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2018-07-31monitor: temporary fix for dead-lock on event recursionMarc-André Lureau
With a Spice port chardev, it is possible to reenter monitor_qapi_event_queue() (when the client disconnects for example). This will dead-lock on monitor_lock. Instead, use some TLS variables to check for recursion and queue the events. Fixes: (gdb) bt #0 0x00007fa69e7217fd in __lll_lock_wait () at /lib64/libpthread.so.0 #1 0x00007fa69e71acf4 in pthread_mutex_lock () at /lib64/libpthread.so.0 #2 0x0000563303567619 in qemu_mutex_lock_impl (mutex=0x563303d3e220 <monitor_lock>, file=0x5633036589a8 "/home/elmarco/src/qq/monitor.c", line=645) at /home/elmarco/src/qq/util/qemu-thread-posix.c:66 #3 0x0000563302fa6c25 in monitor_qapi_event_queue (event=QAPI_EVENT_SPICE_DISCONNECTED, qdict=0x56330602bde0, errp=0x7ffc6ab5e728) at /home/elmarco/src/qq/monitor.c:645 #4 0x0000563303549aca in qapi_event_send_spice_disconnected (server=0x563305afd630, client=0x563305745360, errp=0x563303d8d0f0 <error_abort>) at qapi/qapi-events-ui.c:149 #5 0x00005633033e600f in channel_event (event=3, info=0x5633061b0050) at /home/elmarco/src/qq/ui/spice-core.c:235 #6 0x00007fa69f6c86bb in reds_handle_channel_event (reds=<optimized out>, event=3, info=0x5633061b0050) at reds.c:316 #7 0x00007fa69f6b193b in main_dispatcher_self_handle_channel_event (info=0x5633061b0050, event=3, self=0x563304e088c0) at main-dispatcher.c:197 #8 0x00007fa69f6b193b in main_dispatcher_channel_event (self=0x563304e088c0, event=event@entry=3, info=0x5633061b0050) at main-dispatcher.c:197 #9 0x00007fa69f6d0833 in red_stream_push_channel_event (s=s@entry=0x563305ad8f50, event=event@entry=3) at red-stream.c:414 #10 0x00007fa69f6d086b in red_stream_free (s=0x563305ad8f50) at red-stream.c:388 #11 0x00007fa69f6b7ddc in red_channel_client_finalize (object=0x563304df2360) at red-channel-client.c:347 #12 0x00007fa6a56b7fb9 in g_object_unref () at /lib64/libgobject-2.0.so.0 #13 0x00007fa69f6ba212 in red_channel_client_push (rcc=0x563304df2360) at red-channel-client.c:1341 #14 0x00007fa69f68b259 in red_char_device_send_msg_to_client (client=<optimized out>, msg=0x5633059b6310, dev=0x563304e08bc0) at char-device.c:305 #15 0x00007fa69f68b259 in red_char_device_send_msg_to_clients (msg=0x5633059b6310, dev=0x563304e08bc0) at char-device.c:305 #16 0x00007fa69f68b259 in red_char_device_read_from_device (dev=0x563304e08bc0) at char-device.c:353 #17 0x000056330317d01d in spice_chr_write (chr=0x563304cafe20, buf=0x563304cc50b0 "{\"timestamp\": {\"seconds\": 1532944763, \"microseconds\": 326636}, \"event\": \"SHUTDOWN\", \"data\": {\"guest\": false}}\r\n", len=111) at /home/elmarco/src/qq/chardev/spice.c:199 #18 0x00005633034deee7 in qemu_chr_write_buffer (s=0x563304cafe20, buf=0x563304cc50b0 "{\"timestamp\": {\"seconds\": 1532944763, \"microseconds\": 326636}, \"event\": \"SHUTDOWN\", \"data\": {\"guest\": false}}\r\n", len=111, offset=0x7ffc6ab5ea70, write_all=false) at /home/elmarco/src/qq/chardev/char.c:112 #19 0x00005633034df054 in qemu_chr_write (s=0x563304cafe20, buf=0x563304cc50b0 "{\"timestamp\": {\"seconds\": 1532944763, \"microseconds\": 326636}, \"event\": \"SHUTDOWN\", \"data\": {\"guest\": false}}\r\n", len=111, write_all=false) at /home/elmarco/src/qq/chardev/char.c:147 #20 0x00005633034e1e13 in qemu_chr_fe_write (be=0x563304dbb800, buf=0x563304cc50b0 "{\"timestamp\": {\"seconds\": 1532944763, \"microseconds\": 326636}, \"event\": \"SHUTDOWN\", \"data\": {\"guest\": false}}\r\n", len=111) at /home/elmarco/src/qq/chardev/char-fe.c:42 #21 0x0000563302fa6334 in monitor_flush_locked (mon=0x563304dbb800) at /home/elmarco/src/qq/monitor.c:425 #22 0x0000563302fa6520 in monitor_puts (mon=0x563304dbb800, str=0x563305de7e9e "") at /home/elmarco/src/qq/monitor.c:468 #23 0x0000563302fa680c in qmp_send_response (mon=0x563304dbb800, rsp=0x563304df5730) at /home/elmarco/src/qq/monitor.c:517 #24 0x0000563302fa6905 in qmp_queue_response (mon=0x563304dbb800, rsp=0x563304df5730) at /home/elmarco/src/qq/monitor.c:538 #25 0x0000563302fa6b5b in monitor_qapi_event_emit (event=QAPI_EVENT_SHUTDOWN, qdict=0x563304df5730) at /home/elmarco/src/qq/monitor.c:624 #26 0x0000563302fa6c4b