[v2] LoongArch: KVM: Add missing slots_lock for IO bus device register/unregister

[PATCH v2 net] LoongArch: KVM: Add missing slots_lock for IO bus device register/unregister

Posted by Zeng Chi 2 weeks ago

From: Zeng Chi <zengchi@kylinos.cn>

kvm_io_bus_register_dev() and kvm_io_bus_unregister_dev() should be
called under kvm->slots_lock. The unregister calls in ipi.c, pch_pic.c
and eiointc.c were missing this protection. Add it to match the
register side.

Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
---
 arch/loongarch/kvm/intc/eiointc.c | 6 ++++++
 arch/loongarch/kvm/intc/ipi.c     | 2 ++
 arch/loongarch/kvm/intc/pch_pic.c | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
index 2ab7fafa86d5..2b14485d14a7 100644
--- a/arch/loongarch/kvm/intc/eiointc.c
+++ b/arch/loongarch/kvm/intc/eiointc.c
@@ -645,10 +645,14 @@ static int kvm_eiointc_create(struct kvm_device *dev, u32 type)
 
 	device = &s->device_vext;
 	kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
+	mutex_lock(&kvm->slots_lock);
 	ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
 			EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
+	mutex_unlock(&kvm->slots_lock);
 	if (ret < 0) {
+		mutex_lock(&kvm->slots_lock);
 		kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
+		mutex_unlock(&kvm->slots_lock);
 		kfree(s);
 		return ret;
 	}
@@ -667,8 +671,10 @@ static void kvm_eiointc_destroy(struct kvm_device *dev)
 
 	kvm = dev->kvm;
 	eiointc = kvm->arch.eiointc;
+	mutex_lock(&kvm->slots_lock);
 	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device);
 	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device_vext);
+	mutex_unlock(&kvm->slots_lock);
 	kfree(eiointc);
 	kfree(dev);
 }
diff --git a/arch/loongarch/kvm/intc/ipi.c b/arch/loongarch/kvm/intc/ipi.c
index 1f6ebbd0af5c..4fa0897d7bdb 100644
--- a/arch/loongarch/kvm/intc/ipi.c
+++ b/arch/loongarch/kvm/intc/ipi.c
@@ -447,7 +447,9 @@ static void kvm_ipi_destroy(struct kvm_device *dev)
 
 	kvm = dev->kvm;
 	ipi = kvm->arch.ipi;
+	mutex_lock(&kvm->slots_lock);
 	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->device);
+	mutex_unlock(&kvm->slots_lock);
 	kfree(ipi);
 	kfree(dev);
 }
diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c
index aa0ed59ae8cf..175a630aceb4 100644
--- a/arch/loongarch/kvm/intc/pch_pic.c
+++ b/arch/loongarch/kvm/intc/pch_pic.c
@@ -481,7 +481,9 @@ static void kvm_pch_pic_destroy(struct kvm_device *dev)
 	kvm = dev->kvm;
 	s = kvm->arch.pch_pic;
 	/* unregister pch pic device and free it's memory */
+	mutex_lock(&kvm->slots_lock);
 	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device);
+	mutex_unlock(&kvm->slots_lock);
 	kfree(s);
 	kfree(dev);
 }
-- 
2.25.1

Re: [PATCH v2 net] LoongArch: KVM: Add missing slots_lock for IO bus device register/unregister

Posted by Bibo Mao 2 weeks ago


On 2026/5/25 下午5:26, Zeng Chi wrote:
> From: Zeng Chi <zengchi@kylinos.cn>
> 
> kvm_io_bus_register_dev() and kvm_io_bus_unregister_dev() should be
> called under kvm->slots_lock. The unregister calls in ipi.c, pch_pic.c
> and eiointc.c were missing this protection. Add it to match the
> register side.
one small nit, the mail tile is [PATCH v2 net], I think it should be 
[PATCH v2] :)

