[v1] accel/kvm: Cleanups around kvm_arch_put_registers()

[PATCH 3/3] accel/kvm: Factor kvm_cpu_synchronize_put() out

Posted by Philippe Mathieu-Daudé 4 months ago

The same code is duplicated 3 times: factor a common method.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 accel/kvm/kvm-all.c | 47 ++++++++++++++++++---------------------------
 1 file changed, 19 insertions(+), 28 deletions(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 9060599cd73..de79f4ca099 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2935,22 +2935,32 @@ void kvm_cpu_synchronize_state(CPUState *cpu)
     }
 }
 
-static void do_kvm_cpu_synchronize_post_reset(CPUState *cpu, run_on_cpu_data arg)
+static bool kvm_cpu_synchronize_put(CPUState *cpu, KvmPutState state,
+                                    const char *desc)
 {
     Error *err = NULL;
-    int ret = kvm_arch_put_registers(cpu, KVM_PUT_RESET_STATE, &err);
+    int ret = kvm_arch_put_registers(cpu, state, &err);
     if (ret) {
         if (err) {
-            error_reportf_err(err, "Restoring resisters after reset: ");
+            error_reportf_err(err, "Restoring resisters %s: ", desc);
         } else {
-            error_report("Failed to put registers after reset: %s",
+            error_report("Failed to put registers %s: %s", desc,
                          strerror(-ret));
         }
-        cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);
-        vm_stop(RUN_STATE_INTERNAL_ERROR);
+        return false;
     }
 
     cpu->vcpu_dirty = false;
+
+    return true;
+}
+
+static void do_kvm_cpu_synchronize_post_reset(CPUState *cpu, run_on_cpu_data arg)
+{
+    if (kvm_cpu_synchronize_put(cpu, KVM_PUT_RESET_STATE, "after reset")) {
+        cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);
+        vm_stop(RUN_STATE_INTERNAL_ERROR);
+    }
 }
 
 void kvm_cpu_synchronize_post_reset(CPUState *cpu)
@@ -2964,19 +2974,9 @@ void kvm_cpu_synchronize_post_reset(CPUState *cpu)
 
 static void do_kvm_cpu_synchronize_post_init(CPUState *cpu, run_on_cpu_data arg)
 {
-    Error *err = NULL;
-    int ret = kvm_arch_put_registers(cpu, KVM_PUT_FULL_STATE, &err);
-    if (ret) {
-        if (err) {
-            error_reportf_err(err, "Putting registers after init: ");
-        } else {
-            error_report("Failed to put registers after init: %s",
-                         strerror(-ret));
-        }
+    if (kvm_cpu_synchronize_put(cpu, KVM_PUT_FULL_STATE, "after init")) {
         exit(1);
     }
-
-    cpu->vcpu_dirty = false;
 }
 
 void kvm_cpu_synchronize_post_init(CPUState *cpu)
@@ -3166,20 +3166,11 @@ int kvm_cpu_exec(CPUState *cpu)
         MemTxAttrs attrs;
 
         if (cpu->vcpu_dirty) {
-            Error *err = NULL;
-            ret = kvm_arch_put_registers(cpu, KVM_PUT_RUNTIME_STATE, &err);
-            if (ret) {
-                if (err) {
-                    error_reportf_err(err, "Putting registers after init: ");
-                } else {
-                    error_report("Failed to put registers after init: %s",
-                                 strerror(-ret));
-                }
+            if (kvm_cpu_synchronize_put(cpu, KVM_PUT_RUNTIME_STATE,
+                                        "at runtime")) {
                 ret = -1;
                 break;
             }
-
-            cpu->vcpu_dirty = false;
         }
 
