'blockdev-add' allows us to use qemu to format images to our desired
format. This patch implements helpers which convert a
virStorageSourcePtr into JSON objects describing the required
configuration.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

To allow using -blockdev with blockjobs QEMU needs to reopen files in
read-write mode when modifying the backing chain. To achieve this we
need to use 'auto-read-only' for the backing files rather than the
normal 'read-only' property. That way qemu knows that the files need to
be reopened.

Note that the format drivers (e.g. qcow2) are still opened with the
read-only property enabled when being a member of the backing chain
since they are supposed to be immutable unless a block job is started.

QEMU v4.0 (since commit 23dece19da4) allows also dynamic behaviour for
auto-read-only which allows us to use sVirt as we only grant write
permissions to files when doing a blockjob.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

To allow reusing the formatters in the code for creating JSON properties
for 'blockdev-create' we need to create everything except the 'driver'
attribute.

Use the new helper virJSONValueObjectPrependString to put the driver at
the same place so that we don't change any output.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

When formatting new qcow2 images we need to provide the backing store
string which should not contain any authentication or irrelevant data.

Add a flag for qemuBlockStorageSourceGetBackendProps which allows to
skip the irrelevant data.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Split up the addition of a storage source into the following sub-steps:
1) storage access dependencies (TLS transport, persistent reservation)
2) storage acccess node (file/gluster/nbd...)
3) format driver dependencies (encryption secret)
4) format driver node (qcow2, raw, ...)

The functions split out will be later reused when implementing support
for 'blockdev-create' as we'll need the dependencies plugged in first,
then blockdev-create will be called and after that successfully finishes
blockdev-add will be added.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

These are meant to replace the ad-hoc helpers qemuHotplugDiskSourceAttach...
and the open-coded version in qemu_command.c for use in command line
generation.

The functions for preparing for attach of chains unfortunately need to
be in qemu_command.c as they use function defined by that file and
inclusion hierarchy.

In this patch new functions are introduced and subsequent patches then
refactor individual parts to use them.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Move it to qemu_block.c and call it qemuBlockStorageSourceDetachPrepare.
It will be reused in other parts as well.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Demonstrate how VIR_RETURN_PTR is used by refactoring qemu_block.c
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

This is a locally used helper struct but we can make use of automatic
freeing for it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NYuri Chornoivan <yurchor@ukr.net>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

The copy on read functionality is done using a separate layer in the
backing chain. Add function to generate properties for it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Turns out that 'query-nodes' is not what we want and the
'query-blockstats' command was in fact buggy. Revert the new field since
it's not needed.

This reverts commit 50edca13.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

The 'query-blockstats' command does not return statistics for the
explicitly named nodes unless the new argument is specified. Add
infrastrucuture that will allow us to use the new approach if desired.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

With 'transaction' support we don't need to keep around the multipurpose
code which would create the snapshot if 'transaction' is not supported.

To simplify this add a new helper that just wraps the arguments for
'blockdev-snapshot-sync' operation in 'transaction' and use it instead
of qemuBlockSnapshotAddLegacy.

Additionally this allows to format the arguments prior to creating the
file for simpler cleanup.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

To allow using -blockdev with RBD we need to support the recently added
RBD authentication.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Introduce a new setup function for all the related configuration and
move the setup and attachment of the PR code.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Create a new "Prepare" function and move the drive add code into the new
helpers. This will eventually allow to simplify and unify the attaching
code for use with blockdev at the same time as providing compatibility
with older qemus.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Emphasize that it's for the 'drive' part of the disk.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

To keep feature parity, we need to be able to format the PR manager
alias when using blockdev.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

These helpers add infrastructure which simplifies adding and rolling
back virStorageSources to a running qemu instance. Using of the helper
structure and separate functions allows for a much cleaner code in the
section dealing with the monitor.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

Reference the storage via node name rather than inlining it. This is
the approach that will be used with -blockdev/blockdev-add since it
allows more control and is more future proof.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

When using blockdev-add and friends, libvirt will need to create also
properties for the qcow2/raw/... format handler in qemu. This patch adds
the infrastructure and implements all formats known to libvirt including
all properties which are expressed at the format level in qemu.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

Enabling discard for the storage node allows the format drivers to
discard snapshots and other things, while configuration of the format
layer actually decides whether to actually discard data on request from
the host.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

This will be required when doing blockdev-add to conform with the
approach qemu choses to create the disks.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

When used directly with blockdev-add/-blockdev the cache mode will need
to be specified directly for every image rather than just for the disk
itself. This implements the backing options 'direct' and 'no-flush'.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

qemu declares node-name as a 32 byte buffer and silently truncates
anything longer than that. This is unacceptable for libvirt, so we need
to make sure that we won't ever supply a node-name exceeding 31 chars.

Add a function which will do the validation and use it to validate
storage-protocol node names.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

The gluster protocol in qemu uses two styles, one of which is legacy and
not covered by the QAPI schema.

To allow using of the new style in the blockdev-add code, add a
parameter for qemuBlockStorageSourceGetBackendProps which will switch
between the two modes.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

Block storage should actually be passed to qemu via 'host_device' or
'host_cdrom' according to the device type. There were no users of this
behaviour so we thankfully can change it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

Handle VIR_STORAGE_TYPE_DIR in qemuBlockStorageSourceGetBackendProps so
that a 'vvfat' driver is used, which emulates a FAT filesystem
containing the folders.

qemu requires us to add it as a storage layer, since a 'raw' layer is
usually put on top of it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

'file' backend in qemu supports few more options than the current
implementation. Extract it so that changes don't pollute the code.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>