Adding some CONFIG_TCG tests to be finally able to compile QEMU
on s390x also without TCG.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <1500886370-14572-6-git-send-email-thuth@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

These functions can not be compiled with --disable-tcg. But since we
need the other functions from helper.c in the non-tcg build, we can also
not simply remove helper.c from the non-tcg builds. Thus the problematic
functions have to be moved into a separate new file instead that we
can later omit in the non-tcg builds.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <1500886370-14572-5-git-send-email-thuth@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

misc_helper.c won't be compiled with --disable-tcg anymore, but we
still need the program_interrupt() function in that case. Move it
to interrupt.c instead, and refactor it to re-use the code from
trigger_pgm_exception() (for TCG) and enter_pgmcheck() (for KVM,
which now got renamed to kvm_s390_program_interrupt() for
clarity).
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <1500886370-14572-4-git-send-email-thuth@redhat.com>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

misc_helper.c won't be compiled with --disable-tcg anymore, but we
still need the diag helpers in KVM builds, too, so move the helper
functions to a separate file.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <1500886370-14572-3-git-send-email-thuth@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

translate.c can not be compiled with --disable-tcg, but we need
the s390_cpu_dump_state() in KVM-only builds, too. So let's move
that function to helper.c instead, which will also be compiled
when --disable-tcg has been specified.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <1500886370-14572-2-git-send-email-thuth@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

There are certain features that we put into base models, but that are
not relevant for the actual search. The most famous example are
MSA subfunctions that might be disabled on certain real hardware out
there.

While the kvm host model detection will usually detect the correct model
on such machines (as it will in the common case not pass features to check
for into s390_find_cpu_def()), baselining will fall back to a quite old
model just because some MSA subfunctions are missing.

Let's improve that by ignoring lack of these features while performing
the search for a base model.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170720123721.12366-6-david@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170720123721.12366-5-david@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

Using ordinary bitmap operations to set/test bits does not work properly
on architectures !s390x. Let's drop (test|set)_bit_inv and introduce
(test|set)_be_bit instead. These functions work on uint8_t array, not on
unsigned longs arrays and are for now only used in the context of
CPU features.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170720123721.12366-4-david@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

We'll have to do the same for TCG, so let's just move it in there.
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170720123721.12366-3-david@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

Unused and broken, let's just get rid of it.
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170720123721.12366-2-david@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

The SIE_KSS feature will allow a guest to use KSS for a nested guest.
To create a nested guest the SIE_F2 facility is still necessary.
Since SIE_F2 is not part of the default model it does not make
a lot of sense to provide the SIE_KSS feature in the default model.
Let's also create a dependency check.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NJason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: NJanosch Frank <frankja@linux.vnet.ibm.com>
Message-Id: <1500550051-7821-2-git-send-email-borntraeger@de.ibm.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

Commit 7da624e2 ("vfio: Test realized when using VFIOGroup.device_list
iterator") introduced a pointer to the Object DeviceState in the VFIO
common base-device and skipped non-realized devices as we iterate
VFIOGroup.device_list. While it missed to initialize the pointer for
the vfio-ccw case. Let's fix it.

Fixes: 7da624e2 ("vfio: Test realized when using VFIOGroup.device_list
                  iterator")

Cc: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: NHalil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>
Message-Id: <20170718014926.44781-3-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

When allocating memory for the vfio_irq_info parameter of the
VFIO_DEVICE_GET_IRQ_INFO ioctl, we used the wrong size. Let's
fix it by using the right size.
Reviewed-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NJing Zhang <bjzhjing@linux.vnet.ibm.com>
Signed-off-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170718014926.44781-2-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

target-arm queue:
 * fix a TCG temporary leak in aarch64 rev16
 * fsl_imx*: migrate the ROM contents
 * integratorcp: don't use vmstate_register_ram_global for flash
 * mps2: Correctly set parent bus for SCC device

# gpg: Signature made Mon 24 Jul 2017 18:05:06 BST
# gpg:                using RSA key 0x3C2525ED14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20170724:
  integratorcp: Don't migrate flash using vmstate_register_ram_global()
  mps2: Correctly set parent bus for SCC device
  fsl_imx*: Migrate ROM contents
  target/arm: fix TCG temp leak in aarch64 rev16
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Instead of migrating the flash by creating the memory region
with memory_region_init_ram_nomigrate() and then calling
vmstate_register_ram_global(), just use memory_region_init_ram(),
which now handles migration registration automatically.

