Images that became the backing chain of the current image due to the
snapshot need to be unlocked in the lock manager. Also if qemu was
paused during the snapshot the current top level images need to be
released until qemu is resumed so that they can be acquired properly.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1191901

The code at first changed the definition and then rolled it back in case
of failure. This was ridiculous. Refactor the code so that the image in
the definition is changed only when the snapshot is successful.

The refactor will also simplify further fix of image locking when doing
snapshots.

Libvirt is able to properly model what happens to the backing chain
after a snapshot so there's no real need to redetect the data.
Additionally with the _REUSE_EXT flag this might end up in redetecting
wrong data if the user puts wrong backing chain reference into the
snapshot image.

The code at the very bottom of the DAC secdriver that calls
chown() should be fine with read-only data. If something needs to
be prepared it should have been done beforehand.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

When coldplugging vcpus to a VM that already has a few hotpluggable
vcpus the code might generate invalid configuration as
non-hotpluggable cpus need to be clustered starting from vcpu 0.

This fix forces the added vcpus to be hotpluggable in such case.

Fixes a corner case described in:
https://bugzilla.redhat.com/show_bug.cgi?id=1370357

This patch adds support and documentation for
a generalized hardware cache event called cache_l1d
perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

When changing the metadata via virDomainSetMetadata, we now
emit an event to notify the app of changes. This is useful
when co-ordinating different applications read/write of
custom metadata.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Commit 4b951d1e missed the fact that the
VM needs to be resumed after a live external checkpoint (memory
snapshot) where the cpus would be paused by the migration rather than
libvirt.

According to commit id '0282ca45' the 'physical' value should
essentially be the last offset of the image or the host physical
size in bytes of the image container. However, commit id '15fa84ac'
refactored the GetBlockInfo to use the same returned data as the
GetStatsBlock API for an active domain. For the 'entry->physical'
that would end up being the "actual-size" as set through the
qemuMonitorJSONBlockStatsUpdateCapacityOne (commit '7b11f5e5').
Digging deeper into QEMU code one finds that actual_size is
filled in using the same algorithm as GetBlockInfo has used for
setting the 'allocation' field when the domain is inactive.

The difference in values is seen primarily in sparse raw files
and other container type files (such as qcow2), which will return
a smaller value via the stat API for 'st_blocks'. Additionally
for container files, the 'capacity' field (populated via the
QEMU "virtual-size" value) may be slightly different (smaller)
in order to accomodate the overhead for the container. For
sparse files, the state 'st_size' field is returned.

This patch thus alters the allocation and physical values for
sparse backed storage files to be more appropriate to the API
contract. The result for GetBlockInfo is the following:

 capacity: logical size in bytes of the image (how much storage
           the guest will see)
 allocation: host storage in bytes occupied by the image (such
             as highest allocated extent if there are no holes,
             similar to 'du')
 physical: host physical size in bytes of the image container
           (last offset, similar to 'ls')

NB: The GetStatsBlock API allows a different contract for the
values:

 "block.<num>.allocation" - offset of the highest written sector
                            as unsigned long long.
 "block.<num>.capacity" - logical size in bytes of the block device
                          backing image as unsigned long long.
 "block.<num>.physical" - physical size in bytes of the container
                          of the backing image as unsigned long long.

The error would be overwritten otherwise producing a meaningless error
message.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1302171

Similarly to 29bb0669 forbid paths used with blockjobs to be relative.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1300177

This patch adds support and documentation for
the ref_cpu_cycles perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation for
the stalled_cycles_backend perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation
for the stalled_cycles_frontend perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation
for the bus_cycles perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

External disk-only snapshots with recent enough qemu don't require
libvirt to pause the VM. The logic determining when to resume cpus was
slightly flawed and attempted to resume them even if they were not
paused by the snapshot code. This normally was not a problem, but with
locking enabled the code would attempt to acquire the lock twice.

The fallout of this bug would be a error from the API, but the actual
snapshot being created. The bug was introduced with when adding support
for external snapshots with memory (checkpoints) in commit f569b87f.

Resolves problems described by:
https://bugzilla.redhat.com/show_bug.cgi?id=1403691

When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This patch adds support and documentation
for the branch_misses perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

Current call to qemuAgentGetFSInfo in qemuDomainGetFSInfo is
unsafe. Domain lock is dropped and we use vm->def. Let's make
def copy to fix that.

The libvirt-domain.h documentation indicates that for a qcow2 file
in a filesystem being used for a backing store should report the disk
space occupied by a file; however, commit id '15fa84ac' altered the
code to trust that the wr_highest_offset should be used whenever
wr_highest_offset_valid was set.

As it turns out this will lead to indeterminite results. For an active
domain when qemu hasn't yet had the need to find the wr_highest_offset
value, qemu will report 0 even though qemu-img will report the proper
disk size. This causes reporting of the following XML:

  <disk type='file' device='disk'>
    <driver name='qemu' type='qcow2'/>
    <source file='/path/to/test-1g.qcow2'/>

to be as follows:

Capacity:       1073741824
Allocation:     0
Physical:       1074139136

with qemu-img indicating:

image: /path/to/test-1g.qcow2
file format: qcow2
virtual size: 1.0G (1073741824 bytes)
disk size: 1.0G

Once the backing source file is opened on the guest, then wr_highest_offset
is updated, but only to the high water mark and not the size of the file.

This patch will adjust the logic to check for the file backed qcow2 image
and enforce setting the allocation to the returned 'physical' value, which
is the 'actual-size' value from a 'query-block' operation.

