Yes, that is correct. It's more work but also more maintainable. Thanks, Paolo Il ven 31 lug 2020, 22:09 Robert Foley ha scritto: > On Fri, 31 Jul 2020 at 14:02, Paolo Bonzini wrote: > > > > On 31/07/20 14:51, Robert Foley wrote: > > > This change removes the implied BQL from the cpu_handle_interrupt, > > > and cpu_handle_exception paths. We can now select per-arch if > > > the BQL is needed or not by using the bql_interrupt flag. > > > By default, the core code holds the BQL. > > > One benefit of this change is that it leaves it up to the arch > > > to make the change to remove BQL when it makes sense. > > > > > > Signed-off-by: Robert Foley > > > > No, please just modify all implementation to do lock/unlock. It's a > > simpler patch than this on. > > Sure, we will update the patch based on this. > > To clarify, the suggestion here is to remove the bql_interrupt flag > that we added and change all the per-arch interrupt callback code to > do the lock/unlock of the BQL? So for example change > x86_cpu_exec_interrupt, and arm_cpu_exec_interrupt, etc to lock/unlock BQL? > > Thanks, > -Rob > > > > > > Paolo > > > > > --- > > > accel/tcg/cpu-exec.c | 34 ++++++++++++++++++++++++++-------- > > > 1 file changed, 26 insertions(+), 8 deletions(-) > > > > > > diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c > > > index 80d0e649b2..cde27ee0bf 100644 > > > --- a/accel/tcg/cpu-exec.c > > > +++ b/accel/tcg/cpu-exec.c > > > @@ -517,9 +517,13 @@ static inline bool cpu_handle_exception(CPUState > *cpu, int *ret) > > > #else > > > if (replay_exception()) { > > > CPUClass *cc = CPU_GET_CLASS(cpu); > > > - qemu_mutex_lock_iothread(); > > > + if (cc->bql_interrupt) { > > > + qemu_mutex_lock_iothread(); > > > + } > > > cc->do_interrupt(cpu); > > > - qemu_mutex_unlock_iothread(); > > > + if (cc->bql_interrupt) { > > > + qemu_mutex_unlock_iothread(); > > > + } > > > cpu->exception_index = -1; > > > > > > if (unlikely(cpu->singlestep_enabled)) { > > > @@ -558,7 +562,7 @@ static inline bool cpu_handle_interrupt(CPUState > *cpu, > > > if (unlikely(cpu_interrupt_request(cpu))) { > > > int interrupt_request; > > > > > > - qemu_mutex_lock_iothread(); > > > + cpu_mutex_lock(cpu); > > > interrupt_request = cpu_interrupt_request(cpu); > > > if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) { > > > /* Mask out external interrupts for this step. */ > > > @@ -567,7 +571,7 @@ static inline bool cpu_handle_interrupt(CPUState > *cpu, > > > if (interrupt_request & CPU_INTERRUPT_DEBUG) { > > > cpu_reset_interrupt(cpu, CPU_INTERRUPT_DEBUG); > > > cpu->exception_index = EXCP_DEBUG; > > > - qemu_mutex_unlock_iothread(); > > > + cpu_mutex_unlock(cpu); > > > return true; > > > } > > > if (replay_mode == REPLAY_MODE_PLAY && > !replay_has_interrupt()) { > > > @@ -577,13 +581,15 @@ static inline bool cpu_handle_interrupt(CPUState > *cpu, > > > cpu_reset_interrupt(cpu, CPU_INTERRUPT_HALT); > > > cpu_halted_set(cpu, 1); > > > cpu->exception_index = EXCP_HLT; > > > - qemu_mutex_unlock_iothread(); > > > + cpu_mutex_unlock(cpu); > > > return true; > > > } > > > #if defined(TARGET_I386) > > > else if (interrupt_request & CPU_INTERRUPT_INIT) { > > > X86CPU *x86_cpu = X86_CPU(cpu); > > > CPUArchState *env = &x86_cpu->env; > > > + cpu_mutex_unlock(cpu); > > > + qemu_mutex_lock_iothread(); > > > replay_interrupt(); > > > cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0, 0); > > > do_cpu_init(x86_cpu); > > > @@ -595,7 +601,7 @@ static inline bool cpu_handle_interrupt(CPUState > *cpu, > > > else if (interrupt_request & CPU_INTERRUPT_RESET) { > > > replay_interrupt(); > > > cpu_reset(cpu); > > > - qemu_mutex_unlock_iothread(); > > > + cpu_mutex_unlock(cpu); > > > return true; > > > } > > > #endif > > > @@ -604,7 +610,15 @@ static inline bool cpu_handle_interrupt(CPUState > *cpu, > > > True when it is, and we should restart on a new TB, > > > and via longjmp via cpu_loop_exit. */ > > > else { > > > + cpu_mutex_unlock(cpu); > > > + if (cc->bql_interrupt) { > > > + qemu_mutex_lock_iothread(); > > > + } > > > if (cc->cpu_exec_interrupt(cpu, interrupt_request)) { > > > + if (cc->bql_interrupt) { > > > + qemu_mutex_unlock_iothread(); > > > + } > > > + cpu_mutex_lock(cpu); > > > replay_interrupt(); > > > /* > > > * After processing the interrupt, ensure an > EXCP_DEBUG is > > > @@ -614,6 +628,11 @@ static inline bool cpu_handle_interrupt(CPUState > *cpu, > > > cpu->exception_index = > > > (cpu->singlestep_enabled ? EXCP_DEBUG : -1); > > > *last_tb = NULL; > > > + } else { > > > + if (cc->bql_interrupt) { > > > + qemu_mutex_unlock_iothread(); > > > + } > > > + cpu_mutex_lock(cpu); > > > } > > > /* The target hook may have updated the > 'cpu->interrupt_request'; > > > * reload the 'interrupt_request' value */ > > > @@ -627,7 +646,7 @@ static inline bool cpu_handle_interrupt(CPUState > *cpu, > > > } > > > > > > /* If we exit via cpu_loop_exit/longjmp it is reset in > cpu_exec */ > > > - qemu_mutex_unlock_iothread(); > > > + cpu_mutex_unlock(cpu); > > > } > > > > > > /* Finally, check if we need to exit to the main loop. */ > > > @@ -691,7 +710,6 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, > TranslationBlock *tb, > > > } > > > #endif > > > } > > > - > > > /* main execution loop */ > > > > > > int cpu_exec(CPUState *cpu) > > > > > > >