> 
> Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
> ---
>   arch/loongarch/kvm/intc/eiointc.c | 6 ++++++
>   arch/loongarch/kvm/intc/ipi.c     | 2 ++
>   arch/loongarch/kvm/intc/pch_pic.c | 2 ++
>   3 files changed, 10 insertions(+)
> 
> diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
> index 2ab7fafa86d5..2b14485d14a7 100644
> --- a/arch/loongarch/kvm/intc/eiointc.c
> +++ b/arch/loongarch/kvm/intc/eiointc.c
> @@ -645,10 +645,14 @@ static int kvm_eiointc_create(struct kvm_device *dev, u32 type)
>   
>   	device = &s->device_vext;
>   	kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
> +	mutex_lock(&kvm->slots_lock);
>   	ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
>   			EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
> +	mutex_unlock(&kvm->slots_lock);
>   	if (ret < 0) {
> +		mutex_lock(&kvm->slots_lock);
>   		kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
> +		mutex_unlock(&kvm->slots_lock);
>   		kfree(s);
>   		return ret;
>   	}

I prefer something like this, however it is only my personal option.
--- a/arch/loongarch/kvm/intc/eiointc.c
+++ b/arch/loongarch/kvm/intc/eiointc.c
@@ -645,13 +645,16 @@ static int kvm_eiointc_create(struct kvm_device 
*dev, u32 type)

         device = &s->device_vext;
         kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
+       mutex_lock(&kvm->slots_lock);
         ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
                         EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
         if (ret < 0) {
                 kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
+               mutex_unlock(&kvm->slots_lock);
                 kfree(s);
                 return ret;
         }
+       mutex_unlock(&kvm->slots_lock);
         kvm->arch.eiointc = s;

@chenhuacai what is your option?

The others look good to me.

Regards
Bibo Mao
> @@ -667,8 +671,10 @@ static void kvm_eiointc_destroy(struct kvm_device *dev)
>   
>   	kvm = dev->kvm;
>   	eiointc = kvm->arch.eiointc;
> +	mutex_lock(&kvm->slots_lock);
>   	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device);
>   	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device_vext);
> +	mutex_unlock(&kvm->slots_lock);
>   	kfree(eiointc);
>   	kfree(dev);
>   }
> diff --git a/arch/loongarch/kvm/intc/ipi.c b/arch/loongarch/kvm/intc/ipi.c
> index 1f6ebbd0af5c..4fa0897d7bdb 100644
> --- a/arch/loongarch/kvm/intc/ipi.c
> +++ b/arch/loongarch/kvm/intc/ipi.c
> @@ -447,7 +447,9 @@ static void kvm_ipi_destroy(struct kvm_device *dev)
>   
>   	kvm = dev->kvm;
>   	ipi = kvm->arch.ipi;
> +	mutex_lock(&kvm->slots_lock);
>   	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->device);
> +	mutex_unlock(&kvm->slots_lock);
>   	kfree(ipi);
>   	kfree(dev);
>   }
> diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c
> index aa0ed59ae8cf..175a630aceb4 100644
> --- a/arch/loongarch/kvm/intc/pch_pic.c
> +++ b/arch/loongarch/kvm/intc/pch_pic.c
> @@ -481,7 +481,9 @@ static void kvm_pch_pic_destroy(struct kvm_device *dev)
>   	kvm = dev->kvm;
>   	s = kvm->arch.pch_pic;
>   	/* unregister pch pic device and free it's memory */
> +	mutex_lock(&kvm->slots_lock);
>   	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device);
> +	mutex_unlock(&kvm->slots_lock);
>   	kfree(s);
>   	kfree(dev);
>   }
>

Re: [PATCH v2 net] LoongArch: KVM: Add missing slots_lock for IO bus device register/unregister

