riscv/qemu - qemu - Gitea: Git with a cup of tea

Commit Graph

Author	SHA1	Message	Date
Markus Armbruster	25b1ef31db	qapi: Make 'allow-oob' optional in SchemaInfoCommand Making 'allow-oob' optional in SchemaInfoCommand permits omitting it in the common case. Shrinks query-qmp-schema's output from 122.1KiB to 118.6KiB for me. Note that out-of-band execution is still experimental (you have to configure the monitor with x-oob=on to use it). Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180718090557.17248-1-armbru@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com>	8 years ago
Markus Armbruster	1f214ee1b8	qapi: Do not expose "allow-preconfig" in query-qmp-schema According to commit `047f7038f5`, option --preconfig [...] allows pausing QEMU in the new RUN_STATE_PRECONFIG state, allowing the configuration of QEMU from QMP before the machine jumps into board initialization code of machine_run_board_init() The intent is to allow management to query machine state and additionally configure it using previous query results within one QEMU instance (i.e. eliminate the need to start QEMU twice, 1st to query board specific parameters and 2nd for actual VM start using query results for additional parameters). The implementation is a bit of a hack: it splices in an additional main loop before machine creation, in special runstate preconfig. New command exit-preconfig exits that main loop. QEMU continues initializing, creates the machine, and runs the good old main loop. The replacement of the main loop is transparent to monitors. Sadly, some commands expect initialization to be complete. Running them in --preconfig's main loop violates their preconditions. Since we don't really know which commands are safe, we use a whitelist. This drags the concept of run state into the QMP core. The whitelist is done as a command flag in the QAPI schema (commit `d6fe3d02e9`). Drags the concept of run state further into the QAPI language. The command flag is exposed in query-qmp-schema (also commit `d6fe3d02e9`). This makes it ABI. I consider the whole thing an offensively ugly hack, but sometimes an ugly hack is the best we can do to solve a problem people have. The need described by the commit message quote above is genuine. The proper solution would be a main loop that permits complete configuration via QMP. This is out of reach, thus the hack. However, even though the need is genuine, it isn't urgent: libvirt is not going to use this anytime soon. Baking a hack into ABI before it has any users is a bad idea. This commit reverts the parts of commit `d6fe3d02e9` that affect ABI via query-qmp-schema. The commit did the following: (1) Add command flag 'allow-preconfig' to the QAPI schema language (2) Pass it to code generators (3) Have the commands.py code generator pass it to the command registry (so commit `047f7038f5` can use it as whitelist) (4) Add 'allow-preconfig' to SchemaInfoCommand (neglecting to update qapi-code-gen.txt section "Client JSON Protocol introspection") (5) Set 'allow-preconfig': true for commands qmp_capabilities, query-commands, query-command-line-options, query-status Revert exactly (4), plus a bit of documentation added to qemu-tech.info in commit `047f7038f5`. Shrinks query-qmp-schema's output from 126.5KiB to 121.8KiB for me. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180705091402.26244-2-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Acked-by: Eduardo Habkost <ehabkost@redhat.com> Acked-by: Igor Mammedov <imammedo@redhat.com> [Straightforward conflict with commit `d626b6c1ae` resolved]	8 years ago
Igor Mammedov	d6fe3d02e9	qapi: introduce new cmd option "allow-preconfig" New option will be used to allow commands, which are prepared/need to run, during preconfig state. Other commands that should be able to run in preconfig state, should be amended to not expect machine in initialized state or deal with it. For compatibility reasons, commands that don't use new flag 'allow-preconfig' explicitly are not permitted to run in preconfig state but allowed in all other states like they used to be. Within this patch allow following commands in preconfig state: qmp_capabilities query-qmp-schema query-commands query-command-line-options query-status exit-preconfig to allow qmp connection, basic introspection and moving to the next state. PS: set-numa-node and query-hotpluggable-cpus will be enabled later in a separate patches. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <1526057503-39287-1-git-send-email-imammedo@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> [ehabkost: Changed "since 2.13" to "since 3.0"] Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>	8 years ago
Peter Xu	876c67512e	qapi: introduce new cmd option "allow-oob" Here "oob" stands for "Out-Of-Band". When "allow-oob" is set, it means the command allows out-of-band execution. The "oob" idea is proposed by Markus Armbruster in following thread: https://lists.gnu.org/archive/html/qemu-devel/2017-09/msg02057.html This new "allow-oob" boolean will be exposed by "query-qmp-schema" as well for command entries, so that QMP clients can know which commands can be used in out-of-band calls. For example the command "migrate" originally looks like: {"name": "migrate", "ret-type": "17", "meta-type": "command", "arg-type": "86"} And it'll be changed into: {"name": "migrate", "ret-type": "17", "allow-oob": false, "meta-type": "command", "arg-type": "86"} This patch only provides the QMP interface level changes. It does not contain the real out-of-band execution implementation yet. Suggested-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180309090006.10018-18-peterx@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: rebase on introspection done by qlit] Signed-off-by: Eric Blake <eblake@redhat.com>	8 years ago
