diff mbox series

[RFC,v2,6/8] cpu: Declare cpu_has_work() in 'sysemu/tcg.h'

Message ID 20210304222323.1954755-7-f4bug@amsat.org
State New
Headers show
Series cpu: Move CPUClass::has_work() to TCGCPUOps | expand

Commit Message

Philippe Mathieu-Daudé March 4, 2021, 10:23 p.m. UTC
We can only check if a vCPU has work with TCG.
Move the cpu_has_work() prototype to "sysemu/tcg.h".

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
RFC: could another accelerator do that?
     can we rename this tcg_vcpu_has_work()?
---
 include/hw/core/cpu.h | 16 ----------------
 include/sysemu/tcg.h  | 11 +++++++++++
 accel/tcg/cpu-exec.c  |  7 +++++++
 softmmu/cpus.c        |  1 +
 4 files changed, 19 insertions(+), 16 deletions(-)

Comments

Claudio Fontana March 8, 2021, 12:13 p.m. UTC | #1
On 3/4/21 11:23 PM, Philippe Mathieu-Daudé wrote:
> We can only check if a vCPU has work with TCG.
> Move the cpu_has_work() prototype to "sysemu/tcg.h".
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> RFC: could another accelerator do that?
>      can we rename this tcg_vcpu_has_work()?
> ---
>  include/hw/core/cpu.h | 16 ----------------
>  include/sysemu/tcg.h  | 11 +++++++++++
>  accel/tcg/cpu-exec.c  |  7 +++++++
>  softmmu/cpus.c        |  1 +
>  4 files changed, 19 insertions(+), 16 deletions(-)
> 
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 1376e496a3f..66109bcca35 100644
> --- a/include/hw/core/cpu.h
> +++ b/include/hw/core/cpu.h
> @@ -670,22 +670,6 @@ CPUState *cpu_create(const char *typename);
>   */
>  const char *parse_cpu_option(const char *cpu_option);
>  
> -/**
> - * cpu_has_work:
> - * @cpu: The vCPU to check.
> - *
> - * Checks whether the CPU has work to do.
> - *
> - * Returns: %true if the CPU has work, %false otherwise.
> - */
> -static inline bool cpu_has_work(CPUState *cpu)
> -{
> -    CPUClass *cc = CPU_GET_CLASS(cpu);
> -
> -    g_assert(cc->has_work);
> -    return cc->has_work(cpu);
> -}
> -
>  /**
>   * qemu_cpu_is_self:
>   * @cpu: The vCPU to check against.
> diff --git a/include/sysemu/tcg.h b/include/sysemu/tcg.h
> index c16c13c3c69..3d46b0a7a93 100644
> --- a/include/sysemu/tcg.h
> +++ b/include/sysemu/tcg.h
> @@ -10,6 +10,7 @@
>  
>  #ifndef CONFIG_TCG
>  #define tcg_enabled() 0
> +#define cpu_has_work(cpu) false


I am not sure I like this approach,

it is misleading for the reader: cpu_has_work should not be called for TCG at all,
or at least a clue should be given that it is indeed a TCG-only function.

Otherwise, from the common code, the reader does not have any clue from the context that this is actually meaningful for TCG only.

Where is this actually used..?


