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283 Commits

Author SHA1 Message Date
Peter Maydell f68419eee9 Block layer patches
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Thu 12 May 2016 14:37:05 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (69 commits)
  qemu-iotests: iotests: fail hard if not run via "check"
  block: enable testing of LUKS driver with block I/O tests
  block: add support for encryption secrets in block I/O tests
  block: add support for --image-opts in block I/O tests
  qemu-io: Add 'write -z -u' to test MAY_UNMAP flag
  qemu-io: Add 'write -f' to test FUA flag
  qemu-io: Allow unaligned access by default
  qemu-io: Use bool for command line flags
  qemu-io: Make 'open' subcommand more like command line
  qemu-io: Add missing option documentation
  qmp: add monitor command to add/remove a child
  quorum: implement bdrv_add_child() and bdrv_del_child()
  Add new block driver interface to add/delete a BDS's child
  qemu-img: check block status of backing file when converting.
  iotests: fix the redirection order in 083
  block: Inactivate all children
  block: Drop superfluous invalidating bs->file from drivers
  block: Invalidate all children
  nbd: Simplify client FUA handling
  block: Honor BDRV_REQ_FUA during write_zeroes
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-05-12 16:33:40 +01:00
Wen Congyang 7f82159769 qmp: add monitor command to add/remove a child
The new QMP command name is x-blockdev-change. It's just for adding/removing
quorum's child now, and doesn't support all kinds of children, all kinds of
operations, nor all block drivers. So it is experimental now.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1462865799-19402-4-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Eric Blake 68ab47e4b4 qapi: Change visit_type_FOO() to no longer return partial objects
Returning a partial object on error is an invitation for a careless
caller to leak memory.  We already fixed things in an earlier
patch to guarantee NULL if visit_start fails ("qapi: Guarantee
NULL obj on input visitor callback error"), but that does not
help the case where visit_start succeeds but some other failure
happens before visit_end, such that we leak a partially constructed
object outside visit_type_FOO(). As no one outside the testsuite
was actually relying on these semantics, it is cleaner to just
document and guarantee that ALL pointer-based visit_type_FOO()
functions always leave a safe value in *obj during an input visitor
(either the new object on success, or NULL if an error is
encountered), so callers can now unconditionally use
qapi_free_FOO() to clean up regardless of whether an error occurred.

The decision is done by adding visit_is_input(), then updating the
generated code to check if additional cleanup is needed based on
the type of visitor in use.

Note that we still leave *obj unchanged after a scalar-based
visit_type_FOO(); I did not feel like auditing all uses of
visit_type_Enum() to see if the callers would tolerate a specific
sentinel value (not to mention having to decide whether it would
be better to use 0 or ENUM__MAX as that sentinel).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-25-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake d9f62dde13 qapi: Simplify semantics of visit_next_list()
The semantics of the list visit are somewhat baroque, with the
following pseudocode when FooList is used:

start()
for (prev = head; cur = next(prev); prev = &cur) {
    visit(&cur->value)
}

Note that these semantics (advance before visit) requires that
the first call to next() return the list head, while all other
calls return the next element of the list; that is, every visitor
implementation is required to track extra state to decide whether
to return the input as-is, or to advance.  It also requires an
argument of 'GenericList **' to next(), solely because the first
iteration might need to modify the caller's GenericList head, so
that all other calls have to do a layer of dereferencing.

Thankfully, we only have two uses of list visits in the entire
code base: one in spapr_drc (which completely avoids
visit_next_list(), feeding in integers from a different source
than uint8List), and one in qapi-visit.py.  That is, all other
list visitors are generated in qapi-visit.c, and share the same
paradigm based on a qapi FooList type, so we can refactor how
lists are laid out with minimal churn among clients.

We can greatly simplify things by hoisting the special case
into the start() routine, and flipping the order in the loop
to visit before advance:

start(head)
for (tail = *head; tail; tail = next(tail)) {
    visit(&tail->value)
}

With the simpler semantics, visitors have less state to track,
the argument to next() is reduced to 'GenericList *', and it
also becomes obvious whether an input visitor is allocating a
FooList during visit_start_list() (rather than the old way of
not knowing if an allocation happened until the first
visit_next_list()).  As a minor drawback, we now allocate in
two functions instead of one, and have to pass the size to
both functions (unless we were to tweak the input visitors to
cache the size to start_list for reuse during next_list, but
that defeats the goal of less visitor state).

The signature of visit_start_list() is chosen to match
visit_start_struct(), with the new parameters after 'name'.

The spapr_drc case is a virtual visit, done by passing NULL for
list, similarly to how NULL is passed to visit_start_struct()
when a qapi type is not used in those visits.  It was easy to
provide these semantics for qmp-output and dealloc visitors,
and a bit harder for qmp-input (several prerequisite patches
refactored things to make this patch straightforward).  But it
turned out that the string and opts visitors munge enough other
state during visit_next_list() to make it easier to just
document and require a GenericList visit for now; an assertion
will remind us to adjust things if we need the semantics in the
future.

Several pre-requisite cleanup patches made the reshuffling of
the various visitors easier; particularly the qmp input visitor.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-24-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake 74f24cb630 qapi: Fix string input visitor handling of invalid list
As shown in the previous commit, the string input visitor was
treating bogus input as an empty list rather than an error.
Fix parse_str() to set errp, then the callers to exit early if
an error was reported.

