diff mbox series

[v2,2/5] hw/i386/apic: Defer error check from apic_get_class to kvm_apic_realize

Message ID 20231003082728.83496-3-philmd@linaro.org
State New
Headers show
Series hw/intc/apic: QOM cleanup | expand

Commit Message

Philippe Mathieu-Daudé Oct. 3, 2023, 8:27 a.m. UTC
apic_get_class() isn't supposed to fail. kvm_apic_realize() is
DeviceRealize() handler, which can fail. Defer the error check
to the latter.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/i386/kvm/apic.c       | 5 +++++
 target/i386/cpu-sysemu.c | 8 --------
 2 files changed, 5 insertions(+), 8 deletions(-)

Comments

Peter Xu Oct. 3, 2023, 8:49 p.m. UTC | #1
On Tue, Oct 03, 2023 at 10:27:25AM +0200, Philippe Mathieu-Daudé wrote:
> apic_get_class() isn't supposed to fail. kvm_apic_realize() is
> DeviceRealize() handler, which can fail. Defer the error check
> to the latter.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  hw/i386/kvm/apic.c       | 5 +++++
>  target/i386/cpu-sysemu.c | 8 --------
>  2 files changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/i386/kvm/apic.c b/hw/i386/kvm/apic.c
> index 1e89ca0899..4883308247 100644
> --- a/hw/i386/kvm/apic.c
> +++ b/hw/i386/kvm/apic.c
> @@ -228,6 +228,11 @@ static void kvm_apic_realize(DeviceState *dev, Error **errp)
>  {
>      APICCommonState *s = APIC_COMMON(dev);
>  
> +    if (!kvm_irqchip_in_kernel()) {
> +        error_setg(errp, "KVM does not support userspace APIC");
> +        return;
> +    }

IMO the code reads a bit weird, that we are already trying to create
kvm-apic even if !kvm_irqchip_in_kernel()..

Would it be better to check this in i386's kvm_arch_irqchip_create()?

> +
>      memory_region_init_io(&s->io_memory, OBJECT(s), &kvm_apic_io_ops, s,
>                            "kvm-apic-msi", APIC_SPACE_SIZE);
>  
> diff --git a/target/i386/cpu-sysemu.c b/target/i386/cpu-sysemu.c
> index 2375e48178..6a228c9178 100644
> --- a/target/i386/cpu-sysemu.c
> +++ b/target/i386/cpu-sysemu.c
> @@ -253,10 +253,6 @@ APICCommonClass *apic_get_class(Error **errp)
>  
>      /* TODO: in-kernel irqchip for hvf */
>      if (kvm_enabled()) {
> -        if (!kvm_irqchip_in_kernel()) {
> -            error_setg(errp, "KVM does not support userspace APIC");
> -            return NULL;
> -        }
>          apic_type = "kvm-apic";
>      } else if (xen_enabled()) {
>          apic_type = "xen-apic";
> @@ -272,10 +268,6 @@ void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
>      APICCommonState *apic;
>      APICCommonClass *apic_class = apic_get_class(errp);
>  
> -    if (!apic_class) {
> -        return;
> -    }
> -
>      cpu->apic_state = DEVICE(object_new_with_class(OBJECT_CLASS(apic_class)));
>      object_property_add_child(OBJECT(cpu), "lapic",
>                                OBJECT(cpu->apic_state));
> -- 
> 2.41.0
>
Bernhard Beschow Oct. 3, 2023, 11:21 p.m. UTC | #2
Am 3. Oktober 2023 08:27:25 UTC schrieb "Philippe Mathieu-Daudé" <philmd@linaro.org>:
>apic_get_class() isn't supposed to fail. kvm_apic_realize() is
>DeviceRealize() handler, which can fail. Defer the error check
>to the latter.
>
>Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>---
> hw/i386/kvm/apic.c       | 5 +++++
> target/i386/cpu-sysemu.c | 8 --------
> 2 files changed, 5 insertions(+), 8 deletions(-)
>
>diff --git a/hw/i386/kvm/apic.c b/hw/i386/kvm/apic.c
>index 1e89ca0899..4883308247 100644
>--- a/hw/i386/kvm/apic.c
>+++ b/hw/i386/kvm/apic.c
>@@ -228,6 +228,11 @@ static void kvm_apic_realize(DeviceState *dev, Error **errp)
> {
>     APICCommonState *s = APIC_COMMON(dev);
> 
>+    if (!kvm_irqchip_in_kernel()) {
>+        error_setg(errp, "KVM does not support userspace APIC");
>+        return;
>+    }
>+
>     memory_region_init_io(&s->io_memory, OBJECT(s), &kvm_apic_io_ops, s,
>                           "kvm-apic-msi", APIC_SPACE_SIZE);
> 
>diff --git a/target/i386/cpu-sysemu.c b/target/i386/cpu-sysemu.c
>index 2375e48178..6a228c9178 100644
>--- a/target/i386/cpu-sysemu.c
>+++ b/target/i386/cpu-sysemu.c
>@@ -253,10 +253,6 @@ APICCommonClass *apic_get_class(Error **errp)
> 
>     /* TODO: in-kernel irqchip for hvf */
>     if (kvm_enabled()) {
>-        if (!kvm_irqchip_in_kernel()) {
>-            error_setg(errp, "KVM does not support userspace APIC");
>-            return NULL;
>-        }
>         apic_type = "kvm-apic";
>     } else if (xen_enabled()) {
>         apic_type = "xen-apic";
>@@ -272,10 +268,6 @@ void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
>     APICCommonState *apic;
>     APICCommonClass *apic_class = apic_get_class(errp);
> 
>-    if (!apic_class) {
>-        return;
>-    }
>-

