accel/tcg: allow plugin instrumentation to be disable via cflags

When icount is enabled and we recompile an MMIO access we end up
double counting the instruction execution. To avoid this we introduc

accel/tcg: allow plugin instrumentation to be disable via cflags

When icount is enabled and we recompile an MMIO access we end up
double counting the instruction execution. To avoid this we introduce
the CF_MEMI cflag which only allows memory instrumentation for the
next TB (which won't yet have been counted). As this is part of the
hashed compile flags we will only execute the generated TB while
coming out of a cpu_io_recompile.

While we are at it delete the old TODO. We might as well keep the
translation handy as it's likely you will repeatedly hit it on each
MMIO access.

Reported-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-21-alex.bennee@linaro.org>

show more ...

accel/tcg/plugin-gen: fix the call signature for inline callbacks

A recent change to the handling of constants in TCG changed the
pattern of ops emitted for a constant add. We no longer emit a mov a

accel/tcg/plugin-gen: fix the call signature for inline callbacks

A recent change to the handling of constants in TCG changed the
pattern of ops emitted for a constant add. We no longer emit a mov and
the constant can be applied directly to the TCG_op_add arguments. This
was causing SEGVs when running the insn plugin with arg=inline. Fix
this by updating copy_add_i64 to do the right thing while also adding
a comment at the top of the append section as an aide memoir if
something like this happens again.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Cc: Emilio G. Cota <cota@braap.org>
Message-Id: <20210213130325.14781-10-alex.bennee@linaro.org>

show more ...

Merge remote-tracking branch 'remotes/rth-gitlab/tags/pull-tcg-20210113' into staging

Improvements to tcg constant handling.
Force utf8 for decodetree.

# gpg: Signature made Thu 14 Jan 2021 02:15:4

Merge remote-tracking branch 'remotes/rth-gitlab/tags/pull-tcg-20210113' into staging

Improvements to tcg constant handling.
Force utf8 for decodetree.

# gpg: Signature made Thu 14 Jan 2021 02:15:42 GMT
# gpg: using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg: issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A 05C0 64DF 38E8 AF7E 215F

* remotes/rth-gitlab/tags/pull-tcg-20210113: (24 commits)
decodetree: Open files with encoding='utf-8'
tcg/aarch64: Use tcg_constant_vec with tcg vec expanders
tcg/ppc: Use tcg_constant_vec with tcg vec expanders
tcg: Remove tcg_gen_dup{8,16,32,64}i_vec
tcg/i386: Use tcg_constant_vec with tcg vec expanders
tcg: Add tcg_reg_alloc_dup2
tcg: Remove movi and dupi opcodes
tcg/tci: Add special tci_movi_{i32,i64} opcodes
tcg: Use tcg_constant_{i32,i64,vec} with gvec expanders
tcg: Use tcg_constant_{i32,i64} with tcg plugins
tcg: Use tcg_constant_{i32,i64} with tcg int expanders
tcg: Use tcg_constant_i32 with icount expander
tcg: Convert tcg_gen_dupi_vec to TCG_CONST
tcg/optimize: Use tcg_constant_internal with constant folding
tcg/optimize: Adjust TempOptInfo allocation
tcg/optimize: Improve find_better_copy
tcg: Introduce TYPE_CONST temporaries
tcg: Expand TempOptInfo to 64-bits
tcg: Rename struct tcg_temp_info to TempOptInfo
tcg: Expand TCGTemp.val to 64-bits
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

tcg: Use tcg_constant_{i32,i64} with tcg plugins

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Merge remote-tracking branch 'remotes/stsquad/tags/pull-tcg-plugins-281019-4' into staging

TCG Plugins initial implementation

- use --enable-plugins @ configure
- low impact introspection (-plu

Merge remote-tracking branch 'remotes/stsquad/tags/pull-tcg-plugins-281019-4' into staging

TCG Plugins initial implementation

- use --enable-plugins @ configure
- low impact introspection (-plugin empty.so to measure overhead)
- plugins cannot alter guest state
- example plugins included in source tree (tests/plugins)
- -d plugin to enable plugin output in logs
- check-tcg runs extra tests when plugins enabled
- documentation in docs/devel/plugins.rst

# gpg: Signature made Mon 28 Oct 2019 15:13:23 GMT
# gpg: using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8 DF35 FBD0 DB09 5A9E 2A44

* remotes/stsquad/tags/pull-tcg-plugins-281019-4: (57 commits)
travis.yml: enable linux-gcc-debug-tcg cache
MAINTAINERS: add me for the TCG plugins code
scripts/checkpatch.pl: don't complain about (foo, /* empty */)
.travis.yml: add --enable-plugins tests
include/exec: wrap cpu_ldst.h in CONFIG_TCG
accel/stubs: reduce headers from tcg-stub
tests/plugin: add hotpages to analyse memory access patterns
tests/plugin: add instruction execution breakdown
tests/plugin: add a hotblocks plugin
tests/tcg: enable plugin testing
tests/tcg: drop test-i386-fprem from TESTS when not SLOW
tests/tcg: move "virtual" tests to EXTRA_TESTS
tests/tcg: set QEMU_OPTS for all cris runs
tests/tcg/Makefile.target: fix path to config-host.mak
tests/plugin: add sample plugins
linux-user: support -plugin option
vl: support -plugin option
plugin: add qemu_plugin_outs helper
plugin: add qemu_plugin_insn_disas helper
plugin: expand the plugin_init function to include an info block
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

plugin-gen: add module for TCG-related code

We first inject empty instrumentation from translator_loop.
After translation, we go through the plugins to see what
they want to register for, filling in

plugin-gen: add module for TCG-related code

We first inject empty instrumentation from translator_loop.
After translation, we go through the plugins to see what
they want to register for, filling in the empty instrumentation.
If if turns out that some instrumentation remains unused, we
remove it.

This approach supports the following features:

- Inlining TCG code for simple operations. Note that we do not
export TCG ops to plugins. Instead, we give them a C API to
insert inlined ops. So far we only support adding an immediate
to a u64, e.g. to count events.

- "Direct" callbacks. These are callbacks that do not go via
a helper. Instead, the helper is defined at run-time, so that
the plugin code is directly called from TCG. This makes direct
callbacks as efficient as possible; they are therefore used
for very frequent events, e.g. memory callbacks.

- Passing the host address to memory callbacks. Most of this
is implemented in a later patch though.

- Instrumentation of memory accesses performed from helpers.
See the corresponding comment, as well as a later patch.

Signed-off-by: Emilio G. Cota <cota@braap.org>
[AJB: add alloc_tcg_plugin_context, use glib, rm hwaddr]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

show more ...