Re: [PATCH] block/export/fuse.c: fix musl build

2021-10-24 Thread Michael Tokarev

22.10.2021 12:52, Fabrice Fontaine пишет:

Include linux/falloc.h if CONFIG_FALLOCATE_ZERO_RANGE is defined to fix
https://gitlab.com/qemu-project/qemu/-/commit/50482fda98bd62e072c30b7ea73c985c4e9d9bbb
and avoid the following build failure on musl:

../block/export/fuse.c: In function 'fuse_fallocate':
../block/export/fuse.c:643:21: error: 'FALLOC_FL_ZERO_RANGE' undeclared (first 
use in this function)
   643 | else if (mode & FALLOC_FL_ZERO_RANGE) {
   | ^~~~

Fixes:
  - 
http://autobuild.buildroot.org/results/be24433a429fda681fb66698160132c1c99bc53b

Signed-off-by: Fabrice Fontaine 
---
  block/export/fuse.c | 4 
  1 file changed, 4 insertions(+)

diff --git a/block/export/fuse.c b/block/export/fuse.c
index 2e3bf8270b..823c126d23 100644
--- a/block/export/fuse.c
+++ b/block/export/fuse.c
@@ -31,6 +31,10 @@
  #include 
  #include 
  
+#if defined(CONFIG_FALLOCATE_ZERO_RANGE)


shouldn't it be "if !defined" ?

/mjt


+#include 
+#endif
+
  #ifdef __linux__
  #include 
  #endif






[PATCH 6/9] qapi: Generalize command policy checking

2021-10-24 Thread Markus Armbruster
The code to check command policy can see special feature flag
'deprecated' as command flag QCO_DEPRECATED.  I want to make feature
flag 'unstable' visible there as well, so I can add policy for it.

To let me make it visible, add member @special_features (a bitset of
QapiSpecialFeature) to QmpCommand, and adjust the generator to pass it
through qmp_register_command().  Then replace "QCO_DEPRECATED in
@flags" by QAPI_DEPRECATED in @special_features", and drop
QCO_DEPRECATED.

Signed-off-by: Markus Armbruster 
---
 include/qapi/qmp/dispatch.h  | 5 +++--
 monitor/misc.c   | 6 --
 qapi/qmp-dispatch.c  | 2 +-
 qapi/qmp-registry.c  | 4 +++-
 storage-daemon/qemu-storage-daemon.c | 3 ++-
 scripts/qapi/commands.py | 9 -
 6 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/include/qapi/qmp/dispatch.h b/include/qapi/qmp/dispatch.h
index 0ce88200b9..1e4240fd0d 100644
--- a/include/qapi/qmp/dispatch.h
+++ b/include/qapi/qmp/dispatch.h
@@ -25,7 +25,6 @@ typedef enum QmpCommandOptions
 QCO_ALLOW_OOB =  (1U << 1),
 QCO_ALLOW_PRECONFIG   =  (1U << 2),
 QCO_COROUTINE =  (1U << 3),
-QCO_DEPRECATED=  (1U << 4),
 } QmpCommandOptions;
 
 typedef struct QmpCommand
@@ -34,6 +33,7 @@ typedef struct QmpCommand
 /* Runs in coroutine context if QCO_COROUTINE is set */
 QmpCommandFunc *fn;
 QmpCommandOptions options;
+unsigned special_features;
 QTAILQ_ENTRY(QmpCommand) node;
 bool enabled;
 const char *disable_reason;
@@ -42,7 +42,8 @@ typedef struct QmpCommand
 typedef QTAILQ_HEAD(QmpCommandList, QmpCommand) QmpCommandList;
 
 void qmp_register_command(QmpCommandList *cmds, const char *name,
-  QmpCommandFunc *fn, QmpCommandOptions options);
+  QmpCommandFunc *fn, QmpCommandOptions options,
+  unsigned special_features);
 const QmpCommand *qmp_find_command(const QmpCommandList *cmds,
const char *name);
 void qmp_disable_command(QmpCommandList *cmds, const char *name,
diff --git a/monitor/misc.c b/monitor/misc.c
index 3556b177f6..c2d227a07c 100644
--- a/monitor/misc.c
+++ b/monitor/misc.c
@@ -230,11 +230,13 @@ static void monitor_init_qmp_commands(void)
 
 qmp_init_marshal(&qmp_commands);
 
-qmp_register_command(&qmp_commands, "device_add", qmp_device_add, 0);
+qmp_register_command(&qmp_commands, "device_add",
+ qmp_device_add, 0, 0);
 
 QTAILQ_INIT(&qmp_cap_negotiation_commands);
 qmp_register_command(&qmp_cap_negotiation_commands, "qmp_capabilities",
- qmp_marshal_qmp_capabilities, QCO_ALLOW_PRECONFIG);
+ qmp_marshal_qmp_capabilities,
+ QCO_ALLOW_PRECONFIG, 0);
 }
 
