qemu/plugins, branch master

plugins: fix race condition with scoreboards

2024-08-16T13:13:07Z

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 Message-Id: <20240812220748.95167-2-pierrick.bouvier@linaro.org> [AJB: tweak var position to meet coding style] Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Message-Id: <20240813202329.1237572-22-alex.bennee@linaro.org>

buildsys: Fix building without plugins on Darwin

2024-08-16T13:04:19Z

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: ... 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 Acked-by: Richard Henderson Message-Id: <20240813112457.92560-1-philmd@linaro.org> Signed-off-by: Alex Bennée Message-Id: <20240813202329.1237572-9-alex.bennee@linaro.org>

plugin/loader: handle basic help query

2024-07-30T10:44:21Z

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 Message-Id: <20240729144414.830369-15-alex.bennee@linaro.org>

accel/tcg: Move qemu_plugin_vcpu_init__async() to plugins/

2024-07-05T11:34:55Z

Calling qemu_plugin_vcpu_init__async() on the vCPU thread is a detail of plugins, not relevant to TCG vCPU management. Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Reviewed-by: Pierrick Bouvier Message-Id: <20240606124010.2460-4-philmd@linaro.org> Signed-off-by: Alex Bennée Message-Id: <20240705084047.857176-30-alex.bennee@linaro.org>

plugins: Ensure vCPU index is assigned in init/exit hooks

2024-07-05T11:34:48Z

Since vCPUs are hashed by their index, this index can't be uninitialized (UNASSIGNED_CPU_INDEX). Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Pierrick Bouvier Message-Id: <20240606124010.2460-2-philmd@linaro.org> Signed-off-by: Alex Bennée Message-Id: <20240705084047.857176-28-alex.bennee@linaro.org>

meson: merge plugin_ldflags into emulator_link_args

2024-07-03T16:41:25Z

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

plugins: fix inject_mem_cb rw masking

2024-06-24T09:15:16Z

These are not booleans, but masks. Issue found by Richard Henderson. Fixes: f86fd4d8721 ("plugins: distinct types for callbacks") Signed-off-by: Richard Henderson Signed-off-by: Pierrick Bouvier Message-Id: <20240612195147.93121-3-pierrick.bouvier@linaro.org> Signed-off-by: Alex Bennée Message-Id: <20240620152220.2192768-12-alex.bennee@linaro.org>

plugins: add migration blocker

2024-06-24T09:15:10Z

If the plugin in controlling time there is some state that might be missing from the plugin tracking it. Migration is unlikely to work in this case so lets put a migration blocker in to let the user know if they try. Suggested-by: Dr. David Alan Gilbert Reviewed-by: Thomas Huth Reviewed-by: Richard Henderson Signed-off-by: Alex Bennée Message-Id: <20240620152220.2192768-10-alex.bennee@linaro.org>

plugins: add time control API

2024-06-24T09:15:04Z

Expose the ability to control time through the plugin API. Only one plugin can control time so it has to request control when loaded. There are probably more corner cases to catch here. Signed-off-by: Pierrick Bouvier [AJB: tweaked user-mode handling, merged QEMU_PLUGIN_API fix] Message-Id: <20240530220610.1245424-6-pierrick.bouvier@linaro.org> Signed-off-by: Alex Bennée Message-Id: <20240620152220.2192768-9-alex.bennee@linaro.org>

plugins: Ensure register handles are not NULL

2024-06-24T09:14:22Z

Ensure register handles are not NULL so that a plugin can assume NULL is invalid as a register handle. Signed-off-by: Akihiko Odaki Reviewed-by: Pierrick Bouvier Message-Id: <20240229-null-v1-1-e716501d981e@daynix.com> Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Message-Id: <20240620152220.2192768-4-alex.bennee@linaro.org>