[v3,0/3] plugins: add tb convenience functions

Message

Luke Craig Jan. 31, 2025, 9:07 p.m. UTC

This PR extends the plugin API with two functions which allow convenient access
around tbs.

The first, qemu_plugin_tb_size, provides a mechanism for determining the total
size of a translation block.

The second, qemu_plugin_tb_get_insn_by_vaddr, allows users to get a reference
to an instruction by its virtual address rather than just its index.

In response to feedback from Pierrick I have updated the implementation of
qemu_plugin_tb_size.

Additionally, I have added these functions to the insn.c test plugin in
response to Alex's feedback.

Lastly, I'll provide a reply to Alex's feeback (repeated below):

> But the general comment is this is an example of tying the plugin API
> too deeply with the internals of the translator. Why does a plugin need
> to know what is an implementation detail?

Finding the line between implementation detail and relevant to plugins is
challenging, but I submitted this change because I found myself implementing
these functions in plugins. If you'd like for me to enumerate examples where
knowing the tb_size is relevant to analysis I'd be happy to submit some.

The change relevant from v2 and v3 is adding a sign off on the commits (thank you Perrick).

Luke Craig (3):
  plugin: extend API with qemu_plugin_tb_get_insn_by_vaddr
  plugin: extend API with qemu_plugin_tb_size
  plugins: extend insn test for new convenience functions

 include/qemu/qemu-plugin.h | 21 +++++++++++++++++++++
 plugins/api.c              | 20 ++++++++++++++++++++
 tests/tcg/plugins/insn.c   | 10 ++++++++++
 3 files changed, 51 insertions(+)