Without this we can get see loops through cpu_io_recompile,
in which the cpu makes no progress.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Initialize can_do_io to true if this the TB has CF_LAST_IO
and will consist of a single instruction. This avoids a
set to 0 followed immediately by a set to 1.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Simplify translator_io_start by recording the current
known value of can_do_io within DisasContextBase.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The condition checked is loop invariant; check it only once.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
With CF_NOIRQ and without !CF_USE_ICOUNT, the load isn't used.
Avoid emitting it.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
RSx for d regs and e regs now use the same numbering. This makes sure
that mixing d and e registers in an insn test will not overwrite data
between registers.
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-ID: <20230913105326.40832-2-kbastian@mail.uni-paderborn.de>
we would crash if width was 0 for these insns, as tcg_gen_deposit() is
undefined for that case. For TriCore, width = 0 is a mov from the src reg
to the dst reg, so we special case this here.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-ID: <20230828112651.522058-9-kbastian@mail.uni-paderborn.de>
this is not something other ISAs do, so clarify it with a comment.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-ID: <20230828112651.522058-6-kbastian@mail.uni-paderborn.de>
when we reconstructed PSW using psw_read(), we were trying to clear the
cached USB bits out of env->PSW. The mask was wrong and we would clear
PSW.RM as well.
when we write the PSW using psw_write() we update the rounding modes in
env->fp_status for softfloat. The order of bits used by TriCore is not
the one used by softfloat.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-ID: <20230828112651.522058-4-kbastian@mail.uni-paderborn.de>
we don't want to exclude ISA v1.6.2 insns from our tests.
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-Id: <20230828112651.522058-2-kbastian@mail.uni-paderborn.de>
Now that the return path thread is allowed to finish during a paused
migration, we can move the cleanup of the QEMUFiles to the main
migration thread.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-9-farosas@suse.de>
Replace the return path retry logic with finishing and restarting the
thread. This fixes a race when resuming the migration that leads to a
segfault.
Currently when doing postcopy we consider that an IO error on the
return path file could be due to a network intermittency. We then keep
the thread alive but have it do cleanup of the 'from_dst_file' and
wait on the 'postcopy_pause_rp' semaphore. When the user issues a
migrate resume, a new return path is opened and the thread is allowed
to continue.
There's a race condition in the above mechanism. It is possible for
the new return path file to be setup *before* the cleanup code in the
return path thread has had a chance to run, leading to the *new* file
being closed and the pointer set to NULL. When the thread is released
after the resume, it tries to dereference 'from_dst_file' and crashes:
Thread 7 "return path" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffd1dbf700 (LWP 9611)]
0x00005555560e4893 in qemu_file_get_error_obj (f=0x0, errp=0x0) at ../migration/qemu-file.c:154
154 return f->last_error;
(gdb) bt
#0 0x00005555560e4893 in qemu_file_get_error_obj (f=0x0, errp=0x0) at ../migration/qemu-file.c:154
#1 0x00005555560e4983 in qemu_file_get_error (f=0x0) at ../migration/qemu-file.c:206
#2 0x0000555555b9a1df in source_return_path_thread (opaque=0x555556e06000) at ../migration/migration.c:1876
#3 0x000055555602e14f in qemu_thread_start (args=0x55555782e780) at ../util/qemu-thread-posix.c:541
#4 0x00007ffff38d76ea in start_thread (arg=0x7fffd1dbf700) at pthread_create.c:477
#5 0x00007ffff35efa6f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Here's the race (important bit is open_return_path happening before
migration_release_dst_files):
migration | qmp | return path
--------------------------+-----------------------------+---------------------------------
qmp_migrate_pause()
shutdown(ms->to_dst_file)
f->last_error = -EIO
migrate_detect_error()
postcopy_pause()
set_state(PAUSED)
wait(postcopy_pause_sem)
qmp_migrate(resume)
migrate_fd_connect()
resume = state == PAUSED
open_return_path <-- TOO SOON!
set_state(RECOVER)
post(postcopy_pause_sem)
(incoming closes to_src_file)
res = qemu_file_get_error(rp)
migration_release_dst_files()
ms->rp_state.from_dst_file = NULL
post(postcopy_pause_rp_sem)
postcopy_pause_return_path_thread()
wait(postcopy_pause_rp_sem)
rp = ms->rp_state.from_dst_file
goto retry
qemu_file_get_error(rp)
SIGSEGV
-------------------------------------------------------------------------------------------
We can keep the retry logic without having the thread alive and
waiting. The only piece of data used by it is the 'from_dst_file' and
it is only allowed to proceed after a migrate resume is issued and the
semaphore released at migrate_fd_connect().
Move the retry logic to outside the thread by waiting for the thread
to finish before pausing the migration.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-8-farosas@suse.de>
We'll start calling the await_return_path_close_on_source() function
from other parts of the code, so move all of the related checks and
tracepoints into it.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-7-farosas@suse.de>
This file is owned by the return path thread which is already doing
cleanup.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-6-farosas@suse.de>
It's not safe to call qemu_file_shutdown() on the to_dst_file without
first checking for the file's presence under the lock. The cleanup of
this file happens at postcopy_pause() and migrate_fd_cleanup() which
are not necessarily running in the same thread as migrate_fd_cancel().
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-5-farosas@suse.de>
We cannot call qemu_file_shutdown() on the return path file without
taking the file lock. The return path thread could be running it's
cleanup code and have just cleared the from_dst_file pointer.
Checking ms->to_dst_file for errors could also race with
migrate_fd_cleanup() which clears the to_dst_file pointer.
Protect both accesses by taking the file lock.