This is a migration compatibility break for the integratorcp
board, because the RAM region's migration name changes to
include the device path. This is OK because we don't guarantee
migration compatibility for this board.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1500310341-28931-1-git-send-email-peter.maydell@linaro.org

A cut-and-paste error meant that instead of setting the
qdev parent bus for the SCC device we were setting it
twice for the ARMv7M container device. Fix this bug.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1500634509-28011-1-git-send-email-peter.maydell@linaro.org

The fsl-imx* boards accidentally forgot to register the ROM memory
regions for migration.  This used to require a manual step of calling
vmstate_register_ram(), but following commits
1cfe48c1..b08199c6 we can use memory_region_init_rom() to
have it do the migration for us.

This is a migration break, but the migration code currently does not
handle the case of having two RAM regions which were not registered
for migration, and so prior to this commit a migration load would
always fail with:
  "qemu-system-arm: Length mismatch: 0x4000 in != 0x18000: Invalid argument"

NB: migration appears at this point to be broken for this board
anyway -- it succeeds but the destination hangs; probably some
device in the system does not yet support migration.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1500309775-18361-1-git-send-email-peter.maydell@linaro.org

Fix a TCG temporary leak in the new aarch64 rev16 handling.
Signed-off-by: NEmilio G. Cota <cota@braap.org>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Block layer patches for 2.10.0-rc0

# gpg: Signature made Mon 24 Jul 2017 15:16:42 BST
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  qemu-iotests: Avoid unnecessary sleeps
  block: Skip implicit nodes in query-block/blockstats
  qcow2: Fix sector calculation in qcow2_measure()
  dirty-bitmap: Report BlockDirtyInfo.count in bytes, as documented
  iotests: Remove a few tests from 'quick' group
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

nbd patches for 2017-07-24

- Eric Blake: [0/2] Update qemu-nbd version

# gpg: Signature made Mon 24 Jul 2017 14:58:23 BST
# gpg:                using RSA key 0xA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2017-07-24:
  maint: Reorder include directives for qemu-{nbd, io}
  qemu-nbd: Update version string
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

HACKING recommends listing system includes right after osdep.h,
and before any other in-project headers.
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <20170721135047.25005-3-eblake@redhat.com>

qemu-io and qemu-img already mirror the qemu version string,
time to make qemu-nbd do the same.
Reported-by: N陳培泓 <pahome.chen@mirlab.org>
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <20170721135047.25005-2-eblake@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>

Error reporting patches for 2017-07-24

# gpg: Signature made Mon 24 Jul 2017 13:17:49 BST
# gpg:                using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2017-07-24:
  error: Revert unwanted change of warning messages
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Test cases 030, 041 and 055 used to sleep for a second after calling
block-job-pause to make sure that the block job had time to actually
get into paused state. We can instead poll its status and use that one
second only as a timeout.

The tests also slept a second for checking that the block jobs don't
make progress while being paused. Half a second is more than enough for
this.

These changes reduce the total time for the three tests by 25 seconds on
my laptop (from 155 seconds to 130).
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Commits 0db832f4 and 6cdbceb1 introduced the automatic insertion of filter
nodes above the top layer of mirror and commit block jobs. The
assumption made there was that since libvirt doesn't do node-level
management of the block layer yet, it shouldn't be affected by added
nodes.

This is true as far as commands issued by libvirt are concerned. It only
uses BlockBackend names to address nodes, so any operations it performs
still operate on the root of the tree as intended.

However, the assumption breaks down when you consider query commands,
which return data for the wrong node now. These commands also return
information on some child nodes (bs->file and/or bs->backing), which
libvirt does make use of, and which refer to the wrong nodes, too.

One of the consequences is that oVirt gets wrong information about the
image size and stops the VM in response as long as a mirror or commit
job is running:

https://bugzilla.redhat.com/show_bug.cgi?id=1470634

This patch fixes the problem by hiding the implicit nodes created
automatically by the mirror and commit block jobs in the output of
query-block and BlockBackend-based query-blockstats as long as the user
doesn't indicate that they are aware of those nodes by providing a node
name for them in the QMP command to start the block job.