in monitor_qapi_event_queue (event=QAPI_EVENT_SHUTDOWN, qdict=0x563304df5730, errp=0x7ffc6ab5ed00) at /home/elmarco/src/qq/monitor.c:649 #27 0x0000563303548cce in qapi_event_send_shutdown (guest=false, errp=0x563303d8d0f0 <error_abort>) at qapi/qapi-events-run-state.c:58 #28 0x000056330313bcd7 in main_loop_should_exit () at /home/elmarco/src/qq/vl.c:1822 #29 0x000056330313bde3 in main_loop () at /home/elmarco/src/qq/vl.c:1862 #30 0x0000563303143781 in main (argc=3, argv=0x7ffc6ab5f068, envp=0x7ffc6ab5f088) at /home/elmarco/src/qq/vl.c:4644 Note that error report is now moved to the first caller, which may receive an error for a recursed event. This is probably fine (95% of callers use &error_abort, the rest have NULL error and ignore it) Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180731150144.14022-1-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [*_no_recurse renamed to *_no_reenter, local variables reordered] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-23monitor: Fix unsafe sharing of @cur_mon among threadsPeter Xu
@cur_mon is null unless the main thread is running monitor code, either HMP code within monitor_read(), or QMP code within monitor_qmp_dispatch(). Use of @cur_mon outside the main thread is therefore unsafe. Most of its uses are in monitor command handlers. These run in the main thread. However, there are also uses hiding elsewhere, such as in error_vprintf(), and thus error_report(), making these functions unsafe outside the main thread. No such unsafe uses are known at this time. Regardless, this is an unnecessary trap. It's an ancient trap, though. More recently, commit cf869d53172 "qmp: support out-of-band (oob) execution" spiced things up: the monitor I/O thread assigns to @cur_mon when executing commands out-of-band. Having two threads save, set and restore @cur_mon without synchronization is definitely unsafe. We can end up with @cur_mon null while the main thread runs monitor code, or non-null while it runs non-monitor code. We could fix this by making the I/O thread not mess with @cur_mon, but that would leave the trap armed and ready. Instead, make @cur_mon thread-local. It's now reliably null unless the thread is running monitor code. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> [peterx: update subject and commit message written by Markus] Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180720033451.32710-1-peterx@redhat.com>
2018-07-16monitor: Fix tracepoint crash on JSON syntax errorMarkus Armbruster
When tracepoint handle_qmp_command is enabled, we crash on JSON syntax errors. Broken in commit 1cc37471525. Fix by skipping the tracepoint on JSON syntax error. Before the flawed commit, we skipped it by returning early. Fixes: CID 1394216 Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180716091012.29510-1-armbru@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com>
2018-07-11monitor: fix double-free of request errorMarc-André Lureau
qmp_error_response() will free the given error. Fix double-free in later qmp_request_free(). Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180705164201.9853-1-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Fixes: 1cc37471525d03f963bc71d724f0dc9eab888fc1 Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-05Merge remote-tracking branch ↵Peter Maydell
'remotes/armbru/tags/pull-monitor-2018-07-03-v2' into staging Monitor patches for 2018-07-03 # gpg: Signature made Tue 03 Jul 2018 22:20:13 BST # gpg: using RSA key 3870B400EB918653 # gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" # gpg: aka "Markus Armbruster <armbru@pond.sub.org>" # Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653 * remotes/armbru/tags/pull-monitor-2018-07-03-v2: (32 commits) qapi: Polish command flags documentation in qapi-code-gen.txt monitor: Improve some comments qmp: Clean up capability negotiation after commit 02130314d8c qobject: Let qobject_from_jsonf() fail instead of abort qmp: Switch timestamp_put() to qdict_from_jsonf_nofail() qmp: Add some comments around null responses qmp: Simplify monitor_qmp_respond() qmp: Replace get_qmp_greeting() by qmp_greeting() qmp: Replace monitor_json_emitter{,raw}() by qmp_{queue,send}_response() qmp: Use QDict * instead of QObject * for response objects qmp: De-duplicate error response building qobject: New qdict_from_jsonf_nofail() monitor: Peel off @mon_global wrapper monitor: Rename use_io_thr to use_io_thread qmp: Don't let JSON errors jump the queue qmp: Don't let malformed in-band commands jump the queue tests/qmp-test: Demonstrate QMP errors jumping the queue qmp: Simplify code around monitor_qmp_dispatch_one() qmp: Always free QMPRequest with qmp_request_free() qmp: Revert change to handle_qmp_command tracepoint ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-03monitor: Improve some commentsMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-32-armbru@redhat.com>
2018-07-03qmp: Clean up capability negotiation after commit 02130314d8cMarkus Armbruster
qmp_greeting() offers capabilities to the client, and qmp_qmp_capabilities() accepts or denies capabilities requested by the client. The two compute the set of available capabilities independently. Not nice. Clean this up as follows. Compute available capabilities just once in monitor_qmp_caps_reset(), and store them in Monitor member qmp.capab_offered[]. Have qmp_greeting() and qmp_qmp_capabilities() use that. Both are now oblivious of capability details. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-31-armbru@redhat.com>
2018-07-03qmp: Simplify monitor_qmp_respond()Markus Armbruster
monitor_qmp_respond() takes both a response object and an error object. If an error object is non-null, the response object must be null, and the response is built from the error object. Of the two callers, one always passes a null response object, and one a null error object. Move building the response object from the error object to the latter, and drop the error object parameter. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-27-armbru@redhat.com>
2018-07-03qmp: Replace get_qmp_greeting() by qmp_greeting()Markus Armbruster
get_qmp_greeting() returns a QDict * as QObject *. It's caller converts it right back. Return QDict * instead. While there, rename to qmp_greeting(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-26-armbru@redhat.com>
2018-07-03qmp: Replace monitor_json_emitter{,raw}() by qmp_{queue,send}_response()Markus Armbruster
monitor_json_emitter() and monitor_json_emitter_raw() are unnecessarily general: they can send arbitrary JSON values, even though we only ever use them for QMP, which may send only JSON objects. Specialize the argument from QObject * to QDict *, and rename to qmp_queue_response(), qmp_send_response(). All callers but one lose an upcast. The lone exception gains a downcast; the next commit will get rid of it. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-25-armbru@redhat.com>
2018-07-03qmp: Use QDict * instead of QObject * for response objectsMarkus Armbruster
By using the more specific type, we get fewer downcasts. The downcasts are safe, but not obviously so, at least not locally. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-24-armbru@redhat.com>
2018-07-03qmp: De-duplicate error response buildingMarkus Armbruster
All callers of qmp_build_error_object() duplicate the code to wrap it in a response object. Replace it by qmp_error_response() that captures the duplicated code, including error_free(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-23-armbru@redhat.com>
2018-07-03monitor: Peel off @mon_global wrapperMarkus Armbruster
Wrapping global variables in a struct without a use for the wrapper struct buys us nothing but longer lines. Unwrap them. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-21-armbru@redhat.com>
2018-07-03monitor: Rename use_io_thr to use_io_threadMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-20-armbru@redhat.com>
2018-07-03qmp: Don't let JSON errors jump the queueMarkus Armbruster
handle_qmp_command() reports JSON syntax errors right away. This is wrong when OOB is enabled, because the errors can "jump the queue" then. The previous commit fixed the same bug for semantic errors, by delaying the checking until dispatch. We can't delay the checking, so delay the reporting. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-19-armbru@redhat.com>