Posted by Huacai Chen 2 weeks ago

On Mon, May 25, 2026 at 5:53 PM Bibo Mao <maobibo@loongson.cn> wrote:
>
>
>
> On 2026/5/25 下午5:26, Zeng Chi wrote:
> > From: Zeng Chi <zengchi@kylinos.cn>
> >
> > kvm_io_bus_register_dev() and kvm_io_bus_unregister_dev() should be
> > called under kvm->slots_lock. The unregister calls in ipi.c, pch_pic.c
> > and eiointc.c were missing this protection. Add it to match the
> > register side.
> one small nit, the mail tile is [PATCH v2 net], I think it should be
> [PATCH v2] :)
>
> >
> > Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
> > ---
> >   arch/loongarch/kvm/intc/eiointc.c | 6 ++++++
> >   arch/loongarch/kvm/intc/ipi.c     | 2 ++
> >   arch/loongarch/kvm/intc/pch_pic.c | 2 ++
> >   3 files changed, 10 insertions(+)
> >
> > diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
> > index 2ab7fafa86d5..2b14485d14a7 100644
> > --- a/arch/loongarch/kvm/intc/eiointc.c
> > +++ b/arch/loongarch/kvm/intc/eiointc.c
> > @@ -645,10 +645,14 @@ static int kvm_eiointc_create(struct kvm_device *dev, u32 type)
> >
> >       device = &s->device_vext;
> >       kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
> > +     mutex_lock(&kvm->slots_lock);
> >       ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
> >                       EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
> > +     mutex_unlock(&kvm->slots_lock);
> >       if (ret < 0) {
> > +             mutex_lock(&kvm->slots_lock);
> >               kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
> > +             mutex_unlock(&kvm->slots_lock);
> >               kfree(s);
> >               return ret;
> >       }
>
> I prefer something like this, however it is only my personal option.
> --- a/arch/loongarch/kvm/intc/eiointc.c
> +++ b/arch/loongarch/kvm/intc/eiointc.c
> @@ -645,13 +645,16 @@ static int kvm_eiointc_create(struct kvm_device
> *dev, u32 type)
>
>          device = &s->device_vext;
>          kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
> +       mutex_lock(&kvm->slots_lock);
>          ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
>                          EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
>          if (ret < 0) {
>                  kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
> +               mutex_unlock(&kvm->slots_lock);
>                  kfree(s);
>                  return ret;
>          }
> +       mutex_unlock(&kvm->slots_lock);
>          kvm->arch.eiointc = s;
>
> @chenhuacai what is your option?
Both are OK for me. If we want to minimize the critical section, then
this patch is a little better.

Huacai
>
> The others look good to me.
>
> Regards
> Bibo Mao
> > @@ -667,8 +671,10 @@ static void kvm_eiointc_destroy(struct kvm_device *dev)
> >
> >       kvm = dev->kvm;
> >       eiointc = kvm->arch.eiointc;
> > +     mutex_lock(&kvm->slots_lock);
> >       kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device);
> >       kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device_vext);
> > +     mutex_unlock(&kvm->slots_lock);
> >       kfree(eiointc);
> >       kfree(dev);
> >   }
> > diff --git a/arch/loongarch/kvm/intc/ipi.c b/arch/loongarch/kvm/intc/ipi.c
> > index 1f6ebbd0af5c..4fa0897d7bdb 100644
> > --- a/arch/loongarch/kvm/intc/ipi.c
> > +++ b/arch/loongarch/kvm/intc/ipi.c
> > @@ -447,7 +447,9 @@ static void kvm_ipi_destroy(struct kvm_device *dev)
> >
> >       kvm = dev->kvm;
> >       ipi = kvm->arch.ipi;
> > +     mutex_lock(&kvm->slots_lock);
> >       kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->device);
> > +     mutex_unlock(&kvm->slots_lock);
> >       kfree(ipi);
> >       kfree(dev);
> >   }
> > diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c
> > index aa0ed59ae8cf..175a630aceb4 100644
> > --- a/arch/loongarch/kvm/intc/pch_pic.c
> > +++ b/arch/loongarch/kvm/intc/pch_pic.c
> > @@ -481,7 +481,9 @@ static void kvm_pch_pic_destroy(struct kvm_device *dev)
> >       kvm = dev->kvm;
> >       s = kvm->arch.pch_pic;
> >       /* unregister pch pic device and free it's memory */
> > +     mutex_lock(&kvm->slots_lock);
> >       kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device);
> > +     mutex_unlock(&kvm->slots_lock);
> >       kfree(s);
> >       kfree(dev);
> >   }
> >
>

Re: [PATCH v2 net] LoongArch: KVM: Add missing slots_lock for IO bus device register/unregister

