Commit Graph

5912 Commits

Author SHA1 Message Date
Jiri Denemark
19e06cfa25 qemu: Ignore non-boolean CPU model properties
The query-cpu-model-expansion is currently implemented for s390(x) only
and all CPU properties it returns are booleans. However, x86
implementation will report more types of properties. Without making the
code more tolerant older libvirt would fail to probe newer QEMU
versions.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2017-01-12 11:58:25 +01:00
Jiri Denemark
ec23791517 qemu: Don't check CPU model property key
The qemuMonitorJSONParseCPUModelProperty function is a callback for
virJSONValueObjectForeachKeyValue and is called for each key/value pair,
thus it doesn't really make sense to check whether key is NULL.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2017-01-12 11:58:25 +01:00
Michal Privoznik
cbc45525cb qemuDomainCreateDevice: Canonicalize paths
So far the decision whether /dev/* entry is created in the qemu
namespace is really simple: does the path starts with "/dev/"?
This can be easily fooled by providing path like the following
(for any considered device like disk, rng, chardev, ..):

  /dev/../var/lib/libvirt/images/disk.qcow2

Therefore, before making the decision the path should be
canonicalized.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 18:08:13 +01:00
Michal Privoznik
49f326edc0 qemu: Use namespaces iff available on the host kernel
So far the namespaces were turned on by default unconditionally.
For all non-Linux platforms we provided stub functions that just
ignored whatever namespaces setting there was in qemu.conf and
returned 0 to indicate success. Moreover, we didn't really check
if namespaces are available on the host kernel.

This is suboptimal as we might have ignored user setting.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 18:07:43 +01:00
Michal Privoznik
41816751a7 util: Introduce virFileMoveMount
This is a simple wrapper over mount(). However, not every system
out there is capable of moving a mount point. Therefore, instead
of having to deal with this fact in all the places of our code we
can have a simple wrapper and deal with this fact at just one
place.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 18:06:30 +01:00
Michal Privoznik
2ff8c30548 qemuDomainSetupAllInputs: Update debug message
Due to a copy-paste error, the debug message reads:

  Setting up disks

It should have been:

  Setting up inputs.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-11 17:39:24 +01:00
Laine Stump
5949b53aec conf: eliminate virDomainPCIAddressReleaseSlot() in favor of ...Addr()
Surprisingly there was a virDomainPCIAddressReleaseAddr() function
already, but it was completely unused. Since we don't reserve entire
slots at once any more, there is no need to release entire slots
either, so we just replace the single call to
virDomainPCIAddressReleaseSlot() with a call to
virDomainPCIAddressReleaseAddr() and remove the now unused function.

The keen observer may be concerned that ...Addr() doesn't call
virDomainPCIAddressValidate(), as ...Slot() did. But really the
validation was pointless anyway - if the device hadn't been suitable
to be connected at that address, it would have failed validation
before every being reserved in the first place, so by definition it
will pass validation when it is being unplugged. (And anyway, even if
something "bad" happened and we managed to have a device incorrectly
at the given address, we would still want to be able to free it up for
use by a device that *did* validate properly).
2017-01-11 05:00:34 -05:00
Laine Stump
6cc2014202 qemu: rename qemuDomainPCIAddressReserveNextSlot() to ...Addr()
This function doesn't actually reserve an entire slot any more, it
reserves a single PCI address, so this name is more appropriate.
2017-01-11 05:00:08 -05:00
Laine Stump
c5aea19d56 qemu: remove qemuDomainPCIAddressReserveNextAddr()
This function is only called in two places, and the function itself is
just adding a single argument and calling
virDomainPCIAddressReserveNextAddr(), so we can remove it and instead
call virDomainPCIAddressReserveNextAddr() directly. (The main
motivation for doing this is to free up the name so that
qemuDomainPCIAddressReserveNextSlot() can be renamed in the next
patch, as its current name is now inaccurate and misleading).
2017-01-11 04:59:42 -05:00
Laine Stump
27b0f971c4 conf: rename virDomainPCIAddressReserveSlot() to ...Addr()
This function doesn't actually reserve an entire slot any more, it
reserves a single PCI address, so this name is more appropriate.
2017-01-11 04:58:32 -05:00
Laine Stump
905859a6e5 qemu: replace virDomainPCIAddressReserveAddr with virDomainPCIAddressReserveSlot
All occurences of the former use fromConfig=true, and that's exactly
how virDomainPCIAddressReserveSlot() calls
virDomainPCIaddressReserveAddr(), so just use *Slot() so that *Addr()
can be made static to conf/domain_addr.c (both functions will be
renamed in upcoming patches).
2017-01-11 04:55:06 -05:00
Laine Stump
b59bbdba4b conf: fix fromConfig argument to virDomainPCIAddressValidate()
fromConfig should be true if the caller wants
virDomainPCIAddressValidate() to loosen restrictions on its
interpretation of the pciConnectFlags. In particular, either
PCI_DEVICE or PCIE_DEVICE will be counted as equivalent to both, and
HOTPLUG will be ignored. In a few cases where libvirt was manually
overriding automatic address assignment, it was setting fromConfig to
false when validating the hardcoded manual override. This patch
changes those to fromConfig=true as a preemptive strike against any
future bugs that might otherwise surface.
2017-01-11 04:51:54 -05:00
Laine Stump
79901543b9 conf: fix fromConfig argument to virDomainPCIAddressReserveAddr()
Although setting virDomainPCIAddressReserveAddr()'s fromConfig=true is
correct when a PCI addres is coming from a domain's config, the *true*
purpose of the fromConfig argument is to lower restrictions on what
kind of device can plug into what kind of controller - if fromConfig
is true, then a PCIE_DEVICE can plug into a slot that is marked as
only compatible with PCI_DEVICE (and vice versa), and the HOTPLUG flag
is ignored.