Markus Armbruster	a885cd3915	qapi-schema: Introspection doc is in the wrong section, fix Bug: introspection documentation is in section "Tracing commands". Cause: sub-schema qapi/introspect.json lacks a section header, and therefore goes into whatever section precedes its include. Fix: add a section header. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1503602048-12268-3-git-send-email-armbru@redhat.com>	9 years ago
Philippe Mathieu-Daudé	b3125e73d4	docs: fix broken paths to docs/devel/qapi-code-gen.txt With the move of some docs to docs/interop on `ac06724a71`, a couple of references were not updated. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>	9 years ago
Markus Armbruster	1d8bda128d	qapi: The #optional tag is redundant, drop We traditionally mark optional members #optional in the doc comment. Before commit `3313b61`, this was entirely manual. Commit `3313b61` added some automation because its qapi2texi.py relied on #optional to determine whether a member is optional. This is no longer the case since the previous commit: the only thing qapi2texi.py still does with #optional is stripping it out. We still reject bogus qapi-schema.json and six places for qga/qapi-schema.json. Thus, you can't actually rely on #optional to see whether something is optional. Yet we still make people add it manually. That's just busy-work. Drop the code to check, fix up and strip out #optional, along with all instances of #optional. To keep it out, add code to reject it, to be dropped again once the dust settles. No change to generated documentation. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <1489582656-31133-18-git-send-email-armbru@redhat.com>	9 years ago
Marc-André Lureau	5807ff88b1	qapi: Reorder doc comments for future doc generator The doc generator we're going to add expects a fairly rigid doc comment structure. Reorder / rephrase some doc comments to please it. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20170113144135.5150-8-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [Commit message rewritten] Signed-off-by: Markus Armbruster <armbru@redhat.com>	9 years ago
Marc-André Lureau	e22da431a7	qapi: Format TODO comments more consistently Consistently put a colon after TODO. This will make the TODOs stand out in the documentation we're going to generate. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20170113144135.5150-4-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [Commit message rewritten] Signed-off-by: Markus Armbruster <armbru@redhat.com>	9 years ago
Marc-André Lureau	5072f7b38b	qapi: add missing colon-ending for section name The documentation parser we are going to add expects a section name to end with ':', otherwise the comment is treated as free-form text body. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20161117155504.21843-9-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>	10 years ago
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>	10 years ago
Eric Blake	39a65e2c24	qapi: Document introspection stability considerations We are not ready (and might never be ready) to declare introspection stable between releases. Clients written to control multiple versions of qemu, and desiring to know whether a particular member is supported for a given command, must be prepared to locate that member in spite of qapi changes that may affect the member's location or type within the overall object, even though such changes did not break QMP wire back-compatibility. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1447264202-19554-1-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>	11 years ago
Eric Blake	f545504420	qapi-introspect: Document lack of sorting qapi-code-gen.txt already claims that types, commands, and events share a common namespace; set this in stone by further documenting that our introspection output will never have collisions with the same name tied to more than one meta-type. Our largest QMP enum currently has 125 values, our largest object type has 27 members, and the mean for each is less than 10. These sizes are small enough that the per-element overhead of O(log n) binary searching probably outweighs the speed possible with direct O(n) linear searching (a better algorithm with more overhead will only beat a leaner naive algorithm only as you scale to larger input sizes). Arguably, the overall SchemaInfo array could be sorted by name; there, we currently have 531 entities, large enough for a binary search to be faster than linear. However, remember that we have mutually-recursive types, which means there is no topological ordering that will allow clients to learn all information about that type in a single linear pass; thus clients will want to do random access over the data, and they will probably read the introspection output into a hashtable for O(1) lookup rather than O(log n) binary searching, at which point, pre-sorting our introspection output doesn't help the client. It doesn't help that sorting can be subjective if you introduce locales into the mix (I'm not experienced enough with Python to know for sure, but at least it looks like it defaults to sorting in the C locale even when run under a different locale). And while our current introspection output is deterministic (because we visit entities in a sorted order), we may want to change that order in the future (such as using OrderedDict to stick to .json declaration order). For these reasons, we simply document that clients should not rely on any particular order of items in introspection output. And since it is now a documented part of the contract, we have the freedom to later rearrange output if needed, without worrying about breaking well-written clients. