On aarch64, gcc 9.3 is generating
qemu/exec.c: In function ‘address_space_translate_iommu’:
qemu/exec.c:431:28: note: parameter passing for argument of type \
‘MemTxAttrs’ {aka ‘struct MemTxAttrs’} changed in GCC 9.1
and many other repetitions. This structure, and the functions
amongst which it is passed, are not part of a QEMU public API.
Therefore we do not care how the compiler passes the argument,
so long as the compiler is self-consistent.
The only portion of QEMU which does have a public api, and so
must have a stable abi, is "qemu/plugin.h". We test this by
forcing -Wpsabi in tests/plugin/Makefile.
Buglink: https://bugs.launchpad.net/qemu/+bug/1881552
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200617201309.1640952-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When we make changes to the TCG we sometimes cause regressions that
are deep into the execution cycle of the guest. Debugging this often
requires comparing large volumes of trace information to figure out
where behaviour has diverged.
The lockstep plugin utilises a shared socket so two QEMU's running
with the plugin will write their current execution position and wait
to receive the position of their partner process. When execution
diverges the plugins output where they were and the previous few
blocks before unloading themselves and letting execution continue.
Originally I planned for this to be most useful with -icount but it
turns out you can get divergence pretty quickly due to asynchronous
qemu_cpu_kick_rr_cpus() events causing one side to eventually run into
a short block a few cycles before the other side. For this reason I've
added a bit of tracking and I think the divergence reporting could be
finessed to report only if we really start to diverge in execution.
An example run would be:
qemu-system-sparc -monitor none -parallel none -net none \
-M SS-20 -m 256 -kernel day11/zImage.elf \
-plugin ./tests/plugin/liblockstep.so,arg=lockstep-sparc.sock \
-d plugin,nochain
with an identical command in another window in the same working
directory.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Robert Foley <robert.foley@linaro.org>
Tested-by: Robert Foley <robert.foley@linaro.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20200610155509.12850-3-alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200605154929.26910-4-alex.bennee@linaro.org>
TCG plugins are responsible for their own memory usage and although
the plugin_exit is tied to the end of execution in this case it is
still poor practice. Ensure we delete the hash table and related data
when we are done to be a good plugin citizen.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Robert Foley <robert.foley@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200225124710.14152-16-alex.bennee@linaro.org>
According to the glibc function requirements, we need initialise
the variable. Otherwise there will be compilation warnings:
glib-autocleanups.h:28:3: warning: ‘out’ may be
used uninitialized in this function [-Wmaybe-uninitialized]
g_free (*pp);
^~~~~~~~~~~~
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200206093238.203984-1-kuhn.chenqun@huawei.com>
[AJB: uses Thomas's single line allocation]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200225124710.14152-13-alex.bennee@linaro.org>
This is a very simple versioning API which allows the plugin
infrastructure to check the API a plugin was built against. We also
expose a min/cur API version to the plugin via the info block in case
it wants to avoid using old deprecated APIs in the future.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Robert Foley <robert.foley@linaro.org>
This plugin gives a summary of access patterns grouped by "pages" and
showing read/write patterns by vCPUS.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This gives a break down of instruction classes and individual
instruction types.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This is a simple plugin to track which translation blocks are call
most often. As we don't have a view of the internals of TCG we can
only work by the address of the start of the block so we also need to
tracks how often the address is translated.
As there will be multiple blocks starting at the same address. We can
try and work around this by futzing the value to feed to the hash with
the insn count.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Pass arguments with -plugin=libfoo.so,arg=bar,arg=baz
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