2018-07-03qmp: Don't let malformed in-band commands jump the queueMarkus Armbruster
handle_qmp_command() reports certain errors right away. This is wrong when OOB is enabled, because the errors can "jump the queue" then, as the previous commit demonstrates. To fix, we need to delay errors until dispatch. Do that for semantic errors, mostly by reverting ill-advised parts of commit cf869d53172 "qmp: support out-of-band (oob) execution". Bonus: doesn't run qmp_dispatch_check_obj() twice, once in handle_qmp_command(), and again in do_qmp_dispatch(). That's also due to commit cf869d53172. The next commit will fix queue jumping for syntax errors. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-18-armbru@redhat.com>
2018-07-03tests/qmp-test: Demonstrate QMP errors jumping the queueMarkus Armbruster
When OOB is enabled, out-of-band commands are executed right away, everything else is queued. This lets out-of-band commands "jump the queue". However, certain errors are always reported right away, and therefore can jump the queue even when the erroneous input does not request out-of-band execution. These errors are pretty unlikely to occur in production, but it's wrong all the same. Mark FIXME. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Message-Id: <20180703085358.13941-17-armbru@redhat.com>
2018-07-03qmp: Simplify code around monitor_qmp_dispatch_one()Markus Armbruster
Change monitor_qmp_dispatch_one() to take its parameters unwrapped, move monitor_resume() to the one caller that needs it, rename the function to monitor_qmp_dispatch(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-16-armbru@redhat.com>
2018-07-03qmp: Always free QMPRequest with qmp_request_free()Markus Armbruster
monitor_qmp_dispatch_one() frees a QMPRequest manually, because it needs to keep a reference to ->id. Premature optimization. Take an additional reference so we can use qmp_request_free(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-15-armbru@redhat.com>
2018-07-03qmp: Revert change to handle_qmp_command tracepointMarkus Armbruster
Commit 71da4667db6 "monitor: separate QMP parser and dispatcher" moved the handle_qmp_command tracepoint from handle_qmp_command() to monitor_qmp_dispatch_one(). This delays tracing from enqueue time to dequeue time. Revert that. Dequeue remains adequately visible via tracepoint monitor_qmp_cmd_in_band. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-14-armbru@redhat.com>
2018-07-03qmp: Redo how the client requests out-of-band executionMarkus Armbruster
Commit cf869d53172 "qmp: support out-of-band (oob) execution" added a general mechanism for command-independent arguments just for an out-of-band flag: The "control" key is introduced to store this extra flag. "control" field is used to store arguments that are shared by all the commands, rather than command specific arguments. Let "run-oob" be the first. However, it failed to reject unknown members of "control". For instance, in QMP command {"execute": "query-name", "id": 42, "control": {"crap": true}} "crap" gets silently ignored. Instead of fixing this, revert the general "control" mechanism (because YAGNI), and do it the way I initially proposed, with key "exec-oob". Simpler code, simpler interface. An out-of-band command {"execute": "migrate-pause", "id": 42, "control": {"run-oob": true}} becomes {"exec-oob": "migrate-pause", "id": 42} Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-13-armbru@redhat.com> [Commit message typo fixed]
2018-07-03qmp qemu-ga: Fix qemu-ga not to accept "control"Markus Armbruster
Commit cf869d53172 "qmp: support out-of-band (oob) execution" accidentally made qemu-ga accept and ignore "control". Fix that. Out-of-band execution in a monitor that doesn't support it now fails with {"error": {"class": "GenericError", "desc": "QMP input member 'control' is unexpected"}} instead of {"error": {"class": "GenericError", "desc": "Please enable out-of-band first for the session during capabilities negotiation"}} The old description is suboptimal when out-of-band cannot not be enabled, or the command doesn't support out-of-band execution. The new description is a bit unspecific, but it'll do. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-12-armbru@redhat.com>
