Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

To allow backups work across external snapshots we need to improve the
algorithm which calculates which bitmaps to merge.

The algorithm must look for appropriately named bitmaps in the image and
possibly descend into a backing image if the current image does not have
the bitmap.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

This function looks up a named bitmap for a virStorageSource in the data
returned from query-named-block-nodes.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Add test code which will crawl a fake internal list of checkpoints and
generate the list of bitmaps for merging to gather the final bitmap for
the backup.

The initial tests cover the basic case of all bitmaps being present in
the top layer of the backing chain.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

The function will require the bitmap topology for the full
implementation. To facilitate testing, add the propagation of the
necessary data beforehand so that the test code can stay unchanged
during the changes.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Separate the for now incomplete code that collects the bitmaps to be
merged for an incremental backup into a separate function. This will
allow adding testing prior to the improvement of the algorithm to
include snapshots.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

The object itself has no extra value and it would make testing the code
harder. Refactor it to remove just the definition pointer.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Add test data gathered from a run of qemu after creating bitmaps and
snapshots together in various combinations.

The following sequence of commands was used to achieve the
configuration:

virsh checkpoint-create-as VM --name a
virsh snapshot-create-as VM --disk-only
virsh snapshot-create-as VM --disk-only
virsh checkpoint-create-as VM --name b
virsh checkpoint-create-as VM --name c
virsh snapshot-create-as VM --disk-only
virsh checkpoint-create-as VM --name d
virsh snapshot-create-as VM --disk-only
virsh checkpoint-create-as VM --name current

Note that VM was restarted after these operations to allow renumbering
of the bitmaps in a more human-readable way.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Re-create any active persistent bitmap in the snapshot overlay image so
that tracking for a checkpoint is persisted. While this basically
duplicates data in the allocation map it's currently the only possible
way as qemu can't mirror the allocation map into a dirty bitmap if we'd
ever want to do a backup.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

qemuDomainSnapshotDiskPrepareOne is already called for each disk which
is member of the snapshot so we don't need to iterate through the
snapshot list again to generate members of the 'transaction' command for
each snapshot.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Check that the value is less than 0.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

The real data gathered for the 'basic' test case don't exercise some
fields. Add a copy with a few values modified manually.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Test the extraction of data about changed block tracking bitmaps. The
first test case adds a simple scenario of multiple bitmaps in one layer.

The test data will be also later reused for testing the code that
determines which bitmaps to merge for an incremental backup.

The sequence of bitmaps was created by the libvirt checkpoint API with
the following sequence of commands:

virsh checkpoint-create-as VM --name a
virsh checkpoint-create-as VM --name b
virsh checkpoint-create-as VM --name c
virsh checkpoint-create-as VM --name d
virsh checkpoint-create-as VM --name current
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

For testing purposes it will be beneficial to be able to parse the data
from JSON directly rather than trying to simulate the monitor. Extract
the worker bits and export them.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

We will need to inspect the presence and attributes for dirty bitmaps.
Extract them when processing reply of query-named-block-nodes.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Support for the mips architecture has been dropped from Debian
sid. Move the mipsel job from Debian 9 to Debian sid at the same
time to keep things balanced.
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

The use of the parseOpaque parameter was mistakenly removed in

  commit 4a4132b4
  Author: Daniel P. Berrangé <berrange@redhat.com>
  Date:   Tue Dec 3 10:49:49 2019 +0000

    conf: don't use passed in caps in post parse method

causing the method to re-fetch qemuCaps that were already just
fetched and put into parseOpaque.

This is inefficient when parsing incoming XML, but for live
XML this is more serious as it means we use the capabilities
for the current QEMU binary on disk, rather than the running
QEMU.

That commit, however, did have a useful side effect of fixing
a crasher bug in the qemu post parse callback introduced by

  commit 5e939cea
  Author: Jiri Denemark <jdenemar@redhat.com>
  Date:   Thu Sep 26 18:42:02 2019 +0200

    qemu: Store default CPU in domain XML

The qemuDomainDefSetDefaultCPU() method in that patch did not
allow for the possibility that qemuCaps would be NULL and thus
resulted in a SEGV.

