Commit Graph

25332 Commits

Author SHA1 Message Date
Michal Privoznik
f73e62a17c Revert "qemu: add socket datagram capability"
This reverts commit 0cebb6422a.

This capability is not used anywhere and also it is not contained
in any release so it's safe to just remove it.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-09-19 11:38:44 +02:00
Michal Privoznik
ccf41a4b57 qemu: Enable slirp-helper iff dbus-vmstate present
The fact that qemu is capable -netdev socket is not enough to
start a migratable domain. It also needs dbus-vmstate capability.
Since there are already some qemu releases which have
net-socket-dgram capability and don't have dbus-vmstate we need
to check for dbus-vmstate.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-09-19 11:36:44 +02:00
Michal Privoznik
5d98074c7b Revert "qemu_capabilities: Temporarily disable dbus-vmstate capability"
This reverts commit 929e0bd267.

I've mistakenly pushed wrong branch.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-19 11:27:12 +02:00
Michal Privoznik
c83412bd3c Revert "Temporarily disable bla"
This reverts commit 385543a543.

I've mistakenly pushed wrong branch.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-19 11:26:56 +02:00
Michal Privoznik
385543a543 Temporarily disable bla
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-18 17:01:07 +02:00
Michal Privoznik
929e0bd267 qemu_capabilities: Temporarily disable dbus-vmstate capability
The qemu side is not merged in yet, so there is a chance that the
interface will change. Don't detect the capability just yet then.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-18 17:01:07 +02:00
Ján Tomko
caa1b711e8 qemuBuildMemoryCellBackendStr: remove useless ret variable
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-18 11:33:18 +02:00
Ján Tomko
dfe0ce93f2 qemuBuildMemoryBackendProps: use 'rc' instead of ret.
Do not overwrite the 'ret' value more than once.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-18 11:33:18 +02:00
Ján Tomko
77de0d36df qemuBuildMemoryBackendProps: remove useless cleanup label
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-18 11:33:18 +02:00
Ján Tomko
6bb8edafd9 qemuBuildSoundCommandLine: reduce scope of codecstr
Copy the declaration into the smallest blocks it's used in
and mark it as VIR_AUTOFREE.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-18 11:33:17 +02:00
Ján Tomko
f9b650a848 qemuBuildHostNetStr: remove unnecessary cleanup label
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-18 11:33:17 +02:00
Ján Tomko
1a8e03f886 qemuBuildHostNetStr: remove unused 'driver' argument
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-18 11:33:17 +02:00
Ján Tomko
9ec3ec30a6 qemuBuildHostNetStr: remove unused cfg
As of commit 2d80fbb14d this variable
is unused.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-18 11:33:17 +02:00
Nikolay Shirokovskiy
e6fd586197 vz: build fix for passing qemuCaps to virDomainDefParseNode
Missing piece for [1]

[1]: 577a1f98: qemu: Pass correct qemuCaps to virDomainDefParseNode

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
2019-09-18 09:59:32 +03:00
Nikolay Shirokovskiy
0991baa1c3 vz: build fix for passing qemuCaps to virDomainDeviceDefPostParse
Missing piece for [1].

[1] b449c2704: qemu: Pass correct qemuCaps to virDomainDeviceDefPostParse

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
2019-09-18 09:57:08 +03:00
Nikolay Shirokovskiy
cd9cbeffe9 virStrncpy: fix to successfully copy empty string
After [1] we got failure on attempt to copy empty string.
Before the patch empty string was copied successfuly.
Restore the original behaviour.

[1] 7d70a63b util: Improve virStrncpy() implementation

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2019-09-18 09:25:17 +03:00
Michael Chapman
522b3d2b24 remote: fix registration of TLS socket
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Michael Chapman <mike@very.puzzling.org>
2019-09-17 10:35:53 +01:00
Michael Chapman
425e5783f9 util: fix byte order of port in virSocketAddrResolveService
The ports in the socket address structures returned by getaddrinfo() are
in network byte order. Convert to host byte order before returning them.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Michael Chapman <mike@very.puzzling.org>
2019-09-17 10:35:50 +01:00
Daniel P. Berrangé
7d84ce059e remote: pass identity across to newly opened daemons
When opening a connection to a second driver inside the daemon, we must
ensure the identity of the current user is passed across. This allows
the second daemon to perform access control checks against the real end
users, instead of against the libvirt daemon that's proxying across the
API calls.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:53 +01:00
Daniel P. Berrangé
4471003836 util: allow identity to be imported/exported as typed parameters
Add ability to import/export all the parameters associated with an
identity, so that they can be exposed via the public API.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:45 +01:00
Daniel P. Berrangé
b1aa312185 util: store identity attrs as virTypedParameter internally
We'll shortly be exposing the identity as virTypedParameter in the
public header, so it simplifies life to use that as the internal
representation too.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:39 +01:00
Daniel P. Berrangé
45b273d981 util: sanitize return values for virIdentity getters
The virIdentity getters are unusual in that they return -1 to indicate
"not found" and don't report any error. Change them to return -1 for
real errors, 0 for not found, and 1 for success.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:34 +01:00
Daniel P. Berrangé
f3fa662353 util: removed unused virIdentityIsEqual method
It is simpler to remove this unused method than to rewrite it using
typed parameters in the next patch.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:30 +01:00
Daniel P. Berrangé
1bbc53c264 util: make generic identity accessors private
Only expose the type safe getters/setters to other code in preparation
for changing the internal storage of data.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:23 +01:00
Daniel P. Berrangé
4597a23f50 util: change identity class attribute names
Remove the "UNIX" tag from the names for user name, group name,
process ID and process time, since these attributes are all usable
for non-UNIX platforms like Windows.

