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Re: [Qemu-devel] [RFC v1 10/11] tcg: grab iothread lock in cpu-exec inte
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [RFC v1 10/11] tcg: grab iothread lock in cpu-exec interrupt handling |
Date: |
Fri, 18 Mar 2016 17:48:11 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 |
On 18/03/2016 17:18, Alex Bennée wrote:
> From: "Emilio G. Cota" <address@hidden>
>
> Signed-off-by: Emilio G. Cota <address@hidden>
> Signed-off-by: Alex Bennée <address@hidden>
>
> ---
> v1 (ajb)
> - pulled from emilio/mttcg series
> ---
> cpu-exec.c | 33 +++++++++++++++++++++++++++------
> include/qom/cpu.h | 1 +
> 2 files changed, 28 insertions(+), 6 deletions(-)
>
> diff --git a/cpu-exec.c b/cpu-exec.c
> index 76891fd..6acaf25 100644
> --- a/cpu-exec.c
> +++ b/cpu-exec.c
> @@ -351,6 +351,29 @@ static void cpu_handle_debug_exception(CPUState *cpu)
> cc->debug_excp_handler(cpu);
> }
>
> +#ifdef CONFIG_SOFTMMU
> +static inline void cpu_exit_loop_lock(CPUState *cpu)
> +{
> + qemu_mutex_lock_iothread();
> + cpu->cpu_loop_exit_locked = true;
> +}
> +
> +static inline void cpu_exit_loop_lock_reset(CPUState *cpu)
> +{
> + if (cpu->cpu_loop_exit_locked) {
> + cpu->cpu_loop_exit_locked = false;
> + qemu_mutex_unlock_iothread();
> + }
> +}
In the meanwhile we got qemu_mutex_iothread_locked(), so these two
inlines are not necessary anymore.
Paolo
> +#else
> +static inline void cpu_exit_loop_lock(CPUState *cpu)
> +{ }
> +
> +static inline void cpu_exit_loop_lock_reset(CPUState *cpu)
> +{ }
> +#endif
> +
> /* main execution loop */
>
> int cpu_exec(CPUState *cpu)
> @@ -450,12 +473,7 @@ int cpu_exec(CPUState *cpu)
> for(;;) {
> interrupt_request = cpu->interrupt_request;
> if (unlikely(interrupt_request)) {
> - /* FIXME: this needs to take the iothread lock.
> - * For this we need to find all places in
> - * cc->cpu_exec_interrupt that can call cpu_loop_exit,
> - * and call qemu_unlock_iothread_mutex() there. Else,
> - * add a flag telling cpu_loop_exit() to unlock it.
> - */
> + cpu_exit_loop_lock(cpu);
>
> if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) {
> /* Mask out external interrupts for this step. */
> @@ -510,6 +528,8 @@ int cpu_exec(CPUState *cpu)
> next_tb = 0;
> }
>
> + cpu_exit_loop_lock_reset(cpu);
> +
> }
> if (unlikely(cpu->exit_request
> || replay_has_interrupt())) {
> @@ -630,6 +650,7 @@ int cpu_exec(CPUState *cpu)
>
> cpu->can_do_io = 1;
> tb_lock_reset();
> + cpu_exit_loop_lock_reset(cpu);
> }
> } /* for(;;) */
>
> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> index d6cb7b8..954d97d 100644
> --- a/include/qom/cpu.h
> +++ b/include/qom/cpu.h
> @@ -295,6 +295,7 @@ struct CPUState {
> bool crash_occurred;
> bool exit_request;
> bool tb_invalidated_flag;
> + bool cpu_loop_exit_locked;
> uint32_t interrupt_request;
> int singlestep_enabled;
> int64_t icount_extra;
>
[Qemu-devel] [RFC v1 04/11] tcg: protect TBContext with tb_lock., Alex Bennée, 2016/03/18
[Qemu-devel] [RFC v1 08/11] tcg: add kick timer for single-threaded vCPU emulation, Alex Bennée, 2016/03/18
[Qemu-devel] [RFC v1 07/11] tcg: add options for enabling MTTCG, Alex Bennée, 2016/03/18
[Qemu-devel] [RFC v1 10/11] tcg: grab iothread lock in cpu-exec interrupt handling, Alex Bennée, 2016/03/18
- Re: [Qemu-devel] [RFC v1 10/11] tcg: grab iothread lock in cpu-exec interrupt handling,
Paolo Bonzini <=
[Qemu-devel] [RFC v1 11/11] tcg: enable thread-per-vCPU, Alex Bennée, 2016/03/18
[Qemu-devel] [RFC v1 09/11] tcg: drop global lock during TCG code execution, Alex Bennée, 2016/03/18