Meanwhile, fix the testsuite to use the generated
qapi_free_int16List() instead of rolling our own, and to
validate the fixed behavior, while at the same time documenting
one more change that we'd like to make in a later patch (a
failed visit_start_list should guarantee a NULL pointer,
regardless of what things were on input).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-23-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake 15c2f669e3 qapi: Split visit_end_struct() into pieces
As mentioned in previous patches, we want to call visit_end_struct()
functions unconditionally, so that visitors can release resources
tied up since the matching visit_start_struct() without also having
to worry about error priority if more than one error occurs.

Even though error_propagate() can be safely used to ignore a second
error during cleanup caused by a first error, it is simpler if the
cleanup cannot set an error.  So, split out the error checking
portion (basically, input visitors checking for unvisited keys) into
a new function visit_check_struct(), which can be safely skipped if
any earlier errors are encountered, and leave the cleanup portion
(which never fails, but must be called unconditionally if
visit_start_struct() succeeded) in visit_end_struct().

Generated code in qapi-visit.c has diffs resembling:

|@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v,
|         goto out_obj;
|     }
|     visit_type_ACPIOSTInfo_members(v, obj, &err);
|-    error_propagate(errp, err);
|-    err = NULL;
|+    if (err) {
|+        goto out_obj;
|+    }
|+    visit_check_struct(v, &err);
| out_obj:
|-    visit_end_struct(v, &err);
|+    visit_end_struct(v);
| out:

and in qapi-event.c:

@@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP
|         goto out;
|     }
|     visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, &param, &err);
|-    visit_end_struct(v, err ? NULL : &err);
|+    if (!err) {
|+        visit_check_struct(v, &err);
|+    }
|+    visit_end_struct(v);
|     if (err) {
|         goto out;

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com>
[Conflict with a doc fixup resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake 56a6f02b8c qmp: Tighten output visitor rules
Tighten assertions in the QMP output visitor, so that:

- qmp_output_get_qobject() can only be called after pairing a
visit_end_* for every visit_start_* (rather than allowing it on
a partially built object)

- qmp_output_get_qobject() cannot be called unless at least one
visit_type_* or visit_start/visit_end pair has occurred since
creation/reset (the accidental return of NULL fixed by commit
ab8bf1d7 would have been much easier to diagnose)

- ensure that we are encountering the expected object or list
type, to provide protection against mismatched push(struct)/
pop(list) or push(list)/pop(struct), similar to the qmp-input
protection added in commit bdd8e6b5.

- ensure that except for the root, 'name' is non-null inside a
dict, and NULL inside a list (this may need changing later if
we add "name.0" support for better error messages for a list,
but for now it makes sure all users are at least consistent)

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-19-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake 3df016f185 qmp: Support explicit null during visits
Implement the new type_null() callback for the qmp input and
output visitors. While we don't yet have a use for this in QAPI
input (the generator will need some tweaks first), some
potential usages have already been discussed on the list.
Meanwhile, the output visitor could already output explicit null
via type_any, but this gives us finer control.

At any rate, it's easy to test that we can round-trip an explicit
null through manual use of visit_type_null() wrapped by a virtual
visit_start_struct() walk, even if we can't do the visit in a
QAPI type.  Repurpose the test_visitor_out_empty test,
particularly since a future patch will tighten semantics to
forbid use of qmp_output_get_qobject() without at least one
intervening visit_type_*.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake 3bc97fd592 qapi: Add visit_type_null() visitor
Right now, qmp-output-visitor happens to produce a QNull result
if nothing is actually visited between the creation of the visitor
and the request for the resulting QObject.  A stronger protocol
would require that a QMP output visit MUST visit something.  But
to still be able to produce a JSON 'null' output, we need a new
visitor function that states our intentions.  Yes, we could say
that such a visit must go through visit_type_any(), but that
feels clunky.

So this patch introduces the new visit_type_null() interface and
its no-op interface in the dealloc visitor, and stubs in the
qmp visitors (the next patch will finish the implementation).
For the visitors that will not implement the callback, document
the situation. The code in qapi-visit-core unconditionally
dereferences the callback pointer, so that a segfault will inform
a developer if they need to implement the callback for their
choice of visitor.

Note that JSON has a primitive null type, with the single value
null; likewise with the QNull type for QObject; but for QAPI,
we just have the 'null' value without a null type.  We may
eventually want to add more support in QAPI for null (most likely,
we'd use it via an alternate type that permits 'null' or an
object); but we'll create that usage when we need it.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake adfb264c9e qapi: Document visitor interfaces, add assertions
The visitor interface for mapping between QObject/QemuOpts/string
and QAPI is scandalously under-documented, making changes to visitor
core, individual visitors, and users of visitors difficult to
coordinate.  Among other questions: when is it safe to pass NULL,
vs. when a string must be provided; which visitors implement which
callbacks; the difference between concrete and virtual visits.

Correct this by retrofitting proper contracts, and document where some
of the interface warts remain (for example, we may want to modify
visit_end_* to require the same 'obj' as the visit_start counterpart,
so the dealloc visitor can be simplified).  Later patches in this
series will tackle some, but not all, of these warts.