         kvm_arch_pre_run(cpu, run);
-- 
2.51.0

Re: [PATCH 3/3] accel/kvm: Factor kvm_cpu_synchronize_put() out

Posted by Richard Henderson 4 months ago

On 10/7/25 01:16, Philippe Mathieu-Daudé wrote:
> The same code is duplicated 3 times: factor a common method.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   accel/kvm/kvm-all.c | 47 ++++++++++++++++++---------------------------
>   1 file changed, 19 insertions(+), 28 deletions(-)
> 
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index 9060599cd73..de79f4ca099 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -2935,22 +2935,32 @@ void kvm_cpu_synchronize_state(CPUState *cpu)
>       }
>   }
>   
> -static void do_kvm_cpu_synchronize_post_reset(CPUState *cpu, run_on_cpu_data arg)
> +static bool kvm_cpu_synchronize_put(CPUState *cpu, KvmPutState state,
> +                                    const char *desc)
>   {
>       Error *err = NULL;
> -    int ret = kvm_arch_put_registers(cpu, KVM_PUT_RESET_STATE, &err);
> +    int ret = kvm_arch_put_registers(cpu, state, &err);
>       if (ret) {
>           if (err) {
> -            error_reportf_err(err, "Restoring resisters after reset: ");
> +            error_reportf_err(err, "Restoring resisters %s: ", desc);
>           } else {
> -            error_report("Failed to put registers after reset: %s",
> +            error_report("Failed to put registers %s: %s", desc,
>                            strerror(-ret));
>           }

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

For the to-do list: the arch routine really should be using error_setg_errno, not 
deferring the test of errno to here.  But it seems i386 is the only target that actually 
sets errp.


r~

Re: [PATCH 3/3] accel/kvm: Factor kvm_cpu_synchronize_put() out

Posted by Andrew Jones 4 months ago

On Tue, Oct 07, 2025 at 10:16:16AM +0200, Philippe Mathieu-Daudé wrote:
> The same code is duplicated 3 times: factor a common method.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  accel/kvm/kvm-all.c | 47 ++++++++++++++++++---------------------------
>  1 file changed, 19 insertions(+), 28 deletions(-)
> 
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index 9060599cd73..de79f4ca099 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -2935,22 +2935,32 @@ void kvm_cpu_synchronize_state(CPUState *cpu)
>      }
>  }
>  
> -static void do_kvm_cpu_synchronize_post_reset(CPUState *cpu, run_on_cpu_data arg)
> +static bool kvm_cpu_synchronize_put(CPUState *cpu, KvmPutState state,
> +                                    const char *desc)
>  {
>      Error *err = NULL;
> -    int ret = kvm_arch_put_registers(cpu, KVM_PUT_RESET_STATE, &err);
> +    int ret = kvm_arch_put_registers(cpu, state, &err);
>      if (ret) {
>          if (err) {
> -            error_reportf_err(err, "Restoring resisters after reset: ");
> +            error_reportf_err(err, "Restoring resisters %s: ", desc);
>          } else {
> -            error_report("Failed to put registers after reset: %s",
> +            error_report("Failed to put registers %s: %s", desc,
>                           strerror(-ret));
>          }
> -        cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);
> -        vm_stop(RUN_STATE_INTERNAL_ERROR);
> +        return false;
>      }
>  
>      cpu->vcpu_dirty = false;
> +
> +    return true;
> +}
> +
> +static void do_kvm_cpu_synchronize_post_reset(CPUState *cpu, run_on_cpu_data arg)
> +{
> +    if (kvm_cpu_synchronize_put(cpu, KVM_PUT_RESET_STATE, "after reset")) {

This should be !kvm_cpu_synchronize_put() and same comment for the other
calls below.