User ID and group ID are left with a "UNIX" tag, since there's no
equivalent on Windows. The closest equivalent concept on Windows,
SID, is a struct containing a number of integer fields, which is
commonly represented in string format instead. This would require
a separate attribute, and is left for a future exercise, since
the daemons are not currently built on Windows anyway.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:10 +01:00
Daniel P. Berrangé
305cdc37f0 api: introduce virConnectSetIdentity for passing uid, gid, selinux info
When using the fine grained access control mechanism for APIs, when a
client connects to libvirtd, the latter will fetch the uid, gid, selinux
info of the remote client on the UNIX domain socket. This is then used
as the identity when checking ACLs.

With the new split daemons things are a bit more complicated. The user
can connect to virtproxyd, which in turn connects to virtqemud. When
virtqemud requests the identity over the UNIX domain socket, it will
get the identity that virtproxyd is running as, not the identity of
the real end user/application.

virproxyd knows what the real identity is, and needs to be able to
forward this information to virtqemud. The virConnectSetIdentity API
provides a mechanism for doing this. Obviously virtqemud should not
accept such identity overrides from any client, it must only honour it
from a trusted client, aka one running as the same uid/gid as itself.

The typed parameters exposed in the API are the same as those currently
supported by the internal virIdentity class, with a few small name
changes.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-16 11:25:01 +01:00
Peter Krempa
87c8e7dbf5 qemu: blockjob: Refuse to register blockjob if disk already has one
Most code paths prevent starting a blockjob if we already have one but
the job registering function does not do this check. While this isn't a
problem for regular cases we had a bad test case where we registered two
jobs for a single disk which leaked one of the jobs. Prevent this in the
registering function until we allow having multiple jobs per disk.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
ACKed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2019-09-16 11:50:28 +02:00
Laine Stump
70a29b378a qemu: call common NetDef validation for hotplug and device update
qemuDomainAttachNetDevice() (hotplug) previously had some of the
validation that is in qemuDomainValidateActualNetDef(), but it was
incomplete. qemuDomainChangeNet() had none of that validation, but it
is all appropriate in both cases.

This is the final piece of a previously partial resolution to
https://bugzilla.redhat.com/1502754

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-15 20:18:13 -04:00
Laine Stump
3cff23f7f1 qemu: move runtime netdev validation into a separate function
The same validation should be done for both static network devices and
hotplugged devices, but they are currently inconsistent. Move all the
relevant validation from qemuBuildInterfaceCommandLine() into the new
function qemuDomainValidateActualNetDef() and call the latter from
the former.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-15 20:17:55 -04:00
Laine Stump
57de1988c4 conf: make arg to virDomainNetGetActualVirtPortProfile() a const
It needs to be used by a function that only has a const pointer to
virDomainNetDef.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-15 20:17:03 -04:00
Jim Fehlig
281a7f1d40 apparmor: avoid copying empty profile name
AppArmorGetSecurityProcessLabel copies the VM's profile name to the
label member of virSecurityLabel struct. If the profile is not loaded,
the name is set empty before calling virStrcpy to copy it. However,
virStrcpy will fail if src is empty (0 length), causing
AppArmorGetSecurityProcessLabel to needlessly fail. Simple operations
that report security driver information will subsequently fail

virsh dominfo test
Id:             248
Name:           test
...
Security model: apparmor
Security DOI:   0
error: internal error: error copying profile name

Avoid copying an empty profile name when the profile is not loaded.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-13 12:26:51 -06:00
Daniel P. Berrangé
d6b144b1fe network: add debug when bandwidth settings are not applied
To aid in troubleshooting add some debug messages wrt
bandwidth settings and networks.