The node-based commands query-named-block-nodes and query-blockstats
with query-nodes=true still show all nodes, including implicit ones.
This ensures that users that are capable of node-level management can
still access the full information; users that only know BlockBackends
won't use these commands.

Cc: qemu-stable@nongnu.org
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Tested-by: NEric Blake <eblake@redhat.com>

We used MAX() instead of the intended MIN() when computing how many
sectors to view in the current loop iteration of qcow2_measure(),
and passed in a value of INT_MAX sectors instead of our more usual
limit of BDRV_REQUEST_MAX_SECTORS (the latter avoids 32-bit overflow
on conversion to bytes).  For small files, the bug is harmless:
bdrv_get_block_status_above() clamps its *pnum answer to the BDS
size, regardless of any insanely larger input request.  However, for
any file at least 2T in size, we can very easily end up going into an
infinite loop (the maximum of 0x100000000 sectors and INT_MAX is a
64-bit quantity, which becomes 0 when assigned to int; once nb_sectors
is 0, we never make progress).
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We've been documenting the value in bytes since its introduction
in commit b9a9b3a4 (v1.3), where it was actually reported in bytes.

Commit e4654d2d (v2.0) then removed things from block/qapi.c, in
preparation for a rewrite to a list of dirty sectors in the next
commit 21b56835 in block.c, but the new code mistakenly started
reporting in sectors.

Fixes: https://bugzilla.redhat.com/1441460

CC: qemu-stable@nongnu.org
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

A run of './check -qcow2 -g quick' on my machine produced only
two tests that took longer than 5 seconds; 178 took 18, and
189 took 7.  Remove them from the quick group.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

QAPI patches for 2017-07-18

# gpg: Signature made Mon 24 Jul 2017 12:40:56 BST
# gpg:                using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2017-07-18-v2:
  migration: Use JSON null instead of "" to reset parameter to default
  migration: Unshare MigrationParameters struct for now
  migration: Add TODO comments on duplication of QAPI_CLONE()
  migration: Clean up around tls_creds, tls_hostname
  hmp: Clean up and simplify hmp_migrate_set_parameter()
  block: Use JSON null instead of "" to disable backing file
  tests/test-qobject-input-visitor: Drop redundant test
  qapi: Introduce a first class 'null' type
  qapi: Use QNull for a more regular visit_type_null()
  qapi: Separate type QNull from QObject
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Commit 97f40301 changed warning messages from

    timestamp-if-enabled progname ":" location "warning: " message

to

    "warning: " timestamp-if-enabled progname ":" location message

This regressed qemu-iotests 051.  Put "warning: " right back where it
was, along with "info: ".
Reported-by: NKevin Wolf <kwolf@redhat.com>
Cc: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1500449614-16811-1-git-send-email-armbru@redhat.com>
Reviewed-by: NAlistair Francis <alistair.francis@xilinx.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>

Clang 3.9 passes the CONFIG_AVX2_OPT configure test.  However, the
supplied <cpuid.h> does not contain the bit_AVX2 define that we use
when detecting whether the routine can be enabled.

Introduce a qemu-specific header that uses the compiler's definition
of __cpuid et al, but supplies any missing bit_* definitions needed.
This avoids introducing any extra ifdefs to util/bufferiszero.c, and
allows quite a few to be removed from tcg/i386/tcg-target.inc.c.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 20170719044018.18063-1-rth@twiddle.net
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

migrate-set-parameters sets migration parameters according to is
arguments like this:

* Present means "set the parameter to this value"

* Absent means "leave the parameter unchanged"

* Except for parameters tls_creds and tls_hostname, "" means "reset
  the parameter to its default value

The first two are perfectly normal: presence of the parameter makes
the command do something.

The third one overloads the parameter with a second meaning.  The
overloading is *implicit*, i.e. it's not visible in the types.  Works
here, because "" is neither a valid TLS credentials ID, nor a valid
host name.

Pressing argument values the schema accepts, but are semantically
invalid, into service to mean "reset to default" is not general, as
suitable invalid values need not exist.  I also find it ugly.

To clean this up, we could add a separate flag argument to ask for
"reset to default", or add a distinct value to @tls_creds and
@tls_hostname.  This commit implements the latter: add JSON null to
the values of @tls_creds and @tls_hostname, deprecate "".

