Re: [PATCH 1/4] plugins: fix optimization in plugin_gen_disable_mem_helpers

[Aaron Lindsay]

On Jan 08 11:47, Emilio Cota wrote:
> We were mistakenly checking tcg_ctx->plugin_insn as a canary to know
> whether the TB had emitted helpers that might have accessed memory.
> 
> The problem is that tcg_ctx->plugin_insn gets updated on every
> instruction in the TB, which results in us wrongly performing the
> optimization (i.e. not clearing cpu->plugin_mem_cbs) way too often,
> since it's not rare that the last instruction in the TB doesn't
> use helpers.
> 
> Fix it by tracking a per-TB canary.
> 
> While at it, expand documentation.
> 
> Related: #1381
> 
> Signed-off-by: Emilio Cota <cota@braap.org>
> ---
>  accel/tcg/plugin-gen.c | 26 ++++++++++++++++++--------
>  include/qemu/plugin.h  |  7 +++++++
>  2 files changed, 25 insertions(+), 8 deletions(-)

Tested-by: Aaron Lindsay <aaron@os.amperecomputing.com>