Some analysis greatly benefits, or depends on, information about certain types of dicontinuities such as interrupts. For example, we may need to handle the execution of a new translation block differently if it is not the result of normal program flow but of an interrupt.
Even with the existing interfaces, it is more or less possible to discern these situations, e.g. as done by the cflow plugin. However, this process poses a considerable overhead to the core analysis one may intend to perform. These changes introduce a generic and easy-to-use interface for plugin authors in the form of a callback for discontinuities. Patch 1 defines an enumeration of some trap-related discontinuities including somewhat narrow definitions of the discontinuity evetns and a callback type. Patch 2 defines the callback registration function. Patch 3 adds some hooks for triggering the callbacks. Patch 4 adds an example plugin showcasing the new API. Patches 5 through 6 call the hooks for a selection of architectures, mapping architecture specific events to the three categories defined in patch 1. Future non-RFC patchsets will call these hooks for all architectures (that have some concept of trap or interrupt). Finally, patch 11 supplies a test plugin asserting that the next PC provided to the plugin points to the next instruction executed. Sidenote: I'm likely doing something wrong for one architecture or the other. These patches are untested for most of them. Since v2 (tcg-plugins: add hooks for interrupts, exceptions and traps): - Switched from traps as core concept to more generic discontinuities - Switched from semihosting to hostcall as term for emulated traps - Added enumeration of events and dedicated callback type - Make callback receive event type as well as origin and target PC (as requested by Pierrick Bouvier) - Combined registration functions for different traps into a single one for all types of discontinuities (as requested by Pierrick Bouvier) - Migrated records in example plugin from fully pre-allocated to a scoreboard (as suggested by Pierrick Bouvier) - Handle PSCI calls as hostcall (as pointed out by Peter Maydell) - Added hooks for ARM Cortex M arches (as pointed out by Peter Maydell) - Added hooks for Alpha targets - Added hooks for MIPS targets - Added a plugin for testing some of the interface behaviour Since v1: - Split the one callback into multiple callbacks - Added a target-agnostic definition of the relevant event(s) - Call hooks from architecture-code rather than accel/tcg/cpu-exec.c - Added a plugin showcasing API usage Julian Ganz (11): plugins: add types for callbacks related to certain discontinuities plugins: add API for registering discontinuity callbacks plugins: add hooks for new discontinuity related callbacks contrib/plugins: add plugin showcasing new dicontinuity related API target/alpha: call plugin trap callbacks target/arm: call plugin trap callbacks target/avr: call plugin trap callbacks target/mips: call plugin trap callbacks target/riscv: call plugin trap callbacks target/sparc: call plugin trap callbacks tests: add plugin asserting correctness of discon event's to_pc contrib/plugins/meson.build | 3 +- contrib/plugins/traps.c | 96 +++++++++++++++++++++++++++++ include/qemu/plugin-event.h | 3 + include/qemu/plugin.h | 13 ++++ include/qemu/qemu-plugin.h | 58 +++++++++++++++++ plugins/core.c | 67 ++++++++++++++++++++ target/alpha/helper.c | 12 ++++ target/arm/helper.c | 25 ++++++++ target/arm/tcg/m_helper.c | 18 ++++++ target/avr/helper.c | 3 + target/mips/tcg/sysemu/tlb_helper.c | 11 ++++ target/riscv/cpu_helper.c | 9 +++ target/sparc/int32_helper.c | 7 +++ target/sparc/int64_helper.c | 10 +++ tests/tcg/plugins/discons.c | 95 ++++++++++++++++++++++++++++ tests/tcg/plugins/meson.build | 2 +- 16 files changed, 430 insertions(+), 2 deletions(-) create mode 100644 contrib/plugins/traps.c create mode 100644 tests/tcg/plugins/discons.c -- 2.45.2