Peter Maydell [Mon, 19 Oct 2015 09:52:39 +0000 (10:52 +0100)]
Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging
* KVM page size fix for PPC
* Support for Linux 4.4's new Hyper-V features
* Eliminate g_slice from areas I maintain
* checkpatch fix
* Peter's cpu_reload_memory_map() cleanups
* More changes to MAINTAINERS
* Require Python 2.6
* chardev creation fixes
* PCI requester id for ARM KVM
* cleanups and doc fixes
* Allow customization of the Hyper-V vendor id
# gpg: Signature made Mon 19 Oct 2015 09:13:10 BST using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <[email protected]>"
# gpg: aka "Paolo Bonzini <[email protected]>"
* remotes/bonzini/tags/for-upstream: (49 commits)
kvm: Allow the Hyper-V vendor ID to be specified
kvm: Move x86-specific functions into target-i386/kvm.c
kvm: Pass PCI device pointer to MSI routing functions
hw/pci: Introduce pci_requester_id()
kvm: Make KVM_CAP_SIGNAL_MSI globally available
doc/rcu: fix g_free_rcu() usage example
qemu-char: cleanup after completed conversion to cd->create
qemu-char: convert ringbuf backend to data-driven creation
qemu-char: convert vc backend to data-driven creation
qemu-char: convert spice backend to data-driven creation
qemu-char: convert console backend to data-driven creation
qemu-char: convert stdio backend to data-driven creation
qemu-char: convert testdev backend to data-driven creation
qemu-char: convert braille backend to data-driven creation
qemu-char: convert msmouse backend to data-driven creation
qemu-char: convert mux backend to data-driven creation
qemu-char: convert null backend to data-driven creation
qemu-char: convert pty backend to data-driven creation
qemu-char: convert UDP backend to data-driven creation
qemu-char: convert socket backend to data-driven creation
...
Alex Williamson [Fri, 16 Oct 2015 15:38:22 +0000 (09:38 -0600)]
kvm: Allow the Hyper-V vendor ID to be specified
According to Microsoft documentation, the signature in the standard
hypervisor CPUID leaf at 0x40000000 identifies the Vendor ID and is
for reporting and diagnostic purposes only. We can therefore allow
the user to change it to whatever they want, within the 12 character
limit. Add a new hv-vendor-id option to the -cpu flag to allow
for this, ex:
Pavel Fedin [Thu, 15 Oct 2015 13:44:52 +0000 (16:44 +0300)]
kvm: Pass PCI device pointer to MSI routing functions
In-kernel ITS emulation on ARM64 will require to supply requester IDs.
These IDs can now be retrieved from the device pointer using new
pci_requester_id() function.
This patch adds pci_dev pointer to KVM GSI routing functions and makes
callers passing it.
x86 architecture does not use requester IDs, but hw/i386/kvm/pci-assign.c
also made passing PCI device pointer instead of NULL for consistency with
the rest of the code.
Pavel Fedin [Thu, 15 Oct 2015 13:44:51 +0000 (16:44 +0300)]
hw/pci: Introduce pci_requester_id()
For GICv3 ITS implementation we are going to use requester IDs in KVM IRQ
routing code. This patch introduces reusable convenient way to obtain this
ID from the device pointer. The new function is now used in some places,
where the same calculation was used.
MemTxAttrs.stream_id also renamed to requester_id in order to better
reflect semantics of the field.
Sergey Fedorov [Wed, 14 Oct 2015 15:46:44 +0000 (18:46 +0300)]
doc/rcu: fix g_free_rcu() usage example
The first argument of g_free_rcu() is a pointer to a structure. But
foo_reclaim is used as a function name in the previous example along
with &foo as a pointer to the structure being reclaimed. Make the
example consistent with the previous one.
Paolo Bonzini [Mon, 12 Oct 2015 07:51:41 +0000 (09:51 +0200)]
qemu-char: cleanup after completed conversion to cd->create
All backends now return errors through Error*, so the "Failed to
create chardev" placeholder error can only be reached if the backend
is not available (and only from the chardev-add QMP command; instead,
the -chardev command line option fails earlier).
