Commit Graph

17 Commits

Author SHA1 Message Date
Markus Armbruster
20076f4a8c monitor: Use GString instead of QString for output buffer
GString has a richer set of string operations than QString.  It should
be preferred to QString except where we need a QObject or reference
counting.  We don't here.  Switch to GString, and put its richer
interface to use.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-3-armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-12-19 10:38:35 +01:00
Kevin Wolf
357bda9590 monitor: Fix order in monitor_cleanup()
We can only destroy Monitor objects after we're sure that they are not
in use by the dispatcher coroutine any more. This fixes crashes like the
following where we tried to destroy a monitor mutex while the dispatcher
coroutine still holds it:

 (gdb) bt
 #0  0x00007fe541cf4bc5 in raise () at /lib64/libc.so.6
 #1  0x00007fe541cdd8a4 in abort () at /lib64/libc.so.6
 #2  0x000055c24e965327 in error_exit (err=16, msg=0x55c24eead3a0 <__func__.33> "qemu_mutex_destroy") at ../util/qemu-thread-posix.c:37
 #3  0x000055c24e9654c3 in qemu_mutex_destroy (mutex=0x55c25133e0f0) at ../util/qemu-thread-posix.c:70
 #4  0x000055c24e7cfaf1 in monitor_data_destroy_qmp (mon=0x55c25133dfd0) at ../monitor/qmp.c:439
 #5  0x000055c24e7d23bc in monitor_data_destroy (mon=0x55c25133dfd0) at ../monitor/monitor.c:615
 #6  0x000055c24e7d253a in monitor_cleanup () at ../monitor/monitor.c:644
 #7  0x000055c24e6cb002 in qemu_cleanup () at ../softmmu/vl.c:4549
 #8  0x000055c24e0d259b in main (argc=24, argv=0x7ffff66b0d58, envp=0x7ffff66b0e20) at ../softmmu/main.c:51

Reported-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201013125027.41003-1-kwolf@redhat.com>
Tested-by: Ben Widawsky <ben.widawsky@intel.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-15 16:06:28 +02:00
Kevin Wolf
9ce44e2ce2 qmp: Move dispatcher to a coroutine
This moves the QMP dispatcher to a coroutine and runs all QMP command
handlers that declare 'coroutine': true in coroutine context so they
can avoid blocking the main loop while doing I/O or waiting for other
events.

For commands that are not declared safe to run in a coroutine, the
dispatcher drops out of coroutine context by calling the QMP command
handler from a bottom half.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201005155855.256490-10-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:20 +02:00
Kevin Wolf
e69ee454b5 monitor: Make current monitor a per-coroutine property
This way, a monitor command handler will still be able to access the
current monitor, but when it yields, all other code code will correctly
get NULL from monitor_cur().

This uses a hash table to map the coroutine pointer to the current
monitor of that coroutine.  Outside of coroutine context, we associate
the current monitor with the leader coroutine of the current thread.

Approaches to implement some form of coroutine local storage directly in
the coroutine core code have been considered and discarded because they
didn't end up being much more generic than the hash table and their
performance impact on coroutines not using coroutine local storage was
unclear. As the block layer uses a coroutine per I/O request, this is a
fast path and we have to be careful. It's safest to just stay out of
this path with code only used by the monitor.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20201005155855.256490-8-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:19 +02:00
Kevin Wolf
947e47448d monitor: Use getter/setter functions for cur_mon
cur_mon really needs to be coroutine-local as soon as we move monitor
command handlers to coroutines and let them yield. As a first step, just
remove all direct accesses to cur_mon so that we can implement this in
the getter function later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201005155855.256490-4-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:19 +02:00
Stefan Hajnoczi
d73415a315 qemu/atomic.h: rename atomic_ to qatomic_
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-09-23 16:07:44 +01:00
Markus Armbruster
b11a093c60 qapi: Smooth another visitor error checking pattern
Convert

    visit_type_FOO(v, ..., &ptr, &err);
    ...
    if (err) {
        ...
    }

to

    visit_type_FOO(v, ..., &ptr, errp);
    ...
    if (!ptr) {
        ...
    }

for functions that set @ptr to non-null / null on success / error.

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-40-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
David Hildenbrand
722a3c783e virtio-pci: Send qapi events when the virtio-mem size changes
Let's register the notifier and trigger the qapi event with the right
device id.

MEMORY_DEVICE_SIZE_CHANGE is similar to BALLOON_CHANGE, however on a
memory device level.