Posted by Bibo Mao 1 week, 6 days ago


On 2026/5/25 下午5:58, Huacai Chen wrote:
> On Mon, May 25, 2026 at 5:53 PM Bibo Mao <maobibo@loongson.cn> wrote:
>>
>>
>>
>> On 2026/5/25 下午5:26, Zeng Chi wrote:
>>> From: Zeng Chi <zengchi@kylinos.cn>
>>>
>>> kvm_io_bus_register_dev() and kvm_io_bus_unregister_dev() should be
>>> called under kvm->slots_lock. The unregister calls in ipi.c, pch_pic.c
>>> and eiointc.c were missing this protection. Add it to match the
>>> register side.
>> one small nit, the mail tile is [PATCH v2 net], I think it should be
>> [PATCH v2] :)
>>
>>>
>>> Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
>>> ---
>>>    arch/loongarch/kvm/intc/eiointc.c | 6 ++++++
>>>    arch/loongarch/kvm/intc/ipi.c     | 2 ++
>>>    arch/loongarch/kvm/intc/pch_pic.c | 2 ++
>>>    3 files changed, 10 insertions(+)
>>>
>>> diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
>>> index 2ab7fafa86d5..2b14485d14a7 100644
>>> --- a/arch/loongarch/kvm/intc/eiointc.c
>>> +++ b/arch/loongarch/kvm/intc/eiointc.c
>>> @@ -645,10 +645,14 @@ static int kvm_eiointc_create(struct kvm_device *dev, u32 type)
>>>
>>>        device = &s->device_vext;
>>>        kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
>>> +     mutex_lock(&kvm->slots_lock);
>>>        ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
>>>                        EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
>>> +     mutex_unlock(&kvm->slots_lock);
>>>        if (ret < 0) {
>>> +             mutex_lock(&kvm->slots_lock);
>>>                kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
>>> +             mutex_unlock(&kvm->slots_lock);
>>>                kfree(s);
>>>                return ret;
>>>        }
>>
>> I prefer something like this, however it is only my personal option.
>> --- a/arch/loongarch/kvm/intc/eiointc.c
>> +++ b/arch/loongarch/kvm/intc/eiointc.c
>> @@ -645,13 +645,16 @@ static int kvm_eiointc_create(struct kvm_device
>> *dev, u32 type)
>>
>>           device = &s->device_vext;
>>           kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
>> +       mutex_lock(&kvm->slots_lock);
>>           ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
>>                           EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
>>           if (ret < 0) {
>>                   kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
>> +               mutex_unlock(&kvm->slots_lock);
>>                   kfree(s);
>>                   return ret;
>>           }
>> +       mutex_unlock(&kvm->slots_lock);
>>           kvm->arch.eiointc = s;
>>
>> @chenhuacai what is your option?
> Both are OK for me. If we want to minimize the critical section, then
> this patch is a little better.
That is fine.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
> 
> Huacai
>>
>> The others look good to me.
>>
>> Regards
>> Bibo Mao
>>> @@ -667,8 +671,10 @@ static void kvm_eiointc_destroy(struct kvm_device *dev)
>>>
>>>        kvm = dev->kvm;
>>>        eiointc = kvm->arch.eiointc;
>>> +     mutex_lock(&kvm->slots_lock);
>>>        kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device);
>>>        kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device_vext);
>>> +     mutex_unlock(&kvm->slots_lock);
>>>        kfree(eiointc);
>>>        kfree(dev);
>>>    }
>>> diff --git a/arch/loongarch/kvm/intc/ipi.c b/arch/loongarch/kvm/intc/ipi.c
>>> index 1f6ebbd0af5c..4fa0897d7bdb 100644
>>> --- a/arch/loongarch/kvm/intc/ipi.c
>>> +++ b/arch/loongarch/kvm/intc/ipi.c
>>> @@ -447,7 +447,9 @@ static void kvm_ipi_destroy(struct kvm_device *dev)
>>>
>>>        kvm = dev->kvm;
>>>        ipi = kvm->arch.ipi;
>>> +     mutex_lock(&kvm->slots_lock);
>>>        kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->device);
>>> +     mutex_unlock(&kvm->slots_lock);
>>>        kfree(ipi);
>>>        kfree(dev);
>>>    }
>>> diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c
>>> index aa0ed59ae8cf..175a630aceb4 100644
>>> --- a/arch/loongarch/kvm/intc/pch_pic.c
>>> +++ b/arch/loongarch/kvm/intc/pch_pic.c
>>> @@ -481,7 +481,9 @@ static void kvm_pch_pic_destroy(struct kvm_device *dev)
>>>        kvm = dev->kvm;
>>>        s = kvm->arch.pch_pic;
>>>        /* unregister pch pic device and free it's memory */
>>> +     mutex_lock(&kvm->slots_lock);
>>>        kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device);
>>> +     mutex_unlock(&kvm->slots_lock);
>>>        kfree(s);
>>>        kfree(dev);
>>>    }
>>>
>>