Peter Maydell [Sat, 17 Oct 2015 11:31:33 +0000 (12:31 +0100)]
Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20151016' into staging
target-arm queue:
* break TBs after ISB instructions
* more support code for future implementation of EL2 and 64-bit EL3
* tell guest if KVM is enabled in SMBIOS version string
* implement OSLAR/OSLSR system registers
* provide better help text for Sharp PDA machine names
* rename imx25_pdk to imx25-pdk (since it has never been released
with the underscore-version name)
* fix MMIO writes in zynq_slcr
* implement MDCR_EL2
* virt: allow the guest to configure PCI BARs with zero PCI addresses
* fix breakpoint handling code
Peter Maydell [Fri, 16 Oct 2015 16:13:05 +0000 (17:13 +0100)]
Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-10-15' into staging
QAPI patches
# gpg: Signature made Thu 15 Oct 2015 07:40:46 BST using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <[email protected]>"
# gpg: aka "Markus Armbruster <[email protected]>"
* remotes/armbru/tags/pull-qapi-2015-10-15:
qapi: Track location that created an implicit type
qapi: Create simple union type member earlier
qapi: Lazy creation of array types
qapi: Don't use info as witness of implicit object type
qapi: Drop redundant args-member-array test
qapi: Drop redundant flat-union-reverse-define test
qapi: Drop redundant returns-int test
qapi: Move empty-enum to compile-time test
qapi: Drop redundant alternate-good test
qapi: Prepare for errors during check()
qapi: Use predicate callback to determine visit filtering
qapi: Fix regression with '-netdev help'
# gpg: Signature made Thu 15 Oct 2015 07:25:27 BST using RSA key ID 5872D723
# gpg: Good signature from "Juan Quintela <[email protected]>"
# gpg: aka "Juan Quintela <[email protected]>"
* remotes/juanquintela/tags/migration/20151015:
migration: fix deadlock
migration: announce VM's new home just before VM is runnable
Migration: Generate the completed event only when we complete
Sergey Fedorov [Tue, 13 Oct 2015 09:56:28 +0000 (12:56 +0300)]
target-arm: Fix CPU breakpoint handling
A QEMU breakpoint match is not definitely an architectural breakpoint
match. If an exception is generated unconditionally during translation,
it is hardly possible to ignore it in the debug exception handler.
Generate a call to a helper to check CPU breakpoints and raise an
exception only if any breakpoint matches architecturally.
Fam Zheng [Fri, 16 Oct 2015 10:46:04 +0000 (18:46 +0800)]
blkdebug: Don't confuse image as backing file
The word "backing file" nowadays refers to the backing_hd in the
external snapshot sense (i.e. bs->backing_hd), instead of the file sense
(bs->file). Correct the comment to use the right term.
Stefan Hajnoczi [Thu, 23 Jul 2015 12:48:35 +0000 (13:48 +0100)]
blockdev: always compile in -drive aio= parsing
CONFIG_LINUX_AIO is an implementation detail of raw-posix.c. Don't
mention CONFIG_LINUX_AIO in blockdev.c. Let block drivers decide what
to do with BDRV_O_NATIVE_AIO. They may print an error if it is
unsupported.
Stefan Hajnoczi [Thu, 23 Jul 2015 12:48:34 +0000 (13:48 +0100)]
raw-posix: warn about BDRV_O_NATIVE_AIO if libaio is unavailable
raw-posix.c silently ignores BDRV_O_NATIVE_AIO if libaio is unavailable.
It is confusing when aio=native performance is identical to aio=threads
because the binary was accidentally built without libaio.
Print a deprecation warning if -drive aio=native is used with a binary
that does not support libaio. There are probably users using aio=native
who would be inconvenienced if QEMU suddenly refused to start their
guests. In the future this will become an error.
Jeff Cody [Mon, 12 Oct 2015 23:36:49 +0000 (19:36 -0400)]
util - add automated ID generation utility
Multiple sub-systems in QEMU may find it useful to generate IDs
for objects that a user may reference via QMP or HMP. This patch
presents a standardized way to do it, so that automatic ID generation
follows the same rules.
This patch enforces the following rules when generating an ID:
1.) Guarantee no collisions with a user-specified ID
2.) Identify the sub-system the ID belongs to
3.) Guarantee of uniqueness
4.) Spoiling predictability, to avoid creating an assumption
of object ordering and parsing (i.e., we don't want users to think
they can guess the next ID based on prior behavior).