For a long time there have been several calls to
virDomainPCIAddressReserveAddr() that have fromConfig incorrectly set
to false - it's correct that the addresses aren't coming from user
config, but they are coming from hardcoded exceptions in libvirt that
should, if anything, pay *even less* attention to following the
pciConnectFlags (under the assumption that the libvirt programmer knew
what they were doing).

See commit b87703cf7 for an example of an actual bug caused by the
incorrect setting of the "fromConfig" argument to
virDomainPCIAddressReserveAddr(). Although they haven't resulted in
any reported bugs, this patch corrects all the other incorrect
settings of fromConfig in calls to virDomainPCIAddressReserveAddr().
2017-01-11 04:47:12 -05:00
Laine Stump
48d39cf96d conf: aggregate multiple devices on a slot when assigning PCI addresses
If a PCI device has VIR_PCI_CONNECT_AGGREGATE_SLOT set in its
pciConnectFlags, then during address assignment we allow multiple
instances of this type of device to be auto-assigned to multiple
functions on the same device. A slot is used for aggregating multiple
devices only if the first device assigned to that slot had
VIR_PCI_CONNECT_AGGREGATE_SLOT set. but any device types that have
AGGREGATE_SLOT set might be mix/matched on the same slot.

(NB: libvirt should never set the AGGREGATE_SLOT flag for a device
type that might need to be hotplugged. Currently it is only planned
for pcie-root-port and possibly other PCI controller types, and none
of those are hotpluggable anyway)

There aren't yet any devices that use this flag. That will be in a
later patch.
2017-01-11 04:43:22 -05:00
Laine Stump
8f4008713a qemu: use virDomainPCIAddressSetAllMulti() to set multi when needed
If there are multiple devices assigned to the different functions of a
single PCI slot, they will not work properly if the device at function
0 doesn't have its "multi" attribute turned on, so it makes sense for
libvirt to turn it on during PCI address assignment. Setting multi
then assures that the new setting is stored in the config (so it will
be used next time the domain is started), preventing any potential
problems in the case that a future change in the configuration
eliminates the devices on all non-0 functions (multi will still be set
for function 0 even though it is the only function in use on the slot,
which has no useful purpose, but also doesn't cause any problems).

(NB: If we were to instead just decide on the setting for
multifunction at runtime, a later removal of the non-0 functions of a
slot would result in a silent change in the guest ABI for the
remaining device on function 0 (although it may seem like an
inconsequential guest ABI change, it *is* a guest ABI change to turn
off the multi bit).)
2017-01-11 04:42:08 -05:00
Laine Stump
9ff9d9f5a9 conf: eliminate concept of "reserveEntireSlot"
setting reserveEntireSlot really accomplishes nothing - instead of
going to the trouble of computing the value for reserveEntireSlot and
then possibly setting *all* functions of the slot as in-use, we can
just set the in-use bit only for the specific function being used by a
device.  Later we will know from the context (the PCI connect flags,
and whether we are reserving a specific address or asking for "the
next available") whether or not it is okay to allocate other functions
on the same slot.