Add assertions to (partially) enforce the contract.  Some of these
were only made possible by recent cleanup commits.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-13-git-send-email-eblake@redhat.com>
[Doc fix from Eric squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake fcf3cb2178 qmp-input: Refactor when list is advanced
In the QMP input visitor, visiting a list traverses two objects:
the QAPI GenericList of the caller (which gets advanced in
visit_next_list() regardless of this patch), and the QList input
that we are converting to QAPI.  For consistency with QDict
visits, we want to consume elements from the input QList during
the visit_type_FOO() for the list element; that is, we want ALL
the code for consuming an input to live in qmp_input_get_object(),
rather than having it split according to whether we are visiting
a dict or a list.  Making qmp_input_get_object() the common point
of consumption will make it easier for a later patch to refactor
visit_start_list() to cover the GenericList * head of a QAPI list,
and in turn will get rid of the 'first' flag (which lived in
qmp_input_next_list() pre-patch, and is hoisted to StackObject
by this patch).

This patch is therefore altering the post-condition use of 'entry',
while keeping what gets visited unchanged, from:

        start_list next_list type_ELT ... next_list type_ELT next_list end_list
 visits                      1st elt                last elt
 entry  NULL       1st elt   1st elt      last elt  last elt NULL      gone

where type_ELT() returns (entry ? entry : 1st elt) and next_list() steps
entry

to this usage:

        start_list next_list type_ELT ... next_list type_ELT next_list end_list
 visits                      1st elt                last elt
 entry  1st elt    1nd elt   2nd elt      last elt  NULL     NULL      gone

where type_ELT() steps entry and returns the old entry, and next_list()
leaves entry alone.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-12-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake ce140b1769 qmp-input: Require struct push to visit members of top dict
Don't embed the root of the visit into the stack of current
containers being visited.  That way, we no longer get confused
on whether the first visit of a dictionary is to the dictionary
itself or to one of the members of the dictionary, based on
whether the caller passed name=NULL; and makes the QMP Input
visitor like other visitors where the value of 'name' is now
ignored on the root visit.  (We may someday want to revisit
the rules on what 'name' should be on a top-level visit,
rather than just ignoring it; but that would be the topic of
another patch).

An audit of all qmp_input_visitor_new() call sites shows that
there were only two places where callers had previously been
visiting to a QDict with a non-NULL name to bypass a call to
visit_start_struct(), and those were fixed in prior patches.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-11-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake e5826a2fd7 qmp-input: Don't consume input when checking has_member
Commit e8316d7 mistakenly passed consume=true within
qmp_input_optional() when checking if an optional member was
present, but the mistake was silently ignored since the code
happily let us extract a member more than once.  Fix
qmp_input_optional() to not consume anything, then tighten up
the input visitor to ensure that a member is consumed exactly
once (all generated code follows this pattern; and the new
assert will catch any hand-written code that tries to visit
the same key more than once).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-8-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake fc471c18d5 qapi: Consolidate QMP input visitor creation
Rather than having two separate ways to create a QMP input
visitor, where the safer approach has the more verbose name,
it is better to consolidate things into a single function
where the caller must explicitly choose whether to be strict
or to ignore excess input.  This patch is the strictly
mechanical conversion; the next patch will then audit which
uses can be made stricter.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-6-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake b471d012e5 qmp-input: Clean up stack handling
Management of the top of stack was a bit verbose; creating a
temporary variable and adding some comments makes the existing
code more legible before the next few patches improve things.
No semantic changes other than asserting that we are always
visiting a QObject, and not a NULL value.  In particular, the
check for 'name && qobject_type(qobj) == QTYPE_QDICT)' is a
bit overkill (a dict visit should always have a name); a later
patch revisits that, while this patch is only changing one
layer of indentation due to dropping 'if (qobj)'.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake 42a502a7a6 qmp: Drop dead command->type
Ever since QMP was first added back in commit 43c20a43, we have
never had any QmpCommandType other than QCT_NORMAL.  It's
pointless to carry around the cruft.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake e58d695e6c qapi: Guarantee NULL obj on input visitor callback error
Our existing input visitors were not very consistent on errors in a
function taking 'TYPE **obj'.  These are start_struct(),
start_alternate(), type_str(), and type_any().  next_list() is
similar, but can't fail (see commit 08f9541).  While all of them set
'*obj' to allocated storage on success, it was not obvious whether
'*obj' was guaranteed safe on failure, or whether it was left
uninitialized.  But a future patch wants to guarantee that
visit_type_FOO() does not leak a partially-constructed obj back to
the caller; it is easier to implement this if we can reliably state
that input visitors assign '*obj' regardless of success or failure,
and that on failure *obj is NULL.  Add assertions to enforce
consistency in the final setting of err vs. *obj.

The opts-visitor start_struct() doesn't set an error, but it
also was doing a weird check for 0 size; all callers pass in
non-zero size if obj is non-NULL.

The testsuite has at least one spot where we no longer need
to pre-initialize a variable prior to a visit; valgrind confirms
that the test is still fine with the cleanup.