This was caught by inspection, it should be rare, but the next patches
will start calling this code from other places, so let's do the
correct thing.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-4-farosas@suse.de>
We don't need to set the rp_state.error right after a shutdown because
qemu_file_shutdown() always sets the QEMUFile error, so the return
path thread would have seen it and set the rp error itself.
Setting the error outside of the thread is also racy because the
thread could clear it after we set it.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-3-farosas@suse.de>
We hit intermit CI issue on failing at migration-test over the unit test
preempt/plain:
qemu-system-x86_64: Unable to read from socket: Connection reset by peer
Memory content inconsistency at 5b43000 first_byte = bd last_byte = bc current = 4f hit_edge = 1
**
ERROR:../tests/qtest/migration-test.c:300:check_guests_ram: assertion failed: (bad == 0)
(test program exited with status code -6)
Fabiano debugged into it and found that the preempt thread can quit even
without receiving all the pages, which can cause guest not receiving all
the pages and corrupt the guest memory.
To make sure preempt thread finished receiving all the pages, we can rely
on the page_requested_count being zero because preempt channel will only
receive requested page faults. Note, not all the faulted pages are required
to be sent via the preempt channel/thread; imagine the case when a
requested page is just queued into the background main channel for
migration, the src qemu will just still send it via the background channel.
Here instead of spinning over reading the count, we add a condvar so the
main thread can wait on it if that unusual case happened, without burning
the cpu for no good reason, even if the duration is short; so even if we
spin in this rare case is probably fine. It's just better to not do so.
The condvar is only used when that special case is triggered. Some memory
ordering trick is needed to guarantee it from happening (against the
preempt thread status field), so the main thread will always get a kick
when that triggers correctly.
Closes: https://gitlab.com/qemu-project/qemu/-/issues/1886
Debugged-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230918172822.19052-2-farosas@suse.de>
Python 3 removed `dict.iteritems()` in favor of `dict.items()`. This
means the script currently doesn't work on Python 3.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-15-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
In my work to refactor simpletrace.py, I noticed that there's no
maintainer of it, and has the status of "odd fixes". I'm using it from
time to time, so I'd like to maintain the script.
I've added myself as reviewer under "Tracing" to be informed of changes
that might affect simpletrace.py.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-14-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
By moving the dynamic argument construction to keyword-arguments,
we can remove all of the specialized handling, and streamline it.
If a tracing method wants to access these, they can define the
kwargs, or ignore it be placing `**kwargs` at the end of the
function's arguments list.
Added deprecation warning to Analyzer class to make users aware
of the Analyzer2 class. No removal date is planned.
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-13-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Moved event processing to the Analyzer class to separate specific analyzer
logic (like caching and function signatures) from the _process function.
This allows for new types of Analyzer-based subclasses without changing
the core code.
Note, that the fn_cache is important for performance in cases where the
analyzer is branching away from the catch-all a lot. The cache has no
measurable performance penalty.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-12-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
To avoid duplicate code depending on input types and to better handle
open/close of log with a context-manager, we move the logic of process into
_process.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-11-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Moved event_mapping and event_id_to_name down one level in the function
call-stack to keep variable instantiation and usage closer (`process`
and `run` has no use of the variables; `read_trace_records` does).
Instead of passing event_mapping and event_id_to_name to the bottom of
the call-stack, we move their use to `read_trace_records`. This
separates responsibility and ownership of the information.
`read_record` now just reads the arguments from the file-object by
knowning the total number of bytes. Parsing it to specific arguments is
moved up to `read_trace_records`.
Special handling of dropped events removed, as they can be handled
by the general code.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-10-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Instead of explicitly calling `begin` and `end`, we can change the class
to use the context-manager paradigm. This is mostly a styling choice,
used in modern Python code. But it also allows for more advanced analyzers
to handle exceptions gracefully in the `__exit__` method (not
demonstrated here).
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-9-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Define `SimpleException` to differentiate our exceptions from generic
exceptions (IOError, etc.). Adapted simpletrace to support this and
output to stderr.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-8-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
A failed call to `read_header` wouldn't be handled the same for the two
different code paths (one path would try to use `None` as a list).
Changed to raise exception to be handled centrally. This also allows for
easier unpacking, as errors has been filtered out.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-7-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The call to `getargspec` was deprecated and in Python 3.11 it has been
removed in favor of `getfullargspec`. `getfullargspec` is compatible
with QEMU's requirement of at least Python version 3.6.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-6-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Readability is subjective, but I've expanded the naming of the variables
and arguments, to help with understanding for new eyes on the code.
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20230926103436.25700-5-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The arguments extracted from `sys.argv` named and unpacked to make it
clear what the arguments are and what they're used for.
The two input files were opened, but never explicitly closed. File usage
changed to use `with` statement to take care of this. At the same time,
ownership of the file-object is moved up to `run` function. Added option
to process to support file-like objects.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-4-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
It wasn't clear where the constants and structs came from, so I added
comments to help.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-3-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
It was unclear what was the supported public interface. I.e. when
refactoring the code, what functions/classes are important to retain.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
Message-id: 20230926103436.25700-2-mads@ynddal.dk
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The marking should be extended transitively to all functions that call
these ones, so that static analysis can be done much more efficiently.
However, this is a start and makes it possible to use vrc's path-based
searches to find potential bugs where coroutine_fns call blocking functions.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Just remove the declaration. There is nothing in the function after the
switch statement, so it is safe to do.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Originally meant to avoid a shadowed variable "s", which was fixed by
renaming the outer declaration to "qts". Avoid the chance of an overflow
in the computation of ABS(t - s).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