2018-07-03qmp qemu-ga: Revert change that accidentally made qemu-ga accept "id"Markus Armbruster
Commit cf869d53172 "qmp: support out-of-band (oob) execution" changed how we check "id": Note that in the patch I exported qmp_dispatch_check_obj() to be used to check the request earlier, and at the same time allowed "id" field to be there since actually we always allow that. The part after "and" is ill-advised: it makes qemu-ga accept and ignore "id". Revert. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-10-armbru@redhat.com>
2018-07-03qmp: Make "id" optional again even in "oob" monitorsMarkus Armbruster
Commit cf869d53172 "qmp: support out-of-band (oob) execution" made "id" mandatory for all commands when the client accepted capability "oob". This is rather onerous when you play with QMP by hand, and unnecessarily so: only out-of-band commands need an ID for reliable matching of response to command. Revert that part of commit cf869d53172 for now, but have documentation advise on the need to use "id" with out-of-band commands. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180703085358.13941-8-armbru@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2018-07-03qmp: Document COMMAND_DROPPED design flawMarkus Armbruster
Events are broadcast to all monitors. If another monitor's client has a command with the same ID in flight, the event will incorrectly claim that command was dropped. This must be fixed before out-of-band execution can graduate from "experimental". Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-5-armbru@redhat.com>
2018-07-03qapi: add conditions to SPICE type/commands/events on the schemaMarc-André Lureau
Add #if defined(CONFIG_SPICE) in generated code, and adjust the qmp/hmp code accordingly. query-qmp-schema no longer reports the command/events etc as available when disabled at compile time. Commands made conditional: * query-spice Before the patch, the command for !CONFIG_SPICE is unregistered. It will fail with the same error. Events made conditional: * SPICE_CONNECTED, SPICE_INITIALIZED, SPICE_DISCONNECTED, SPICE_MIGRATE_COMPLETED Add TODO for conditional SPICE chardevs, delayed until the supports for conditional members lands. No HMP change, the code was already conditional. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Gerd Hoffmann <kraxel@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180703155648.11933-15-marcandre.lureau@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-03monitor: Spell "I/O thread" consistently in commentsMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-3-armbru@redhat.com>
2018-07-03qmp: Say "out-of-band" instead of "Out-Of-Band"Markus Armbruster
Affects documentation and a few error messages. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-2-armbru@redhat.com>
2018-07-02monitor: Use the IEC binary prefix definitionsPhilippe Mathieu-Daudé
It eases code review, unit is explicit. Patch generated using: $ git grep -n '[<>][<>]= ?[1-5]0' and modified manually. Suggested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20180625124238.25339-43-f4bug@amsat.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-30monitor: flush qmp responses when CLOSEDPeter Xu
Previously we clean up the queues when we got CLOSED event. It was used to make sure we won't send leftover replies/events of a old client to a new client which makes perfect sense. However this will also drop the replies/events even if the output port of the previous chardev backend is still open, which can lead to missing of the last replies/events. Now this patch does an extra operation to flush the response queue before cleaning up. In most cases, a QMP session will be based on a bidirectional channel (a TCP port, for example, we read/write to the same socket handle), so in port and out port of the backend chardev are fundamentally the same port. In these cases, it does not really matter much on whether we'll flush the response queue since flushing will fail anyway. However there can be cases where in & out ports of the QMP monitor's backend chardev are separated. Here is an example: cat $QMP_COMMANDS | qemu -qmp stdio ... | filter_commands In this case, the backend is fd-typed, and it is connected to stdio where in port is stdin and out port is stdout. Now if we drop all the events on the response queue then filter_command process might miss some events that it might expect. The thing is that, when stdin closes, stdout might still be there alive! In practice, I encountered SHUTDOWN event missing when running test with iotest 087 with Out-Of-Band enabled. Here is one of the ways that this can happen (after "quit" command is executed and QEMU quits the main loop): 1. [main thread] QEMU queues a SHUTDOWN event into response queue. 