 /* Set the current CPU defined by the user. Callers must hold BQL. */
diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index 7e943a0af5..8cca18c891 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -176,7 +176,7 @@ QDict *qmp_dispatch(const QmpCommandList *cmds, QObject 
*request,
   "The command %s has not been found", command);
 goto out;
 }
-if (cmd->options & QCO_DEPRECATED) {
+if (cmd->special_features & 1u << QAPI_DEPRECATED) {
 switch (compat_policy.deprecated_input) {
 case COMPAT_POLICY_INPUT_ACCEPT:
 break;
diff --git a/qapi/qmp-registry.c b/qapi/qmp-registry.c
index f78c064aae..485bc5e6fc 100644
--- a/qapi/qmp-registry.c
+++ b/qapi/qmp-registry.c
@@ -16,7 +16,8 @@
 #include "qapi/qmp/dispatch.h"
 
 void qmp_register_command(QmpCommandList *cmds, const char *name,
-  QmpCommandFunc *fn, QmpCommandOptions options)
+  QmpCommandFunc *fn, QmpCommandOptions options,
+  unsigned special_features)
 {
 QmpCommand *cmd = g_malloc0(sizeof(*cmd));
 
@@ -27,6 +28,7 @@ void qmp_register_command(QmpCommandList *cmds, const char 
*name,
 cmd->fn = fn;
 cmd->enabled = true;
 cmd->options = options;
+cmd->special_features = special_features;
 QTAILQ_INSERT_TAIL(cmds, cmd, node);
 }
 
diff --git a/storage-daemon/qemu-storage-daemon.c 
b/storage-daemon/qemu-storage-daemon.c
index 10a1a33761..52cf17e8ac 100644
--- a/storage-daemon/qemu-storage-daemon.c
+++ b/storage-daemon/qemu-storage-daemon.c
@@ -146,7 +146,8 @@ static void init_qmp_commands(void)
 
 QTAILQ_INIT(&qmp_cap_negotiation_commands);
 qmp_register_command(&qmp_cap_negotiation_commands, "qmp_capabilities",
- qmp_marshal_qmp_capabilities, QCO_ALLOW_PRECONFIG);
+ qmp_marshal_qmp_capabilities,
+ QCO_ALLOW_PRECONFIG, 0);
 }
 
 static int getopt_set_loc(int argc, char **argv, const char *optstring,
diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index c8a

[PATCH 8/9] qapi: Factor out compat_policy_input_ok()

2021-10-24 Thread Markus Armbruster
The code to check policy for handling deprecated input is triplicated.
Factor it out into compat_policy_input_ok() before I mess with it in
the next commit.

Signed-off-by: Markus Armbruster 
---
 include/qapi/compat-policy.h |  7 +
 qapi/qapi-visit-core.c   | 18 +
 qapi/qmp-dispatch.c  | 51 +++-
 qapi/qobject-input-visitor.c | 19 +++---
 4 files changed, 55 insertions(+), 40 deletions(-)

diff --git a/include/qapi/compat-policy.h b/include/qapi/compat-policy.h
index 1083f95122..8b7b25c0b5 100644
--- a/include/qapi/compat-policy.h
+++ b/include/qapi/compat-policy.h
@@ -13,10 +13,17 @@
 #ifndef QAPI_COMPAT_POLICY_H
 #define QAPI_COMPAT_POLICY_H
 
+#include "qapi/error.h"
 #include "qapi/qapi-types-compat.h"
 
 extern CompatPolicy compat_policy;
 
+bool compat_policy_input_ok(unsigned special_features,
+const CompatPolicy *policy,
+ErrorClass error_class,
+const char *kind, const char *name,
+Error **errp);
+
 /*
  * Create a QObject input visitor for @obj for use with QMP
  *
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 5572d90efb..a1ddfe8831 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -13,6 +13,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qapi/compat-policy.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "qapi/visitor.h"
@@ -408,18 +409,11 @@ static bool input_type_enum(Visitor *v, const char *name, 
int *obj,
 }
 
 if (lookup->special_features
-&& (lookup->special_features[value] & QAPI_DEPRECATED)) {
-switch (v->compat_policy.deprecated_input) {
-case COMPAT_POLICY_INPUT_ACCEPT:
-break;
-case COMPAT_POLICY_INPUT_REJECT:
-error_setg(errp, "Deprecated value '%s' disabled by policy",
-   enum_str);
-return false;
-case COMPAT_POLICY_INPUT_CRASH:
-default:
-abort();
-}
+&& !compat_policy_input_ok(lookup->special_features[value],
+   &v->compat_policy,
+   ERROR_CLASS_GENERIC_ERROR,
+   "value", enum_str, errp)) {
+return false;
 }
 
 *obj = value;
diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index 8cca18c891..e29ade134c 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -28,6 +28,40 @@
 
 CompatPolicy compat_policy;
 
