util/log: re-allow switching away from stderr log file

Commit 59bde21374 ("util/log: do not close and reopen log files when
flags are turned off") prevented switching away from stderr on a
subsequen

util/log: re-allow switching away from stderr log file

Commit 59bde21374 ("util/log: do not close and reopen log files when
flags are turned off") prevented switching away from stderr on a
subsequent invocation of qemu_set_log_internal(). This prevented
switching away from stderr with the 'logfile' monitor command as well
as an invocation like
> ./qemu-system-x86_64 -trace 'qemu_mutex_lock,file=log'
from opening the specified log file.

Fixes: 59bde21374 ("util/log: do not close and reopen log files when flags are turned off")
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20231004124446.491481-1-f.ebner@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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util/log: Add vector registers to log

Added QEMU option 'vpu' to log vector extension registers such as gpr\fpu.

Signed-off-by: Ivan Klokov <ivan.klokov@syntacore.com>
Reviewed-by: Alistair Francis

util/log: Add vector registers to log

Added QEMU option 'vpu' to log vector extension registers such as gpr\fpu.

Signed-off-by: Ivan Klokov <ivan.klokov@syntacore.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230410124451.15929-2-ivan.klokov@syntacore.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

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log: Remove unneeded new line

The help text of the -d plugin option has a new line at the end which
is not needed as one is added automatically. Fixing it removes the
unexpected empty line in -d hel

log: Remove unneeded new line

The help text of the -d plugin option has a new line at the end which
is not needed as one is added automatically. Fixing it removes the
unexpected empty line in -d help output.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230119214033.600FB74645F@zero.eik.bme.hu>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

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util/log: Always send errors to logfile when daemonized

When QEMU is started with `-daemonize`, all stdio descriptors get
redirected to `/dev/null`. This basically means that anything
printed with e

util/log: Always send errors to logfile when daemonized

When QEMU is started with `-daemonize`, all stdio descriptors get
redirected to `/dev/null`. This basically means that anything
printed with error_report() and friends is lost.

Current logging code allows to redirect to a file with `-D` but
this requires to enable some logging item with `-d` as well to
be functional.

Relax the check on the log flags when QEMU is daemonized, so that
other users of stderr can benefit from the redirection, without the
need to enable unwanted debug logs. Previous behaviour is retained
for the non-daemonized case. The logic is unrolled as an `if` for
better readability. The qemu_log_level and log_per_thread globals
reflect the state we want to transition to at this point : use
them instead of the intermediary locals for correctness.

qemu_set_log_internal() is adapted to open a per-thread log file
when '-d tid' is passed. This is done by hijacking qemu_try_lock()
which seems simpler that refactoring the code.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20221108140032.1460307-3-groug@kaod.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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util/log: do not close and reopen log files when flags are turned off

log_append makes sure that if you turn off the logging (which clears
log_flags and makes need_to_open_file false) the old log is

util/log: do not close and reopen log files when flags are turned off

log_append makes sure that if you turn off the logging (which clears
log_flags and makes need_to_open_file false) the old log is not
overwritten. The usecase is that if you remove or move the file
QEMU will not keep writing to the old file. However, this is
not always the desited behavior, in particular having log_append==1
after changing the file name makes little sense.

When qemu_set_log_internal is called from the logfile monitor
command, filename must be non-NULL and therefore changed_name must
be true. Therefore, the only case where the file is closed and
need_to_open_file == false is indeed when log_flags becomes
zero. In this case, just flush the file and do not bother
closing it, thus faking the same append behavior as previously.

The behavioral change is that changing the logfile twice, for
example log1 -> log2 -> log1, will cause log1 to be overwritten.
This can simply be documented, since it is not a particularly
surprising behavior.

Suggested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20221025092119.236224-1-pbonzini@redhat.com>
[groug: nullify global_file before actually closing the file]
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20221108140032.1460307-2-groug@kaod.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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util/log: Ignore per-thread flag if global file already there

If QEMU is started with `-D qemu.log.%d` without any `-d` option,
doing `log all` in the monitor fails with:

Filename template with '%d

util/log: Ignore per-thread flag if global file already there

If QEMU is started with `-D qemu.log.%d` without any `-d` option,
doing `log all` in the monitor fails with:

Filename template with '%d' required for 'tid'

It is confusing since '%d' was actually passed.

This happens because QEMU caches the log file name with %d converted
to getpid() since `tid` wasn't required. This name isn't suitable
for a subsequent enablement of per-thread logs. There's little cause
to change the behavior as `-d tid` is mostly used at user-only startup.