Reviewed-by: Laine Stump <laine@laine.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-13 17:34:09 +01:00
Daniel P. Berrangé
0a85aad582 network: apply bandwidth settings for forward mode=bridge
We previously allowed bandwidth settings when attaching NICs
to networks with forward mode=bridge:

  commit 42a92ee93d
  Author: Daniel P. Berrangé <berrange@redhat.com>
  Date:   Tue Nov 20 11:30:05 2018 +0000

    network: add missing bandwidth limits for bridge forward type

    In the case of a network with forward=bridge, which has a bridge device
    listed, we are capable of setting bandwidth limits but fail to call the
    function to register them.

    Reviewed-by: Cole Robinson <crobinso@redhat.com>
    Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

Unfortunately the wrong version of this patch was posted and
reviewed and thus it lacked the code to actually apply the
bandwidth settings to the bridge itself.

Reviewed-by: Laine Stump <laine@laine.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-13 17:34:04 +01:00
Daniel P. Berrangé
7ab9bdd470 network: fix connection usage counts after restart
Since the introduction of the virNetworkPort object, the network driver
has a persistent record of ports that have been created against the
networks. Thus the hypervisor drivers no longer communicate to the
network driver during libvirtd restart.

This change, however, meant that the connection usage counts were
no longer re-initialized during a libvirtd restart. To deal with this we
must iterate over all virNetworkPortDefPtr objects we have and invoke
the notify callback to record the connection usage count.

Reviewed-by: Laine Stump <laine@laine.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-13 17:33:58 +01:00
Daniel P. Berrangé
b9ed82c9fb qemu: fix detach of hostdev based network interface
This fixes bug in

  commit bbe2aa627f
  Author: Daniel P. Berrangé <berrange@redhat.com>
  Date:   Thu Jul 26 17:24:30 2018 +0100

    conf: simplify link from hostdev back to network device

    hostdevs have a link back to the original network device. This is fairly
    generic accepting any type of device, however, we don't intend to make
    use of this approach in future. It can thus be specialized to network
    devices.

    Reviewed-by: Cole Robinson <crobinso@redhat.com>
    Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

which mistakenly deleted the assignment to the 'net' variable,
which meant we never invoked the network driver release callback

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-13 15:09:02 +01:00
Daniel P. Berrangé
6de994cd3e util: make string functions abort on OOM
The functions are left returning an "int" to avoid an immediate
big-bang cleanup. They'll simply never return anything other
than 0.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-13 10:05:17 +01:00
Daniel P. Berrangé
252e9b388c util: remove several unused _QUIET allocation macro variants
Only a few of the _QUIET allocation macros are used. Since we're no
longer reporting OOM as errors, we want to eliminate all the _QUIET
variants. This starts with the easy, unused, cases.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-13 10:05:17 +01:00
Daniel P. Berrangé
52117fa97e util: make allocation functions abort on OOM
The functions are left returning an "int" to avoid an immediate
big-bang cleanup. They'll simply never return anything other
than 0, except for virInsertN which can still return an error
if the requested insertion index is out of range. Interestingly
in that case, the _QUIET function would none the less report
an error.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-13 10:05:17 +01:00
Daniel P. Berrangé
2c52ecd960 util: purge all code for testing OOM handling
The OOM handling requires special build time options which we never
enable in our CI. Even once enabled the tests are incredibly slow and
typically require manual inspection of the results to weed out false
positives.

Since there was previous agreement to switch to abort on OOM in libvirt
code, there's no point continuing to keep the unused OOM testing code.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-13 10:05:17 +01:00
Daniel P. Berrangé
e0cb57c552 conf: correctly convert 'managed' attribute from network port
The virNetworkPortDef config stores the 'managed' attribute
as the virTristateBool type.

The virDomainDef config stores the 'managed' attribute as
the bool type.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-12 16:52:49 +01:00
Daniel P. Berrangé
fb0239ff30 conf: avoid looking up network port that doesn't exist
If the hypervisor driver has not yet created the network port, the
portid field will be "00000000-0000-0000-0000-000000000000".

If a failure occurs during early VM startup, the hypervisor driver may
none the less try to release the network port, resulting in an
undesirable warning:

2019-09-12 13:17:42.349+0000: 16544: error :
virNetworkObjLookupPort:1679 : network port not found: Network port with
UUID 00000000-0000-0000-0000-000000000000 does not exist

By checking if the portid UUID is valid, we can avoid polluting the logs
in this way.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-12 16:06:57 +01:00
Jiang Kun
38816336a5 node_device_conf: Don't leak @physical_function in virNodeDeviceGetPCISRIOVCaps
The pci_dev->physical_function is rewritten in
virPCIGetPhysicalFunction() to a newly allocated pointer.
Therefore, we must free the old one to avoid memleak.