A later patch will document the design constraint implemented
here.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-3-git-send-email-eblake@redhat.com>
[visit_start_alternate()'s assertion tightened, commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake 983f52d4b3 qapi-visit: Add visitor.type classification
We have three classes of QAPI visitors: input, output, and dealloc.
Currently, all implementations of these visitors have one thing in
common based on their visitor type: the implementation used for the
visit_type_enum() callback.  But since we plan to add more such
common behavior, in relation to documenting and further refining
the semantics, it makes more sense to have the visitor
implementations advertise which class they belong to, so the common
qapi-visit-core code can use that information in multiple places.

A later patch will better document the types of visitors directly
in visitor.h.

For this patch, knowing the class of a visitor implementation lets
us make input_type_enum() and output_type_enum() become static
functions, by replacing the callback function Visitor.type_enum()
with the simpler enum member Visitor.type.  Share a common
assertion in qapi-visit-core as part of the refactoring.

Move comments in opts-visitor.c to match the refactored layout.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake 0a40bdab0d qapi: Don't pass NULL to printf in string input visitor
Make sure the error message for visit_type_uint64() gracefully
handles a NULL 'name' when called from the top level or a list
context, as not all the world behaves like glibc in allowing
NULL through a printf-family %s.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-21-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-04-29 11:11:36 +02:00
Daniel P. Berrange 78368575a6 block: add generic full disk encryption driver
Add a block driver that is capable of supporting any full disk
encryption format. This utilizes the previously added block
encryption code, and at this time supports the LUKS format.

The driver code is capable of supporting any format supported
by the QCryptoBlock module, so it registers one block driver
for each format. This patch only registers the "luks" driver
since the "qcow" driver is there only for back-compatibility
with existing qcow built-in encryption.

New LUKS compatible volumes can be formatted using qemu-img
with defaults for all settings.

$ qemu-img create --object secret,data=123456,id=sec0 \
      -f luks -o key-secret=sec0 demo.luks 10G

Alternatively the cryptographic settings can be explicitly
set

$ qemu-img create --object secret,data=123456,id=sec0 \
      -f luks -o key-secret=sec0,cipher-alg=aes-256,\
                 cipher-mode=cbc,ivgen-alg=plain64,hash-alg=sha256 \
      demo.luks 10G

And query its size

$ qemu-img info demo.img
image: demo.img
file format: luks
virtual size: 10G (10737418240 bytes)
disk size: 132K
encrypted: yes

Note that it was not necessary to provide the password
when querying info for the volume. The password is only
required when performing I/O on the volume

All volumes created by this new 'luks' driver should be
capable of being opened by the kernel dm-crypt driver.

The only algorithms listed in the LUKS spec that are
not currently supported by this impl are sha512 and
ripemd160 hashes and cast6 cipher.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
[ kwolf - Added #include to resolve conflict with da34e65c ]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-30 12:11:26 +02:00
Kevin Wolf aaa436f998 block: Remove cache.writeback from blockdev-add
The WCE bit is a frontend property and should not be part of the backend
configuration. This is especially important because the same BDS can be
used by different users with different WCE requirements.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-30 11:59:32 +02:00
Veronia Bahaa f348b6d1a5 util: move declarations out of qemu-common.h
Move declarations out of qemu-common.h for functions declared in
utils/ files: e.g. include/qemu/path.h for utils/path.c.
Move inline functions out of qemu-common.h and into new files (e.g.
include/qemu/bcd.h)

Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:17 +01:00
Markus Armbruster da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Peter Maydell 4829e0378d QAPI patches for 2016-03-18
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Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-03-18' into staging

QAPI patches for 2016-03-18

# gpg: Signature made Fri 18 Mar 2016 09:54:57 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2016-03-18:
  qapi: Use anonymous bases in QMP flat unions
  qapi: Allow anonymous base for flat union
  qapi: Make BlockdevOptions doc example closer to reality
  qapi: Don't special-case simple union wrappers
  qapi: Drop unused c_null()
  qapi: Inline gen_visit_members() into lone caller
  qapi-commands: Inline single-use helpers of gen_marshal()
  qapi-commands: Utilize implicit struct visits
  qapi-event: Utilize implicit struct visits
  qapi-event: Drop qmp_output_get_qobject() null check
  qapi: Emit implicit structs in generated C
  qapi: Adjust names of implicit types
  qapi: Make c_type() more OO-like
  qapi: Fix command with named empty argument type
  qapi: Assert in places where variants are not handled

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-03-18 17:18:41 +00:00
Eric Blake 3666a97f78 qapi: Use anonymous bases in QMP flat unions
Now that the generator supports it, we might as well use an
anonymous base rather than breaking out a single-use Base
structure, for all three of our current QMP flat unions.

Oddly enough, this change does not affect the resulting
introspection output (because we already inline the members of
a base type into an object, and had no independent use of the
base type reachable from a command).

The case_whitelist now has to list the name of an implicit
type; which is not too bad (consider it a feature if it makes
it harder for developers to make the whitelist grow :)

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18 10:29:26 +01:00
Daniel P. Berrange 3e308f20ed crypto: implement the LUKS block encryption format
Provide a block encryption implementation that follows the
LUKS/dm-crypt specification.