>  #else
>  
>  void tcg_exec_init(unsigned long tb_size, int splitwx);
> @@ -26,6 +27,16 @@ extern bool tcg_allowed;
>  extern bool mttcg_enabled;
>  #define qemu_tcg_mttcg_enabled() (mttcg_enabled)
>  
> +/**
> + * cpu_has_work:
> + * @cpu: The vCPU to check.
> + *
> + * Checks whether the CPU has work to do.
> + *
> + * Returns: %true if the CPU has work, %false otherwise.
> + */
> +bool cpu_has_work(CPUState *cpu);
> +
>  #endif /* CONFIG_TCG */
>  
>  #endif
> diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
> index 7e67ade35b9..b9ce36e59e2 100644
> --- a/accel/tcg/cpu-exec.c
> +++ b/accel/tcg/cpu-exec.c
> @@ -447,6 +447,13 @@ static inline TranslationBlock *tb_find(CPUState *cpu,
>      return tb;
>  }
>  
> +bool cpu_has_work(CPUState *cpu)
> +{
> +    CPUClass *cc = CPU_GET_CLASS(cpu);
> +
> +    return cc->has_work(cpu);
> +}
> +
>  static inline bool cpu_handle_halt(CPUState *cpu)
>  {
>      if (cpu->halted) {
> diff --git a/softmmu/cpus.c b/softmmu/cpus.c
> index a7ee431187a..548ab9236f1 100644
> --- a/softmmu/cpus.c
> +++ b/softmmu/cpus.c
> @@ -42,6 +42,7 @@
>  #include "sysemu/runstate.h"
>  #include "sysemu/cpu-timers.h"
>  #include "sysemu/whpx.h"
> +#include "sysemu/tcg.h"
>  #include "hw/boards.h"
>  #include "hw/hw.h"
>  
>
Claudio Fontana March 8, 2021, 12:17 p.m. UTC | #2
On 3/4/21 11:23 PM, Philippe Mathieu-Daudé wrote:
> We can only check if a vCPU has work with TCG.
> Move the cpu_has_work() prototype to "sysemu/tcg.h".
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> RFC: could another accelerator do that?
>      can we rename this tcg_vcpu_has_work()?
> ---
>  include/hw/core/cpu.h | 16 ----------------
>  include/sysemu/tcg.h  | 11 +++++++++++
>  accel/tcg/cpu-exec.c  |  7 +++++++
>  softmmu/cpus.c        |  1 +
>  4 files changed, 19 insertions(+), 16 deletions(-)
> 
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 1376e496a3f..66109bcca35 100644
> --- a/include/hw/core/cpu.h
> +++ b/include/hw/core/cpu.h
> @@ -670,22 +670,6 @@ CPUState *cpu_create(const char *typename);
>   */
>  const char *parse_cpu_option(const char *cpu_option);
>  
> -/**
> - * cpu_has_work:
> - * @cpu: The vCPU to check.
> - *
> - * Checks whether the CPU has work to do.
> - *
> - * Returns: %true if the CPU has work, %false otherwise.
> - */
> -static inline bool cpu_has_work(CPUState *cpu)
> -{
> -    CPUClass *cc = CPU_GET_CLASS(cpu);
> -
> -    g_assert(cc->has_work);
> -    return cc->has_work(cpu);
> -}
> -
>  /**
>   * qemu_cpu_is_self:
>   * @cpu: The vCPU to check against.
> diff --git a/include/sysemu/tcg.h b/include/sysemu/tcg.h
> index c16c13c3c69..3d46b0a7a93 100644
> --- a/include/sysemu/tcg.h
> +++ b/include/sysemu/tcg.h
> @@ -10,6 +10,7 @@
>  
>  #ifndef CONFIG_TCG
>  #define tcg_enabled() 0
> +#define cpu_has_work(cpu) false

email errors, so not sure if my previous message went off.

I am not convinced by this approach of _hiding_ the fact that cpu_has_work is TCG-only from the context where it is used.

When reading the actual code using this, how to get an immediate clue that this is TCG-only?

I think cpu_has_work should either be renamed to tcg_cpu_has_work(), thus providing the context in the name,
or it should not be visible/called for non-TCG at all, its call protected in some way (if (tcg_enabled() or ifdef or such..)