2. "cat" terminates (to distinguish it from the animal, I quote it). 3. [monitor iothread] QEMU's monitor iothread reads EOF from stdin. 4. [monitor iothread] QEMU's monitor iothread calls the CLOSED event hook for the monitor, which will destroy the response queue of the monitor, then the SHUTDOWN event is dropped. 5. [main thread] QEMU's main thread cleans up the monitors in monitor_cleanup(). When trying to flush pending responses, it sees nothing. SHUTDOWN is lost forever. Note that before the monitor iothread was introduced, step [4]/[5] could never happen since the main loop was the only place to detect the EOF event of stdin and run the CLOSED event hooks. Now things can happen in parallel in the iothread. Without this patch, iotest 087 will have ~10% chance to miss the SHUTDOWN event and fail when with Out-Of-Band enabled: --- /home/peterx/git/qemu/tests/qemu-iotests/087.out +++ /home/peterx/git/qemu/bin/tests/qemu-iotests/087.out.bad @@ -8,7 +8,6 @@ {"return": {}} {"error": {"class": "GenericError", "desc": "'node-name' must be specified for the root node"}} {"return": {}} -{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}} === Duplicate ID === @@ -53,7 +52,6 @@ {"return": {}} {"return": {}} {"return": {}} -{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}} This patch fixes the problem. Fixes: 6d2d563f8c ("qmp: cleanup qmp queues properly", 2018-03-27) Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180620073223.31964-4-peterx@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [Commit message and a comment touched up] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-30monitor: rename *_pop_one to *_pop_anyPeter Xu
The old names are confusing since both of the old functions are popping an item from multiple queues rather than a single queue. In that sense, *_pop_any() suites better than *_pop_one(). Since at it, touch up the function monitor_qmp_response_pop_any() a bit to let the callers pass in a QMPResponse struct instead of returning a struct. Change the return value to boolean to mark whether we have popped a valid response instead. Suggested-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180620073223.31964-3-peterx@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-29Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into stagingPeter Maydell
The Darwin host support still needs some more work. It won't make it for soft-freeze, but I'd like these preparatory patches to be merged anyway. # gpg: Signature made Fri 29 Jun 2018 11:39:04 BST # gpg: using RSA key 71D4D5E5822F73D6 # gpg: Good signature from "Greg Kurz <groug@kaod.org>" # gpg: aka "Gregory Kurz <gregory.kurz@free.fr>" # gpg: aka "[jpeg image of size 3330]" # Primary key fingerprint: B482 8BAF 9431 40CE F2A3 4910 71D4 D5E5 822F 73D6 * remotes/gkurz/tags/for-upstream: 9p: darwin: Explicitly cast comparisons of mode_t with -1 cutils: Provide strchrnul Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-06-29cutils: Provide strchrnulKeno Fischer
strchrnul is a GNU extension and thus unavailable on a number of targets. In the review for a commit removing strchrnul from 9p, I was asked to create a qemu_strchrnul helper to factor out this functionality. Do so, and use it in a number of other places in the code base that inlined the replacement pattern in a place where strchrnul could be used. Signed-off-by: Keno Fischer <keno@juliacomputing.com> Acked-by: Greg Kurz <groug@kaod.org> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-28memory/hmp: Print owners/parents in "info mtree"Alexey Kardashevskiy