Although it's not used yet, we allow specifying "-1" for the function
number when looking for the "next available slot" - this is going to
end up meaning "return the lowest available function in the slot, but
since we currently only provide a function from an otherwise unused
slot, "-1" ends up meaning "0".
2017-01-11 04:36:34 -05:00
Laine Stump
9838cad9cd conf: use struct instead of int for each slot in virDomainPCIAddressBus
When keeping track of which functions of which slots are allocated, we
will need to have more information than just the current bitmap with a
bit for each function that is currently stored for each slot in a
virDomainPCIAddressBus. To prepare for adding more per-slot info, this
patch changes "uint8_t slots" into "virDomainPCIAddressSlot slot", which
currently has a single member named "functions" that serves the same
purpose previously served directly by "slots".
2017-01-11 04:29:48 -05:00
Michal Privoznik
269589146c qemu_domain: Move qemuDomainGetPreservedMounts
This function is used only from code compiled on Linux. Therefore
on non-Linux platforms it triggers compilation error:

../../src/qemu/qemu_domain.c:209:1: error: unused function 'qemuDomainGetPreservedMounts' [-Werror,-Wunused-function]

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 19:23:49 +01:00
Peter Krempa
b469853812 qemu: blockjob: Fix locking of block copy/active block commit
For the blockjobs, where libvirt is able to track the state internally
we can fix locking of images we can remove the appropriate locks.

Also when doing a pivoting operation we should not acquire the lock on
any of those images since both are actually locked already.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1302168
2017-01-10 19:12:19 +01:00
Peter Krempa
f61e40610d qemu: snapshot: Properly handle image locking
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
2017-01-10 19:12:19 +01:00
Peter Krempa
cbb4d229de qemu: snapshot: Refactor snapshot rollback on failure
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.
2017-01-10 19:12:19 +01:00
Peter Krempa
7456c4f5f0 qemu: snapshot: Don't redetect backing chain after snapshot
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.
2017-01-10 19:12:19 +01:00
Michal Privoznik
406e390962 qemu: Drop qemuDomainDeleteNamespace
After previous commits, this function is no longer needed.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:57 +01:00
Michal Privoznik
5d198c2b2c qemuDomainCreateNamespace: move mkdir to qemuDomainBuildNamespace
Again, there is no need to create /var/lib/libvirt/$domain.*
directories in CreateNamespace(). It is sufficient to create them
as soon as we need them which is in BuildNamespace. This way we
don't leave them around for the whole lifetime of domain.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:57 +01:00
Michal Privoznik
5d30057695 qemuDomainGetPreservedMounts: Do not special case /dev
The c1140eb9e got me thinking. We don't want to special case /dev
in qemuDomainGetPreservedMounts(), but in all other places in the
code we special case it anyway. I mean,
/var/run/libvirt/$domain.dev path is constructed separately just
so that it is not constructed here. It makes only a little sense
(if any at all).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:57 +01:00
Michal Privoznik
40ebbf72d5 qemuDomainCreateNamespace: s/unlink/rmdir/
If something goes wrong in this function we try a rollback. That
is unlink all the directories we created earlier. For some weird
reason unlink() was called instead of rmdir().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:57 +01:00
Michal Privoznik
095f042ed6 qemu: Use transactions from security driver
So far if qemu is spawned under separate mount namespace in order
to relabel everything it needs an access to the security driver
to run in that namespace too. This has a very nasty down side -
it is being run in a separate process, so any internal state
transition is NOT reflected in the daemon. This can lead to many
sleepless nights. Therefore, use the transaction APIs so that
libvirt developers can sleep tight again.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 13:04:11 +01:00
Michal Privoznik
39779eb195 security_dac: Resolve virSecurityDACSetOwnershipInternal const correctness
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: Michal Privoznik <mprivozn@redhat.com>
2017-01-10 12:49:59 +01:00
Andrea Bolognani
1d8454639f qemu: Use virtio-pci by default for mach-virt guests
virtio-pci is the way forward for aarch64 guests: it's faster
and less alien to people coming from other architectures.
Now that guest support is finally getting there (Fedora 24,
CentOS 7.3, Ubuntu 16.04 and Debian testing all support
virtio-pci out of the box), we'd like to start using it by
default instead of virtio-mmio.

Users and applications can already opt-in by explicitly using

  <address type='pci'/>

inside the relevant elements, but that's kind of cumbersome and
requires all users and management applications to adapt, which
we'd really like to avoid.

What we can do instead is use virtio-mmio only if the guest
already has at least one virtio-mmio device, and use virtio-pci
in all other situations.