[PTACH v3] LoongArch: KVM: Add missing slots_lock for IO bus device register/unregister

Posted by Zeng Chi 3 days, 14 hours ago

From: Zeng Chi <zengchi@kylinos.cn>

kvm_io_bus_register_dev() and kvm_io_bus_unregister_dev() should be
called under kvm->slots_lock. The unregister calls in ipi.c, pch_pic.c
and eiointc.c were missing this protection. Add it to match the
register side.

Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
---
v3: fix subject prefix (drop "net", LoongArch KVM does not go through the
    net tree); add Reviewed-by from Bibo Mao. No code change.
v2: extend the fix from the EIOINTC virtual extension device registration
    (v1) to the ipi.c / pch_pic.c / eiointc.c destroy paths as well.
---
 arch/loongarch/kvm/intc/eiointc.c | 6 ++++++
 arch/loongarch/kvm/intc/ipi.c     | 2 ++
 arch/loongarch/kvm/intc/pch_pic.c | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
index 2ab7fafa86d5..2b14485d14a7 100644
--- a/arch/loongarch/kvm/intc/eiointc.c
+++ b/arch/loongarch/kvm/intc/eiointc.c
@@ -645,10 +645,14 @@ static int kvm_eiointc_create(struct kvm_device *dev, u32 type)
 
 	device = &s->device_vext;
 	kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
+	mutex_lock(&kvm->slots_lock);
 	ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
 			EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
+	mutex_unlock(&kvm->slots_lock);
 	if (ret < 0) {
+		mutex_lock(&kvm->slots_lock);
 		kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
+		mutex_unlock(&kvm->slots_lock);
 		kfree(s);
 		return ret;
 	}
@@ -667,8 +671,10 @@ static void kvm_eiointc_destroy(struct kvm_device *dev)
 
 	kvm = dev->kvm;
 	eiointc = kvm->arch.eiointc;
+	mutex_lock(&kvm->slots_lock);
 	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device);
 	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device_vext);
+	mutex_unlock(&kvm->slots_lock);
 	kfree(eiointc);
 	kfree(dev);
 }
diff --git a/arch/loongarch/kvm/intc/ipi.c b/arch/loongarch/kvm/intc/ipi.c
index 1f6ebbd0af5c..4fa0897d7bdb 100644
--- a/arch/loongarch/kvm/intc/ipi.c
+++ b/arch/loongarch/kvm/intc/ipi.c
@@ -447,7 +447,9 @@ static void kvm_ipi_destroy(struct kvm_device *dev)
 
 	kvm = dev->kvm;
 	ipi = kvm->arch.ipi;
+	mutex_lock(&kvm->slots_lock);
 	kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->device);
+	mutex_unlock(&kvm->slots_lock);
 	kfree(ipi);
 	kfree(dev);
 }
diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c
index aa0ed59ae8cf..175a630aceb4 100644
--- a/arch/loongarch/kvm/intc/pch_pic.c
+++ b/arch/loongarch/kvm/intc/pch_pic.c
@@ -481,7 +481,9 @@ static void kvm_pch_pic_destroy(struct kvm_device *dev)
 	kvm = dev->kvm;
 	s = kvm->arch.pch_pic;
 	/* unregister pch pic device and free it's memory */
+	mutex_lock(&kvm->slots_lock);
 	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device);
+	mutex_unlock(&kvm->slots_lock);
 	kfree(s);
 	kfree(dev);
 }
-- 
2.25.1

Re: [PTACH v3] LoongArch: KVM: Add missing slots_lock for IO bus device register/unregister

Posted by Huacai Chen 3 days, 8 hours ago

Applied, thanks.