This supports all combinations of hash, cipher algorithm,
cipher mode and iv generator that are implemented by the
current crypto layer.

There is support for opening existing volumes formatted
by dm-crypt, and for formatting new volumes. In the latter
case it will only use key slot 0.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-17 16:50:40 +00:00
Daniel P. Berrange 7d9690148a crypto: add block encryption framework
Add a generic framework for supporting different block encryption
formats. Upon instantiating a QCryptoBlock object, it will read
the encryption header and extract the encryption keys. It is
then possible to call methods to encrypt/decrypt data buffers.

There is also a mode whereby it will create/initialize a new
encryption header on a previously unformatted volume.

The initial framework comes with support for the legacy QCow
AES based encryption. This enables code in the QCow driver to
be consolidated later.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-17 14:41:15 +00:00
Daniel P. Berrange eaec903c5b crypto: wire up XTS mode for cipher APIs
Introduce 'XTS' as a permitted mode for the cipher APIs.
With XTS the key provided must be twice the size of the
key normally required for any given algorithm. This is
because the key will be split into two pieces for use
in XTS mode.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-17 14:41:15 +00:00
Daniel P. Berrange 50f6753e27 crypto: add support for the twofish cipher algorithm
New cipher algorithms 'twofish-128', 'twofish-192' and
'twofish-256' are defined for the Twofish algorithm.
The gcrypt backend does not support 'twofish-192'.

The nettle and gcrypt cipher backends are updated to
support the new cipher and a test vector added to the
cipher test suite. The new algorithm is enabled in the
LUKS block encryption driver.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-17 14:41:15 +00:00
Daniel P. Berrange 94318522ed crypto: add support for the serpent cipher algorithm
New cipher algorithms 'serpent-128', 'serpent-192' and
'serpent-256' are defined for the Serpent algorithm.

The nettle and gcrypt cipher backends are updated to
support the new cipher and a test vector added to the
cipher test suite. The new algorithm is enabled in the
LUKS block encryption driver.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-17 14:41:15 +00:00
Daniel P. Berrange 084a85eedd crypto: add support for the cast5-128 cipher algorithm
A new cipher algorithm 'cast-5-128' is defined for the
Cast-5 algorithm with 128 bit key size. Smaller key sizes
are supported by Cast-5, but nothing in QEMU should use
them, so only 128 bit keys are permitted.

The nettle and gcrypt cipher backends are updated to
support the new cipher and a test vector added to the
cipher test suite. The new algorithm is enabled in the
LUKS block encryption driver.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-17 14:41:15 +00:00
Daniel P. Berrange cb730894ae crypto: add support for generating initialization vectors
There are a number of different algorithms that can be used
to generate initialization vectors for disk encryption. This
introduces a simple internal QCryptoBlockIV object to provide
a consistent internal API to the different algorithms. The
initially implemented algorithms are 'plain', 'plain64' and
'essiv', each matching the same named algorithm provided
by the Linux kernel dm-crypt driver.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-17 14:41:14 +00:00
Changlong Xie 0ae053b7e1 qmp event: Refactor QUORUM_REPORT_BAD
Introduce QuorumOpType, and make QUORUM_REPORT_BAD compatible
with it.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-14 16:46:43 +01:00
Peter Maydell 586fc27e6a * Asynchronous dump-guest-memory from Peter
* improved logging with -D -daemonize from Dimitris
 * more address_space_* optimization from Gonglei
 * TCG xsave/xrstor thinko fix
 * chardev bugfix and documentation patch
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Asynchronous dump-guest-memory from Peter
* improved logging with -D -daemonize from Dimitris
* more address_space_* optimization from Gonglei
* TCG xsave/xrstor thinko fix
* chardev bugfix and documentation patch

# gpg: Signature made Thu 25 Feb 2016 15:12:27 GMT using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"

* remotes/bonzini/tags/for-upstream:
  target-i386: fix confusion in xcr0 bit position vs. mask
  chardev: Properly initialize ChardevCommon components
  memory: Remove unreachable return statement
  memory: optimize qemu_get_ram_ptr and qemu_ram_ptr_length
  exec: store RAMBlock pointer into memory region
  log: Redirect stderr to logfile if deamonized
  dump-guest-memory: add qmp event DUMP_COMPLETED
  Dump: add hmp command "info dump"
  Dump: add qmp command "query-dump"
  DumpState: adding total_size and written_size fields
  dump-guest-memory: add "detach" support
  dump-guest-memory: disable dump when in INMIGRATE state
  dump-guest-memory: introduce dump_process() helper function.
  dump-guest-memory: add dump_in_progress() helper function
  dump-guest-memory: using static DumpState, add DumpStatus
  dump-guest-memory: add "detach" flag for QMP/HMP interfaces.
  dump-guest-memory: cleanup: removing dump_{error|cleanup}().
  scripts/kvm/kvm_stat: Fix missing right parantheses and ".format(...)"
  qemu-options.hx: Improve documentation of chardev multiplexing mode