Drop the per-thread from the requested flags in this case : `log all`
will thus enable everything except `tid` instead of failing. This is
preferable over forcing the user to enable each log item individually.

With this patch, `tid` is now truely immutable : it can only be set
or unset from the command line and never changed afterwards.

Fixes: 4e51069d6793 ("util/log: Support per-thread log files")
Cc: richard.henderson@linaro.org
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221104120059.678470-3-groug@kaod.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

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util/log: Make the per-thread flag immutable

Per-thread logging was implemented under the assumption that once
enabled, it is not possible to switch back to single file logging.
This isn't enforced

util/log: Make the per-thread flag immutable

Per-thread logging was implemented under the assumption that once
enabled, it is not possible to switch back to single file logging.
This isn't enforced though and it is possible to go through the
global file opening sequence in per-thread mode. The code isn't
ready for this and produces unexpected results as detailed below.

Start QEMU in system emulation mode with `-D ./qemu.log.%d -d tid`
and then change the log level from the monitor to something that
doesn't have tid, e.g. `log cpu_reset`. The value of log_flags
is zero and per_thread is set to false : the rest of the code
then assumes it is running in the global log case and opens a
file named `qemu.log.%d`, which is obviously not an expected
behavior.

Enforce the immutability of the flag early in qemu_set_log_internal()
so that its value is correct for all subsequent users.

Fixes: 4e51069d6793 ("util/log: Support per-thread log files")
Cc: richard.henderson@linaro.org
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221104120059.678470-2-groug@kaod.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

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util/log: Close per-thread log file on thread termination

When `-D ${logfile} -d tid` is passed, qemu_log_trylock() creates
a dedicated log file for the current thread and opens it. The
correspondin

util/log: Close per-thread log file on thread termination

When `-D ${logfile} -d tid` is passed, qemu_log_trylock() creates
a dedicated log file for the current thread and opens it. The
corresponding file descriptor is cached in a __thread variable.
Nothing is done to close the corresponding file descriptor when the
thread terminates though and the file descriptor is leaked.

The issue was found during code inspection and reproduced manually.

Fix that with an atexit notifier.

Fixes: 4e51069d6793 ("util/log: Support per-thread log files")
Cc: richard.henderson@linaro.org
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20221021105734.555797-1-groug@kaod.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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util/log: Support per-thread log files

Add a new log flag, tid, to turn this feature on.
Require the log filename to be set, and to contain %d.

Do not allow tid to be turned off once it is on, nor

util/log: Support per-thread log files

Add a new log flag, tid, to turn this feature on.
Require the log filename to be set, and to contain %d.

Do not allow tid to be turned off once it is on, nor let
the filename be change thereafter. This avoids the need
for signalling each thread to re-open on a name change.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-40-richard.henderson@linaro.org>

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util/log: Limit RCUCloseFILE to file closing

Use FILE* for global_file. We can perform an rcu_read on that
just as easily as RCUCloseFILE*. This simplifies a couple of
places, where previously we

util/log: Limit RCUCloseFILE to file closing

Use FILE* for global_file. We can perform an rcu_read on that
just as easily as RCUCloseFILE*. This simplifies a couple of
places, where previously we required taking the rcu_read_lock
simply to avoid racing to dereference RCUCloseFile->fd.

Only allocate the RCUCloseFile prior to call_rcu.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-39-richard.henderson@linaro.org>

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util/log: Rename QemuLogFile to RCUCloseFILE

s/QemuLogFile/RCUCloseFILE/
s/qemu_logfile_free/rcu_close_file/

Emphasize that this is only a carrier for passing a pointer
to call_rcu for closing, and

util/log: Rename QemuLogFile to RCUCloseFILE

s/QemuLogFile/RCUCloseFILE/
s/qemu_logfile_free/rcu_close_file/

Emphasize that this is only a carrier for passing a pointer
to call_rcu for closing, and not the real logfile.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-38-richard.henderson@linaro.org>

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util/log: Combine two logfile closes

Merge the close from the changed_name block with the close
from the !need_to_open_file block.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: R

util/log: Combine two logfile closes

Merge the close from the changed_name block with the close
from the !need_to_open_file block.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-37-richard.henderson@linaro.org>

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util/log: Hoist the eval of is_daemonized in qemu_set_log_internal

Only call is_daemonized once.
We require the result on all paths after this point.