Huacai

On Fri, Jun 5, 2026 at 4:31 PM Zeng Chi <zeng_chi911@163.com> wrote:
>
> From: Zeng Chi <zengchi@kylinos.cn>
>
> kvm_io_bus_register_dev() and kvm_io_bus_unregister_dev() should be
> called under kvm->slots_lock. The unregister calls in ipi.c, pch_pic.c
> and eiointc.c were missing this protection. Add it to match the
> register side.
>
> Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
> Reviewed-by: Bibo Mao <maobibo@loongson.cn>
> ---
> v3: fix subject prefix (drop "net", LoongArch KVM does not go through the
>     net tree); add Reviewed-by from Bibo Mao. No code change.
> v2: extend the fix from the EIOINTC virtual extension device registration
>     (v1) to the ipi.c / pch_pic.c / eiointc.c destroy paths as well.
> ---
>  arch/loongarch/kvm/intc/eiointc.c | 6 ++++++
>  arch/loongarch/kvm/intc/ipi.c     | 2 ++
>  arch/loongarch/kvm/intc/pch_pic.c | 2 ++
>  3 files changed, 10 insertions(+)
>
> diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
> index 2ab7fafa86d5..2b14485d14a7 100644
> --- a/arch/loongarch/kvm/intc/eiointc.c
> +++ b/arch/loongarch/kvm/intc/eiointc.c
> @@ -645,10 +645,14 @@ static int kvm_eiointc_create(struct kvm_device *dev, u32 type)
>
>         device = &s->device_vext;
>         kvm_iodevice_init(device, &kvm_eiointc_virt_ops);
> +       mutex_lock(&kvm->slots_lock);
>         ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS,
>                         EIOINTC_VIRT_BASE, EIOINTC_VIRT_SIZE, device);
> +       mutex_unlock(&kvm->slots_lock);
>         if (ret < 0) {
> +               mutex_lock(&kvm->slots_lock);
>                 kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
> +               mutex_unlock(&kvm->slots_lock);
>                 kfree(s);
>                 return ret;
>         }
> @@ -667,8 +671,10 @@ static void kvm_eiointc_destroy(struct kvm_device *dev)
>
>         kvm = dev->kvm;
>         eiointc = kvm->arch.eiointc;
> +       mutex_lock(&kvm->slots_lock);
>         kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device);
>         kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &eiointc->device_vext);
> +       mutex_unlock(&kvm->slots_lock);
>         kfree(eiointc);
>         kfree(dev);
>  }
> diff --git a/arch/loongarch/kvm/intc/ipi.c b/arch/loongarch/kvm/intc/ipi.c
> index 1f6ebbd0af5c..4fa0897d7bdb 100644
> --- a/arch/loongarch/kvm/intc/ipi.c
> +++ b/arch/loongarch/kvm/intc/ipi.c
> @@ -447,7 +447,9 @@ static void kvm_ipi_destroy(struct kvm_device *dev)
>
>         kvm = dev->kvm;
>         ipi = kvm->arch.ipi;
> +       mutex_lock(&kvm->slots_lock);
>         kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->device);
> +       mutex_unlock(&kvm->slots_lock);
>         kfree(ipi);
>         kfree(dev);
>  }
> diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c
> index aa0ed59ae8cf..175a630aceb4 100644
> --- a/arch/loongarch/kvm/intc/pch_pic.c
> +++ b/arch/loongarch/kvm/intc/pch_pic.c
> @@ -481,7 +481,9 @@ static void kvm_pch_pic_destroy(struct kvm_device *dev)
>         kvm = dev->kvm;
>         s = kvm->arch.pch_pic;
>         /* unregister pch pic device and free it's memory */
> +       mutex_lock(&kvm->slots_lock);
>         kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &s->device);
> +       mutex_unlock(&kvm->slots_lock);
>         kfree(s);
>         kfree(dev);
>  }
> --
> 2.25.1
>