Did you intend to remove these lines in the next commit? There you're writing to simplify x86_cpu_apic_create() which you're doing here already.

Best regards,
Bernhard

>     cpu->apic_state = DEVICE(object_new_with_class(OBJECT_CLASS(apic_class)));
>     object_property_add_child(OBJECT(cpu), "lapic",
>                               OBJECT(cpu->apic_state));
Philippe Mathieu-Daudé Oct. 5, 2023, 7:06 a.m. UTC | #3
Hi Bernhard,

On 4/10/23 01:21, Bernhard Beschow wrote:
> Am 3. Oktober 2023 08:27:25 UTC schrieb "Philippe Mathieu-Daudé" <philmd@linaro.org>:
>> apic_get_class() isn't supposed to fail. kvm_apic_realize() is
>> DeviceRealize() handler, which can fail. Defer the error check
>> to the latter.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>> hw/i386/kvm/apic.c       | 5 +++++
>> target/i386/cpu-sysemu.c | 8 --------
>> 2 files changed, 5 insertions(+), 8 deletions(-)

                         "kvm-apic-msi", APIC_SPACE_SIZE);
>>
>> diff --git a/target/i386/cpu-sysemu.c b/target/i386/cpu-sysemu.c
>> index 2375e48178..6a228c9178 100644
>> --- a/target/i386/cpu-sysemu.c
>> +++ b/target/i386/cpu-sysemu.c
>> @@ -253,10 +253,6 @@ APICCommonClass *apic_get_class(Error **errp)
>>
>>      /* TODO: in-kernel irqchip for hvf */
>>      if (kvm_enabled()) {
>> -        if (!kvm_irqchip_in_kernel()) {
>> -            error_setg(errp, "KVM does not support userspace APIC");
>> -            return NULL;
>> -        }
>>          apic_type = "kvm-apic";
>>      } else if (xen_enabled()) {
>>          apic_type = "xen-apic";
>> @@ -272,10 +268,6 @@ void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
>>      APICCommonState *apic;
>>      APICCommonClass *apic_class = apic_get_class(errp);
>>
>> -    if (!apic_class) {
>> -        return;
>> -    }
>> -
> 
> Did you intend to remove these lines in the next commit? There you're writing to simplify x86_cpu_apic_create() which you're doing here already.

No: apic_get_class() doesn't return NULL anymore, so this is dead code.