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-02-25 15:30:57 +00:00
Peter Xu d42a0d1484 dump-guest-memory: add qmp event DUMP_COMPLETED
One new QMP event DUMP_COMPLETED is added. When a dump finishes, one
DUMP_COMPLETED event will occur to notify the user.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by:   Fam Zheng <famz@redhat.com>
Message-Id: <1455772616-8668-12-git-send-email-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-22 18:40:29 +01:00
Alberto Garcia f5a845fdb4 qapi: Correct the name of the iops_rd parameter
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-02-22 14:08:06 +01:00
Alberto Garcia 398befdf50 qapi: Add burst length fields to BlockDeviceInfo
This patch adds the new bps_*_max_length and iops_*_max_length
parameters to the BlockDeviceInfo struct.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-02-22 14:08:06 +01:00
Alberto Garcia dce13204a0 qapi: Add burst length parameters to block_set_io_throttle
This patch adds the new bps_*_max_length and iops_*_max_length
parameters to the block_set_io_throttle command.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-02-22 14:08:06 +01:00
Eric Blake dbf1192262 qapi: Change visit_start_implicit_struct to visit_start_alternate
After recent changes, the only remaining use of
visit_start_implicit_struct() is for allocating the space needed
when visiting an alternate.  Since the term 'implicit struct' is
hard to explain, rename the function to its current usage.  While
at it, we can merge the functionality of visit_get_next_type()
into the same function, making it more like visit_start_struct().

Generated code is now slightly smaller:

| {
|     Error *err = NULL;
|
|-    visit_start_implicit_struct(v, (void**) obj, sizeof(BlockdevRef), &err);
|+    visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
|+                          true, &err);
|     if (err) {
|         goto out;
|     }
|-    visit_get_next_type(v, name, &(*obj)->type, true, &err);
|-    if (err) {
|-        goto out_obj;
|-    }
|     switch ((*obj)->type) {
|     case QTYPE_QDICT:
|         visit_start_struct(v, name, NULL, 0, &err);
...
|     }
|-out_obj:
|-    visit_end_implicit_struct(v);
|+    visit_end_alternate(v);
| out:
|     error_propagate(errp, err);
| }

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:57 +01:00
Eric Blake 544a373159 qapi: Don't box branches of flat unions
There's no reason to do two malloc's for a flat union; let's just
inline the branch struct directly into the C union branch of the
flat union.

Surprisingly, fewer clients were actually using explicit references
to the branch types in comparison to the number of flat unions
thus modified.

This lets us reduce the hack in qapi-types:gen_variants() added in
the previous patch; we no longer need to distinguish between
alternates and flat unions.

The change to unboxed structs means that u.data (added in commit
cee2dedb) is now coincident with random fields of each branch of
the flat union, whereas beforehand it was only coincident with
pointers (since all branches of a flat union have to be objects).
Note that this was already the case for simple unions - but there
we got lucky.  Remember, visit_start_union() blindly returns true
for all visitors except for the dealloc visitor, where it returns
the value !!obj->u.data, and that this result then controls
whether to proceed with the visit to the variant.  Pre-patch,
this meant that flat unions were testing whether the boxed pointer
was still NULL, and thereby skipping visit_end_implicit_struct()
and avoiding a NULL dereference if the pointer had not been
allocated.  The same was true for simple unions where the current
branch had pointer type, except there we bypassed visit_type_FOO().
But for simple unions where the current branch had scalar type, the
contents of that scalar meant that the decision to call
visit_type_FOO() was data-dependent - the reason we got lucky there
is that visit_type_FOO() for all scalar types in the dealloc visitor
is a no-op (only the pointer variants had anything to free), so it
did not matter whether the dealloc visit was skipped.  But with this
patch, we would risk leaking memory if we could skip a call to
visit_type_FOO_fields() based solely on a data-dependent decision.

But notice: in the dealloc visitor, visit_type_FOO() already handles
a NULL obj - it was only the visit_type_implicit_FOO() that was
failing to check for NULL. And now that we have refactored things to
have the branch be part of the parent struct, we no longer have a
separate pointer that can be NULL in the first place.  So we can just
delete the call to visit_start_union() altogether, and blindly visit
the branch type; there is no change in behavior except to the dealloc
visitor, where we now unconditionally visit the branch, but where that
visit is now always safe (for a flat union, we can no longer
dereference NULL, and for a simple union, visit_type_FOO() was already
safely handling NULL on pointer types).

Unfortunately, simple unions are not as easy to switch to unboxed
layout; because we are special-casing the hidden implicit type with
a single 'data' member, we really DO need to keep calling another
layer of visit_start_struct(), with a second malloc; although there
are some cleanups planned for simple unions in later patches.

visit_start_union() and gen_visit_implicit_struct() are now unused.
Drop them.

Note that after this patch, the only remaining use of
visit_start_implicit_struct() is for alternate types; the next patch
will do further cleanup based on that fact.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-14-git-send-email-eblake@redhat.com>
[Dead code deletion squashed in, commit message updated accordingly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:57 +01:00
Eric Blake e65d89bf1a qapi: Adjust layout of FooList types
By sticking the next pointer first, we don't need a union with
64-bit padding for smaller types.  On 32-bit platforms, this
can reduce the size of uint8List from 16 bytes (or 12, depending
on whether 64-bit ints can tolerate 4-byte alignment) down to 8.
It has no effect on 64-bit platforms (where alignment still
dictates a 16-byte struct); but fewer anonymous unions is still
a win in my book.