+static bool compat_policy_input_ok1(const char *adjective,
+CompatPolicyInput policy,
+ErrorClass error_class,
+const char *kind, const char *name,
+Error **errp)
+{
+switch (policy) {
+case COMPAT_POLICY_INPUT_ACCEPT:
+return true;
+case COMPAT_POLICY_INPUT_REJECT:
+error_set(errp, error_class, "%s %s %s disabled by policy",
+  adjective, kind, name);
+return false;
+case COMPAT_POLICY_INPUT_CRASH:
+default:
+abort();
+}
+}
+
+bool compat_policy_input_ok(unsigned special_features,
+const CompatPolicy *policy,
+ErrorClass error_class,
+const char *kind, const char *name,
+Error **errp)
+{
+if ((special_features & 1u << QAPI_DEPRECATED)
+&& !compat_policy_input_ok1("Deprecated",
+policy->deprecated_input,
+error_class, kind, name, errp)) {
+return false;
+}
+return true;
+}
+
 Visitor *qobject_input_visitor_new_qmp(QObject *obj)
 {
 Visitor *v = qobject_input_visitor_new(obj);
@@ -176,19 +210,10 @@ QDict *qmp_dispatch(const QmpCommandList *cmds, QObject 
*request,
   "The command %s has not been found", command);
 goto out;
 }
-if (cmd->special_features & 1u << QAPI_DEPRECATED) {
-switch (compat_policy.deprecated_input) {
-case COMPAT_POLICY_INPUT_ACCEPT:
-break;
-case COMPAT_POLICY_INPUT_REJECT:
-error_set(&err, ERROR_CLASS_COMMAND_NOT_FOUND,
-  "Deprecated command %s disabled by policy",
-  command);
-goto out;
-case COMPAT_POLICY_INPUT_CRASH:
-default:
-abort();
-}
+if (!compat_policy_input_ok(cmd->special_features, &compat_policy,
+ERROR_CLASS_COMMAND_NOT_FOUND,
+"command", command, &err)) {
+goto out;
 }
 if (!cmd->enabled) {
 error_set(&err, ERROR_CLASS_COMMAND_NOT_FOUND,
diff --git a/qapi/qobject-input-visitor.c b/qapi/qobject-input-visitor.c
index fda485614b..f0b4c7ca9d 100644
--- a/qapi/qobject-

[PATCH 9/9] qapi: Extend -compat to set policy for unstable interfaces

2021-10-24 Thread Markus Armbruster
New option parameters unstable-input and unstable-output set policy
for unstable interfaces just like deprecated-input and
deprecated-output set policy for deprecated interfaces (see commit
6dd75472d5 "qemu-options: New -compat to set policy for deprecated
interfaces").  This is intended for testing users of the management
interfaces.  It is experimental.

For now, this covers only syntactic aspects of QMP, i.e. stuff tagged
with feature 'unstable'.  We may want to extend it to cover semantic
aspects, or the command line.

Note that there is no good way for management application to detect
presence of these new option parameters: they are not visible output
of query-qmp-schema or query-command-line-options.  Tolerable, because
it's meant for testing.  If running with -compat fails, skip the test.

Signed-off-by: Markus Armbruster 
---
 qapi/compat.json  |  6 +-
 include/qapi/util.h   |  1 +
 qapi/qmp-dispatch.c   |  6 ++
 qapi/qobject-output-visitor.c |  8 ++--
 qemu-options.hx   | 20 +++-
 scripts/qapi/events.py| 10 ++
 scripts/qapi/schema.py| 10 ++
 7 files changed, 49 insertions(+), 12 deletions(-)

diff --git a/qapi/compat.json b/qapi/compat.json
index 74a8493d3d..9bc9804abb 100644
--- a/qapi/compat.json
+++ b/qapi/compat.json
@@ -47,9 +47,13 @@
 #
 # @deprecated-input: how to handle deprecated input (default 'accept')
 # @deprecated-output: how to handle deprecated output (default 'accept')
+# @unstable-input: how to handle unstable input (default 'accept')
+# @unstable-output: how to handle unstable output (default 'accept')
 #
 # Since: 6.0
 ##
 { 'struct': 'CompatPolicy',
   'data': { '*deprecated-input': 'CompatPolicyInput',
-'*deprecated-output': 'CompatPolicyOutput' } }
+'*deprecated-output': 'CompatPolicyOutput',
+'*unstable-input': 'CompatPolicyInput',
+'*unstable-output': 'CompatPolicyOutput' } }
diff --git a/include/qapi/util.h b/include/qapi/util.h
index 0cc98db9f9..81a2b13a33 100644
--- a/include/qapi/util.h
+++ b/include/qapi/util.h
@@ -13,6 +13,7 @@
 
 typedef enum {
 QAPI_DEPRECATED,
+QAPI_UNSTABLE,
 } QapiSpecialFeature;
 
 typedef struct QEnumLookup {
diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index e29ade134c..c5c6e521a2 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -59,6 +59,12 @@ bool compat_policy_input_ok(unsigned special_features,
 error_class, kind, name, errp)) {
 return false;
 }
+if ((special_features & (1u << QAPI_UNSTABLE))
+&& !compat_policy_input_ok1("Unstable",
+policy->unstable_input,
+error_class, kind, name, errp)) {
+return false;
+}
 return true;
 }
 
diff --git a/qapi/qobject-output-visitor.c b/qapi/qobject-output-visitor.c
index b5c6564cbb..74770edd73 100644
--- a/qapi/qobject-output-visitor.c
+++ b/qapi/qobject-output-visitor.c
@@ -212,8 +212,12 @@ static bool qobject_output_type_null(Visitor *v, const 
char *name,
 static bool qobject_output_policy_skip(Visitor *v, const char *name,
unsigned special_features)
 {
-return !(special_features && 1u << QAPI_DEPRECATED)
-|| v->compat_policy.deprecated_output == COMPAT_POLICY_OUTPUT_HIDE;
+CompatPolicy *pol = &v->compat_policy;
+
+return ((special_features & 1u << QAPI_DEPRECATED)
+&& pol->deprecated_output == COMPAT_POLICY_OUTPUT_HIDE)
+|| ((special_features & 1u << QAPI_UNSTABLE)
+&& pol->unstable_output == COMPAT_POLICY_OUTPUT_HIDE);
 }
 