> 
> Best regards,
> Bernhard
Bernhard Beschow Oct. 5, 2023, 7:40 a.m. UTC | #4
Am 5. Oktober 2023 07:06:38 UTC schrieb "Philippe Mathieu-Daudé" <philmd@linaro.org>:
>Hi Bernhard,
>
>On 4/10/23 01:21, Bernhard Beschow wrote:
>> Am 3. Oktober 2023 08:27:25 UTC schrieb "Philippe Mathieu-Daudé" <philmd@linaro.org>:
>>> apic_get_class() isn't supposed to fail. kvm_apic_realize() is
>>> DeviceRealize() handler, which can fail. Defer the error check
>>> to the latter.
>>> 
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>>> ---
>>> hw/i386/kvm/apic.c       | 5 +++++
>>> target/i386/cpu-sysemu.c | 8 --------
>>> 2 files changed, 5 insertions(+), 8 deletions(-)
>
>                        "kvm-apic-msi", APIC_SPACE_SIZE);
>>> 
>>> diff --git a/target/i386/cpu-sysemu.c b/target/i386/cpu-sysemu.c
>>> index 2375e48178..6a228c9178 100644
>>> --- a/target/i386/cpu-sysemu.c
>>> +++ b/target/i386/cpu-sysemu.c
>>> @@ -253,10 +253,6 @@ APICCommonClass *apic_get_class(Error **errp)
>>> 
>>>      /* TODO: in-kernel irqchip for hvf */
>>>      if (kvm_enabled()) {
>>> -        if (!kvm_irqchip_in_kernel()) {
>>> -            error_setg(errp, "KVM does not support userspace APIC");
>>> -            return NULL;
>>> -        }
>>>          apic_type = "kvm-apic";
>>>      } else if (xen_enabled()) {
>>>          apic_type = "xen-apic";
>>> @@ -272,10 +268,6 @@ void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
>>>      APICCommonState *apic;
>>>      APICCommonClass *apic_class = apic_get_class(errp);
>>> 
>>> -    if (!apic_class) {
>>> -        return;
>>> -    }
>>> -
>> 
>> Did you intend to remove these lines in the next commit? There you're writing to simplify x86_cpu_apic_create() which you're doing here already.
>
>No: apic_get_class() doesn't return NULL anymore, so this is dead code.

Yes, makes sense.

Maybe move "It can't return NULL neither, so simplify x86_cpu_apic_create()." of the next commit message here? There, you're applying the same change to various functions but point out x86_cpu_apic_create() explicitly which is the part I was confused about. Though this may not warrant a respin.

Best regards,
Bernhard

>
>> 
>> Best regards,
>> Bernhard
diff mbox series

Patch

diff --git a/hw/i386/kvm/apic.c b/hw/i386/kvm/apic.c
index 1e89ca0899..4883308247 100644
--- a/hw/i386/kvm/apic.c
+++ b/hw/i386/kvm/apic.c
@@ -228,6 +228,11 @@  static void kvm_apic_realize(DeviceState *dev, Error **errp)
 {
     APICCommonState *s = APIC_COMMON(dev);
 
+    if (!kvm_irqchip_in_kernel()) {
+        error_setg(errp, "KVM does not support userspace APIC");
+        return;
+    }
+
     memory_region_init_io(&s->io_memory, OBJECT(s), &kvm_apic_io_ops, s,
                           "kvm-apic-msi", APIC_SPACE_SIZE);
 
diff --git a/target/i386/cpu-sysemu.c b/target/i386/cpu-sysemu.c
index 2375e48178..6a228c9178 100644
--- a/target/i386/cpu-sysemu.c
+++ b/target/i386/cpu-sysemu.c
@@ -253,10 +253,6 @@  APICCommonClass *apic_get_class(Error **errp)
 
     /* TODO: in-kernel irqchip for hvf */
     if (kvm_enabled()) {
-        if (!kvm_irqchip_in_kernel()) {
-            error_setg(errp, "KVM does not support userspace APIC");
-            return NULL;
-        }
         apic_type = "kvm-apic";
     } else if (xen_enabled()) {
         apic_type = "xen-apic";
@@ -272,10 +268,6 @@  void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
     APICCommonState *apic;
     APICCommonClass *apic_class = apic_get_class(errp);
 
-    if (!apic_class) {
-        return;
-    }
-
     cpu->apic_state = DEVICE(object_new_with_class(OBJECT_CLASS(apic_class)));
     object_property_add_child(OBJECT(cpu), "lapic",
                               OBJECT(cpu->apic_state));