This shows a risk in letting each check in the post parse
callback look for qemuCaps == NULL. The safer option is to
check once upfront and immediately stop (postpone) further
validation.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Don't check os type / virt type / arch in the post-parse callback
because we can't assume qemuCaps is non-NULL at this point. It
also conceptually belongs to the validation callback.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The status XML represents a running VM, so we should always have an
ID present for the domain.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

This function will be removed in a future commit because it allows the
caller to acquire both monitor and agent jobs at the same time. Holding
both job types creates a vulnerability to denial of service from a
malicious guest agent.

qemuDomainSetVcpusFlags() always passes NONE for either the monitor job
or the agent job (and thus is not vulnerable to the DoS), so we can
simply replace this function with the functions for acquiring the
appropriate type of job.
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

We have to assume that the guest agent may be malicious so we don't want
to allow any agent queries to block any other libvirt API. By holding
a monitor job while we're querying the agent, we open ourselves up to a
DoS.

Split the function so that the portion issuing the agent command only
holds an agent job and the portion issuing the monitor command holds
only a monitor job.
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

We have to assume that the guest agent may be malicious so we don't want
to allow any agent queries to block any other libvirt API. By holding a
monitor job while we're querying the agent, we open ourselves up to a
DoS.

So split the function up a bit to only hold the monitor job while
querying qemu for whether the domain supports suspend. Then acquire only
an agent job while issuing the agent suspend command.
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

We have to assume that the guest agent may be malicious so we don't want
to allow any agent queries to block any other libvirt API. By holding
a monitor job while we're querying the agent, we open ourselves up to a
DoS.

Split the function so that we only hold the appropriate type of job
while rebooting.
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

We have to assume that the guest agent may be malicious so we don't want
to allow any agent queries to block any other libvirt API. By holding
a monitor job while we're querying the agent, we open ourselves up to a
DoS.  So split the function into separate parts: one that does the agent
shutdown and one that does the monitor shutdown. Each part holds only a
job of the appropriate type.
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Replace all the uses passing a single parameter as the length.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Remove the usage where sanity of the length argument is verified
by other conditions not matching the previous patches.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

We abort on allocation errors now so there is no need to
have a function for it.

Replace the only use by return -1, chosen by fair dice roll.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

My hesitation to remove VIR_STRDUP without VIR_STRNDUP resulted
in these being able to sneak in.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Some versions of the rst2man convertor are buggy failing to
cope with syntax highlighting in code blocks.

This isn't something we really need for the man page code
blocks, so we can just delete the highlighting directive.
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

This reverts commit 7be5fe66.

This commit broke resctrl, because it missed the fact that the
virResctrlInfoGetCache() has side-effects causing it to actually
change the virResctrlInfo parameter, not merely get data from
it.

This code will need some refactoring before we can try separating
it from virCapabilities again.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The CI build machinery is intentionally not handled by autotools,
so for VPATH builds - which are mandatory now - we need to make
sure we're looking into $(srcdir).
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

This commit aims to fix

https://bugzilla.redhat.com/show_bug.cgi?id=1610207

The cause was apparently incorrect handling of jobs in snapshot
revert code which allowed a thread executing snapshot delete to
begin job while snapshot revert was still running on another
thread. The snapshot delete thread then waited on a condition
variable in qemuMonitorSend() while the revert thread finished,
changing (and effectively corrupting) the qemuMonitor structure
under the delete thread which led to its crash.

The incorrect handling of jobs in revert code was due to the fact
that although qemuDomainRevertToSnapshot() correctly begins a job
at the start, the job was implicitly ended when qemuProcessStop()
was called because the job lives in the QEMU driver's private
data (qemuDomainObjPrivate) that was purged during
qemuProcessStop().

This fix prevents qemuProcessStop() from clearing jobs as the
idea of qemuProcessStop() clearing jobs seems wrong in the first
place. It was (inadvertently) introduced in commit
888aa4b6, which is effectively reverted by
the second hunk of this commit. To preserve the desired effects
of the faulty commit, the first hunk is included as suggested by
Michal.
Signed-off-by: NPavel Mores <pmores@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Support by usage name can be considered separately (with a 'usage'
attribute?).
Reviewed-by: NStefan Berger <stefanb@linux.ibm.com>
Reviewed-by: NChristophe de Dinechin <dinechin@redhat.com>
Cc: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

The corresponding libvirt-jenkins-ci commit is f289e64a5fd9.
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>