Re: [Qemu-devel] [RFC v2 04/34] cpu-exec: Migrate some generic fns to cpus.c

[Paolo Bonzini]

On 31/05/2015 08:11, Peter Crosthwaite wrote:
> The goal is to split the functions such that cpu-exec is CPU specific
> content, while cpus.c is generic code only. The function interface to
> cpu-exec needs to be virtualised to prepare support for multi-arch and
> moving these definitions out saves bloating the QOM interface. So
> move these definitions out of cpu-exec to the architecture independent
> cpus.c.
> 
> Signed-off-by: Peter Crosthwaite <address@hidden>
> ---
>  cpu-exec.c | 49 -------------------------------------------------
>  cpus.c     | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 49 insertions(+), 49 deletions(-)
> 
> diff --git a/cpu-exec.c b/cpu-exec.c
> index 0266609..dbea47c 100644
> --- a/cpu-exec.c
> +++ b/cpu-exec.c
> @@ -25,7 +25,6 @@
>  #include "sysemu/qtest.h"
>  #include "qemu/timer.h"
>  #include "exec/address-spaces.h"
> -#include "exec/memory-internal.h"
>  #include "qemu/rcu.h"
>  
>  /* -icount align implementation. */
> @@ -127,52 +126,6 @@ static void init_delay_params(SyncClocks *sc, const 
> CPUState *cpu)
>  }
>  #endif /* CONFIG USER ONLY */
>  
> -void cpu_loop_exit(CPUState *cpu)
> -{
> -    cpu->current_tb = NULL;
> -    siglongjmp(cpu->jmp_env, 1);
> -}
> -
> -/* exit the current TB from a signal handler. The host registers are
> -   restored in a state compatible with the CPU emulator
> - */
> -#if defined(CONFIG_SOFTMMU)
> -void cpu_resume_from_signal(CPUState *cpu, void *puc)
> -{
> -    /* XXX: restore cpu registers saved in host registers */
> -
> -    cpu->exception_index = -1;
> -    siglongjmp(cpu->jmp_env, 1);
> -}
> -
> -void cpu_reload_memory_map(CPUState *cpu)

This doesn't really belong in cpus.c...  I don't have a better
suggestion though, so perhaps just add a FIXME in case one day there is
a cpu-exec-common.c.

Paolo

> -{
> -    AddressSpaceDispatch *d;
> -
> -    if (qemu_in_vcpu_thread()) {
> -        /* Do not let the guest prolong the critical section as much as it
> -         * as it desires.
> -         *
> -         * Currently, this is prevented by the I/O thread's periodinc kicking
> -         * of the VCPU thread (iothread_requesting_mutex, 
> qemu_cpu_kick_thread)
> -         * but this will go away once TCG's execution moves out of the global
> -         * mutex.
> -         *
> -         * This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), 
> which
> -         * only protects cpu->as->dispatch.  Since we reload it below, we can
> -         * split the critical section.
> -         */
> -        rcu_read_unlock();
> -        rcu_read_lock();
> -    }
> -
> -    /* The CPU and TLB are protected by the iothread lock.  */
> -    d = atomic_rcu_read(&cpu->as->dispatch);
> -    cpu->memory_dispatch = d;
> -    tlb_flush(cpu, 1);
> -}
> -#endif
> -
>  /* Execute a TB, and fix up the CPU state afterwards if necessary */
>  static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr)
>  {
> @@ -344,8 +297,6 @@ static void cpu_handle_debug_exception(CPUState *cpu)
>  
>  /* main execution loop */
>  
> -volatile sig_atomic_t exit_request;
> -
>  int cpu_exec(CPUState *cpu)
>  {
>      CPUClass *cc = CPU_GET_CLASS(cpu);
> diff --git a/cpus.c b/cpus.c
> index c8a2911..2dc4a9a 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -28,6 +28,7 @@
>  #include "monitor/monitor.h"
>  #include "qapi/qmp/qerror.h"
>  #include "sysemu/sysemu.h"
> +#include "exec/memory-internal.h"
>  #include "exec/gdbstub.h"
>  #include "sysemu/dma.h"
>  #include "sysemu/kvm.h"
> @@ -64,6 +65,8 @@
>  
>  #endif /* CONFIG_LINUX */
>  
> +volatile sig_atomic_t exit_request;
> +
>  static CPUState *next_cpu;
>  int64_t max_delay;
>  int64_t max_advance;
> @@ -1394,6 +1397,52 @@ static void tcg_exec_all(void)
>      exit_request = 0;
>  }
>  
> +/* exit the current TB from a signal handler. The host registers are
> +   restored in a state compatible with the CPU emulator
> + */
> +#if defined(CONFIG_SOFTMMU)
> +void cpu_resume_from_signal(CPUState *cpu, void *puc)
> +{
> +    /* XXX: restore cpu registers saved in host registers */
> +
> +    cpu->exception_index = -1;
> +    siglongjmp(cpu->jmp_env, 1);
> +}
> +
> +void cpu_reload_memory_map(CPUState *cpu)
> +{
> +    AddressSpaceDispatch *d;
> +
> +    if (qemu_in_vcpu_thread()) {
> +        /* Do not let the guest prolong the critical section as much as it
> +         * as it desires.
> +         *
> +         * Currently, this is prevented by the I/O thread's periodinc kicking
> +         * of the VCPU thread (iothread_requesting_mutex, 
> qemu_cpu_kick_thread)
> +         * but this will go away once TCG's execution moves out of the global
> +         * mutex.
> +         *
> +         * This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), 
> which
> +         * only protects cpu->as->dispatch.  Since we reload it below, we can
> +         * split the critical section.
> +         */
> +        rcu_read_unlock();
> +        rcu_read_lock();
> +    }
> +
> +    /* The CPU and TLB are protected by the iothread lock.  */
> +    d = atomic_rcu_read(&cpu->as->dispatch);
> +    cpu->memory_dispatch = d;
> +    tlb_flush(cpu, 1);
> +}
> +#endif
> +
> +void cpu_loop_exit(CPUState *cpu)
> +{
> +    cpu->current_tb = NULL;
> +    siglongjmp(cpu->jmp_env, 1);
> +}
> +
>  void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
>  {
>      /* XXX: implement xxx_cpu_list for targets that still miss it */
>