 /* Finish building, and return the root object.
diff --git a/qemu-options.hx b/qemu-options.hx
index 5f375bbfa6..f051536b63 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3641,7 +3641,9 @@ DEFHEADING(Debug/Expert options:)
 
 DEF("compat", HAS_ARG, QEMU_OPTION_compat,
 "-compat 
[deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n"
-"Policy for handling deprecated management interfaces\n",
+"Policy for handling deprecated management interfaces\n"
+"-compat 
[unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n"
+"Policy for handling unstable management interfaces\n",
 QEMU_ARCH_ALL)
 SRST
 ``-compat 
[deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]``
@@ -3659,6 +3661,22 @@ SRST
 Suppress deprecated command results and events
 
 Limitation: covers only syntactic aspects of QMP.
+
+``-compat 
[unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]``
+Set policy for handling unstable management interfaces (experimental):
+
+``unstable-input=accept`` (default)
+Accept unstable commands and arguments
+``unstable-input=reject``
+Reject unstable commands and arguments
+   

[PATCH 5/9] qapi: Generalize struct member policy checking

2021-10-24 Thread Markus Armbruster
The generated visitor functions call visit_deprecated_accept() and
visit_deprecated() when visiting a struct member with special feature
flag 'deprecated'.  This makes the feature flag visible to the actual
visitors.  I want to make feature flag 'unstable' visible there as
well, so I can add policy for it.

To let me make it visible, replace these functions by
visit_policy_reject() and visit_policy_skip(), which take the member's
special features as an argument.  Note that the new functions have the
opposite sense, i.e. the return value flips.

Signed-off-by: Markus Armbruster 
---
 include/qapi/visitor-impl.h   |  6 --
 include/qapi/visitor.h| 17 +
 qapi/qapi-forward-visitor.c   | 16 +---
 qapi/qapi-visit-core.c| 22 --
 qapi/qobject-input-visitor.c  | 15 ++-
 qapi/qobject-output-visitor.c |  9 ++---
 qapi/trace-events |  4 ++--
 scripts/qapi/visit.py | 14 +++---
 8 files changed, 63 insertions(+), 40 deletions(-)

diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index 72b6537bef..2badec5ba4 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -114,10 +114,12 @@ struct Visitor
 void (*optional)(Visitor *v, const char *name, bool *present);
 
 /* Optional */
-bool (*deprecated_accept)(Visitor *v, const char *name, Error **errp);
+bool (*policy_reject)(Visitor *v, const char *name,
+  unsigned special_features, Error **errp);
 
 /* Optional */
-bool (*deprecated)(Visitor *v, const char *name);
+bool (*policy_skip)(Visitor *v, const char *name,
+unsigned special_features);
 
 /* Must be set */
 VisitorType type;
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index dcb96018a9..d53a84c9ba 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -461,22 +461,31 @@ void visit_end_alternate(Visitor *v, void **obj);
 bool visit_optional(Visitor *v, const char *name, bool *present);
 
 /*
- * Should we reject deprecated member @name?
+ * Should we reject member @name due to policy?
+ *
+ * @special_features is the member's special features encoded as a
+ * bitset of QapiSpecialFeature.
  *
  * @name must not be NULL.  This function is only useful between
  * visit_start_struct() and visit_end_struct(), since only objects
  * have deprecated members.
  */
-bool visit_deprecated_accept(Visitor *v, const char *name, Error **errp);
+bool visit_policy_reject(Visitor *v, const char *name,
+ unsigned special_features, Error **errp);
 
 /*
- * Should we visit deprecated member @name?
+ *
+ * Should we skip member @name due to policy?
+ *
+ * @special_features is the member's special features encoded as a
+ * bitset of QapiSpecialFeature.
  *
  * @name must not be NULL.  This function is only useful between
  * visit_start_struct() and visit_end_struct(), since only objects
  * have deprecated members.
  */
-bool visit_deprecated(Visitor *v, const char *name);
+bool visit_policy_skip(Visitor *v, const char *name,
+   unsigned special_features);
 
 /*
  * Set policy for handling deprecated management interfaces.
diff --git a/qapi/qapi-forward-visitor.c b/qapi/qapi-forward-visitor.c
index a4b111e22a..25d098aa8a 100644
--- a/qapi/qapi-forward-visitor.c
+++ b/qapi/qapi-forward-visitor.c
@@ -246,25 +246,27 @@ static void forward_field_optional(Visitor *v, const char 
*name, bool *present)
 visit_optional(ffv->target, name, present);
 }
 
-static bool forward_field_deprecated_accept(Visitor *v, const char *name,
-Error **errp)
+static bool forward_field_policy_reject(Visitor *v, const char *name,
+unsigned special_features,
+Error **errp)
 {
 ForwardFieldVisitor *ffv = to_ffv(v);
 
 if (!forward_field_translate_name(ffv, &name, errp)) {
 return false;
 }
-return visit_deprecated_accept(ffv->target, name, errp);
+return visit_policy_reject(ffv->target, name, special_features, errp);
 }
 
-static bool forward_field_deprecated(Visitor *v, const char *name)
+static bool forward_field_policy_skip(Visitor *v, const char *name,
+  unsigned special_features)
 {
 ForwardFieldVisitor *ffv = to_ffv(v);
 
 if (!forward_field_translate_name(ffv, &name, NULL)) {
 return false;
 }
-return visit_deprecated(ffv->target, name);
+return visit_policy_skip(ffv->target, name, special_features);
 }
 
 static void forward_field_complete(Visitor *v, void *opaque)
@@ -313,8 +315,8 @@ Visitor *visitor_forward_field(Visitor *target, const char 
*from, const char *to
 v->visitor.type_any = forward_field_type_any;
 v->visitor.type_null = forward_field_type_null;
 v->visitor.optional = forward_field_optional;
-v->visitor.de

[PATCH 1/9] qapi: New special feature flag "unstable"

2021-10-24 Thread Markus Armbruster
By convention, names starting with "x-" are experimental.  The parts
of external interfaces so named may be withdrawn or changed
incompatibly in future releases.