Because we're so close to the 2.10 freeze, implement it in the
stupidest way possible: have qmp_migrate_set_parameters() rewrite null
to "" before anything else can see the null.  The proper way to do it
would be rewriting "" to null, but that requires fixing up code to
work with null.  Add TODO comments for that.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Commit de63ab61 "migrate: Share common MigrationParameters struct"
reused MigrationParameters for the arguments of
migrate-set-parameters, with the following rationale:

    It is rather verbose, and slightly error-prone, to repeat
    the same set of parameters for input (migrate-set-parameters)
    as for output (query-migrate-parameters), where the only
    difference is whether the members are optional.  We can just
    document that the optional members will always be present
    on output, and then share a common struct between both
    commands.  The next patch can then reduce the amount of
    code needed on input.

I need to unshare them to correct a design flaw in a stupid, but
minimally invasive way, in the next commit.  We can restore the
sharing when we redo that patch in a less stupid way.  Add a suitable
TODO comment.

Note that I revert only the sharing part of commit de63ab61, not the
part that made the members of query-migrate-parameters' result
optional.  The schema (and thus introspection) remains inaccurate for
query-migrate-parameters.  If we decide not to restore the sharing, we
should revert that part, too.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

qmp_query_migrate_parameters() and qmp_migrate_set_parameters()
effectively duplicate QAPI_CLONE() inline.  Add suitable TODO
comments.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Optional MigrationParameters members tls_creds and tls_hostname can't
actually be absent outside qmp_migrate_set_parameters() since commit
4af245dc (v2.9.0).

Note that commit 4af245dc reverted the part of commit de63ab61 (v2.8.0)
that made tls_creds and tls_hostname absent instead of "" in the value
of query-migrate-parameters, even though commit de63ab61 called that a
mistake.  What a mess.

Drop the redundant tests for presence, and update documentation.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

The bulk of hmp_migrate_set_parameter()'s code sets one member of
MigrationParameters according to the command's arguments.  It uses a
string visitor for integer and boolean members, but not for string and
size members.  It calls visit_type_bool() right away, but delays
visit_type_int() some.  The delaying requires a flag variable and a
bit of trickery: we set all integer members instead of just the one we
want, and rely on the has_FOOs to mask the unwanted ones.

Clean this up as follows.  Don't delay calling visit_type_int().  Use
the string visitor for strings, too.  This involves extra allocations
and cleanup, but doing them is simpler and cleaner than avoiding them.

Sadly, using the string visitor for sizes isn't possible, because it
defaults to Bytes rather than Mebibytes.  Add a comment explaining
that.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

BlockdevRef is an alternate of BlockdevOptions (inline definition) and
str (reference to an existing block device by name).  BlockdevRef
value "" is special: "no block device should be referenced."  It's
actually interpreted that way in just one place: optional member
@backing of COW formats.  Semantics:

* Present means "use this block device" as backing storage

* Absent means "default to the one stored in the image"

* Except "" means "don't use backing storage at all"

The first two are perfectly normal: when the parameter is absent, it
defaults to an implied value, but the value's meaning is the same.

The third one overloads the parameter with a second meaning.  The
overloading is *implicit*, i.e. it's not visible in the types.  Works
here, because "" is not a value block device ID.

Pressing argument values the schema accepts, but are semantically
invalid, into service to mean "do something else entirely" is not
general, as suitable invalid values need not exist.  I also find it
ugly.

To clean this up, we could add a separate flag argument to suppress
@backing, or add a distinct value to @backing.  This commit implements
the latter: add JSON null to the values of @backing, deprecate "".

Because we're so close to the 2.10 freeze, implement it in the
stupidest way possible: have qmp_blockdev_add() rewrite null to ""
before anything else can see the null.  Works, because BlockdevRef
occurs only within arguments of blockdev-add.  The proper way to do it
would be rewriting "" to null, preferably in a cleaner way, but that
requires fixing up code to work with null.  Add a TODO comment for
that.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Acked-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

test_visitor_in_alternate() tests UserDefAlternate with inadmissible
input.  test_visitor_in_fail_alternate() does basically the same.
Drop the former, keep the latter.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>

I expect the 'null' type to be useful mostly for members of alternate
types.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

Make visit_type_null() take an @obj argument like its buddies.  This
helps keep the next commit simple.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>