[Qemu-devel] Re: [PATCH 04/32] move kqemu_cpu_exec to kqemu.c

[Anthony Liguori <aliguori@us.ibm.com>]

Glauber Costa wrote:
> Only pieces of code that are frame-safe can be moved.
> compute_all() is an example of a non-frame-safe calling.
> So it has to be done prior to calling kqemu_cpu_exec().
>
> Signed-off-by: Glauber Costa <glommer@redhat.com>
> ---
>  cpu-exec.c |   33 +++++++++++++--------------------
>  kqemu.c    |   18 +++++++++++++++++-
>  2 files changed, 30 insertions(+), 21 deletions(-)
>
> diff --git a/cpu-exec.c b/cpu-exec.c
> index 6d4dcdd..f06df26 100644
> --- a/cpu-exec.c
> +++ b/cpu-exec.c
> @@ -336,27 +336,20 @@ int cpu_exec(CPUState *env1)
>                  env->exception_index = -1;
>              }
>  #ifdef USE_KQEMU
> -            if (kqemu_is_ok(env) && env->interrupt_request == 0) {
> -                int ret;
> -                env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK);
> -                ret = kqemu_cpu_exec(env);
> -                /* put eflags in CPU temporary format */
> -                CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
> -                DF = 1 - (2 * ((env->eflags >> 10) & 1));
> -                CC_OP = CC_OP_EFLAGS;
> -                env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
> -                if (ret == 1) {
> -                    /* exception */
> -                    longjmp(env->jmp_env, 1);
> -                } else if (ret == 2) {
> -                    /* softmmu execution needed */
> +            env->eflags = env->eflags | cc_table[CC_OP].compute_all()  | (DF & DF_MASK);
>   

Can't do this unconditionally since you're now recomputing all condition 
flags even when kqemu is not in use.  So unfortunately I'm not sure the 
code can be cleaned up much more if compute_all() must stay in cpu_exec.

Regards,

Anthony Liguori

> +            ret = kqemu_cpu_exec(env);
> +            env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
> +            if (ret == 1) {
> +                /* exception */
> +                longjmp(env->jmp_env, 1);
> +            } else if (ret == 2) {
> +                /* softmmu execution needed */
> +            } else {
> +                if (env->interrupt_request != 0) {
> +                    /* hardware interrupt will be executed just after */
>                  } else {
> -                    if (env->interrupt_request != 0) {
> -                        /* hardware interrupt will be executed just after */
> -                    } else {
> -                        /* otherwise, we restart */
> -                        longjmp(env->jmp_env, 1);
> -                    }
> +                    /* otherwise, we restart */
> +                    longjmp(env->jmp_env, 1);
>                  }
>              }
>  #endif
> diff --git a/kqemu.c b/kqemu.c
> index 4783aa2..39938e0 100644
> --- a/kqemu.c
> +++ b/kqemu.c
> @@ -30,6 +30,7 @@
>  #ifdef HOST_SOLARIS
>  #include <sys/ioccom.h>
>  #endif
> +#include "exec.h"
>  #include <stdlib.h>
>  #include <stdio.h>
>  #include <stdarg.h>
> @@ -689,7 +690,7 @@ static inline void kqemu_save_seg(SegmentCache *sc,
>      sc->base = ksc->base;
>  }
>
> -int kqemu_cpu_exec(CPUState *env)
> +int kqemu_do_cpu_exec(CPUState *env)
>  {
>      struct kqemu_cpu_state kcpu_state, *kenv = &kcpu_state;
>      int ret, cpl, i;
> @@ -939,6 +940,21 @@ int kqemu_cpu_exec(CPUState *env)
>      return 0;
>  }
>
> +int kqemu_cpu_exec(CPUState *env)
> +{
> +
> +    int ret = 2;
> +    if (kqemu_is_ok(env) && env->interrupt_request == 0) {
> +        ret = kqemu_do_cpu_exec(env);
> +        /* put eflags in CPU temporary format */
> +        CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
> +        DF = 1 - (2 * ((env->eflags >> 10) & 1));
> +        CC_OP = CC_OP_EFLAGS;
> +    }
> +    return ret;
> +}
> +
> +
>  void kqemu_cpu_interrupt(CPUState *env)
>  {
>  #if defined(_WIN32)
>