This is part of a series of changes to remove the implied BQL from the common code of cpu_handle_interrupt and cpu_handle_exception. As part of removing the implied BQL from the common code, we are pushing the BQL holding down into the per-arch implementation functions of do_interrupt and cpu_exec_interrupt.
The purpose of this set of changes is to set the groundwork so that an arch could move towards removing the BQL from the cpu_handle_interrupt/exception paths. This approach was suggested by Paolo Bonzini. For reference, here are two key posts in the discussion, explaining the reasoning/benefits of this approach. https://lists.gnu.org/archive/html/qemu-devel/2020-07/msg08731.html https://lists.gnu.org/archive/html/qemu-devel/2020-08/msg00044.html Signed-off-by: Robert Foley <robert.fo...@linaro.org> --- target/m68k/op_helper.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/target/m68k/op_helper.c b/target/m68k/op_helper.c index 4a032a150e..0c3333476a 100644 --- a/target/m68k/op_helper.c +++ b/target/m68k/op_helper.c @@ -448,7 +448,9 @@ void m68k_cpu_do_interrupt(CPUState *cs) M68kCPU *cpu = M68K_CPU(cs); CPUM68KState *env = &cpu->env; + qemu_mutex_lock_iothread(); do_interrupt_all(env, 0); + qemu_mutex_unlock_iothread(); } static inline void do_interrupt_m68k_hardirq(CPUM68KState *env) @@ -508,6 +510,7 @@ bool m68k_cpu_exec_interrupt(CPUState *cs, int interrupt_request) { M68kCPU *cpu = M68K_CPU(cs); CPUM68KState *env = &cpu->env; + qemu_mutex_lock_iothread(); if (interrupt_request & CPU_INTERRUPT_HARD && ((env->sr & SR_I) >> SR_I_SHIFT) < env->pending_level) { @@ -519,8 +522,10 @@ bool m68k_cpu_exec_interrupt(CPUState *cs, int interrupt_request) */ cs->exception_index = env->pending_vector; do_interrupt_m68k_hardirq(env); + qemu_mutex_unlock_iothread(); return true; } + qemu_mutex_unlock_iothread(); return false; } -- 2.17.1