Drawback: promoting something from experimental to stable involves a
name change.  Client code needs to be updated.

Moreover, the convention is not universally observed:

* QOM type "input-barrier" has properties "x-origin", "y-origin".
  Looks accidental, but it's ABI since 4.2.

* QOM types "memory-backend-file", "memory-backend-memfd",
  "memory-backend-ram", and "memory-backend-epc" have a property
  "x-use-canonical-path-for-ramblock-id" that is documented to be
  stable despite its name.

We could document these exceptions, but documentation helps only
humans.  We want to recognize "unstable" in code, like "deprecated".

Replace the convention by a new special feature flag "unstable".  It
will be recognized by the QAPI generator, like the existing feature
flag "deprecated", and unlike regular feature flags.

This commit updates documentation and prepares tests.  The next commit
updates the QAPI schema.  The remaining patches update the QAPI
generator and wire up -compat policy checking.

Signed-off-by: Markus Armbruster 
---
 docs/devel/qapi-code-gen.rst| 9 ++---
 tests/qapi-schema/qapi-schema-test.json | 7 +--
 tests/qapi-schema/qapi-schema-test.out  | 5 +
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst
index 4071c9074a..38f2d7aad3 100644
--- a/docs/devel/qapi-code-gen.rst
+++ b/docs/devel/qapi-code-gen.rst
@@ -713,6 +713,10 @@ member as deprecated.  It is not supported elsewhere so 
far.
 Interfaces so marked may be withdrawn in future releases in accordance
 with QEMU's deprecation policy.
 
+Feature "unstable" marks a command, event, enum value, or struct
+member as unstable.  It is not supported elsewhere so far.  Interfaces
+so marked may be withdrawn or changed incompatibly in future releases.
+
 
 Naming rules and reserved names
 ---
@@ -746,9 +750,8 @@ Member name ``u`` and names starting with ``has-`` or 
``has_`` are reserved
 for the generator, which uses them for unions and for tracking
 optional members.
 
-Any name (command, event, type, member, or enum value) beginning with
-``x-`` is marked experimental, and may be withdrawn or changed
-incompatibly in a future release.
+Names beginning with ``x-`` used to signify "experimental".  This
+convention has been replaced by special feature "unstable".
 
 Pragmas ``command-name-exceptions`` and ``member-name-exceptions`` let
 you violate naming rules.  Use for new code is strongly discouraged. See
diff --git a/tests/qapi-schema/qapi-schema-test.json 
b/tests/qapi-schema/qapi-schema-test.json
index b677ab861d..43b8697002 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -273,7 +273,7 @@
   'data': { 'foo': { 'type': 'int', 'features': [ 'deprecated' ] } },
   'features': [ 'feature1' ] }
 { 'struct': 'FeatureStruct2',
-  'data': { 'foo': 'int' },
+  'data': { 'foo': { 'type': 'int', 'features': [ 'unstable' ] } },
   'features': [ { 'name': 'feature1' } ] }
 { 'struct': 'FeatureStruct3',
   'data': { 'foo': 'int' },
@@ -331,7 +331,7 @@
 { 'command': 'test-command-features1',
   'features': [ 'deprecated' ] }
 { 'command': 'test-command-features3',
-  'features': [ 'feature1', 'feature2' ] }
+  'features': [ 'unstable', 'feature1', 'feature2' ] }
 
 { 'command': 'test-command-cond-features1',
   'features': [ { 'name': 'feature1', 'if': 'TEST_IF_FEATURE_1'} ] }
@@ -348,3 +348,6 @@
 
 { 'event': 'TEST_EVENT_FEATURES1',
   'features': [ 'deprecated' ] }
+
+{ 'event': 'TEST_EVENT_FEATURES2',
+  'features': [ 'unstable' ] }
diff --git a/tests/qapi-schema/qapi-schema-test.out 
b/tests/qapi-schema/qapi-schema-test.out
index 16846dbeb8..1f9585fa9b 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -308,6 +308,7 @@ object FeatureStruct1
 feature feature1
 object FeatureStruct2
 member foo: int optional=False
+feature unstable
 feature feature1
 object FeatureStruct3
 member foo: int optional=False
@@ -373,6 +374,7 @@ command test-command-features1 None -> None
 feature deprecated
 command test-command-features3 None -> None
 gen=True success_response=True boxed=False oob=False preconfig=False
+feature unstable
 feature feature1
 feature feature2
 command test-command-cond-features1 None -> None
@@ -394,6 +396,9 @@ event TEST_EVENT_FEATURES0 FeatureStruct1
 event TEST_EVENT_FEATURES1 None
 boxed=False
 feature deprecated
+event TEST_EVENT_FEATURES2 None
+boxed=False
+feature unstable
 module include/sub-module.json
 include sub-sub-module.json
 object SecondArrayRef
-- 
2.31.1




[PATCH 7/9] qapi: Generalize enum member policy checking

2021-10-24 Thread Markus Armbruster
The code to check enumeration value policy can see special feature
flag 'deprecated' in QEnumLookup member flags[value].  I want to make
feature flag 'unstable' visible there as well, so I can add policy for
it.

