[Qemu-devel] Re: [PATCH 24/32] check wether kqemu is enabled in open code

[Glauber Costa <glommer@redhat.com>]

On Thu, Oct 23, 2008 at 09:23:18AM -0500, Anthony Liguori wrote:
> Glauber Costa wrote:
>> kqemu is still too much spread around. The proper fix
>> usually involves rethinking a bit of kqemu logic so for now,
>> just check whether or not kqemu is enabled. If the kqemu accelerator
>> is not present, consider it not. Otherwise, check env field.
>>
>> Signed-off-by: Glauber Costa <glommer@redhat.com>
>> ---
>>  cpu-exec.c |    2 +-
>>  kqemu.c    |   21 +++++++++++++++++++++
>>  kqemu.h    |    3 +++
>>  3 files changed, 25 insertions(+), 1 deletions(-)
>>
>> diff --git a/cpu-exec.c b/cpu-exec.c
>> index 18908d5..b47cf43 100644
>> --- a/cpu-exec.c
>> +++ b/cpu-exec.c
>> @@ -599,7 +599,7 @@ int cpu_exec(CPUState *env1)
>>                  {
>>                      if (next_tb != 0 &&
>>  #ifdef USE_KQEMU
>> -                        (env->kqemu_enabled != 2) &&
>> +                        (!kqemu_kernel_enabled(env)) &&
>>  #endif
>>                          tb->page_addr[1] == -1) {
>>                      tb_add_jump((TranslationBlock *)(next_tb & ~3), next_tb & 3, tb);
>> diff --git a/kqemu.c b/kqemu.c
>> index 16ebe7d..f99a4f1 100644
>> --- a/kqemu.c
>> +++ b/kqemu.c
>> @@ -126,6 +126,27 @@ static int is_cpuid_supported(void)
>>  }
>>  #endif
>>
>> +/* FIXME: Should not be needed, since ideally, QEMUAccel would avoid all kqemu tests
>> + * altogether
>> + */
>> +int kqemu_is_enabled(CPUState *env)
>> +{
>> +    if (strcasecmp(current_accel->name, "kqemu")) {
>> +        return 0;
>> +    }
>> +
>> +    return env->kqemu_enabled;
>> +
>> +}
>> +
>> +int kqemu_kernel_enabled(CPUState *env)
>> +{
>> +    if (strcasecmp(current_accel->name, "kqemu")) {
>> +        return 0;
>> +    }
>> +    return env->kqemu_enabled == 2;
>> +}
>>   
>
> Why is kqemu_enabled part of the vcpu state?  Wouldn't it always be 0  
> even if we weren't using the accelerator?
It's temporary, to keep things compiling/working. It's dropped in a later patch.

>
> Regards,
>
> Anthony Liguori
>
>>  static void kqemu_update_cpuid(CPUState *env)
>>  {
>>      int critical_features_mask, features, ext_features, ext_features_mask;
>> diff --git a/kqemu.h b/kqemu.h
>> index cf14179..62ba1d9 100644
>> --- a/kqemu.h
>> +++ b/kqemu.h
>> @@ -157,6 +157,9 @@ struct kqemu_phys_mem {
>>  #define KQEMU_SET_PHYS_MEM     _IOW('q', 5, struct kqemu_phys_mem)
>>  #endif
>>
>> +int kqemu_is_enabled(CPUState *env);
>> +int kqemu_kernel_enabled(CPUState *env);
>> +
>>  typedef struct KQEMUCPUstate {
>>      int kqemu_enabled;
>>      int last_io_time;
>>   
>