This reverts commit b422a7bff6.
The reporter says "The commit breaks go; if you run go build in a loop,
it eventually hangs uninterruptible (except -9) with a couple of zombie
children left over".
Reported-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20260202091753.28459-1-pbonzini@redhat.com>
(cherry picked from commit 251a3d4ca3c961d95cd624252a178a33066455a2)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Whenever user-mode emulation needs to go all the way out of the cpu
exec loop, it uses cpu_exit(), which already sets cpu->exit_request.
Therefore, there is no need for tcg_kick_vcpu_thread() to set
cpu->exit_request again outside system emulation.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make the code common to all accelerators: after seeing cpu->exit_request
set to true, accelerator code needs to reach qemu_process_cpu_events_common().
So for the common cases where they use qemu_process_cpu_events(), go ahead and
clear it in there. Note that the cheap qatomic_set() is enough because
at this point the thread has taken the BQL; qatomic_set_mb() is not needed.
In particular, this is the ordering of the communication between
I/O and vCPU threads is always the same.
In the I/O thread:
(a) store other memory locations that will be checked if cpu->exit_request
or cpu->interrupt_request is 1 (for example cpu->stop or cpu->work_list
for cpu->exit_request)
(b) cpu_exit(): store-release cpu->exit_request, or
(b) cpu_interrupt(): store-release cpu->interrupt_request
>>> at this point, cpu->halt_cond is broadcast and the BQL released
(c) do the accelerator-specific kick (e.g. write icount_decr for TCG,
pthread_kill for KVM, etc.)
In the vCPU thread instead the opposite order is respected:
(c) the accelerator's execution loop exits thanks to the kick
(b) then the inner execution loop checks cpu->interrupt_request
and cpu->exit_request. If needed cpu->interrupt_request is
converted into cpu->exit_request when work is needed outside
the execution loop.
(a) then the other memory locations are checked. Some may need to
be read under the BQL, but the vCPU thread may also take other
locks (e.g. for queued work items) or none at all.
qatomic_set_mb() would only be needed if the halt sleep was done
outside the BQL (though in that case, cpu->exit_request probably
would be replaced by a QemuEvent or something like that).
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Right now, cpu_exit() is not usable from all accelerators because it
includes a TCG-specific thread kick. In fact, cpu_exit() doubles as
the TCG thread-kick via tcg_kick_vcpu_thread().
In preparation for changing that, inline cpu_exit() into
tcg_kick_vcpu_thread(). The direction of the calls can then be
reversed, with an accelerator-independent cpu_exit() calling into
qemu_vcpu_kick() rather than the opposite.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Round-robin TCG is calling into cpu_exit() directly. In preparation
for making cpu_exit() usable from all accelerators, define a generic
thread-kick function for TCG which is used directly in the multi-threaded
case, and through CPU_FOREACH in the round-robin case.
Use it also for user-mode emulation, and take the occasion to move
the implementation to accel/tcg/user-exec.c.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reads and writes cpu->exit_request do not use a load-acquire/store-release
pair right now, but this means that cpu_exit() may not write cpu->exit_request
after any flags that are read by the vCPU thread.
Probably everything is protected one way or the other by the BQL, because
cpu->exit_request leads to the slow path, where the CPU thread often takes
the BQL (for example, to go to sleep by waiting on the BQL-protected
cpu->halt_cond); but it's not clear, so use load-acquire/store-release
consistently.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Open coding cpu_reset_interrupt() can cause bugs if the BQL is not
taken, for example i386 has the call chain kvm_cpu_exec() ->
kvm_put_vcpu_events() -> kvm_arch_put_registers().
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
in cpu_handle_interrupt() the only place where cached interrupt_request
might have effect is when CPU_INTERRUPT_SSTEP_MASK applied and
cached interrupt_request handed over to cpu_exec_interrupt() and
need_replay_interrupt().
Simplify code by moving interrupt_request caching and CPU_INTERRUPT_SSTEP_MASK
masking into the block where it actually matters and drop reloading cached value
from CPUState:interrupt_request as the rest of the code directly uses
CPUState:interrupt_request.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Link: https://lore.kernel.org/r/20250814160600.2327672-9-imammedo@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The helpers form load-acquire/store-release pair and ensure
that appropriate barriers are in place in case checks happen
outside of BQL.
Use them to replace open-coded checkers/setters across the code,
to make sure that barriers are not missed. Helpers also make code a
bit more readable.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Link: https://lore.kernel.org/r/20250821155603.2422553-1-imammedo@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
cpu_interrupt() is not called anymore except by ARM but even there
it is dead code; disentangling the various cpregs accessors from user-mode
emulation is a work in progress.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All targets now provide the function, so we can
make the call unconditional.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move set_helper_retaddr and clear_helper_retaddr
to a new header file.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move the global function name to a hook on TCGCPUOps.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Combine 3 different pointer returns into one structure return.