That means existing virtio-mmio guests will keep using the old
addressing scheme, and new guests will automatically be created
using virtio-pci instead. Users can still override the default
in either direction.

Existing tests such as aarch64-aavmf-virtio-mmio and
aarch64-virtio-pci-default already cover all possible
scenarios, so no additions to the test suites are necessary.
2017-01-10 12:33:53 +01:00
Peter Krempa
a946ea1a33 qemu: setvcpus: Properly coldplug vcpus when hotpluggable vcpus are present
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
2017-01-10 10:47:06 +01:00
Nitesh Konkar
ae16c95f1b perf: Add cache_l1d perf event support
This patch adds support and documentation for
a generalized hardware cache event called cache_l1d
perf event.

Signed-off-by: Nitesh Konkar <nitkon12@linux.vnet.ibm.com>
2017-01-09 18:15:31 -05:00
Daniel P. Berrange
c50070173d Add domain event for metadata changes
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: Daniel P. Berrange <berrange@redhat.com>
2017-01-09 15:53:00 +00:00
Maxim Nestratov
af78cb0486 qemu: Allow to specify pit timer tick policy=discard
Separate out the "policy=discard" into it's own specific
qemu command line.

We'll rename "kvm-pit-device" test case to be "kvm-pit-discard"
since it has the syntax we'd be using.

Signed-off-by: Maxim Nestratov <mnestratov@virtuozzo.com>
2017-01-06 18:27:06 -05:00
Maxim Nestratov
ef5c8bb412 qemu: Fix pit timer tick policy=delay
By a mistake, for the VIR_DOMAIN_TIMER_TICKPOLICY_DELAY qemu
command line creation, 'discard' was used instead of 'delay'
in commit id '1569fa14'.

Test "kvm-pit-delay" is fixed accordingly to show the correct
option being generated.

Remove the (now) redundant kvm-pit-device tests. As it turns
out there is no need to specify both QEMU_CAPS_NO_KVM_PIT and
QEMU_CAPS_KVM_PIT_TICK_POLICY since they are mutually exclusive
and "kvm-pit-device" becomes just the same as "kvm-pit-delay".

Signed-off-by: Maxim Nestratov <mnestratov@virtuozzo.com>
2017-01-06 18:27:06 -05:00
Collin L. Walling
d47db7b16d qemu: command: Support new cpu feature argument syntax
Qemu has abandoned the +/-feature syntax in favor of key=value. Some
architectures (s390) do not support +/-feature. So we update libvirt to handle
both formats.

If we detect a sufficiently new Qemu (indicated by support for qmp
query-cpu-model-expansion) we use key=value else we fall back to +/-feature.

Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
2017-01-06 12:24:57 +01:00
Jiri Denemark
5d513d4659 qemu-caps: Get host model directly from Qemu when available
When qmp query-cpu-model-expansion is available probe Qemu for its view of the
host model. In kvm environments this can provide a more complete view of the
host model because features supported by Qemu and Kvm can be considered.

Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
2017-01-06 12:24:57 +01:00
Collin L. Walling
fab9d6e1a9 qemu: qmp query-cpu-model-expansion command
query-cpu-model-expansion is used to get a list of features for a given cpu
model name or to get the model and features of the host hardware/environment
as seen by Qemu/kvm.

Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
2017-01-06 12:24:57 +01:00
Martin Kletzander
c1140eb9ed qemu: Remove /dev mount info properly
Just so it doesn't bite us in the future, even though it's unlikely.

And fix the comment above it as well.  Commit e08ee7cd34 took the
info from the function it's calling, but that was lie itself in the
first place.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2017-01-05 16:24:55 +01:00
Michal Privoznik
e08ee7cd34 qemuDomainGetPreservedMounts: Fetch list of /dev/* mounts dynamically
With my namespace patches, we are spawning qemu in its own
namespace so that we can manage /dev entries ourselves. However,
some filesystems mounted under /dev needs to be preserved in
order to be shared with the parent namespace (e.g. /dev/pts).
Currently, the list of mount points to preserve is hardcoded
which ain't right - on some systems there might be less or more
items under real /dev that on our list. The solution is to parse
/proc/mounts and fetch the list from there.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-05 16:00:20 +01:00
Michal Privoznik
6de3f11637 qemuProcessLaunch: fix indentation
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-05 14:38:45 +01:00
Wangjing (King, Euler)
3afaae4984 qemu: snapshot: restart CPUs when recover from interrupted snapshot job
If we restart libvirtd while VM was doing external memory snapshot, VM's
state be updated to paused as a result of running a migration-to-file
operation, and then VM will be left as paused state. In this case we must
restart the VM's CPUs to resume it.