Ciao,

Claudio


>  #else
>  
>  void tcg_exec_init(unsigned long tb_size, int splitwx);
> @@ -26,6 +27,16 @@ extern bool tcg_allowed;
>  extern bool mttcg_enabled;
>  #define qemu_tcg_mttcg_enabled() (mttcg_enabled)
>  
> +/**
> + * cpu_has_work:
> + * @cpu: The vCPU to check.
> + *
> + * Checks whether the CPU has work to do.
> + *
> + * Returns: %true if the CPU has work, %false otherwise.
> + */
> +bool cpu_has_work(CPUState *cpu);
> +
>  #endif /* CONFIG_TCG */
>  
>  #endif
> diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
> index 7e67ade35b9..b9ce36e59e2 100644
> --- a/accel/tcg/cpu-exec.c
> +++ b/accel/tcg/cpu-exec.c
> @@ -447,6 +447,13 @@ static inline TranslationBlock *tb_find(CPUState *cpu,
>      return tb;
>  }
>  
> +bool cpu_has_work(CPUState *cpu)
> +{
> +    CPUClass *cc = CPU_GET_CLASS(cpu);
> +
> +    return cc->has_work(cpu);
> +}
> +
>  static inline bool cpu_handle_halt(CPUState *cpu)
>  {
>      if (cpu->halted) {
> diff --git a/softmmu/cpus.c b/softmmu/cpus.c
> index a7ee431187a..548ab9236f1 100644
> --- a/softmmu/cpus.c
> +++ b/softmmu/cpus.c
> @@ -42,6 +42,7 @@
>  #include "sysemu/runstate.h"
>  #include "sysemu/cpu-timers.h"
>  #include "sysemu/whpx.h"
> +#include "sysemu/tcg.h"
>  #include "hw/boards.h"
>  #include "hw/hw.h"
>  
>
Philippe Mathieu-Daudé March 8, 2021, 1:37 p.m. UTC | #3
On 3/8/21 1:17 PM, Claudio Fontana wrote:
> On 3/4/21 11:23 PM, Philippe Mathieu-Daudé wrote:
>> We can only check if a vCPU has work with TCG.
>> Move the cpu_has_work() prototype to "sysemu/tcg.h".
>>
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>> RFC: could another accelerator do that?
>>      can we rename this tcg_vcpu_has_work()?
>> ---
>>  include/hw/core/cpu.h | 16 ----------------
>>  include/sysemu/tcg.h  | 11 +++++++++++
>>  accel/tcg/cpu-exec.c  |  7 +++++++
>>  softmmu/cpus.c        |  1 +
>>  4 files changed, 19 insertions(+), 16 deletions(-)
>>
>> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
>> index 1376e496a3f..66109bcca35 100644
>> --- a/include/hw/core/cpu.h
>> +++ b/include/hw/core/cpu.h
>> @@ -670,22 +670,6 @@ CPUState *cpu_create(const char *typename);
>>   */
>>  const char *parse_cpu_option(const char *cpu_option);
>>  
>> -/**
>> - * cpu_has_work:
>> - * @cpu: The vCPU to check.
>> - *
>> - * Checks whether the CPU has work to do.
>> - *
>> - * Returns: %true if the CPU has work, %false otherwise.
>> - */
>> -static inline bool cpu_has_work(CPUState *cpu)
>> -{
>> -    CPUClass *cc = CPU_GET_CLASS(cpu);
>> -
>> -    g_assert(cc->has_work);
>> -    return cc->has_work(cpu);
>> -}
>> -
>>  /**
>>   * qemu_cpu_is_self:
>>   * @cpu: The vCPU to check against.
>> diff --git a/include/sysemu/tcg.h b/include/sysemu/tcg.h
>> index c16c13c3c69..3d46b0a7a93 100644
>> --- a/include/sysemu/tcg.h
>> +++ b/include/sysemu/tcg.h
>> @@ -10,6 +10,7 @@
>>  
>>  #ifndef CONFIG_TCG
>>  #define tcg_enabled() 0
>> +#define cpu_has_work(cpu) false
> 
> email errors, so not sure if my previous message went off.

Yes, got it.

> 
> I am not convinced by this approach of _hiding_ the fact that cpu_has_work is TCG-only from the context where it is used.
> 
> When reading the actual code using this, how to get an immediate clue that this is TCG-only?
> 
> I think cpu_has_work should either be renamed to tcg_cpu_has_work(), thus providing the context in the name,
> or it should not be visible/called for non-TCG at all, its call protected in some way (if (tcg_enabled() or ifdef or such..)

If no other accelerator can do that, then I agree. I don't know enough
all accelerators to be sure.