This adds owners/parents (which are the same, just occasionally owner==NULL) printing for memory regions; a new '-o' flag enabled new output. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Message-Id: <20180604032511.6980-1-aik@ozlabs.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-21hmp: Allow HMP in preconfig state againDr. David Alan Gilbert
Now we can cope with preconfig in HMP, reenable by reverting commit 71dc578e116599ea73c8a2a4e693134702ec0e83. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <20180620153947.30834-8-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-06-21hmp: Restrict auto-complete in preconfigDr. David Alan Gilbert
Don't show the commands that aren't available. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <20180620153947.30834-4-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-06-21hmp: Allow help on preconfig commandsDr. David Alan Gilbert
Allow the 'help' command in preconfig state but make it only list the preconfig commands. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <20180620153947.30834-3-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-06-21hmp: Add flag for preconfig commandsDr. David Alan Gilbert
Add a flag to command definitions to allow them to be used in preconfig and check it. If users try to use commands that aren't available, tell them to use the exit_preconfig comand we're adding in a few patches. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <20180620153947.30834-2-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-06-21monitor: report entirety of hmp command on errorCollin Walling
When a user incorrectly provides an hmp command, an error response will be printed that prompts the user to try "help <command name>". However, when the command contains multiple parts e.g. "info uuid xyz", only the last whitespace delimited string will be reported (in this example "info" will be dropped and the message will read "Try "help uuid" for more information", which is incorrect). Let's correct this by capturing the entirety of the command from the command line -- excluding any extraneous characters. Reported-by: Mikhail Fokin <fokin@de.ibm.com> Signed-off-by: Collin Walling <walling@linux.ibm.com> Message-Id: <ee680f5e-ac9a-479d-f65e-9f8ae9cfe5d4@linux.ibm.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-06-18monitor: add lock to protect mon_fdsetsPeter Xu
Introduce a new global big lock for mon_fdsets. Take it where needed. The monitor_fdset_get_fd() handling is a bit tricky: now we need to call qemu_mutex_unlock() which might pollute errno, so we need to make sure the correct errno be passed up to the callers. To make things simpler, we let monitor_fdset_get_fd() return the -errno directly when error happens, then in qemu_open() we move it back into errno. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180608035511.7439-8-peterx@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-18monitor: remove event_clock_typePeter Xu
Instead, use a dynamic function to detect which clock we'll use. The problem is that the old code will let monitor initialization depend on configure_accelerator() (that's where qtest_enabled() start to take effect). After this change, we don't have such a dependency any more. We just need to make sure configure_accelerator() is called when we start to use it. Now it's only used in monitor_qapi_event_queue() and monitor_qapi_event_handler(), so we're good. Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180608035511.7439-6-peterx@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [monitor_get_event_clock() name and comment tweaked] Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-18monitor: fix comment for monitor_lockPeter Xu
Fix typo in d622cb5879c. Meanwhile move these variables close to each other. monitor_qapi_event_state can be declared static, add that. Reported-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180608035511.7439-5-peterx@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-18monitor: more comments on lock-free elementsPeter Xu
Add some explicit comments for both Readline and cpu_set/cpu_get helpers that they do not need the mon_lock protection. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180608035511.7439-4-peterx@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-18monitor: protect mon->fds with mon_lockPeter Xu
