[Qemu-devel] [PATCH v2 0/1] virtio-scsi-ccw: fix iotest 068 for s390x

[Qemu-devel] [PATCH v2 0/1] virtio-scsi-ccw: fix iotest 068 for s390x

[QingFeng Hao]

This commit fixes iotest 068 for s390x as s390x uses virtio-scsi-ccw.
It's based on commit c324fd0a39c by Stefan Hajnoczi. 
Thanks!

Change history:
v2:
    Remove Stefan from sign-off list and change the patch's commit message 
    according to Christian Borntraeger's comment.

QingFeng Hao (1):
  virtio-scsi-ccw: use ioeventfd even when KVM is disabled

 hw/s390x/virtio-ccw.c | 2 +-
 target/s390x/kvm.c    | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

-- 
2.11.2

[Qemu-devel] [PATCH v2 1/1] virtio-scsi-ccw: use ioeventfd even when KVM is disabled

[QingFeng Hao]

This patch is based on a similar patch from Stefan Hajnoczi -
commit c324fd0a39c (" virtio-pci: use ioeventfd even when KVM is disabled)

Do not check kvm_eventfds_enabled() when KVM is disabled since it
always returns 0.  Since commit 8c56c1a592b5092d91da8d8943c17777d6462a6f
("memory: emulate ioeventfd") it has been possible to use ioeventfds in
qtest or TCG mode.

This patch makes -device virtio-scsi-ccw,iothread=iothread0 work even
when KVM is disabled.

I have tested that virtio-scsi-ccw works under tcg both with and without
iothread.

This patch fixes qemu-iotests 068, which was accidentally merged early
despite the dependency on ioeventfd.

Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
---
 hw/s390x/virtio-ccw.c | 2 +-
 target/s390x/kvm.c    | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 90d37cb9ff..35896eb007 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -711,7 +711,7 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
         sch->cssid, sch->ssid, sch->schid, sch->devno,
         ccw_dev->devno.valid ? "user-configured" : "auto-configured");
 
-    if (!kvm_eventfds_enabled()) {
+    if (kvm_enabled() && !kvm_eventfds_enabled()) {
         dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
     }
 
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index a3d00196f4..c37f9c3b9e 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -2220,6 +2220,9 @@ int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
         .addr = sch,
         .len = 8,
     };
+    if (!kvm_enabled()) {
+        return 0;
+    }
     if (!kvm_check_extension(kvm_state, KVM_CAP_IOEVENTFD)) {
         return -ENOSYS;
     }
-- 
2.11.2

Re: [Qemu-devel] [PATCH v2 1/1] virtio-scsi-ccw: use ioeventfd even when KVM is disabled

[Christian Borntraeger]

On 07/03/2017 10:51 AM, QingFeng Hao wrote:
> This patch is based on a similar patch from Stefan Hajnoczi -
> commit c324fd0a39c (" virtio-pci: use ioeventfd even when KVM is disabled)
> 
> Do not check kvm_eventfds_enabled() when KVM is disabled since it
> always returns 0.  Since commit 8c56c1a592b5092d91da8d8943c17777d6462a6f
> ("memory: emulate ioeventfd") it has been possible to use ioeventfds in
> qtest or TCG mode.
> 
> This patch makes -device virtio-scsi-ccw,iothread=iothread0 work even
> when KVM is disabled.
> 
> I have tested that virtio-scsi-ccw works under tcg both with and without
> iothread.
> 
> This patch fixes qemu-iotests 068, which was accidentally merged early
> despite the dependency on ioeventfd.
> 
> Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
> ---
>  hw/s390x/virtio-ccw.c | 2 +-
>  target/s390x/kvm.c    | 3 +++
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 90d37cb9ff..35896eb007 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -711,7 +711,7 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
>          sch->cssid, sch->ssid, sch->schid, sch->devno,
>          ccw_dev->devno.valid ? "user-configured" : "auto-configured");
> 
> -    if (!kvm_eventfds_enabled()) {
> +    if (kvm_enabled() && !kvm_eventfds_enabled()) {
>          dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
>      }
> 
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index a3d00196f4..c37f9c3b9e 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -2220,6 +2220,9 @@ int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
>          .addr = sch,
>          .len = 8,
>      };
> +    if (!kvm_enabled()) {
> +        return 0;
> +    }

thinking more about it. wouldnt it be better to do something like this instead

diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 058ddad..cc47831 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -1240,7 +1240,11 @@ static inline int s390_assign_subch_ioeventfd(EventNotifier *notifier,
                                               uint32_t sch_id, int vq,
                                               bool assign)
 {
-    return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
+    if (kvm_enabled()) {
+        return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
+    } else {
+        return 0;
+    }
 }
 
 static inline void s390_crypto_reset(void)


FWIW, it seems that we (s390) do not have a functional equivalent function as commit
8c56c1a592b5092d91da8d8943c17777d6462a6f ("memory: emulate ioeventfd") , so we will
not use the iothreads. 