The scheme for this is as follows (no spaces):
# subsys D RR
Reserved char --| | | |
Subsystem String ----| | |
Unique number (64-bit) --| |
Two-digit random number ---|
For example, a generated node-name for the block sub-system may look
like this:
#block076
The caller of id_generate() is responsible for freeing the generated
node name string with g_free().
Kevin Wolf [Wed, 16 Sep 2015 14:18:38 +0000 (16:18 +0200)]
block: Remove bdrv_swap()
bdrv_swap() is unused now. Remove it and all functions that have
no other users than bdrv_swap(). In particular, this removes the
.bdrv_rebind callbacks from block drivers.
Kevin Wolf [Tue, 15 Sep 2015 09:58:23 +0000 (11:58 +0200)]
block: Add and use bdrv_replace_in_backing_chain()
This cleans up the mess we left behind in the mirror code after the
previous patch. Instead of using bdrv_swap(), just change pointers.
The interface change of the mirror job that callers must consider is
that after job completion, their local BDS pointers still point to the
same node now. qemu-img must change its code accordingly (which makes it
easier to understand); the other callers stays unchanged because after
completion they don't do anything with the BDS, but just with the job,
and the job is still owned by the source BDS.
Kevin Wolf [Wed, 16 Sep 2015 11:34:54 +0000 (13:34 +0200)]
blockjob: Store device name at job creation
Some block jobs change the block device graph on completion. This means
that the device that owns the job and originally was addressed with its
device name may no longer be what the corresponding BlockBackend points
to.
Previously, the effects of bdrv_swap() ensured that the job was (at
least partially) transferred to the target image. Events that contain
the device name could still use bdrv_get_device_name(job->bs) and get
the same result.
After removing bdrv_swap(), this won't work any more. Instead, save the
device name at job creation and use that copy for QMP events and
anything else identifying the job.
Kevin Wolf [Thu, 18 Jun 2015 12:09:57 +0000 (14:09 +0200)]
block: Implement bdrv_append() without bdrv_swap()
Remember all parent nodes and just change the pointers there instead of
swapping the contents of the BlockDriverState.
Handling of snapshot=on must be moved further down in bdrv_open()
because *pbs (which is the bs pointer in the BlockBackend) must already
be set before bdrv_append() is called. Otherwise bdrv_append() changes
the BB's pointer to the temporary snapshot, but bdrv_open() overwrites
it with the read-only original image.
We also need to be careful to update callers as the interface changes
(becomes less insane): Previously, the meaning of the two parameters was
inverted when bdrv_append() returns. Now any BDS pointers keep pointing
to the same node.
Kevin Wolf [Thu, 17 Sep 2015 10:33:26 +0000 (12:33 +0200)]
block: Split bdrv_move_feature_fields()
After bdrv_swap(), some fields must be moved back to their original BDS
to compensate for the effects that a swap of the contents of the objects
has while keeping the old addresses. Other fields must be moved back
because they should logically be moved and must stay on top
When replacing bdrv_swap() with operations changing the pointers in the
parents, we only need the latter and must avoid swapping the former.
Split the function accordingly.
Kevin Wolf [Mon, 14 Sep 2015 13:33:33 +0000 (15:33 +0200)]
block: Manage backing file references in bdrv_set_backing_hd()
This simplifies the code somewhat, especially when dropping whole
backing file subchains.
The exception is the mirroring code that does adventurous things with
bdrv_swap() and in order to keep it working, I had to duplicate most of
bdrv_set_backing_hd() locally. We'll get rid again of this ugliness
shortly.
Kevin Wolf [Wed, 17 Jun 2015 12:55:21 +0000 (14:55 +0200)]
block: Convert bs->backing_hd to BdrvChild
This is the final step in converting all of the BlockDriverState
pointers that block drivers use to BdrvChild.
After this patch, bs->children contains the full list of child nodes
that are referenced by a given BDS, and these children are only
referenced through BdrvChild, so that updating the pointer in there is
enough for changing edges in the graph.
qmp-commands.hx: Update the supported 'transaction' operations
Although the canonical source of reference for QMP commands is
qapi-schema.json, for consistency's sake, update qmp-commands.hx to
state the list of supported transactionable operations, namely:
Alberto Garcia [Mon, 28 Sep 2015 14:23:00 +0000 (17:23 +0300)]
iotests: disable core dumps in test 061
Commit 934659c460 disabled the supression of segmentation faults in
bash tests. The new output of test 061, however, assumes that a core
dump will be produced if a program aborts. This is not necessarily the
case because core dumps can be disabled using ulimit.