mon->fds were protected by BQL. Now protect it by mon_lock so that it can even be used in monitor iothread. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180608035511.7439-3-peterx@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-18monitor: rename out_lock to mon_lockPeter Xu
The out_lock is protecting a few Monitor fields. In the future the monitor code will start to run in multiple threads. We are going to turn it into a bigger lock to protect not only the out buffer but also most of the rest. Since at it, rearrange the Monitor struct a bit. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180608035511.7439-2-peterx@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-01Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into stagingPeter Maydell
* Linux header upgrade (Peter) * firmware.json definition (Laszlo) * IPMI migration fix (Corey) * QOM improvements (Alexey, Philippe, me) * Memory API cleanups (Jay, me, Tristan, Peter) * WHPX fixes and improvements (Lucian) * Chardev fixes (Marc-André) * IOMMU documentation improvements (Peter) * Coverity fixes (Peter, Philippe) * Include cleanup (Philippe) * -clock deprecation (Thomas) * Disable -sandbox unless CONFIG_SECCOMP (Yi Min Zhao) * Configurability improvements (me) # gpg: Signature made Fri 01 Jun 2018 17:42:13 BST # gpg: using RSA key BFFBD25F78C7AE83 # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * remotes/bonzini/tags/for-upstream: (56 commits) hw: make virtio devices configurable via default-configs/ hw: allow compiling out SCSI memory: Make operations using MemoryRegionIoeventfd struct pass by pointer. char: Remove unwanted crlf conversion qdev: Remove DeviceClass::init() and ::exit() qdev: Simplify the SysBusDeviceClass::init path hw/i2c: Use DeviceClass::realize instead of I2CSlaveClass::init hw/i2c/smbus: Use DeviceClass::realize instead of SMBusDeviceClass::init target/i386/kvm.c: Remove compatibility shim for KVM_HINTS_REALTIME Update Linux headers to 4.17-rc6 target/i386/kvm.c: Handle renaming of KVM_HINTS_DEDICATED scripts/update-linux-headers: Handle kernel license no longer being one file scripts/update-linux-headers: Handle __aligned_u64 virtio-gpu-3d: Define VIRTIO_GPU_CAPSET_VIRGL2 elsewhere gdbstub: Prevent fd leakage docs/interop: add "firmware.json" ipmi: Use proper struct reference for KCS vmstate vmstate: Add a VSTRUCT type tcg: remove softfloat from --disable-tcg builds qemu-options: Mark the non-functional -clock option as deprecated ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-06-01hw: Do not include "sysemu/blockdev.h" if it is not necessaryPhilippe Mathieu-Daudé
Remove those unneeded includes to speed up the compilation process a little bit. Code change produced with: $ git grep '#include "sysemu/blockdev.h"' | \ cut -d: -f-1 | \ xargs egrep -L "(BlockInterfaceType|DriveInfo|drive_get|blk_legacy_dinfo|blockdev_mark_auto_del)" | \ xargs sed -i.bak '/#include "sysemu\/blockdev.h"/d' Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20180528232719.4721-15-f4bug@amsat.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-05-30qapi: introduce new cmd option "allow-preconfig"Igor Mammedov
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>
2018-05-30hmp: disable monitor in preconfig stateIgor Mammedov
Ban it for now, if someone would need it to work early, one would have to implement checks if HMP command is valid at preconfig state. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <1525423069-61903-5-git-send-email-imammedo@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-05-04qobject: Modify qobject_ref() to return objMarc-André Lureau
For convenience and clarity, make it possible to call qobject_ref() at the time when the reference is associated with a variable, or argument, by making qobject_ref() return the same pointer as given. Use that to simplify the callers. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180419150145.24795-5-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [Useless change to qobject_ref_impl() dropped, commit message improved slightly] Signed-off-by: Markus Armbruster <armbru@redhat.com>