Fix compiler warnings. The warnings can result in a broken build.
This patch fixes warnings such as:

In file included from /usr/include/glib-2.0/glib.h:111,
                 from ../tests/plugin/syscall.c:13:
../tests/plugin/syscall.c: In function ‘print_entry’:
/usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: ‘out’ may be
       used uninitialized in this function [-Werror=maybe-uninitialized]
   g_free (*pp);
   ^~~~~~~~~~~~
../tests/plugin/syscall.c:82:23: note: ‘out’ was declared here
     g_autofree gchar *out;
                       ^~~
In file included from /usr/include/glib-2.0/glib.h:111,
                 from ../tests/plugin/syscall.c:13:
../tests/plugin/syscall.c: In function ‘vcpu_syscall_ret’:
/usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: ‘out’ may be
        used uninitialized in this function [-Werror=maybe-uninitialized]
   g_free (*pp);
   ^~~~~~~~~~~~
../tests/plugin/syscall.c:73:27: note: ‘out’ was declared here
         g_autofree gchar *out;
                           ^~~
cc1: all warnings being treated as errors

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20211128011551.2115468-1-juro.bystricky@intel.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211129140932.4115115-9-alex.bennee@linaro.org>

This is mostly a convenience feature for identifying frontends that do
multiple repeat loads so I can test changes to the instruction
tracking interface.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20211026102234.3961636-20-alex.bennee@linaro.org>

Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210730135817.17816-13-ma.mandourr@gmail.com>

This commit makes the plugin adhere to the new plugins arg-passing
scheme by expecting full-form boolean args instead of short-form
booleans. This necessitates that we introduce a new argument, here
"track", to accept "r", "w", or "rw".

Also, it makes arguments not positional and we only care about the last
value specified for a certain argument.

callback/inline args are now supplied separately as bool arguments so
that both can be enabled individually.

Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210730135817.17816-12-ma.mandourr@gmail.com>

Made argument "inline" not positional, this has two benefits. First is
that we adhere to how QEMU passes args generally, by taking the last
value of an argument and drop the others. And the second is that this
sets up a framework for potentially adding new args easily.

Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210730135817.17816-11-ma.mandourr@gmail.com>
[AJB: fix check-tcg tests calling arg=inline]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210730135817.17816-10-ma.mandourr@gmail.com>

Added a table-like output which contains the total number of calls
for each used syscall along with the number of errors that occurred.

Per-call tracing is still available through supplying the argument
``print`` to the plugin.

Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210519032409.3041-1-ma.mandourr@gmail.com>
Message-Id: <20210520174303.12310-9-alex.bennee@linaro.org>

This commit adds a new syscalls plugin that displays the syscalls
as they are executed and returned. This plugin outputs the number
of the syscall as well as the syscall return value.

Works in *-user only.

Essentially, this commit restores:

  https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg00846.html



by using the new QEMU plugin API.

Signed-off-by: Matthias Weckbecker <matthias@weckbecker.name>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200812115816.4454-1-matthias@weckbecker.name>
Message-Id: <20210312172821.31647-2-alex.bennee@linaro.org>

This is going to be useful for acceptance tests that check both types
are being called the same number of times, especially when icount is
enabled.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210213130325.14781-23-alex.bennee@linaro.org>

A duplicate insn is one that is appears to be executed twice in a row.
This is currently possible due to -icount and cpu_io_recompile()
causing a re-translation of a block. On it's own this won't trigger
any tests though.

The heuristics that the plugin use can't deal with the x86 rep
instruction which (validly) will look like executing the same
instruction several times. To avoid problems later we tweak the rules
for x86 to run the "inline" version of the plugin. This also has the
advantage of increasing coverage of the plugin code (see bugfix in
previous commit).

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-15-alex.bennee@linaro.org>

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201001163429.1348-3-luoyonggang@gmail.com>
Message-Id: <20201007160038.26953-21-alex.bennee@linaro.org>

We have an exploding complexity problem in the testing so lets just
move the more involved plugins into contrib. tests/plugins still exist
for the basic plugins that exercise the API. We restore the old
pre-meson style Makefile for contrib as it also doubles as a guide for
out-of-tree plugin builds.