Since we cannot guarantee that abort() will produce a core dump, we
should use SIGKILL instead (that does not produce any) and update the
test output accordingly.
The /4 for offset calculation in MMIO writes was happening twice giving
wrong write offsets. Fix.
While touching the code, change the if-else to be a short returning if
and convert the debug message to a GUEST_ERROR, which is more accurate
for this condition.
Added oslar_write function to OSLAR_EL1 sysreg, using a status variable
in ARMCPUState.cp15 struct (oslsr_el1). This variable is also linked
to the newly added read-only OSLSR_EL1 register.
Linux reads from this register during its suspend/resume procedure.
Andrew Jones [Fri, 16 Oct 2015 10:14:53 +0000 (11:14 +0100)]
hw/arm/virt: smbios: inform guest of kvm
ARM/AArch64 KVM guests don't have any way to identify
themselves as KVM guests (x86 guests use a CPUID leaf). Now, we
could discuss all sorts of reasons why guests shouldn't need to
know that, but then there's always some case where it'd be
nice... Anyway, now that we have SMBIOS tables in ARM guests,
it's easy for the guest to know that it's a QEMU instance. This
patch takes that one step further, also identifying KVM, when
appropriate. Again, we could debate why generally nothing
should care whether it's of type QEMU or QEMU/KVM, but again,
sometimes it's nice to know...
Sergey Sorokin [Fri, 16 Oct 2015 10:14:52 +0000 (11:14 +0100)]
target-arm: Avoid calling arm_el_is_aa64() function for unimplemented EL
It is incorrect to call arm_el_is_aa64() function for unimplemented EL.
This patch fixes several attempts to do so.
Signed-off-by: Sergey Sorokin <[email protected]>
[PMM: Reworked several of the comments to be more verbose.] Reviewed-by: Peter Maydell <[email protected]> Signed-off-by: Peter Maydell <[email protected]>
Sergey Sorokin [Fri, 16 Oct 2015 10:14:52 +0000 (11:14 +0100)]
target-arm: Break the TB after ISB to execute self-modified code correctly
If any store instruction writes the code inside the same TB
after this store insn, the execution of the TB must be stopped
to execute new code correctly.
As described in ARMv8 manual D3.4.6 self-modifying code must do an
IC invalidation to be valid, and an ISB after it. So it's enough to end
the TB after ISB instruction on the code translation.
Also this TB break is necessary to take any pending interrupts immediately
after an ISB (as required by ARMv8 ARM D1.14.4).
Eliminate this warning associated with the addRemovableDevicesMenuItems()
function:
ui/cocoa.m:1344:13: warning: function declaration isn't a prototype
[-Wstrict-prototypes]
static void addRemovableDevicesMenuItems()
^
ui/cocoa.m: In function 'addRemovableDevicesMenuItems':
ui/cocoa.m:1344:13: warning: old-style function definition [-Wold-style-definition]
Eric Blake [Tue, 13 Oct 2015 04:22:32 +0000 (22:22 -0600)]
qapi: Track location that created an implicit type
A future patch will move some error checking from the parser
to the various QAPISchema*.check() methods, which run only
after parsing completes. It will thus be possible to create
a python instance representing an implicit QAPI type that
parses fine but will fail validation during check(). Since
all errors have to have an associated 'info' location, we
need a location to be associated with those implicit types.
The intuitive info to use is the location of the enclosing
entity that caused the creation of the implicit type.
Note that we do not anticipate builtin types being used in
an error message (as they are not part of the user's QAPI
input, the user can't cause a semantic error in their
behavior), so we exempt those types from requiring info, by
setting a flag to track the completion of _def_predefineds(),
and tracking that flag in _def_entity().
Eric Blake [Tue, 13 Oct 2015 04:22:29 +0000 (22:22 -0600)]
qapi: Create simple union type member earlier
For simple unions, we were creating the implicit 'type' tag
member during the QAPISchemaObjectTypeVariants constructor.
