[v2] accel: Only include qdev-realized vCPUs in global &cpus_queue

[PATCH v2 02/10] loongarch: reset vcpu after it's created

Posted by Igor Mammedov 1 month, 3 weeks ago

Reseting vcpu before its thread is created, caused various issues in the past
for other targets. It doesn't cause issues for loongarch at the moment but
to be consistent with the rest of targets, move reset during realize time
after qemu_init_vcpu().

That basically prevents reset being run when when vCPU is in incositent state
(i.e. accelerator hasn't initialized vCPU yet).

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
CC: Song Gao <gaosong@loongson.cn>
---
 target/loongarch/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index e91f4a5239..15018d43ae 100644
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -634,8 +634,8 @@ static void loongarch_cpu_realizefn(DeviceState *dev, Error **errp)
 
     loongarch_cpu_register_gdb_regs_for_features(cs);
 
-    cpu_reset(cs);
     qemu_init_vcpu(cs);
+    cpu_reset(cs);
 
     lacc->parent_realize(dev, errp);
 }
-- 
2.43.0

Re: [PATCH v2 02/10] loongarch: reset vcpu after it's created

Posted by Philippe Mathieu-Daudé 1 month, 1 week ago

On 7/2/25 17:20, Igor Mammedov wrote:
> Reseting vcpu before its thread is created, caused various issues in the past
> for other targets. It doesn't cause issues for loongarch at the moment but
> to be consistent with the rest of targets, move reset during realize time
> after qemu_init_vcpu().
> 
> That basically prevents reset being run when when vCPU is in incositent state

"inconsistent"

> (i.e. accelerator hasn't initialized vCPU yet).
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Cc: qemu-stable@nongnu.org

> ---
> CC: Song Gao <gaosong@loongson.cn>
> ---
>   target/loongarch/cpu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
> index e91f4a5239..15018d43ae 100644
> --- a/target/loongarch/cpu.c
> +++ b/target/loongarch/cpu.c
> @@ -634,8 +634,8 @@ static void loongarch_cpu_realizefn(DeviceState *dev, Error **errp)
>   
>       loongarch_cpu_register_gdb_regs_for_features(cs);
>   
> -    cpu_reset(cs);
>       qemu_init_vcpu(cs);
> +    cpu_reset(cs);
>   
>       lacc->parent_realize(dev, errp);
>   }

Re: [PATCH v2 02/10] loongarch: reset vcpu after it's created

Posted by bibo mao 1 month, 1 week ago


On 2025/2/8 上午12:20, Igor Mammedov wrote:
> Reseting vcpu before its thread is created, caused various issues in the past
> for other targets. It doesn't cause issues for loongarch at the moment but
> to be consistent with the rest of targets, move reset during realize time
> after qemu_init_vcpu().
> 
> That basically prevents reset being run when when vCPU is in incositent state
> (i.e. accelerator hasn't initialized vCPU yet).
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> CC: Song Gao <gaosong@loongson.cn>
> ---
>   target/loongarch/cpu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
> index e91f4a5239..15018d43ae 100644
> --- a/target/loongarch/cpu.c
> +++ b/target/loongarch/cpu.c
> @@ -634,8 +634,8 @@ static void loongarch_cpu_realizefn(DeviceState *dev, Error **errp)
>   
>       loongarch_cpu_register_gdb_regs_for_features(cs);
>   
> -    cpu_reset(cs);
>       qemu_init_vcpu(cs);
> +    cpu_reset(cs);
>   
>       lacc->parent_realize(dev, errp);
>   }
>
yes, that is actually a problem in kvm mode. vCPU thread should be 
created and kvm_fd for the vCPU need valid before cpu_reset().

Reviewed-by: Bibo Mao <maobibo@loongson.cn>