While we are at it add some examples to the documentation and a
specific plugins build target.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200909112742.25730-11-alex.bennee@linaro.org>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

While there isn't any easy way to make the inline counts thread safe
we can ensure the callback based ones are. While we are at it we can
reduce introduce a new option ("idle") to dump a report of the current
bb and insn count each time a vCPU enters the idle state.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Robert Foley <robert.foley@linaro.org>
Cc: Dave Bort <dbort@dbort.com>

Message-Id: <20200713200415.26214-8-alex.bennee@linaro.org>

Not all compilers support the -Wpsabi (clang-9 in my case). To handle
this gracefully we pare back the shared build machinery so the
Makefile is relatively "standalone". We still take advantage of
config-host.mak as configure has done a bunch of probing for us but
that is it.

Fixes: bac8d222
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200713200415.26214-6-alex.bennee@linaro.org>

On aarch64, gcc 9.3 is generating

qemu/exec.c: In function ‘address_space_translate_iommu’:
qemu/exec.c:431:28: note: parameter passing for argument of type \
  ‘MemTxAttrs’ {aka ‘struct MemTxAttrs’} changed in GCC 9.1

and many other repetitions.  This structure, and the functions
amongst which it is passed, are not part of a QEMU public API.
Therefore we do not care how the compiler passes the argument,
so long as the compiler is self-consistent.

The only portion of QEMU which does have a public api, and so
must have a stable abi, is "qemu/plugin.h".  We test this by
forcing -Wpsabi in tests/plugin/Makefile.

Buglink: https://bugs.launchpad.net/qemu/+bug/1881552


Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200617201309.1640952-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

When we make changes to the TCG we sometimes cause regressions that
are deep into the execution cycle of the guest. Debugging this often
requires comparing large volumes of trace information to figure out
where behaviour has diverged.

The lockstep plugin utilises a shared socket so two QEMU's running
with the plugin will write their current execution position and wait
to receive the position of their partner process. When execution
diverges the plugins output where they were and the previous few
blocks before unloading themselves and letting execution continue.

Originally I planned for this to be most useful with -icount but it
turns out you can get divergence pretty quickly due to asynchronous
qemu_cpu_kick_rr_cpus() events causing one side to eventually run into
a short block a few cycles before the other side. For this reason I've
added a bit of tracking and I think the divergence reporting could be
finessed to report only if we really start to diverge in execution.

An example run would be:

  qemu-system-sparc -monitor none -parallel none -net none \
    -M SS-20 -m 256 -kernel day11/zImage.elf \
    -plugin ./tests/plugin/liblockstep.so,arg=lockstep-sparc.sock \
    -d plugin,nochain

with an identical command in another window in the same working
directory.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Robert Foley <robert.foley@linaro.org>
Tested-by: Robert Foley <robert.foley@linaro.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20200610155509.12850-3-alex.bennee@linaro.org>

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200605154929.26910-4-alex.bennee@linaro.org>

TCG plugins are responsible for their own memory usage and although
the plugin_exit is tied to the end of execution in this case it is
still poor practice. Ensure we delete the hash table and related data
when we are done to be a good plugin citizen.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Robert Foley <robert.foley@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Message-Id: <20200225124710.14152-16-alex.bennee@linaro.org>

According to the glibc function requirements, we need initialise
 the variable. Otherwise there will be compilation warnings:

glib-autocleanups.h:28:3: warning: ‘out’ may be
used uninitialized in this function [-Wmaybe-uninitialized]
   g_free (*pp);
   ^~~~~~~~~~~~

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200206093238.203984-1-kuhn.chenqun@huawei.com>
[AJB: uses Thomas's single line allocation]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200225124710.14152-13-alex.bennee@linaro.org>

This is a very simple versioning API which allows the plugin
infrastructure to check the API a plugin was built against. We also
expose a min/cur API version to the plugin via the info block in case
it wants to avoid using old deprecated APIs in the future.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Robert Foley <robert.foley@linaro.org>

This plugin gives a summary of access patterns grouped by "pages" and
showing read/write patterns by vCPUS.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

This gives a break down of instruction classes and individual
instruction types.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

This is a simple plugin to track which translation blocks are call
most often. As we don't have a view of the internals of TCG we can
only work by the address of the start of the block so we also need to
tracks how often the address is translated.

As there will be multiple blocks starting at the same address. We can
try and work around this by futzing the value to feed to the hash with
the insn count.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Pass arguments with -plugin=libfoo.so,arg=bar,arg=baz

Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>