This is different from every other implicit QAPISchemaEntity
object, which get created by QAPISchema methods. Hoist the
creation to the caller (renaming _make_tag_enum() to
_make_implicit_tag()), and pass the entity rather than the
string name, so that we have the nice property that no
entities are created as a side effect within a different
entity. A later patch will then have an easier time of
associating location info with each entity creation.
Eric Blake [Tue, 13 Oct 2015 04:22:28 +0000 (22:22 -0600)]
qapi: Lazy creation of array types
Commit ac88219a had several TODO markers about whether we needed
to automatically create the corresponding array type alongside
any other type. It turns out that most of the time, we don't!
There are a few exceptions: 1) We have a few situations where we
use an array type in internal code but do not expose that type
through QMP; fix it by declaring a dummy type that forces the
generator to see that we want to use the array type.
2) The builtin arrays (such as intList for QAPI ['int']) must
always be generated, because of the way our QAPI_TYPES_BUILTIN
compile guard works: we have situations (at the very least
tests/test-qmp-output-visitor.c) that include both top-level
"qapi-types.h" (via "error.h") and a secondary
"test-qapi-types.h". If we were to only emit the builtin types
when used locally, then the first .h file would not include all
types, but the second .h does not declare anything at all because
the first .h set QAPI_TYPES_BUILTIN, and we would end up with
compilation error due to things like unknown type 'int8List'.
Actually, we may need to revisit how we do type guards, and
change from a single QAPI_TYPES_BUILTIN over to a different
usage pattern that does one #ifdef per qapi type - right now,
the only types that are declared multiple times between two qapi
.json files for inclusion by a single .c file happen to be the
builtin arrays. But now that we have QAPI 'include' statements,
it is logical to assume that we will soon reach a point where
we want to reuse non-builtin types (yes, I'm thinking about what
it will take to add introspection to QGA, where we will want to
reuse the SchemaInfo type and friends). One #ifdef per type
will help ensure that generating the same qapi type into more
than one qapi-types.h won't cause collisions when both are
included in the same .c file; but we also have to solve how to
avoid creating duplicate qapi-types.c entry points. So that
is a problem left for another day.
Generated code for qapi-types and qapi-visit is drastically
reduced; less than a third of the arrays that were blindly
created were actually needed (a quick grep shows we dropped
from 219 to 69 *List types), and the .o files lost more than
30% of their bulk. [For best results, diff the generated
files with 'git diff --patience --no-index pre post'.]
Interestingly, the introspection output is unchanged - this is
because we already cull all types that are not indirectly
reachable from a command or event, so introspection was already
using only a subset of array types. The subset of types
introspected is now a much larger percentage of the overall set
of array types emitted in qapi-types.h (since the larger set
shrunk), but still not 100% (evidence that the array types
emitted for our new Dummy structs, and the new struct itself,
don't affect QMP).
Eric Blake [Tue, 13 Oct 2015 04:22:27 +0000 (22:22 -0600)]
qapi: Don't use info as witness of implicit object type
A future patch will enable error reporting from the various
QAPISchema*.check() methods. But to report an error related
to an implicit type, we'll need to associate a location with
the type (the same location as the top-level entity that is
causing the creation of the implicit type), and once we do
that, keying off of whether foo.info exists is no longer a
viable way to determine if foo is an implicit type.
Instead, add an is_implicit() method to QAPISchemaEntity, and use it.
It can be overridden later for ObjectType and EnumType, when implicit
instances of those classes gain info.
Eric Blake [Tue, 13 Oct 2015 18:26:47 +0000 (12:26 -0600)]
qapi: Drop redundant args-member-array test
qapi-schema-test already ensures that we can correctly compile
an array of enums (__org.qemu_x-command), an array of builtins
(UserDefNativeListUnion), and an array of structs (again
__org.qemu_x-command). That means args-member-array is not
adding any additional parse-only test coverage, so drop it.
Eric Blake [Tue, 13 Oct 2015 04:22:26 +0000 (22:22 -0600)]
qapi: Drop redundant flat-union-reverse-define test
As of commit 8c3f8e77, we test compilation of forward references
for a struct base type (UserDefOne), flat union base type
(UserDefUnionBase), and flat union branch type
(UserDefFlatUnion2). The only remaining forward reference being
tested for parsing in flat-union-reverse-define was a forward
enum declaration. Once we make sure that always compiles,
the smaller parse-only test is redundant and can be deleted.