Thanks,
drew

> +        cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);
> +        vm_stop(RUN_STATE_INTERNAL_ERROR);
> +    }
>  }
>  
>  void kvm_cpu_synchronize_post_reset(CPUState *cpu)
> @@ -2964,19 +2974,9 @@ void kvm_cpu_synchronize_post_reset(CPUState *cpu)
>  
>  static void do_kvm_cpu_synchronize_post_init(CPUState *cpu, run_on_cpu_data arg)
>  {
> -    Error *err = NULL;
> -    int ret = kvm_arch_put_registers(cpu, KVM_PUT_FULL_STATE, &err);
> -    if (ret) {
> -        if (err) {
> -            error_reportf_err(err, "Putting registers after init: ");
> -        } else {
> -            error_report("Failed to put registers after init: %s",
> -                         strerror(-ret));
> -        }
> +    if (kvm_cpu_synchronize_put(cpu, KVM_PUT_FULL_STATE, "after init")) {
>          exit(1);
>      }
> -
> -    cpu->vcpu_dirty = false;
>  }
>  
>  void kvm_cpu_synchronize_post_init(CPUState *cpu)
> @@ -3166,20 +3166,11 @@ int kvm_cpu_exec(CPUState *cpu)
>          MemTxAttrs attrs;
>  
>          if (cpu->vcpu_dirty) {
> -            Error *err = NULL;
> -            ret = kvm_arch_put_registers(cpu, KVM_PUT_RUNTIME_STATE, &err);
> -            if (ret) {
> -                if (err) {
> -                    error_reportf_err(err, "Putting registers after init: ");
> -                } else {
> -                    error_report("Failed to put registers after init: %s",
> -                                 strerror(-ret));
> -                }
> +            if (kvm_cpu_synchronize_put(cpu, KVM_PUT_RUNTIME_STATE,
> +                                        "at runtime")) {
>                  ret = -1;
>                  break;
>              }
> -
> -            cpu->vcpu_dirty = false;
>          }
>  
>          kvm_arch_pre_run(cpu, run);
> -- 
> 2.51.0
> 
>

Re: [PATCH 3/3] accel/kvm: Factor kvm_cpu_synchronize_put() out

Posted by Philippe Mathieu-Daudé 4 months ago

On 7/10/25 15:30, Andrew Jones wrote:
> On Tue, Oct 07, 2025 at 10:16:16AM +0200, Philippe Mathieu-Daudé wrote:
>> The same code is duplicated 3 times: factor a common method.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>>   accel/kvm/kvm-all.c | 47 ++++++++++++++++++---------------------------
>>   1 file changed, 19 insertions(+), 28 deletions(-)
>>
>> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
>> index 9060599cd73..de79f4ca099 100644
>> --- a/accel/kvm/kvm-all.c
>> +++ b/accel/kvm/kvm-all.c
>> @@ -2935,22 +2935,32 @@ void kvm_cpu_synchronize_state(CPUState *cpu)
>>       }
>>   }
>>   
>> -static void do_kvm_cpu_synchronize_post_reset(CPUState *cpu, run_on_cpu_data arg)
>> +static bool kvm_cpu_synchronize_put(CPUState *cpu, KvmPutState state,
>> +                                    const char *desc)
>>   {
>>       Error *err = NULL;
>> -    int ret = kvm_arch_put_registers(cpu, KVM_PUT_RESET_STATE, &err);
>> +    int ret = kvm_arch_put_registers(cpu, state, &err);
>>       if (ret) {
>>           if (err) {
>> -            error_reportf_err(err, "Restoring resisters after reset: ");
>> +            error_reportf_err(err, "Restoring resisters %s: ", desc);
>>           } else {
>> -            error_report("Failed to put registers after reset: %s",
>> +            error_report("Failed to put registers %s: %s", desc,
>>                            strerror(-ret));
>>           }
>> -        cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);
>> -        vm_stop(RUN_STATE_INTERNAL_ERROR);
>> +        return false;
>>       }
>>   
>>       cpu->vcpu_dirty = false;
>> +
>> +    return true;
>> +}
>> +
>> +static void do_kvm_cpu_synchronize_post_reset(CPUState *cpu, run_on_cpu_data arg)
>> +{
>> +    if (kvm_cpu_synchronize_put(cpu, KVM_PUT_RESET_STATE, "after reset")) {
> 
> This should be !kvm_cpu_synchronize_put() and same comment for the other
> calls below.

Oops! Thanks :)

> 
> Thanks,
> drew