>      if (!kvm_check_extension(kvm_state, KVM_CAP_IOEVENTFD)) {
>          return -ENOSYS;
>      }
> 

Re: [Qemu-devel] [PATCH v2 1/1] virtio-scsi-ccw: use ioeventfd even when KVM is disabled

[Cornelia Huck]

On Mon, 3 Jul 2017 12:20:03 +0200
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> On 07/03/2017 10:51 AM, QingFeng Hao wrote:
>
> > diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> > index a3d00196f4..c37f9c3b9e 100644
> > --- a/target/s390x/kvm.c
> > +++ b/target/s390x/kvm.c
> > @@ -2220,6 +2220,9 @@ int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
> >          .addr = sch,
> >          .len = 8,
> >      };
> > +    if (!kvm_enabled()) {
> > +        return 0;
> > +    }  
> 
> thinking more about it. wouldnt it be better to do something like this instead
> 
> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
> index 058ddad..cc47831 100644
> --- a/target/s390x/cpu.h
> +++ b/target/s390x/cpu.h
> @@ -1240,7 +1240,11 @@ static inline int s390_assign_subch_ioeventfd(EventNotifier *notifier,
>                                                uint32_t sch_id, int vq,
>                                                bool assign)
>  {
> -    return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
> +    if (kvm_enabled()) {
> +        return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
> +    } else {
> +        return 0;
> +    }
>  }
>  
>  static inline void s390_crypto_reset(void)

Agreed.

> 
> 
> FWIW, it seems that we (s390) do not have a functional equivalent function as commit
> 8c56c1a592b5092d91da8d8943c17777d6462a6f ("memory: emulate ioeventfd") , so we will
> not use the iothreads. 

Should not be a problem, I think. We may want to cook up an equivalent,
though.

> 
> 
> >      if (!kvm_check_extension(kvm_state, KVM_CAP_IOEVENTFD)) {
> >          return -ENOSYS;
> >      }
> >   
> 
> 

Re: [Qemu-devel] [PATCH v2 1/1] virtio-scsi-ccw: use ioeventfd even when KVM is disabled

[QingFeng Hao]

在 2017/7/3 18:20, Christian Borntraeger 写道:
> On 07/03/2017 10:51 AM, QingFeng Hao wrote:
>> This patch is based on a similar patch from Stefan Hajnoczi -
>> commit c324fd0a39c (" virtio-pci: use ioeventfd even when KVM is disabled)
>>
>> Do not check kvm_eventfds_enabled() when KVM is disabled since it
>> always returns 0.  Since commit 8c56c1a592b5092d91da8d8943c17777d6462a6f
>> ("memory: emulate ioeventfd") it has been possible to use ioeventfds in
>> qtest or TCG mode.
>>
>> This patch makes -device virtio-scsi-ccw,iothread=iothread0 work even
>> when KVM is disabled.
>>
>> I have tested that virtio-scsi-ccw works under tcg both with and without
>> iothread.
>>
>> This patch fixes qemu-iotests 068, which was accidentally merged early
>> despite the dependency on ioeventfd.
>>
>> Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
>> ---
>>   hw/s390x/virtio-ccw.c | 2 +-
>>   target/s390x/kvm.c    | 3 +++
>>   2 files changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
>> index 90d37cb9ff..35896eb007 100644
>> --- a/hw/s390x/virtio-ccw.c
>> +++ b/hw/s390x/virtio-ccw.c
>> @@ -711,7 +711,7 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
>>           sch->cssid, sch->ssid, sch->schid, sch->devno,
>>           ccw_dev->devno.valid ? "user-configured" : "auto-configured");
>>
>> -    if (!kvm_eventfds_enabled()) {
>> +    if (kvm_enabled() && !kvm_eventfds_enabled()) {
>>           dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
>>       }
>>
>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>> index a3d00196f4..c37f9c3b9e 100644
>> --- a/target/s390x/kvm.c
>> +++ b/target/s390x/kvm.c
>> @@ -2220,6 +2220,9 @@ int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
>>           .addr = sch,
>>           .len = 8,
>>       };
>> +    if (!kvm_enabled()) {
>> +        return 0;
>> +    }
> thinking more about it. wouldnt it be better to do something like this instead
>
> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
> index 058ddad..cc47831 100644
> --- a/target/s390x/cpu.h
> +++ b/target/s390x/cpu.h
> @@ -1240,7 +1240,11 @@ static inline int s390_assign_subch_ioeventfd(EventNotifier *notifier,
>                                                 uint32_t sch_id, int vq,
>                                                 bool assign)
>   {
> -    return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
> +    if (kvm_enabled()) {
> +        return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
> +    } else {
> +        return 0;
> +    }
>   }
Thanks. It makes sense. I'll change it.
>   static inline void s390_crypto_reset(void)
>
>
> FWIW, it seems that we (s390) do not have a functional equivalent function as commit
> 8c56c1a592b5092d91da8d8943c17777d6462a6f ("memory: emulate ioeventfd") , so we will
> not use the iothreads.
Ok, but might s390 have skipped the iothread arguments and passed the 
test, so we could
still keep this test case?
>
>>       if (!kvm_check_extension(kvm_state, KVM_CAP_IOEVENTFD)) {
>>           return -ENOSYS;
>>       }
>>