Don't unregister the notifier (we neither have finalize() nor unrealize()
for VirtIOPCIProxy, so it's not that simple to do it) - both devices are
expected to vanish at the same time.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200626072248.78761-18-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-07-03 07:57:04 -04:00
Kevin Wolf
a2f411c467 monitor: Add allow_hmp parameter to monitor_init()
Add a new parameter allow_hmp to monitor_init() so that the storage
daemon can disable HMP.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-20-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-06 17:21:28 +01:00
Kevin Wolf
8e9119a807 hmp: Fail gracefully if chardev is already in use
Trying to attach a HMP monitor to a chardev that is already in use
results in a crash because monitor_init_hmp() passes &error_abort to
qemu_chr_fe_init():

$ ./x86_64-softmmu/qemu-system-x86_64 --chardev stdio,id=foo --mon foo --mon foo
QEMU 4.2.50 monitor - type 'help' for more information
(qemu) Unexpected error in qemu_chr_fe_init() at chardev/char-fe.c:220:
qemu-system-x86_64: --mon foo: Device 'foo' is in use
Abgebrochen (Speicherabzug geschrieben)

Fix this by allowing monitor_init_hmp() to return an error and passing
any error in qemu_chr_fe_init() to its caller instead of aborting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-19-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-06 17:21:28 +01:00
Kevin Wolf
f27a9bb3e9 qmp: Fail gracefully if chardev is already in use
Trying to attach a QMP monitor to a chardev that is already in use
results in a crash because monitor_init_qmp() passes &error_abort to
qemu_chr_fe_init():

$ ./x86_64-softmmu/qemu-system-x86_64 --chardev stdio,id=foo --mon foo,mode=control --mon foo,mode=control
Unexpected error in qemu_chr_fe_init() at chardev/char-fe.c:220:
qemu-system-x86_64: --mon foo,mode=control: Device 'foo' is in use
Abgebrochen (Speicherabzug geschrieben)

Fix this by allowing monitor_init_qmp() to return an error and passing
any error in qemu_chr_fe_init() to its caller instead of aborting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-18-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-06 17:21:28 +01:00
Kevin Wolf
f2098725aa monitor: Create QAPIfied monitor_init()
This adds a new QAPI-based monitor_init() function. The existing
monitor_init_opts() is rewritten to simply put its QemuOpts parameter
into a visitor and pass the resulting QAPI object to monitor_init().

This will cause some change in those error messages for the monitor
options in the system emulator that are now generated by the visitor
rather than explicitly checked in monitor_init_opts().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-17-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-06 17:21:28 +01:00
Kevin Wolf
c3e9555182 monitor: Move monitor option parsing to monitor/monitor.c
Both the system emulators and tools with QMP support (specifically, the
planned storage daemon) will need to parse monitor options, so move that
code to monitor/monitor.c, which can be linked into binaries that aren't
a system emulator.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200129102239.31435-2-kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-02-17 13:47:48 +01:00
Markus Armbruster
d5938f29fe Clean up inclusion of sysemu/sysemu.h
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

Almost a third of its inclusions are actually superfluous.  Delete
them.  Downgrade two more to qapi/qapi-types-run-state.h, and move one
from char/serial.h to char/serial.c.

hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and
stubs/semihost.c define variables declared in sysemu/sysemu.h without
including it.  The compiler is cool with that, but include it anyway.

This doesn't reduce actual use much, as it's still included into
widely included headers.  The next commit will tackle that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-27-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2019-08-16 13:31:53 +02:00
Kevin Wolf
fbfc29e3bf monitor: Replace monitor_init() with monitor_init_{hmp, qmp}()
Most callers know which monitor type they want to have. Instead of
calling monitor_init() with flags that can describe both types of
monitors, make monitor_init_{hmp,qmp}() public interfaces that take
specific bools instead of flags and call these functions directly.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-15-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-18 08:14:17 +02:00
Kevin Wolf
920824165c monitor: Split Monitor.flags into separate bools
Monitor.flags contains three different flags: One to distinguish HMP
from QMP; one specific to HMP (MONITOR_USE_READLINE) that is ignored
with QMP; and another one specific to QMP (MONITOR_USE_PRETTY) that is
ignored with HMP.

Split the flags field into three bools and move them to the right
subclass. Flags are still in use for the monitor_init() interface.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-14-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-18 08:14:17 +02:00
Kevin Wolf
1d95db745b monitor: Split out monitor/monitor.c
Move the monitor core infrastructure from monitor/misc.c to
monitor/monitor.c. This is code that can be shared for all targets, so
compile it only once.

What remains in monitor/misc.c after this patch is mostly monitor
command implementations (which could move to hmp-cmds.c or qmp-cmds.c
later) and code that requires a system emulator or is even
target-dependent (including HMP command completion code).

The amount of function and particularly extern variables in
monitor_int.h is probably a bit larger than it needs to be, but this way
no non-trivial code modifications are needed. The interfaces between all
monitor parts can be cleaned up later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-13-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Superfluous #include dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-18 08:14:17 +02:00