Signed-off-by: Jiang kun <jiang.kun2@zte.com.cn>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-12 16:17:35 +02:00
Michal Privoznik
e9d51a221c qemu: Use FW descriptors to report FW image paths
Now that we have qemuFirmwareGetSupported() so that it also
returns a list of FW image paths, we can use it to report them in
domain capabilities instead of the old time default list.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1733940

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-12 12:34:29 +02:00
Michal Privoznik
78f8769a84 qemu_firmware: Extend qemuFirmwareGetSupported to return FW paths
The qemuFirmwareGetSupported() function is called from qemu
driver to generate domain capabilities XML based on FW descriptor
files. However, the function currently reports only some features
from domcapabilities XML and not actual FW image paths. The paths
reported in the domcapabilities XML are still from pre-FW
descriptor era and therefore the XML might be a bit confusing.
For instance, it may say that secure boot is supported but
secboot enabled FW is not in the listed FW image paths.

To resolve this problem, change qemuFirmwareGetSupported() so
that it also returns a list of FW images (we have the list
anyway). Luckily, we already have a structure to represent a FW
image - virFirmware.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1733940

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-12 12:31:39 +02:00
Michal Privoznik
bc7fe2f56d qemu_firmware: Document qemuFirmwareGetSupported
This function is going to get some new arguments. Document the
current ones for clarity.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-12 12:30:03 +02:00
Michal Privoznik
48f8aee2ab virfirmware: Expose and define autoptr for virFirmwareFree
This function frees a _virFirmware struct. So far, it doesn't
need to be called from outside of the module, but this will
change shortly. In the light of recent VIR_DEFINE_AUTOPTR_FUNC()
additions, do the same to virFirmwareFree().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-09-12 12:19:56 +02:00
Maxiwell S. Garcia
152c165d34 snapshot: Store both config and live XML in the snapshot domain
The snapshot-create operation of running guests saves the live
XML and uses it to replace the active and inactive domain in
case of revert. So, the config XML is ignored by the snapshot
process. This commit changes it and adds the config XML in the
snapshot XML as the <inactiveDomain> entry.

In case of offline guest, the behavior remains the same and the
config XML is saved in the snapshot XML as <domain> entry. The
behavior of older snapshots of running guests, that don't have
the new <inactiveDomain>, remains the same too. The revert, in
this case, overrides both active and inactive domain with the
<domain> entry. So, the <inactiveDomain> in the snapshot XML is
not required to snapshot work, but it's useful to preserve the
config XML of running guests.

Signed-off-by: Maxiwell S. Garcia <maxiwell@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2019-09-11 13:09:45 +02:00
Maxiwell S. Garcia
720d98263e qemu: formatting XML from domain def choosing the root name
The function virDomainDefFormatInternal() has the predefined root name
"domain" to format the XML. But to save both active and inactive domain
in the snapshot XML, the new root name "inactiveDomain" was created.
So, the new function virDomainDefFormatInternalSetRootName() allows to
choose the root name of XML. The former function became a tiny wrapper
to call the new function setting the correct parameters.

Signed-off-by: Maxiwell S. Garcia <maxiwell@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2019-09-11 13:09:45 +02:00
Jiri Denemark
33c05f8b44 qemu: Don't leak domain def when RevertToSnapshot fails
Once we copy the domain definition from virDomainSnapshotDef, we either
need to assign it to the domain object or free it to avoid memory leaks.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2019-09-11 13:07:42 +02:00
Eric Blake
4933445a18 qemu: Fix regression in snapshot-revert
Commit f10562799 introduced a regression: if reverting to a snapshot
fails early (such as when we refuse to revert to an external
snapshot), we lose track of the domain's current snapshot.

Before that patch, we were tracking the notion of the domain's current
snapshot via two means: vm->current_snapshot (which was left untouched
on early exit) and snap->def->current (which only controls what gets
written to XML to remember snapshots across libvirtd restarts).  That
patch was fixing a real bug: if a revert operation failed early, later
questions from the same libvirtd did not see any change to the current
snapsthot, but restarting libvirtd would now claim there is no current
snapshot.  But it fixed it in the wrong direction, in that the current
snapshot was forgotten unconditionally, rather than only when the
snapshot to revert to has a chance of being useful.

It didn't help that the code after that patch had two separate spots
clearing the old notion of the current snapshot - one after
determining the snapshot to revert to was viable, the other
unconditionally on all failure exit paths.  At any rate, the fix is
simple: drop the unconditional cleanup on error paths, and rely only
on the normal cleanup after early checks.

Sadly, it is not possible to test this bug in the existing
tests/virsh-snapshot, as the test driver does not have the same
prohibition against reverting to an external snapshot as the qemu
driver.

See: https://bugzilla.redhat.com/1738747
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190909205242.15406-1-eblake@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-09-10 17:30:44 -05:00