Instead of extending flags[], replace it by @special_features (a
bitset of QapiSpecialFeature), because that's how special features get
passed around elsewhere.

Signed-off-by: Markus Armbruster 
---
 include/qapi/util.h|  5 +
 qapi/qapi-visit-core.c |  3 ++-
 scripts/qapi/types.py  | 22 --
 3 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/include/qapi/util.h b/include/qapi/util.h
index 7a8d5c7d72..0cc98db9f9 100644
--- a/include/qapi/util.h
+++ b/include/qapi/util.h
@@ -15,12 +15,9 @@ typedef enum {
 QAPI_DEPRECATED,
 } QapiSpecialFeature;
 
-/* QEnumLookup flags */
-#define QAPI_ENUM_DEPRECATED 1
-
 typedef struct QEnumLookup {
 const char *const *array;
-const unsigned char *const flags;
+const unsigned char *const special_features;
 const int size;
 } QEnumLookup;
 
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index b4a81f1757..5572d90efb 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -407,7 +407,8 @@ static bool input_type_enum(Visitor *v, const char *name, 
int *obj,
 return false;
 }
 
-if (lookup->flags && (lookup->flags[value] & QAPI_ENUM_DEPRECATED)) {
+if (lookup->special_features
+&& (lookup->special_features[value] & QAPI_DEPRECATED)) {
 switch (v->compat_policy.deprecated_input) {
 case COMPAT_POLICY_INPUT_ACCEPT:
 break;
diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
index ab2441adc9..3013329c24 100644
--- a/scripts/qapi/types.py
+++ b/scripts/qapi/types.py
@@ -16,7 +16,7 @@
 from typing import List, Optional
 
 from .common import c_enum_const, c_name, mcgen
-from .gen import QAPISchemaModularCVisitor, ifcontext
+from .gen import QAPISchemaModularCVisitor, gen_special_features, ifcontext
 from .schema import (
 QAPISchema,
 QAPISchemaEnumMember,
@@ -39,7 +39,7 @@ def gen_enum_lookup(name: str,
 members: List[QAPISchemaEnumMember],
 prefix: Optional[str] = None) -> str:
 max_index = c_enum_const(name, '_MAX', prefix)
-flags = ''
+feats = ''
 ret = mcgen('''
 
 const QEnumLookup %(c_name)s_lookup = {
@@ -54,19 +54,21 @@ def gen_enum_lookup(name: str,
 ''',
  index=index, name=memb.name)
 ret += memb.ifcond.gen_endif()
-if 'deprecated' in (f.name for f in memb.features):
-flags += mcgen('''
-[%(index)s] = QAPI_ENUM_DEPRECATED,
-''',
-   index=index)
 
-if flags:
+special_features = gen_special_features(memb.features)
+if special_features != '0':
+feats += mcgen('''
+[%(index)s] = %(special_features)s,
+''',
+   index=index, special_features=special_features)
+
+if feats:
 ret += mcgen('''
 },
-.flags = (const unsigned char[%(max_index)s]) {
+.special_features = (const unsigned char[%(max_index)s]) {
 ''',
  max_index=max_index)
-ret += flags
+ret += feats
 
 ret += mcgen('''
 },
-- 
2.31.1




[PATCH 0/9] Configurable policy for handling unstable interfaces

2021-10-24 Thread Markus Armbruster
Option -compat lets you configure what to do when deprecated
interfaces get used.  This series extends this to unstable interfaces.
Works the same way.  Intended for testing users of the management
interfaces.  It is experimental.

To make it possible, I replace the "x-" naming convention by special
feature flag "unstable".  See PATCH 1 for rationale.

Based on my "[PATCH v4 0/5] qapi: Add feature flags to enum members"

Based-on: Message-Id: <20211025042405.3762351-1-arm...@redhat.com>

Markus Armbruster (9):
  qapi: New special feature flag "unstable"
  qapi: Mark unstable QMP parts with feature 'unstable'
  qapi: Eliminate QCO_NO_OPTIONS for a slight simplification
  qapi: Tools for sets of special feature flags in generated code
  qapi: Generalize struct member policy checking
  qapi: Generalize command policy checking
  qapi: Generalize enum member policy checking
  qapi: Factor out compat_policy_input_ok()
  qapi: Extend -compat to set policy for unstable interfaces

 docs/devel/qapi-code-gen.rst|   9 +-
 qapi/block-core.json| 123 +---
 qapi/compat.json|   6 +-
 qapi/migration.json |  35 +--
 qapi/misc.json  |   6 +-
 qapi/qom.json   |  11 ++-
 include/qapi/compat-policy.h|   7 ++
 include/qapi/qmp/dispatch.h |   6 +-
 include/qapi/util.h |   8 +-
 include/qapi/visitor-impl.h |   6 +-
 include/qapi/visitor.h  |  17 +++-
 monitor/misc.c  |   7 +-
 qapi/qapi-forward-visitor.c |  16 +--
 qapi/qapi-visit-core.c  |  41 
 qapi/qmp-dispatch.c |  57 ---
 qapi/qmp-registry.c |   4 +-
 qapi/qobject-input-visitor.c|  22 ++---
 qapi/qobject-output-visitor.c   |  13 ++-
 storage-daemon/qemu-storage-daemon.c|   3 +-
 qapi/trace-events   |   4 +-
 qemu-options.hx |  20 +++-
 scripts/qapi/commands.py|  12 +--
 scripts/qapi/events.py  |  10 +-
 scripts/qapi/gen.py |  13 +++
 scripts/qapi/schema.py  |  11 ++-
 scripts/qapi/types.py   |  22 +++--
 scripts/qapi/visit.py   |  14 +--
 tests/qapi-schema/qapi-schema-test.json |   7 +-
 tests/qapi-schema/qapi-schema-test.out  |   5 +
 29 files changed, 353 insertions(+), 162 deletions(-)