Reviewed-by: Alex Bennée <alex.bennee@linaro.or

util/log: Hoist the eval of is_daemonized in qemu_set_log_internal

Only call is_daemonized once.
We require the result on all paths after this point.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-36-richard.henderson@linaro.org>

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util/log: Rename qemu_logfile_mutex to global_mutex

Rename to emphasize this covers the file-scope global variables.

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

util/log: Rename qemu_logfile_mutex to global_mutex

Rename to emphasize this covers the file-scope global variables.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-35-richard.henderson@linaro.org>

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util/log: Rename qemu_logfile to global_file

Rename to emphasize this is the file-scope global variable.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug

util/log: Rename qemu_logfile to global_file

Rename to emphasize this is the file-scope global variable.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-34-richard.henderson@linaro.org>

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util/log: Rename logfilename to global_filename

Rename to emphasize this is the file-scope global variable.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4

util/log: Rename logfilename to global_filename

Rename to emphasize this is the file-scope global variable.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-33-richard.henderson@linaro.org>

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util/log: Remove qemu_log_close

The only real use is in cpu_abort, where we have just
flushed the file via qemu_log_unlock, and are just about
to force-crash the application via abort. We do not
re

util/log: Remove qemu_log_close

The only real use is in cpu_abort, where we have just
flushed the file via qemu_log_unlock, and are just about
to force-crash the application via abort. We do not
really need to close the FILE before the abort.

The two uses in test-logging.c can be handled with
qemu_set_log_filename_flags.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-32-richard.henderson@linaro.org>

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util/log: Introduce qemu_set_log_filename_flags

Provide a function to set both filename and flags at
the same time. This is the common case at startup.

Signed-off-by: Richard Henderson <richard.he

util/log: Introduce qemu_set_log_filename_flags

Provide a function to set both filename and flags at
the same time. This is the common case at startup.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-28-richard.henderson@linaro.org>

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include/qemu/log: Move entire implementation out-of-line

Move QemuLogFile, qemu_logfile, and all inline functions into qemu/log.c.
No need to expose these implementation details in the api.

Reviewe

include/qemu/log: Move entire implementation out-of-line

Move QemuLogFile, qemu_logfile, and all inline functions into qemu/log.c.
No need to expose these implementation details in the api.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-26-richard.henderson@linaro.org>

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util/log: Drop call to setvbuf

Now that the log buffer is flushed after every qemu_log_unlock,
which includes every call to qemu_log, we do not need to force
line buffering (or unbuffering for windo

util/log: Drop call to setvbuf

Now that the log buffer is flushed after every qemu_log_unlock,
which includes every call to qemu_log, we do not need to force
line buffering (or unbuffering for windows). Block buffer the
entire loggable unit.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-21-richard.henderson@linaro.org>

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util/log: Remove qemu_log_flush

All uses flush output immediately before or after qemu_log_unlock.
Instead of a separate call, move the flush into qemu_log_unlock.

Reviewed-by: Alex Bennée <alex.be

util/log: Remove qemu_log_flush

All uses flush output immediately before or after qemu_log_unlock.
Instead of a separate call, move the flush into qemu_log_unlock.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-20-richard.henderson@linaro.org>

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util/log: Drop return value from qemu_log

The only user of this feature, tcg_dump_ops, has been
converted to use fprintf directly.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: R

util/log: Drop return value from qemu_log

The only user of this feature, tcg_dump_ops, has been
converted to use fprintf directly.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-18-richard.henderson@linaro.org>

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util/log: Use qemu_log_trylock/unlock in qemu_log

Avoid using QemuLogFile and RCU directly.

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

util/log: Use qemu_log_trylock/unlock in qemu_log

Avoid using QemuLogFile and RCU directly.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-17-richard.henderson@linaro.org>

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util/log: Rename qemu_log_lock to qemu_log_trylock

This function can fail, which makes it more like ftrylockfile
or pthread_mutex_trylock than flockfile or pthread_mutex_lock,
so rename it.

To clos

util/log: Rename qemu_log_lock to qemu_log_trylock

This function can fail, which makes it more like ftrylockfile
or pthread_mutex_trylock than flockfile or pthread_mutex_lock,
so rename it.

To closer match the other trylock functions, release rcu_read_lock
along the failure path, so that qemu_log_unlock need not be called
on failure.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-8-richard.henderson@linaro.org>

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util/log: Move qemu_log_lock, qemu_log_unlock out of line

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <ri

util/log: Move qemu_log_lock, qemu_log_unlock out of line

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-7-richard.henderson@linaro.org>

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