NB: The other consumer of the wr_highest_offset output (GetAllDomainStats)
has a contract that indicates 'allocation' is the offset of the highest
written sector, so it doesn't need adjustment.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Instead of having duplicated code in qemuStorageLimitsRefresh and
virStorageBackendUpdateVolTargetInfo to get capacity specific data
about the storage backing source or volume -- create a common API
to handle the details for both.

As a side effect, virStorageFileProbeFormatFromBuf returns to being
a local/static helper to virstoragefile.c

For the QEMU code - if the probe is done, then the format is saved so
as to avoid future such probes.

For the storage backend code, there is no need to deal with the probe
since we cannot call the new API if target->format == NONE.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Instead of having duplicated code in qemuStorageLimitsRefresh and
virStorageBackendUpdateVolTargetInfoFD to fill in the storage backing
source or volume allocation, capacity, and physical values - create a
common API that will handle the details for both.

The common API will fill in "default" capacity values as well - although
those more than likely will be overridden by subsequent code. Having just
one place to make the determination of what the values should be will
make things be more consistent.

For the QEMU code - the data filled in will be for inactive domains
for the GetBlockInfo and DomainGetStatsOneBlock API's. For the storage
backend code - the data will be filled in during the volume updates.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Commit id '8dc27259' introduced virStorageSourceUpdateBlockPhysicalSize
in order to retrieve the physical size for a block backed source device
for an active domain since commit id '15fa84ac' changed to use the
qemuMonitorGetAllBlockStatsInfo and qemuMonitorBlockStatsUpdateCapacity
API's to (essentially) retrieve the "actual-size" from a 'query-block'
operation for the source device.

However, the code only was made functional for a BLOCK backing type
and it neglected to use qemuOpenFile, instead using just open. After
the open the block lseek would find the end of the block and set the
physical value, close the fd and return.

Since the code would return 0 immediately if the source device wasn't
a BLOCK backed device, the physical would be displayed incorrectly,
such as follows in domblkinfo for a file backed source device:

Capacity:       1073741824
Allocation:     0
Physical:       0

This patch will modify the algorithm to get the physical size for other
backing types and it will make use of the qemuDomainStorageOpenStat
helper in order to open/stat the source file depending on its type.
The qemuDomainGetStatsOneBlock will no longer inhibit printing errors,
but it will still ignore them leaving the physical value set to 0.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Currently just a shim to call virStorageSourceUpdateBlockPhysicalSize
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Split out the opening of the file and fetch of the stat buffer into a
helper qemuDomainStorageOpenStat. This will handle either opening the
local or remote storage.

Additionally split out the cleanup of that into a separate helper
qemuDomainStorageCloseStat which will either close the file or
call the virStorageFileDeinit function.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Originally added by commit id '89646e69' prior to commit id '15fa84ac'
and '71d2c172' which ensured that qemuStorageLimitsRefresh was only called
for inactive domains.

Adjust the comment describing the need for FIXME and move all the text
to the function description.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

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

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

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

When vhostuser interfaces are used, the interface statistics
are not available in /proc/net/dev.

This change looks at the openvswitch interfaces statistics
tables to provide this information for vhostuser interface.

Note that in openvswitch world drop/error doesn't always make sense
for some interface type. When these informations are not available we
set them to 0 on the virDomainInterfaceStats.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

There's nothing to compress if the requested snapshot memory format is
set to 'raw' explicitly. After commit 9e14689e libvirt would try to
run /sbin/raw to process the memory stream if the qemu.conf option
snapshot_image_format is set.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1402726

If you've ever tried running a huge page backed guest under
different user than in qemu.conf, you probably failed. Problem is
even though we have corresponding APIs in the security drivers,
there's no implementation and thus we don't relabel the huge page
path. But even if we did, so far all of the domains share the
same path:

   /hugepageMount/libvirt/qemu

Our only option there would be to set 0777 mode on the qemu dir
which is totally unsafe. Therefore, we can create dir on
per-domain basis, i.e.:

   /hugepageMount/libvirt/qemu/domainName

and chown domainName dir to the user that domain is configured to
run under.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

So far this function takes virDomainObjPtr which:
1) is an overkill,
2) might be not available in all the places we will use it.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

With current perf framework, this patch adds support and documentation
for the branch_instructions perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

Add support to read/parse the iotune group setting for qemu.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Rather than have multiple bool values, create a single enum with bits
representing what fields are set. Fields are generally set in groups
of 3 (read, write, total).

Rather than using negative logic and setting the maxparams to a lesser
value based on which capabilities exist, alter the logic to modify the
maxparams based on a base value plus the found capabilities. Reduces the
chance that some backported feature produces an incorrect value.

The function just returned cached capabilities without checking whether
they are still valid. We should check that and refresh the capabilities
to make sure we don't return stale data. In other words, we should do
what all other lookup functions do.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

If a user asked for a KVM domain capabilities when KVM is not available,
we would happily return data we got when probing through TCG and
pretended they were relevant for KVM. Let's just report KVM is not
supported to avoid confusion.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

When domain capabilities were introduced we did not have enough data to
decide whether KVM works on the host or not and thus working legacy/VFIO
device assignment was used as a witness. Now that we know whether KVM
was enabled when probing QEMU capabilities (and thus we know it's
working), we can use this knowledge to provide better default value for
virttype.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

We have couple of functions that operate over NULL terminated
lits of strings. However, our naming sucks:

virStringJoin
virStringFreeList
virStringFreeListCount
virStringArrayHasString
virStringGetFirstWithPrefix

We can do better:

virStringListJoin
virStringListFree
virStringListFreeCount
virStringListHasString
virStringListGetFirstWithPrefix
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>