Eric Blake [Tue, 13 Oct 2015 04:22:25 +0000 (22:22 -0600)]
qapi: Drop redundant returns-int test
qapi-schema-test was already testing that we could have a
command returning int, but burned a command name in the whitelist.
Merge the redundant positive test returns-int, and pick a name
that reduces the whitelist size.
Eric Blake [Tue, 13 Oct 2015 04:22:23 +0000 (22:22 -0600)]
qapi: Drop redundant alternate-good test
The alternate-good.json test was already covered by
qapi-schema-test.json. As future commits will be tweaking
how alternates are laid out, removing the duplicate test now
reduces churn.
Eric Blake [Tue, 13 Oct 2015 04:22:22 +0000 (22:22 -0600)]
qapi: Prepare for errors during check()
The next few patches will start migrating error checking from
ad hoc parse methods into the QAPISchema*.check() methods. But
for an error message to display, we first have to fix the
overall 'try' to catch those errors. We also want to enable a
few more assertions, such as making sure every attempt to
raise a semantic error is passed a valid location info, or that
various preconditions hold.
The general approach for moving error checking will then be to
relax an assertion into an if that raises an exception if the
condition does not hold, and removing the counterpart ad hoc
check done during the parse phase.
Eric Blake [Tue, 13 Oct 2015 04:22:21 +0000 (22:22 -0600)]
qapi: Use predicate callback to determine visit filtering
Previously, qapi-types and qapi-visit filtered out implicit
objects during visit_object_type() by using 'info' (works since
implicit objects do not [yet] have associated info); meanwhile
qapi-introspect filtered out all schema types on the first pass
by returning a python type from visit_begin(), which was then
used at a distance in QAPISchema.visit() to do the filtering.
Rather than keeping these ad hoc approaches, add a new visitor
callback visit_needed() which returns False to skip a given
entity, and which defaults to True unless overridden. Use the
new mechanism to simplify all three filtering visitors.
Release qemu global mutex before call synchronize_rcu().
synchronize_rcu() waiting for all readers to finish their critical
sections. There is at least one critical section in which we try
to get QGM (critical section is in address_space_rw() and
prepare_mmio_access() is trying to aquire QGM).
Both functions (migration_end() and migration_bitmap_extend())
are called from main thread which is holding QGM.
Thus there is a race condition that ends up with deadlock:
main thread working thread
Lock QGA |
| Call KVM_EXIT_IO handler
| |
| Open rcu reader's critical section
Migration cleanup bh |
| |
synchronize_rcu() is |
waiting for readers |
| prepare_mmio_access() is waiting for QGM
\ /
deadlock
The patch changes bitmap freeing from direct g_free after synchronize_rcu
to free inside call_rcu.
Amit Shah [Wed, 14 Oct 2015 12:07:19 +0000 (17:37 +0530)]
migration: announce VM's new home just before VM is runnable
We were announcing the dest host's IP as our new IP a bit too soon -- if
there were errors detected after this announcement was done, the
migration is failed and the VM could continue running on the src host --
causing problems later.
Move around the qemu_announce_self() call so it's done just before the
VM is runnable.
Migration: Generate the completed event only when we complete
The current migration-completed event is generated a bit too early,
which means that an eager libvirt that's ready to go as soon
as it sees the event ends up racing with the actual end of migration.
This corresponds to RH bug:
https://bugzilla.redhat.com/show_bug.cgi?id=1271145
Paolo Bonzini [Tue, 29 Sep 2015 12:55:59 +0000 (14:55 +0200)]
qemu-char: add create to register_char_driver
Having creation as a member of the CharDriver struct removes the need
to export functions for qemu-char.c's usage. After the conversion,
chardev backends implemented outside qemu-char.c will not need a stub
creation function anymore.
Ultimately all drivers will be converted. For now, support the case
where cd->create == NULL.
Paolo Bonzini [Mon, 12 Oct 2015 07:46:23 +0000 (09:46 +0200)]
qemu-char: cleanup HAVE_CHARDEV_*
Move the #ifdef up into qmp_chardev_add, and avoid duplicating
the code that reports unavailable backends. Split HAVE_CHARDEV_TTY
into HAVE_CHARDEV_SERIAL and HAVE_CHARDEV_PTY.