-- 
2.31.1




[PATCH 4/9] qapi: Tools for sets of special feature flags in generated code

2021-10-24 Thread Markus Armbruster
New enum QapiSpecialFeature enumerates the special feature flags.

New helper gen_special_features() returns code to represent a
collection of special feature flags as a bitset.

The next few commits will put them to use.

Signed-off-by: Markus Armbruster 
---
 include/qapi/util.h|  4 
 scripts/qapi/gen.py| 13 +
 scripts/qapi/schema.py |  3 +++
 3 files changed, 20 insertions(+)

diff --git a/include/qapi/util.h b/include/qapi/util.h
index 257c600f99..7a8d5c7d72 100644
--- a/include/qapi/util.h
+++ b/include/qapi/util.h
@@ -11,6 +11,10 @@
 #ifndef QAPI_UTIL_H
 #define QAPI_UTIL_H
 
+typedef enum {
+QAPI_DEPRECATED,
+} QapiSpecialFeature;
+
 /* QEnumLookup flags */
 #define QAPI_ENUM_DEPRECATED 1
 
diff --git a/scripts/qapi/gen.py b/scripts/qapi/gen.py
index 2ec1e7b3b6..9d07b88cf6 100644
--- a/scripts/qapi/gen.py
+++ b/scripts/qapi/gen.py
@@ -29,6 +29,7 @@
 mcgen,
 )
 from .schema import (
+QAPISchemaFeature,
 QAPISchemaIfCond,
 QAPISchemaModule,
 QAPISchemaObjectType,
@@ -37,6 +38,18 @@
 from .source import QAPISourceInfo
 
 
+def gen_special_features(features: QAPISchemaFeature):
+ret = ''
+sep = ''
+
+for feat in features:
+if feat.is_special():
+ret += ('%s1u << QAPI_%s' % (sep, feat.name.upper()))
+sep = ' | '
+
+return ret or '0'
+
+
 class QAPIGen:
 def __init__(self, fname: str):
 self.fname = fname
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 6d5f46509a..55f82d7389 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -725,6 +725,9 @@ def connect_doc(self, doc):
 class QAPISchemaFeature(QAPISchemaMember):
 role = 'feature'
 
+def is_special(self):
+return self.name in ('deprecated')
+
 
 class QAPISchemaObjectTypeMember(QAPISchemaMember):
 def __init__(self, name, info, typ, optional, ifcond=None, features=None):
-- 
2.31.1




[PATCH 2/9] qapi: Mark unstable QMP parts with feature 'unstable'

2021-10-24 Thread Markus Armbruster
Add special feature 'unstable' everywhere the name starts with 'x-',
except for InputBarrierProperties member x-origin and
MemoryBackendProperties member x-use-canonical-path-for-ramblock-id,
because these two are actually stable.

Signed-off-by: Markus Armbruster 
---
 qapi/block-core.json | 123 +++
 qapi/migration.json  |  35 +---
 qapi/misc.json   |   6 ++-
 qapi/qom.json|  11 ++--
 4 files changed, 130 insertions(+), 45 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 6d3217abb6..ce2c1352cb 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1438,6 +1438,9 @@
 #
 # @x-perf: Performance options. (Since 6.0)
 #
+# Features:
+# @unstable: Member @x-perf is experimental.
+#
 # Note: @on-source-error and @on-target-error only affect background
 #   I/O.  If an error occurs during a guest write request, the device's
 #   rerror/werror actions will be used.
@@ -1452,7 +1455,9 @@
 '*on-source-error': 'BlockdevOnError',
 '*on-target-error': 'BlockdevOnError',
 '*auto-finalize': 'bool', '*auto-dismiss': 'bool',
-'*filter-node-name': 'str', '*x-perf': 'BackupPerf'  } }
+'*filter-node-name': 'str',
+'*x-perf': { 'type': 'BackupPerf',
+ 'features': [ 'unstable' ] } } }
 
 ##
 # @DriveBackup:
@@ -1916,9 +1921,13 @@
 #
 # Get the block graph.
 #
+# Features:
+# @unstable: This command is meant for debugging.
+#
 # Since: 4.0
 ##
-{ 'command': 'x-debug-query-block-graph', 'returns': 'XDbgBlockGraph' }
+{ 'command': 'x-debug-query-block-graph', 'returns': 'XDbgBlockGraph',
+  'features': [ 'unstable' ] }
 