It requires visit_next_list() to gain a size parameter, to know
what size element to allocate; comparable to the size parameter
of visit_start_struct().

I debated about going one step further, to allow for fewer casts,
by doing:
    typedef GenericList GenericList;
    struct GenericList {
        GenericList *next;
    };
    struct FooList {
        GenericList base;
        Foo *value;
    };
so that you convert to 'GenericList *' by '&foolist->base', and
back by 'container_of(generic, GenericList, base)' (as opposed to
the existing '(GenericList *)foolist' and '(FooList *)generic').
But doing that would require hoisting the declaration of
GenericList prior to inclusion of qapi-types.h, rather than its
current spot in visitor.h; it also makes iteration a bit more
verbose through 'foolist->base.next' instead of 'foolist->next'.

Note that for lists of objects, the 'value' payload is still
hidden behind a boxed pointer.  Someday, it would be nice to do:

struct FooList {
    FooList *next;
    Foo value;
};

for one less level of malloc for each list element.  This patch
is a step in that direction (now that 'next' is no longer at a
fixed non-zero offset within the struct, we can store more than
just a pointer's-worth of data as the value payload), but the
actual conversion would be a task for another series, as it will
touch a lot of code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:57 +01:00
Eric Blake f96493b1ab qapi: Simplify excess input reporting in input visitors
When reporting that an unvisited member remains at the end of an
input visit for a struct, we were using g_hash_table_find()
coupled with a callback function that always returns true, to
locate an arbitrary member of the hash table.  But if all we
need is an arbitrary entry, we can get that from a single-use
iterator, without needing a tautological callback function.

Technically, our cast of &(GQueue *) to (void **) is not strict
C (while void * must be able to hold all other pointers, nothing
says a void ** has to be the same width or representation as a
GQueue **).  The kosher way to write it would be the verbose:

    void *tmp;
    GQueue *any;
    if (g_hash_table_iter_next(&iter, NULL, &tmp)) {
        any = tmp;

But our code base (not to mention glib itself) already has other
cases of assuming that ALL pointers have the same width and
representation, where a compiler would have to go out of its way
to mis-compile our borderline behavior.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1455778109-6278-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:56 +01:00
Daniel P. Berrange ddffee3904 nbd: enable use of TLS with nbd-server-start command
This modifies the nbd-server-start QMP command so that it
is possible to request use of TLS. This is done by adding
a new optional parameter "tls-creds" which provides the ID
of a previously created QCryptoTLSCreds object instance.

TLS is only supported when using an IPv4/IPv6 socket listener.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-17-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 17:17:49 +01:00
Eric Blake 455ba08afd qmp: Don't abuse stack to track qmp-output root
The previous commit documented an inconsistency in how we are
using the stack of qmp-output-visitor.  Normally, pushing a
single top-level object puts the object on the stack twice:
once as the root, and once as the current container being
appended to; but popping that struct only pops once.  However,
qmp_ouput_add() was trying to either set up the added object
as the new root (works if you parse two top-level scalars in a
row: the second replaces the first as the root) or as a member
of the current container (works as long as you have an open
container on the stack; but if you have popped the first
top-level container, it then resolves to the root and still
tries to add into that existing container).

Fix the stupidity by not tracking two separate things in the
stack.  Drop the now-useless qmp_output_first() and
qmp_output_last() while at it.

Saved for a later patch: we still are rather sloppy in that
qmp_output_get_object() can be called in the middle of a parse,
rather than requiring that a visit is complete.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-26-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:57 +01:00
Eric Blake a861564015 qmp: Fix reference-counting of qnull on empty output visit
Commit 6c2f9a15 ensured that we would not return NULL when the
caller used an output visitor but had nothing to visit. But
in doing so, it added a FIXME about a reference count leak
that could abort qemu in the (unlikely) case of SIZE_MAX such
visits (more plausible on 32-bit).  (Although that commit
suggested we might fix it in time for 2.5, we ran out of time;
fortunately, it is unlikely enough to bite that it was not
worth worrying about during the 2.5 release.)

This fixes things by documenting the internal contracts, and
explaining why the internal function can return NULL and only
the public facing interface needs to worry about qnull(),
thus avoiding over-referencing the qnull_ global object.

It does not, however, fix the stupidity of the stack mixing
up two separate pieces of information; add a FIXME to explain
that issue, which will be fixed shortly in a future patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Cc: qemu-stable@nongnu.org
Message-Id: <1454075341-13658-25-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:57 +01:00
Eric Blake 08f9541dec qapi: Drop unused error argument for list and implicit struct
No backend was setting an error when ending the visit of a list or
implicit struct, or when moving to the next list node.  Make the
callers a bit easier to follow by making this a part of the contract,
and removing the errp argument - callers can then unconditionally end
an object as part of cleanup without having to think about whether a
second error is dominated by a first, because there is no second
error.

A later patch will then tackle the larger task of splitting
visit_end_struct(), which can indeed set an error.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-24-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:57 +01:00
Eric Blake bdd8e6b5d8 qapi: Tighten qmp_input_end_list()
The only way that qmp_input_pop() will set errp is if a dictionary
was the most recent thing pushed.  Since we don't have any
push(struct)/pop(list) or push(list)/pop(struct) mismatches (such
a mismatch is a programming bug), we therefore cannot set errp
inside qmp_input_end_list().  Make this obvious by
using &error_abort.  A later patch will then remove the errp
parameter of qmp_input_pop(), but that will first require the
larger task of splitting visit_end_struct().

