A deadlock can be created if a new vcpu (a) triggers a scoreboard
reallocation, and another vcpu (b) wants to create a new scoreboard at
the same time.
In this case, (a) holds the plugin lock, and starts an exclusive
section, waiting for (b). But at the same time, (b) is waiting for
plugin lock.
The solution is to drop the lock before entering the exclusive section.
This bug can be easily reproduced by creating a callback for any tb
exec, that allocates a new scoreboard. In this case, as soon as we reach
more than 16 vcpus, the deadlock occurs.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2344
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240812220748.95167-2-pierrick.bouvier@linaro.org>
[AJB: tweak var position to meet coding style]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240813202329.1237572-22-alex.bennee@linaro.org>
Since commit 0082475e26 the plugin symbol list is unconditionally
added to the linker flags, leading to a build failure:
Undefined symbols for architecture arm64:
"_qemu_plugin_entry_code", referenced from:
<initial-undefines>
...
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.
Fix by restricting the whole meson file to the --enable-plugins
configure argument.
Fixes: 0082475e26 ("meson: merge plugin_ldflags into emulator_link_args")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2476
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240813112457.92560-1-philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240813202329.1237572-9-alex.bennee@linaro.org>
As the list of options isn't fixed we do all the parsing by hand.
Without any named arguments we automatically fill the "file" option
with the value give so check if it is requesting help and dump some
basic usage text.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240729144414.830369-15-alex.bennee@linaro.org>
These serve the same purpose, except plugin_ldflags ends up in the linker
command line in a more roundabout way (through specific_ss). Simplify.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Do not pass around a boolean between multiple structures,
just read it from the TranslationBlock in the TCGContext.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Use the bytes that we record for the entire TB, rather than
a per-insn GByteArray. Record the length of the insn in
plugin_gen_insn_end rather than infering from the length
of the array.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Instead of returning a host pointer, copy the data into
storage provided by the caller.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We have qemu_plugin_dyn_cb.type to differentiate the various
callback types, so we do not need to keep them in separate queues.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Since we no longer emit plugin helpers during the initial code
translation phase, we don't need to specially mark plugin helpers.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
By having the qemu_plugin_cb_flags be recorded in the TCGHelperInfo,
we no longer need to distinguish PLUGIN_CB_REGULAR from
PLUGIN_CB_REGULAR_R, so place all TB callbacks in the same queue.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The out-of-line function pointer is mutually exclusive
with inline expansion, so move it into the union.
Wrap the pointer in a structure named 'regular' to match
PLUGIN_CB_REGULAR.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Additionally to the scoreboard, we define a qemu_plugin_u64, which is a
simple struct holding a pointer to a scoreboard, and a given offset.
This allows to have a scoreboard containing structs, without having to
bring offset to operate on a specific field.
Since most of the plugins are simply collecting a sum of per-cpu values,
qemu_plugin_u64 directly support this operation as well.
All inline operations defined later will use a qemu_plugin_u64 as input.
New functions:
- qemu_plugin_u64_add
- qemu_plugin_u64_get
- qemu_plugin_u64_set
- qemu_plugin_u64_sum
New macros:
- qemu_plugin_scoreboard_u64
- qemu_plugin_scoreboard_u64_in_struct
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240304130036.124418-3-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-16-alex.bennee@linaro.org>
We introduce a cpu local storage, automatically managed (and extended)
by QEMU itself. Plugin allocate a scoreboard, and don't have to deal
with how many cpus are launched.
This API will be used by new inline functions but callbacks can benefit
from this as well. This way, they can operate without a global lock for
simple operations.
At any point during execution, any scoreboard will be dimensioned with
at least qemu_plugin_num_vcpus entries.
New functions:
- qemu_plugin_scoreboard_find
- qemu_plugin_scoreboard_free
- qemu_plugin_scoreboard_new
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240304130036.124418-2-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-15-alex.bennee@linaro.org>
We found that vcpu_init_hook was called *after* idle callback.
vcpu_init is called from cpu_realize_fn, while idle/resume cb are called
from qemu_wait_io_event (in vcpu thread).
This change ensures we only call idle and resume cb only once a plugin
was init for a given vcpu.
Next change in the series will run vcpu_init asynchronously, which will
make it run *after* resume callback as well. So we fix this now.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240213094009.150349-4-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-18-alex.bennee@linaro.org>
This commit was created with scripts/clean-includes:
./scripts/clean-includes --git misc net/af-xdp.c plugins/*.c audio/pwaudio.c util/userfaultfd.c
All .c should include qemu/osdep.h first. The script performs three
related cleanups:
* Ensure .c files include qemu/osdep.h first.
* Including it in a .h is redundant, since the .c already includes
it. Drop such inclusions.
* Likewise, including headers qemu/osdep.h includes is redundant.
Drop these, too.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This variable is about the host OS, not the target. It is used a lot
more since the Meson conversion, but the original sin dates back to 2003.
Time to fix it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