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1446791754-23823-13-git-send-email-eblake@redhat.com> [Commit message tweaked] Signed-off-by: Markus Armbruster <armbru@redhat.com>	11 years ago
Markus Armbruster	1a9a507b2e	qapi-introspect: Hide type names To eliminate the temptation for clients to look up types by name (which are not ABI), replace all type names by meaningless strings. Reduces output of query-schema by 13 out of 85KiB. As a debugging aid, provide option -u to suppress the hiding. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <1442401589-24189-27-git-send-email-armbru@redhat.com>	11 years ago
Markus Armbruster	39a1815816	qapi: New QMP command query-qmp-schema for QMP introspection qapi/introspect.json defines the introspection schema. It's designed for QMP introspection, but should do for similar uses, such as QGA. The introspection schema does not reflect all the rules and restrictions that apply to QAPI schemata. A valid QAPI schema has an introspection value conforming to the introspection schema, but the converse is not true. Introspection lowers away a number of schema details, and makes implicit things explicit: * The built-in types are declared with their JSON type. All integer types are mapped to 'int', because how many bits we use internally is an implementation detail. It could be pressed into external interface service as very approximate range information, but that's a bad idea. If we need range information, we better do it properly. * Implicit type definitions are made explicit, and given auto-generated names: - Array types, named by appending "List" to the name of their element type, like in generated C. - The enumeration types implicitly defined by simple union types, named by appending "Kind" to the name of their simple union type, like in generated C. - Types that don't occur in generated C. Their names start with ':' so they don't clash with the user's names. * All type references are by name. * The struct and union types are generalized into an object type. * Base types are flattened. * Commands take a single argument and return a single result. Dictionary argument or list result is an implicit type definition. The empty object type is used when a command takes no arguments or produces no results. The argument is always of object type, but the introspection schema doesn't reflect that. The 'gen': false directive is omitted as implementation detail. The 'success-response' directive is omitted as well for now, even though it's not an implementation detail, because it's not used by QMP. * Events carry a single data value. Implicit type definition and empty object type use, just like for commands. The value is of object type, but the introspection schema doesn't reflect that. * Types not used by commands or events are omitted. Indirect use counts as use. * Optional members have a default, which can only be null right now Instead of a mandatory "optional" flag, we have an optional default. No default means mandatory, default null means optional without default value. Non-null is available for optional with default (possible future extension). * Clients should not look up types by name, because type names are not ABI. Look up the command or event you're interested in, then follow the references. TODO Should we hide the type names to eliminate the temptation? New generator scripts/qapi-introspect.py computes an introspection value for its input, and generates a C variable holding it. It can generate awfully long lines. Marked TODO. A new test-qmp-input-visitor test case feeds its result for both tests/qapi-schema/qapi-schema-test.json and qapi-schema.json to a QmpInputVisitor to verify it actually conforms to the schema. New QMP command query-qmp-schema takes its return value from that variable. Its reply is some 85KiBytes for me right now. If this turns out to be too much, we have a couple of options: * We can use shorter names in the JSON. Not the QMP style. * Optionally return the sub-schema for commands and events given as arguments. Right now qmp_query_schema() sends the string literal computed by qmp-introspect.py. To compute sub-schema at run time, we'd have to duplicate parts of qapi-introspect.py in C. Unattractive. * Let clients cache the output of query-qmp-schema. It changes only on QEMU upgrades, i.e. rarely. Provide a command query-qmp-schema-hash. Clients can have a cache indexed by hash, and re-query the schema only when they don't have it cached. Even simpler: put the hash in the QMP greeting. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>	11 years ago

15 Commits (e321c0597c7590499bacab239d7f86e257f96bcd)