Include a cflags field in TCGTBCPUState, not filled in by
cpu_get_tb_cpu_state, but used by all callers. This fills
a hole in the structure and is useful in some subroutines.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Note that target/i386/cpu.h defines CPU_INTERRUPT_INIT
as CPU_INTERRUPT_RESET. Therefore we can handle the
new TCGCPUOps.cpu_exec_reset hook.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Initialize all instances with cpu_reset(), so that there
is no functional change.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This flag is only tested by target/i386, so including this
makes no functional change. This is similar to other places
like cpu-target.c which use CPU_DUMP_CCOP unconditionally.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Test for the hook being present instead of ifdef TARGET_I386.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
There's nothing left in internal-target.h that is
target specific.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
A few functions now end with a label. The next commit will clean them
up.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250407082643.2310002-3-armbru@redhat.com>
[Straightforward conflict with commit 988ad4cceb (hw/loongarch/virt:
Fix cpuslot::cpu set at last in virt_cpu_plug()) resolved]
Only 2 files requiring "accel/tcg/cpu-ldst.h" API do not
include it:
- accel/tcg/cpu-exec.c
- target/arm/tcg/sve_helper.c
Include it there and remove it from "exec/exec-all.h".
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Now we made sure important defines are included using their direct
path, we can remove cpu.h from cpu-all.h.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250325045915.994760-14-pierrick.bouvier@linaro.org>
All targets have been converted to TCGCPUOps::mmu_index(),
remove the now unused CPUClass::mmu_index().
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250401080938.32278-24-philmd@linaro.org>
Split icount stuff from system/cpu-timers.h.
There are 17 files which only require icount.h, 7 that only
require cpu-timers.h, and 7 that require both.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out mmap_lock, et al from page-protection.h
to a new header.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@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>
TCGCPUOps structure makes more sense in the accelerator context
rather than hardware emulation. Move it under the accel/tcg/ scope.
Mechanical change doing:
$ sed -i -e 's,hw/core/tcg-cpu-ops.h,accel/tcg/cpu-ops.h,g' \
$(git grep -l hw/core/tcg-cpu-ops.h)
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250123234415.59850-11-philmd@linaro.org>
While cpu-exec.c is build for each target,tcg_flags helpers
aren't target specific. Move them to cpu-exec-common.c to
build them once.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250123234415.59850-8-philmd@linaro.org>
These similarly named functions serve different purposes; add
docstrings to highlight them.
Suggested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250116213214.5695-1-iii@linux.ibm.com>
Convert all targets simultaneously, as the gen_intermediate_code
function disappears from the target. While there are possible
workarounds, they're larger than simply performing the conversion.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The TranslationBlock flags are defined in 'exec/translation-block.h'.
tcg_cflags_has/set() use them, it is more logical to declare them in
the same place. Move them there too.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20241212144430.66224-2-philmd@linaro.org>
Move cpu_loop_exit_requested() declaration to "exec/cpu-common.h",
along with the related cpu_loop_exit_noexc(), cpu_loop_exit(),
cpu_loop_exit_atomic() and cpu_loop_exit_restore() methods.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20241217140648.98538-1-philmd@linaro.org>
Move declarations related to TranslationBlock out of the
generic "internal-target.h" to "tb-internal.h".
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20241212185341.2857-11-philmd@linaro.org>
log_pc() is only used within cpu-exec.c, no need to
expose it via "internal-target.h".
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20241212185341.2857-10-philmd@linaro.org>
Move mmap_lock(), mmap_unlock() declarations and the
WITH_MMAP_LOCK_GUARD() definition to 'exec/page-protection.h'.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20241212185341.2857-5-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>
Use of these in helpers goes hand-in-hand with tlb_vaddr_to_host
and other probing functions.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The TCGCPUOps::cpu_exec_interrupt hook is currently not mandatory; if
it is left NULL then we treat it as if it had returned false. However
since pretty much every architecture needs to handle interrupts,
almost every target we have provides the hook. The one exception is
Tricore, which doesn't currently implement the architectural
interrupt handling.
Add a "do nothing" implementation of cpu_exec_hook for Tricore,
assert on startup that the CPU does provide the hook, and remove
the runtime NULL check before calling it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240712113949.4146855-1-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Now that all targets set TCGCPUOps::cpu_exec_halt, we can make it
mandatory and remove the fallback handling that calls cpu_has_work.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
The TCGCPUOps::cpu_exec_halt method is called from cpu_handle_halt()
when the CPU is halted, so that a target CPU emulation can do
anything target-specific it needs to do. (At the moment we only use
this on i386.)
The current specification of the method doesn't allow the target
specific code to do something different if the CPU is about to come
out of the halt state, because cpu_handle_halt() only determines this
after the method has returned. (If the method called cpu_has_work()
itself this would introduce a potential race if an interrupt arrived
between the target's method implementation checking and
cpu_handle_halt() repeating the check.)
Change the definition of the method so that it returns a bool to
tell cpu_handle_halt() whether to stay in halt or not.
We will want this for the Arm target, where FEAT_WFxT wants to do
some work only for the case where the CPU is in halt but about to
leave it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240430140035.3889879-2-peter.maydell@linaro.org
Record the fact that we've found a breakpoint on the page
in which a TranslationBlock is running.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
