Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Do so before extending it to the user-mode emulators, where there is no
such thing as an "I/O thread".
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that cpu_exit() actually kicks all accelerators, use it whenever
the message to another thread is processed in qemu_wait_io_event().
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
CpuState caches its CPUClass since commit 6fbdff8706
("cpu: cache CPUClass in CPUState for hot code paths"),
use it.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250122093028.52416-5-philmd@linaro.org>
The heavily imported "system/cpus.h" header includes "accel-ops.h"
to get AccelOpsClass type declaration. Reduce headers pressure by
forward declaring it in "qemu/typedefs.h", where we already
declare the AccelCPUState type.
Reduce "system/cpus.h" inclusions by only including
"system/accel-ops.h" when necessary.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250123234415.59850-14-philmd@linaro.org>
Headers in include/sysemu/ are not only related to system
*emulation*, they are also used by virtualization. Rename
as system/ which is clearer.
Files renamed manually then mechanical change using sed tool.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Lei Yang <leiyang@redhat.com>
Message-Id: <20241203172445.28576-1-philmd@linaro.org>
This helper provides an easy way to identify the next available free cpu
index which can be used for vcpu creation. Until now, this is being
called at a very later stage and there is a need to be able to call it
earlier (for now, with ppc64) hence the need to export.
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Running qemu-system-aarch64 -M virt -nographic and terminating it will
result in a LeakSanitizer error due to remaining queued CPU work so
free it.
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Link: https://lore.kernel.org/r/20240714-cpu-v1-1-19c2f8de2055@daynix.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The Big QEMU Lock (BQL) has many names and they are confusing. The
actual QemuMutex variable is called qemu_global_mutex but it's commonly
referred to as the BQL in discussions and some code comments. The
locking APIs, however, are called qemu_mutex_lock_iothread() and
qemu_mutex_unlock_iothread().
The "iothread" name is historic and comes from when the main thread was
split into into KVM vcpu threads and the "iothread" (now called the main
loop thread). I have contributed to the confusion myself by introducing
a separate --object iothread, a separate concept unrelated to the BQL.
The "iothread" name is no longer appropriate for the BQL. Rename the
locking APIs to:
- void bql_lock(void)
- void bql_unlock(void)
- bool bql_locked(void)
There are more APIs with "iothread" in their names. Subsequent patches
will rename them. There are also comments and documentation that will be
updated in later patches.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Fabiano Rosas <farosas@suse.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Acked-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20240102153529.486531-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Fix:
hw/core/machine.c:1302:22: error: declaration shadows a variable in the global scope [-Werror,-Wshadow]
const CPUArchId *cpus = possible_cpus->cpus;
^
hw/core/numa.c:69:17: error: declaration shadows a variable in the global scope [-Werror,-Wshadow]
uint16List *cpus = NULL;
^
hw/acpi/aml-build.c:2005:20: error: declaration shadows a variable in the global scope [-Werror,-Wshadow]
CPUArchIdList *cpus = ms->possible_cpus;
^
hw/core/machine-smp.c:77:14: error: declaration shadows a variable in the global scope [-Werror,-Wshadow]
unsigned cpus = config->has_cpus ? config->cpus : 0;
^
include/hw/core/cpu.h:589:17: note: previous declaration is here
extern CPUTailQ cpus;
^
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Ani Sinha <anisinha@redhat.com>
Message-Id: <20231010115048.11856-2-philmd@linaro.org>
We have exec/cpu code split in 2 files for target agnostic
("common") and specific. Rename 'cpu.c' which is target
specific using the '-target' suffix. Update MAINTAINERS.
Remove the 's from 'cpus-common.c' to match the API cpu_foo()
functions.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230914185718.76241-7-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Expose qemu_cpu_list_lock globally so that we can use
WITH_QEMU_LOCK_GUARD and QEMU_LOCK_GUARD to simplify a few code paths
now and in future.