> 
> Ciao,
> 
> Claudio
> 
> 
>>  #else
>>  
>>  void tcg_exec_init(unsigned long tb_size, int splitwx);
>> @@ -26,6 +27,16 @@ extern bool tcg_allowed;
>>  extern bool mttcg_enabled;
>>  #define qemu_tcg_mttcg_enabled() (mttcg_enabled)
>>  
>> +/**
>> + * cpu_has_work:
>> + * @cpu: The vCPU to check.
>> + *
>> + * Checks whether the CPU has work to do.
>> + *
>> + * Returns: %true if the CPU has work, %false otherwise.
>> + */
>> +bool cpu_has_work(CPUState *cpu);
>> +
>>  #endif /* CONFIG_TCG */
>>  
>>  #endif
>> diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
>> index 7e67ade35b9..b9ce36e59e2 100644
>> --- a/accel/tcg/cpu-exec.c
>> +++ b/accel/tcg/cpu-exec.c
>> @@ -447,6 +447,13 @@ static inline TranslationBlock *tb_find(CPUState *cpu,
>>      return tb;
>>  }
>>  
>> +bool cpu_has_work(CPUState *cpu)
>> +{
>> +    CPUClass *cc = CPU_GET_CLASS(cpu);
>> +
>> +    return cc->has_work(cpu);
>> +}
>> +
>>  static inline bool cpu_handle_halt(CPUState *cpu)
>>  {
>>      if (cpu->halted) {
>> diff --git a/softmmu/cpus.c b/softmmu/cpus.c
>> index a7ee431187a..548ab9236f1 100644
>> --- a/softmmu/cpus.c
>> +++ b/softmmu/cpus.c
>> @@ -42,6 +42,7 @@
>>  #include "sysemu/runstate.h"
>>  #include "sysemu/cpu-timers.h"
>>  #include "sysemu/whpx.h"
>> +#include "sysemu/tcg.h"
>>  #include "hw/boards.h"
>>  #include "hw/hw.h"
>>  
>>
> 
>
diff mbox series

Patch

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 1376e496a3f..66109bcca35 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -670,22 +670,6 @@  CPUState *cpu_create(const char *typename);
  */
 const char *parse_cpu_option(const char *cpu_option);
 
-/**
- * cpu_has_work:
- * @cpu: The vCPU to check.
- *
- * Checks whether the CPU has work to do.
- *
- * Returns: %true if the CPU has work, %false otherwise.
- */
-static inline bool cpu_has_work(CPUState *cpu)
-{
-    CPUClass *cc = CPU_GET_CLASS(cpu);
-
-    g_assert(cc->has_work);
-    return cc->has_work(cpu);
-}
-
 /**
  * qemu_cpu_is_self:
  * @cpu: The vCPU to check against.
diff --git a/include/sysemu/tcg.h b/include/sysemu/tcg.h
index c16c13c3c69..3d46b0a7a93 100644
--- a/include/sysemu/tcg.h
+++ b/include/sysemu/tcg.h
@@ -10,6 +10,7 @@ 
 
 #ifndef CONFIG_TCG
 #define tcg_enabled() 0
+#define cpu_has_work(cpu) false
 #else
 
 void tcg_exec_init(unsigned long tb_size, int splitwx);
@@ -26,6 +27,16 @@  extern bool tcg_allowed;
 extern bool mttcg_enabled;
 #define qemu_tcg_mttcg_enabled() (mttcg_enabled)
 
+/**
+ * cpu_has_work:
+ * @cpu: The vCPU to check.
+ *
+ * Checks whether the CPU has work to do.
+ *
+ * Returns: %true if the CPU has work, %false otherwise.
+ */
+bool cpu_has_work(CPUState *cpu);
+
 #endif /* CONFIG_TCG */
 
 #endif
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 7e67ade35b9..b9ce36e59e2 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -447,6 +447,13 @@  static inline TranslationBlock *tb_find(CPUState *cpu,
     return tb;
 }
 
+bool cpu_has_work(CPUState *cpu)
+{
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+
+    return cc->has_work(cpu);
+}
+
 static inline bool cpu_handle_halt(CPUState *cpu)
 {
     if (cpu->halted) {
diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index a7ee431187a..548ab9236f1 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -42,6 +42,7 @@ 
 #include "sysemu/runstate.h"
 #include "sysemu/cpu-timers.h"
 #include "sysemu/whpx.h"
+#include "sysemu/tcg.h"
 #include "hw/boards.h"
 #include "hw/hw.h"