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>
For all targets, the CPU class returned from CPUClass::class_by_name()
and object_class_dynamic_cast(oc, CPU_RESOLVING_TYPE) need to be
compatible. Lets apply the check in cpu_class_by_name() for once,
instead of having the check in CPUClass::class_by_name() for individual
target.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Message-ID: <20231114235628.534334-4-gshan@redhat.com>
Factor the TCG specific code from cpu_common_reset_hold() to
tcg_cpu_reset_hold() within tcg-accel-ops.c. Since this file
is sysemu specific, we can inline tcg_flush_softmmu_tlb(),
removing its declaration in "exec/cpu-common.h".
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230918104153.24433-4-philmd@linaro.org>
Introduce cpu_exec_reset_hold() which call an accelerator
specific AccelOpsClass::cpu_reset_hold() handler.
Define a stub on TCG user emulation, because CPU reset is
irrelevant there.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230918104153.24433-3-philmd@linaro.org>
"exec/cpu-common.h" is meant to contain the declarations
related to CPU usable with any accelerator / target
combination.
tcg_flush_jmp_cache() is specific to TCG, so restrict its
declaration by moving it to "exec/tb-flush.h".
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230918104153.24433-2-philmd@linaro.org>
Minimize the displacement to can_do_io, since it may
be touched at the start of each TranslationBlock.
It fits into other padding within the substructure.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This API allows the accelerators to prevent vcpus from issuing
new ioctls while execting a critical section marked with the
accel_ioctl_inhibit_begin/end functions.
Note that all functions submitting ioctls must mark where the
ioctl is being called with accel_{cpu_}ioctl_begin/end().
This API requires the caller to always hold the BQL.
API documentation is in sysemu/accel-blocker.h
Internally, it uses a QemuLockCnt together with a per-CPU QemuLockCnt
(to minimize cache line bouncing) to keep avoid that new ioctls
run when the critical section starts, and a QemuEvent to wait
that all running ioctls finish.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221111154758.1372674-2-eesposit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
While we initialize this value in cpu_common_reset, that
isn't called during startup, so set it as well in init.
This fixes -singlestep versus the very first TB.
Fixes: 04f5b647ed ("accel/tcg: Handle -singlestep in curr_cflags")
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This reverts commit 1b36e4f5a5.
Despite a comment saying why cpu_common_props cannot be placed in
a file that is compiled once, it was moved anyway. Revert that.
Since then, Property is not defined in hw/core/cpu.h, so it is now
easier to declare a function to install the properties rather than
the Property array itself.
Cc: Eduardo Habkost <ehabkost@redhat.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
No code uses CPUClass::get_memory_mapping() outside of hw/core/cpu.c:
$ git grep -F -- '->get_memory_mapping'
hw/core/cpu.c:87: cc->get_memory_mapping(cpu, list, errp);
hw/core/cpu.c:439: k->get_memory_mapping = cpu_common_get_memory_mapping;
target/i386/cpu.c:7422: cc->get_memory_mapping = x86_cpu_get_memory_mapping;
Check the handler presence in place and remove the common fallback code.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-11-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
No code uses CPUClass::get_paging_enabled() outside of hw/core/cpu.c:
$ git grep -F -- '->get_paging_enabled'
hw/core/cpu.c:74: return cc->get_paging_enabled(cpu);
hw/core/cpu.c:438: k->get_paging_enabled = cpu_common_get_paging_enabled;
target/i386/cpu.c:7418: cc->get_paging_enabled = x86_cpu_get_paging_enabled;
Check the handler presence in place and remove the common fallback code.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-10-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Introduce the cpu_virtio_is_big_endian() generic helper to avoid
calling CPUClass internal virtio_is_big_endian() one.
Similarly to commit bf7663c4bd ("cpu: introduce
CPUClass::virtio_is_big_endian()"), we keep 'virtio' in the method
name to hint this handler shouldn't be called anywhere but from the
virtio code.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-8-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>