Signed-off-by: Jamie Iles <quic_jiles@quicinc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230427020925.51003-2-quic_jiles@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Use a store-release at the end of the work item, and a load-acquire when
waiting for the item to be completed. This is the standard message passing
pattern and is both enough and clearer than mb_read/mb_set.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This code is not target-specific.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221130135241.85060-4-philmd@linaro.org>
Currently dying to one of the core_dump_signal()s deadlocks, because
dump_core_and_abort() calls start_exclusive() two times: first via
stop_all_tasks(), and then via preexit_cleanup() ->
qemu_plugin_user_exit().
There are a number of ways to solve this: resume after dumping core;
check cpu_in_exclusive_context() in qemu_plugin_user_exit(); or make
{start,end}_exclusive() recursive. Pick the last option, since it's
the most straightforward one.
Fixes: da91c19202 ("linux-user: Clean up when exiting due to a signal")
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230214140829.45392-3-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Introduce cpu_list_generation_id to track cpu list generation so
that cpu hotplug/unplug can be detected during measurement of
dirty page rate.
cpu_list_generation_id could be used to detect changes of cpu
list, which is prepared for dirty page rate measurement.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <06e1f1362b2501a471dce796abb065b04f320fa5.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer,
for two reasons. One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.
This commit only touches allocations with size arguments of the form
sizeof(T).
Patch created mechanically with:
$ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
--macro-file scripts/cocci-macro-file.h FILES...
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220315144156.1595462-4-armbru@redhat.com>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.
Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201023123353.19796-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:
$ CC=clang CXX=clang++ ./configure ... && make
../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)
Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.
This patch was generated using:
$ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
sort -u >/tmp/changed_identifiers
$ for identifier in $(</tmp/changed_identifiers); do
sed -i "s%\<$identifier\>%q$identifier%g" \
$(git grep -I -l "\<$identifier\>")
done
I manually fixed line-wrap issues and misaligned rST tables.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
This code was introduced with SMP support in commit 6a00d60127,
later commit 267f685b8b moved CPU list management to common code
but forgot this code. Move now and simplify ifdef'ry.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200702104017.14057-1-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We convert queued work to a QSIMPLEQ, instead of
open-coding it.
While at it, make sure that all accesses to the list are
performed while holding the list's lock.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Robert Foley <robert.foley@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200609200738.445-3-robert.foley@linaro.org>
Message-Id: <20200612190237.30436-6-alex.bennee@linaro.org>
Basing the cpu_index on the number of currently allocated vCPUs fails
when vCPUs aren't removed in a LIFO manner. This is especially true
when we are allocating a cpu_index for each guest thread in
linux-user where there is no ordering constraint on their allocation
and de-allocation.
[I've dropped the assert which is there to guard against out-of-order
removal as this should probably be caught higher up the stack. Maybe
we could just ifdef CONFIG_SOFTTMU it?]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Igor Mammedow <imammedo@redhat.com>
Cc: Nikolay Igotti <igotti@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200520140541.30256-13-alex.bennee@linaro.org>
- ran regexp "qemu_mutex_lock\(.*\).*\n.*if" to find targets
- replaced result with QEMU_LOCK_GUARD if all unlocks at function end
- replaced result with WITH_QEMU_LOCK_GUARD if unlock not at end
Signed-off-by: Daniel Brodsky <dnbrdsky@gmail.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-id: 20200404042108.389635-3-dnbrdsky@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Suggested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
[AJB: moved inside start/end_exclusive fns + cleanup]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190709152053.16670-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Rebased onto merge commit 95a9457fd44; missed instances of qom/cpu.h
in comments replaced]
It was introduced in commit ab129972c8,
with the following motivation:
Because start_exclusive uses CPU_FOREACH, merge exclusive_lock with
qemu_cpu_list_lock: together with a call to exclusive_idle (via
cpu_exec_start/end) in cpu_list_add, this protects exclusive work
against concurrent CPU addition and removal.