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-23-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:57 +01:00
Eric Blake 337283dffb qapi: Drop unused 'kind' for struct/enum visit
visit_start_struct() and visit_type_enum() had a 'kind' argument
that was usually set to either the stringized version of the
corresponding qapi type name, or to NULL (although some clients
didn't even get that right).  But nothing ever used the argument.
It's even hard to argue that it would be useful in a debugger,
as a stack backtrace also tells which type is being visited.

Therefore, drop the 'kind' argument as dead.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-22-git-send-email-eblake@redhat.com>
[Harmless rebase mistake cleaned up]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:57 +01:00
Eric Blake 0b2a0d6bb2 qapi: Swap 'name' in visit_* callbacks to match public API
As explained in the previous patches, matching argument order of
'name, &value' to JSON's "name":value makes sense.  However,
while the last two patches were easy with Coccinelle, I ended up
doing this one all by hand.  Now all the visitor callbacks match
the main interface.

The compiler is able to enforce that all clients match the changed
interface in visitor-impl.h, even where two pointers are being
swapped, because only one of the two pointers is const (if that
were not the case, then C's looseness on treating 'char *' like
'void *' would have made review a bit harder).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-21-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:56 +01:00
Eric Blake 51e72bc1dd qapi: Swap visit_* arguments for consistent 'name' placement
JSON uses "name":value, but many of our visitor interfaces were
called with visit_type_FOO(v, &value, name, errp).  This can be
a bit confusing to have to mentally swap the parameter order to
match JSON order.  It's particularly bad for visit_start_struct(),
where the 'name' parameter is smack in the middle of the
otherwise-related group of 'obj, kind, size' parameters! It's
time to do a global swap of the parameter ordering, so that the
'name' parameter is always immediately after the Visitor argument.

Additional reason in favor of the swap: the existing include/qjson.h
prefers listing 'name' first in json_prop_*(), and I have plans to
unify that file with the qapi visitors; listing 'name' first in
qapi will minimize churn to the (admittedly few) qjson.h clients.

Later patches will then fix docs, object.h, visitor-impl.h, and
those clients to match.

Done by first patching scripts/qapi*.py by hand to make generated
files do what I want, then by running the following Coccinelle
script to affect the rest of the code base:
 $ spatch --sp-file script `git grep -l '\bvisit_' -- '**/*.[ch]'`
I then had to apply some touchups (Coccinelle insisted on TAB
indentation in visitor.h, and botched the signature of
visit_type_enum() by rewriting 'const char *const strings[]' to
the syntactically invalid 'const char*const[] strings').  The
movement of parameters is sufficient to provoke compiler errors
if any callers were missed.

    // Part 1: Swap declaration order
    @@
    type TV, TErr, TObj, T1, T2;
    identifier OBJ, ARG1, ARG2;
    @@
     void visit_start_struct
    -(TV v, TObj OBJ, T1 ARG1, const char *name, T2 ARG2, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
     { ... }

    @@
    type bool, TV, T1;
    identifier ARG1;
    @@
     bool visit_optional
    -(TV v, T1 ARG1, const char *name)
    +(TV v, const char *name, T1 ARG1)
     { ... }

    @@
    type TV, TErr, TObj, T1;
    identifier OBJ, ARG1;
    @@
     void visit_get_next_type
    -(TV v, TObj OBJ, T1 ARG1, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, TErr errp)
     { ... }

    @@
    type TV, TErr, TObj, T1, T2;
    identifier OBJ, ARG1, ARG2;
    @@
     void visit_type_enum
    -(TV v, TObj OBJ, T1 ARG1, T2 ARG2, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
     { ... }

    @@
    type TV, TErr, TObj;
    identifier OBJ;
    identifier VISIT_TYPE =~ "^visit_type_";
    @@
     void VISIT_TYPE
    -(TV v, TObj OBJ, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, TErr errp)
     { ... }

    // Part 2: swap caller order
    @@
    expression V, NAME, OBJ, ARG1, ARG2, ERR;
    identifier VISIT_TYPE =~ "^visit_type_";
    @@
    (
    -visit_start_struct(V, OBJ, ARG1, NAME, ARG2, ERR)
    +visit_start_struct(V, NAME, OBJ, ARG1, ARG2, ERR)
    |
    -visit_optional(V, ARG1, NAME)
    +visit_optional(V, NAME, ARG1)
    |
    -visit_get_next_type(V, OBJ, ARG1, NAME, ERR)
    +visit_get_next_type(V, NAME, OBJ, ARG1, ERR)
    |
    -visit_type_enum(V, OBJ, ARG1, ARG2, NAME, ERR)
    +visit_type_enum(V, NAME, OBJ, ARG1, ARG2, ERR)
    |
    -VISIT_TYPE(V, OBJ, NAME, ERR)
    +VISIT_TYPE(V, NAME, OBJ, ERR)
    )

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-19-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:56 +01:00