 ##
 # @drive-mirror:
@@ -2257,6 +2266,9 @@
 #
 # Get bitmap SHA256.
 #
+# Features:
+# @unstable: This command is meant for debugging.
+#
 # Returns: - BlockDirtyBitmapSha256 on success
 #  - If @node is not a valid block device, DeviceNotFound
 #  - If @name is not found or if hashing has failed, GenericError with 
an
@@ -2265,7 +2277,8 @@
 # Since: 2.10
 ##
 { 'command': 'x-debug-block-dirty-bitmap-sha256',
-  'data': 'BlockDirtyBitmap', 'returns': 'BlockDirtyBitmapSha256' }
+  'data': 'BlockDirtyBitmap', 'returns': 'BlockDirtyBitmapSha256',
+  'features': [ 'unstable' ] }
 
 ##
 # @blockdev-mirror:
@@ -2495,27 +2508,57 @@
 #
 # Properties for throttle-group objects.
 #
-# The options starting with x- are aliases for the same key without x- in
-# the @limits object. As indicated by the x- prefix, this is not a stable
-# interface and may be removed or changed incompatibly in the future. Use
-# @limits for a supported stable interface.
-#
 # @limits: limits to apply for this throttle group
 #
+# Features:
+# @unstable: All members starting with x- are aliases for the same key
+#without x- in the @limits object.  This is not a stable
+#interface and may be removed or changed incompatibly in
+#the future.  Use @limits for a supported stable
+#interface.
+#
 # Since: 2.11
 ##
 { 'struct': 'ThrottleGroupProperties',
   'data': { '*limits': 'ThrottleLimits',
-'*x-iops-total' : 'int', '*x-iops-total-max' : 'int',
-'*x-iops-total-max-length' : 'int', '*x-iops-read' : 'int',
-'*x-iops-read-max' : 'int', '*x-iops-read-max-length' : 'int',
-'*x-iops-write' : 'int', '*x-iops-write-max' : 'int',
-'*x-iops-write-max-length' : 'int', '*x-bps-total' : 'int',
-'*x-bps-total-max' : 'int', '*x-bps-total-max-length' : 'int',
-'*x-bps-read' : 'int', '*x-bps-read-max' : 'int',
-'*x-bps-read-max-length' : 'int', '*x-bps-write' : 'int',
-'*x-bps-write-max' : 'int', '*x-bps-write-max-length' : 'int',
-'*x-iops-size' : 'int' } }
+'*x-iops-total': { 'type': 'int',
+   'features': [ 'unstable' ] },
+'*x-iops-total-max': { 'type': 'int',
+   'features': [ 'unstable' ] },
+'*x-iops-total-max-length': { 'type': 'int',
+  'features': [ 'unstable' ] },
+'*x-iops-read': { 'type': 'int',
+  'features': [ 'unstable' ] },
+'*x-iops-read-max': { 'type': 'int',
+  'features': [ 'unstable' ] },
+'*x-iops-read-max-length': { 'type': 'int',
+ 'features': [ 'unstable' ] },
+'*x-iops-write': { 'type': 'int',
+   'features': [ 'unstable' ] },
+'*x-iops-write-max': { 'type': 'int',
+   'features': [ 'unstable' ] },
+'*x-iops-write-max-length': { 'type': 'int',
+  'features': [ 'unstable' ] },
+'*x-bps-total': { 'type': 'int',
+  'features

[PATCH 3/9] qapi: Eliminate QCO_NO_OPTIONS for a slight simplification

2021-10-24 Thread Markus Armbruster
Signed-off-by: Markus Armbruster 
---
 include/qapi/qmp/dispatch.h | 1 -
 monitor/misc.c  | 3 +--
 scripts/qapi/commands.py| 5 +
 3 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/include/qapi/qmp/dispatch.h b/include/qapi/qmp/dispatch.h
index 075203dc67..0ce88200b9 100644
--- a/include/qapi/qmp/dispatch.h
+++ b/include/qapi/qmp/dispatch.h
@@ -21,7 +21,6 @@ typedef void (QmpCommandFunc)(QDict *, QObject **, Error **);
 
 typedef enum QmpCommandOptions
 {
-QCO_NO_OPTIONS=  0x0,
 QCO_NO_SUCCESS_RESP   =  (1U << 0),
 QCO_ALLOW_OOB =  (1U << 1),
 QCO_ALLOW_PRECONFIG   =  (1U << 2),
diff --git a/monitor/misc.c b/monitor/misc.c
index ffe7966870..3556b177f6 100644
--- a/monitor/misc.c
+++ b/monitor/misc.c
@@ -230,8 +230,7 @@ static void monitor_init_qmp_commands(void)
 
 qmp_init_marshal(&qmp_commands);
 
-qmp_register_command(&qmp_commands, "device_add", qmp_device_add,
- QCO_NO_OPTIONS);
+qmp_register_command(&qmp_commands, "device_add", qmp_device_add, 0);
 
 QTAILQ_INIT(&qmp_cap_negotiation_commands);
 qmp_register_command(&qmp_cap_negotiation_commands, "qmp_capabilities",
diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index 3654825968..c8a975528f 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -229,15 +229,12 @@ def gen_register_command(name: str,
 if coroutine:
 options += ['QCO_COROUTINE']
 
-if not options:
-options = ['QCO_NO_OPTIONS']
-
 ret = mcgen('''
 qmp_register_command(cmds, "%(name)s",
  qmp_marshal_%(c_name)s, %(opts)s);
 ''',
 name=name, c_name=c_name(name),
-opts=" | ".join(options))
+opts=' | '.join(options) or 0)
 return ret
 
 
-- 
2.31.1