However, it seems to be redundant, because the cpu-exclusive
infrastructure provides suffificent protection against the newly added
CPU starting execution while the cpu-exclusive work is running, and the
aforementioned traversing of the cpu list is protected by
qemu_cpu_list_lock.
Besides, this appears to be the only place where the cpu-exclusive
section is entered with the BQL taken, which has been found to trigger
AB-BA deadlock as follows:
vCPU thread main thread
----------- -----------
async_safe_run_on_cpu(self,
async_synic_update)
... [cpu hot-add]
process_queued_cpu_work()
qemu_mutex_unlock_iothread()
[grab BQL]
start_exclusive() cpu_list_add()
async_synic_update() finish_safe_work()
qemu_mutex_lock_iothread() cpu_exec_start()
So remove it. This paves the way to establishing a strict nesting rule
of never entering the exclusive section with the BQL taken.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20190523105440.27045-2-rkagan@virtuozzo.com>
Iterating over the list without using atomics is undefined behaviour,
since the list can be modified concurrently by other threads (e.g.
every time a new thread is created in user-mode).
Fix it by implementing the CPU list as an RCU QTAILQ. This requires
a little bit of extra work to traverse list in reverse order (see
previous patch), but other than that the conversion is trivial.
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20180819091335.22863-12-cota@braap.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This changes the *_run_on_cpu APIs (and helpers) to pass data in a
run_on_cpu_data type instead of a plain void *. This is because we
sometimes want to pass a target address (target_ulong) and this fails on
32 bit hosts emulating 64 bit guests.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20161027151030.20863-24-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Set cpu->running without taking the cpu_list lock, only requiring it if
there is a concurrent exclusive section. This requires adding a new
field to CPUState, which records whether a running CPU is being counted
in pending_cpus.
When an exclusive section is started concurrently with cpu_exec_start,
cpu_exec_start can use the new field to determine if it has to wait for
the end of the exclusive section. Likewise, cpu_exec_end can use it to
see if start_exclusive is waiting for that CPU.
This a separate patch for easier bisection of issues.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It is not necessary to hold qemu_cpu_list_mutex throughout the
exclusive section, because no other exclusive section can run
while pending_cpus != 0.
exclusive_idle() is called in cpu_exec_start(), and that prevents
any CPUs created after start_exclusive() from entering cpu_exec()
during an exclusive section.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
No need to call exclusive_idle() from cpu_exec_end since it is done
immediately afterwards in cpu_exec_start. Any exclusive section could
run as soon as cpu_exec_end leaves, because cpu->running is false and the
mutex is not taken, so the call does not add any protection either.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
async_run_on_cpu is only called from the I/O thread, not from CPU threads,
so it doesn't make any difference. It will make a difference however
for async_safe_run_on_cpu.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This will serve as the base for async_safe_run_on_cpu. Because
start_exclusive uses CPU_FOREACH, merge exclusive_lock with
qemu_cpu_list_lock: together with a call to exclusive_idle (via
cpu_exec_start/end) in cpu_list_add, this protects exclusive work
against concurrent CPU addition and removal.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make CPU work core functions common between system and user-mode
emulation. User-mode does not use run_on_cpu, so do not implement it.
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1470158864-17651-10-git-send-email-alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a mutex for the CPU list to system emulation, as it will be used to
manage safe work. Abstract manipulation of the CPU list in new functions
cpu_list_add and cpu_list_remove.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Philippe Mathieu-Daudé
Paolo Bonzini
Pierrick Bouvier
Harsh Prateek Bora
Akihiko Odaki
Stefan Hajnoczi
Jamie Iles
Ilya Leoshkevich
Hyman Huang(黄勇)
Markus Armbruster
Chetan Pant
Philippe Mathieu-Daudé
Emilio G. Cota
Alex Bennée
Daniel Brodsky
Roman Kagan
Sergey Fedorov