Signed-off-by: Wang King <king.wang@huawei.com>
2017-01-05 10:47:03 +01:00
Peter Krempa
2e86c0816f qemu: snapshot: Resume VM after live snapshot
Commit 4b951d1e38 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.
2017-01-04 16:50:18 +01:00
Michal Privoznik
dd78da09b0 qemuDomainCreateDevice: Be more careful about device path
Again, not something that I'd hit, but there is a chance in
theory that this might bite us. Currently the way we decide
whether or not to create /dev entry for a device is by marching
first four characters of path with "/dev". This might be not
enough. Just imagine somebody has a disk image stored under
"/devil/path/to/disk". We ought to be matching against "/dev/".

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-04 15:36:42 +01:00
Michal Privoznik
ce01a2b11c qemuDomainAttachDeviceMknodHelper: Don't unlink() so often
Not that I'd encounter any bug here, but the code doesn't look
100% correct. Imagine, somebody is trying to attach a device to a
domain, and the device's /dev entry already exists in the qemu
namespace. This is handled gracefully and the control continues
with setting up ACLs and calling security manager to set up
labels. Now, if any of these steps fail, control jump on the
'cleanup' label and unlink() the file straight away. Even when it
was not us who created the file in the first place. This can be
possibly dangerous.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-04 15:36:42 +01:00
Michal Privoznik
3aae99fe71 qemu: Handle EEXIST gracefully in qemuDomainCreateDevice
https://bugzilla.redhat.com/show_bug.cgi?id=1406837

Imagine you have a domain configured in such way that you are
assigning two PCI devices that fall into the same IOMMU group.
With mount namespace enabled what happens is that for the first
PCI device corresponding /dev/vfio/X entry is created and when
the code tries to do the same for the second mknod() fails as
/dev/vfio/X already exists:

2016-12-21 14:40:45.648+0000: 24681: error :
qemuProcessReportLogError:1792 : internal error: Process exited
prior to exec: libvirt: QEMU Driver error : Failed to make device
/var/run/libvirt/qemu/windoze.dev//vfio/22: File exists

Worse, by default there are some devices that are created in the
namespace regardless of domain configuration (e.g. /dev/null,
/dev/urandom, etc.). If one of them is set as backend for some
guest device (e.g. rng, chardev, etc.) it's the same story as
described above.

Weirdly, in attach code this is already handled.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-04 15:36:42 +01:00
John Ferlan
7f7d990483 qemu: Don't assume secret provided for LUKS encryption
https://bugzilla.redhat.com/show_bug.cgi?id=1405269

If a secret was not provided for what was determined to be a LUKS
encrypted disk (during virStorageFileGetMetadata processing when
called from qemuDomainDetermineDiskChain as a result of hotplug
attach qemuDomainAttachDeviceDiskLive), then do not attempt to
look it up (avoiding a libvirtd crash) and do not alter the format
to "luks" when adding the disk; otherwise, the device_add would
fail with a message such as:

   "unable to execute QEMU command 'device_add': Property 'scsi-hd.drive'
    can't find value 'drive-scsi0-0-0-0'"

because of assumptions that when the format=luks that libvirt would have
provided the secret to decrypt the volume.

Access to unlock the volume will thus be left to the application.
2017-01-03 12:59:18 -05:00
Shivaprasad G Bhat
5f65c96e8d Allow virtio-console on PPC64
virQEMUCapsSupportsChardev existing checks returns true
for spapr-vty alone. Instead verify spapr-vty validity
and let the logic to return true for other device types
so that virtio-console passes.

The non-pseries machines dont have spapr-vio-bus. So, the
function always returned false for them before.

Fixes - https://bugzilla.redhat.com/show_bug.cgi?id=1257813

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
2016-12-21 18:01:10 +01:00
Nikolay Shirokovskiy
9f08b76631 qemu: clean out unused migrate to unix 2016-12-21 16:24:59 +01:00
John Ferlan
b9b1aa6392 qemu: Adjust qemuDomainGetBlockInfo data for sparse backed files
According to commit id '0282ca45a' 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.
2016-12-20 12:56:44 -05:00
Marc Hartmayer
fb2cd32c9a qemu: qemuDomainDiskChangeSupported: Add missing 'address' check
Disk->info is not live updatable so add a check for this. Otherwise
libvirt reports success even though no data was updated.

Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
2016-12-20 11:22:44 +01:00