handle template reinstallation - where
VM directory is moved away to call create_on_disk again.
QubesOS/qubes-issues#2412
'-' is invalid character in python identifier, so all the properties
have '_'. But in previous versions qvm-* tools accepted names with '-',
so lets not break this.
QubesOS/qubes-issues#2412
/var/log/qubes directory have setgid set, so all the files will be owned
by qubes group (that's ok), but there is no enforcement of creating it
group writable, which undermine group ownership (logs created by root
would not be writable by normal user)
QubesOS/qubes-issues#2412
In case of LVM (at least), "internal" flag is initialized only when
listing volume attached to given VM, but not when listing them from the
pool. This looks like a limitation (bug?) of pool driver, it looks like
much nicer fix is to handle the flag in qvm-block tool (which list VMs
volumes anyway), than in LVM storage pool driver (which would need to
keep second copy of volumes list - just like file driver).
QubesOS/qubes-issues#2256
There are mutiple cases when snapshots are inconsistently created, for
example:
- "-back" snapshot created from the "new" data, instead of old one
- "-snap" created even when volume.snap_on_start=False
- probably more
Fix this by following volume.snap_on_start and volume.save_on_stop
directly, instead of using abstraction of old volume types.
QubesOS/qubes-issues#2256
Just calling pool.init_volume isn't enough - a lot of code depends on
additional data loaded into vm.storage object. Provide a convenient
wrapper for this.
At the same time, fix loading extra volumes from qubes.xml - don't fail
on volume not mentioned in initial vm.volume_config.
QubesOS/qubes-issues#2256
- add missing lvm remove call when commiting changes
- delay creating volatile image until domain startup (it will be created
then anyway)
- reset cache only when really changed anything
- attach VM to the volume (snapshot) created for its runtime - to not
expose changes (for example in root volume) to child VMs until
shutdown
QubesOS/qubes-issues#2412QubesOS/qubes-issues#2256
The wrapper doesn't do anything else than translating command
parameters, but it's load time is significant (because of python imports
mostly). Since we can't use python lvm API from non-root user anyway,
lets drop the wrapper and call `lvm` directly (or through sudo when
necessary).
This makes VM startup much faster - storage preparation is down from
over 10s to about 3s.
QubesOS/qubes-issues#2256
...instead of manual copy in python. DD is much faster and when used
with `conv=sparse` it will correctly preserve sparse image.
QubesOS/qubes-issues#2256
Set parameters for possibly hiding domain's real IP before attaching
network to it, otherwise we'll have race condition with vif-route-qubes
script.
QubesOS/qubes-issues#1143
This is the IP known to the domain itself and downstream domains. It may
be a different one than seen be its upstream domain.
Related to QubesOS/qubes-issues#1143`
This helps hiding VM IP for anonymous VMs (Whonix) even when some
application leak it. VM will know only some fake IP, which should be set
to something as common as possible.
The feature is mostly implemented at (Proxy)VM side using NAT in
separate network namespace. Core here is only passing arguments to it.
It is designed the way that multiple VMs can use the same IP and still
do not interfere with each other. Even more: it is possible to address
each of them (using their "native" IP), even when multiple of them share
the same "fake" IP.
Original approach (marmarek/old-qubes-core-admin#2) used network script
arguments by appending them to script name, but libxl in Xen >= 4.6
fixed that side effect and it isn't possible anymore. So use QubesDB
instead.
From user POV, this adds 3 "features":
- net/fake-ip - IP address visible in the VM
- net/fake-gateway - default gateway in the VM
- net/fake-netmask - network mask
The feature is enabled if net/fake-ip is set (to some IP address) and is
different than VM native IP. All of those "features" can be set on
template, to affect all of VMs.
Firewall rules etc in (Proxy)VM should still be applied to VM "native"
IP.
FixesQubesOS/qubes-issues#1143
Core3 keep information whether property have default value for all the
properties (not only few like netvm or kernel). Try to use this feature
as much as possible.
When user included/excluded some VMs for restoration, it may be
neceesarry to fix dependencies between them (for example when default
template is no longer going to be restored).
Also fix handling conflicting names.
Now, when file name is also integrity protected (prefixed to the
passphrase), we can make sure that input files are given in the same
order. And are parts of the same VM.
QubesOS/qubes-issues#971
This prevent switching parts of backup of the same VM between different
backups made by the same user (or actually: with the same passphrase).
QubesOS/qubes-issues#971
`openssl dgst` and `openssl enc` used previously poorly handle key
stretching - in case of `openssl enc` encryption key is derived using
single MD5 iteration, without even any salt. This hardly prevent
brute force or even rainbow tables attacks. To make things worse, the
same key is used for encryption and integrity protection which ease
brute force even further.
All this is still about brute force attacks, so when using long, high
entropy passphrase, it should be still relatively safe. But lets do
better.
According to discussion in QubesOS/qubes-issues#971, scrypt algorithm is
a good choice for key stretching (it isn't the best of all existing, but
a good one and widely adopted). At the same time, lets switch away from
`openssl` tool, as it is very limited and apparently not designed for
production use. Use `scrypt` tool, which is very simple and does exactly
what we need - encrypt the data and integrity protect it. Its archive
format have own (simple) header with data required by the `scrypt`
algorithm, including salt. Internally data is encrypted with AES256-CTR
and integrity protected with HMAC-SHA256. For details see:
https://github.com/tarsnap/scrypt/blob/master/FORMAT
This means change of backup format. Mainly:
1. HMAC is stored in scrypt header, so don't use separate file for it.
Instead have data in files with `.enc` extension.
2. For compatibility leave `backup-header` and `backup-header.hmac`. But
`backup-header.hmac` is really scrypt-encrypted version of `backup-header`.
3. For each file, prepend its identifier to the passphrase, to
authenticate filename itself too. Having this we can guard against
reordering archive files within a single backup and across backups. This
identifier is built as:
backup ID (from backup-header)!filename!
For backup-header itself, there is no backup ID (just 'backup-header!').
FixesQubesOS/qubes-issues#971
Have a generic function `handle_streams`, instead of
`wait_backup_feedback` with open coded process names and manual
iteration over them.
No functional change, besides minor logging change.
Use just introduced tar writer to archive content of LVM volumes (or
more generally: block devices). Place them as 'private.img' and
'root.img' files in the backup - just like in old format. This require
support for replacing file name in tar header - another thing trivially
supported with tar writer.
tar can't write archive with _contents_ of block device. We need this to
backup LVM-based disk images. To avoid dumping image to a file first,
create a simple tar archiver just for this purpose.
Python is not the fastest possible technology, it's 3 times slower than
equivalent written in C. But it's much easier to read, much less
error-prone, and still process 1GB image under 1s (CPU time, leaving
along actual disk reads). So, it's acceptable.
Old backup metadata (old qubes.xml) does not contain info about
individual volume sizes. So, extract it from tar header (using verbose
output during restore) and resize volume accordingly.
Without this, restoring volumes larger than default would be impossible.
To ease all this, rework restore workflow: first create QubesVM objects,
and all their files (as for fresh VM), then override them with data
from backup - possibly redirecting some files to new location. This
allows generic code to create LVM volumes and then only restore its
content.
1. Add a helper function on vm.storage. This is equivalent of:
vm.storage.get_pool(vm.volumes[name]).export(vm.volumes[name])
2. Make sure the path returned by `export` on LVM volume is accessible.