-- 
Regards
QingFeng Hao

Re: [Qemu-devel] [PATCH v2 1/1] virtio-scsi-ccw: use ioeventfd even when KVM is disabled

[Christian Borntraeger]

On 07/04/2017 05:41 AM, QingFeng Hao wrote:
> 
> 
> 在 2017/7/3 18:20, Christian Borntraeger 写道:
>> On 07/03/2017 10:51 AM, QingFeng Hao wrote:
>>> This patch is based on a similar patch from Stefan Hajnoczi -
>>> commit c324fd0a39c (" virtio-pci: use ioeventfd even when KVM is disabled)
>>>
>>> Do not check kvm_eventfds_enabled() when KVM is disabled since it
>>> always returns 0.  Since commit 8c56c1a592b5092d91da8d8943c17777d6462a6f
>>> ("memory: emulate ioeventfd") it has been possible to use ioeventfds in
>>> qtest or TCG mode.
>>>
>>> This patch makes -device virtio-scsi-ccw,iothread=iothread0 work even
>>> when KVM is disabled.
>>>
>>> I have tested that virtio-scsi-ccw works under tcg both with and without
>>> iothread.
>>>
>>> This patch fixes qemu-iotests 068, which was accidentally merged early
>>> despite the dependency on ioeventfd.
>>>
>>> Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
>>> ---
>>>   hw/s390x/virtio-ccw.c | 2 +-
>>>   target/s390x/kvm.c    | 3 +++
>>>   2 files changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
>>> index 90d37cb9ff..35896eb007 100644
>>> --- a/hw/s390x/virtio-ccw.c
>>> +++ b/hw/s390x/virtio-ccw.c
>>> @@ -711,7 +711,7 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
>>>           sch->cssid, sch->ssid, sch->schid, sch->devno,
>>>           ccw_dev->devno.valid ? "user-configured" : "auto-configured");
>>>
>>> -    if (!kvm_eventfds_enabled()) {
>>> +    if (kvm_enabled() && !kvm_eventfds_enabled()) {
>>>           dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
>>>       }
>>>
>>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>>> index a3d00196f4..c37f9c3b9e 100644
>>> --- a/target/s390x/kvm.c
>>> +++ b/target/s390x/kvm.c
>>> @@ -2220,6 +2220,9 @@ int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
>>>           .addr = sch,
>>>           .len = 8,
>>>       };
>>> +    if (!kvm_enabled()) {
>>> +        return 0;
>>> +    }
>> thinking more about it. wouldnt it be better to do something like this instead
>>
>> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
>> index 058ddad..cc47831 100644
>> --- a/target/s390x/cpu.h
>> +++ b/target/s390x/cpu.h
>> @@ -1240,7 +1240,11 @@ static inline int s390_assign_subch_ioeventfd(EventNotifier *notifier,
>>                                                 uint32_t sch_id, int vq,
>>                                                 bool assign)
>>   {
>> -    return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
>> +    if (kvm_enabled()) {
>> +        return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
>> +    } else {
>> +        return 0;
>> +    }
>>   }
> Thanks. It makes sense. I'll change it.
>>   static inline void s390_crypto_reset(void)
>>
>>
>> FWIW, it seems that we (s390) do not have a functional equivalent function as commit
>> 8c56c1a592b5092d91da8d8943c17777d6462a6f ("memory: emulate ioeventfd") , so we will
>> not use the iothreads.
> Ok, but might s390 have skipped the iothread arguments and passed the test, so we could
> still keep this test case?

Yes, lets just fix the test case. We can implement emulated ioeventfds later.

Re: [Qemu-devel] [PATCH v2 1/1] virtio-scsi-ccw: use ioeventfd even when KVM is disabled

[QingFeng Hao]

在 2017/7/4 15:06, Christian Borntraeger 写道:
> On 07/04/2017 05:41 AM, QingFeng Hao wrote:
>>
>> 在 2017/7/3 18:20, Christian Borntraeger 写道:
>>> On 07/03/2017 10:51 AM, QingFeng Hao wrote:
>>>> This patch is based on a similar patch from Stefan Hajnoczi -
>>>> commit c324fd0a39c (" virtio-pci: use ioeventfd even when KVM is disabled)
>>>>
>>>> Do not check kvm_eventfds_enabled() when KVM is disabled since it
>>>> always returns 0.  Since commit 8c56c1a592b5092d91da8d8943c17777d6462a6f
>>>> ("memory: emulate ioeventfd") it has been possible to use ioeventfds in
>>>> qtest or TCG mode.
>>>>
>>>> This patch makes -device virtio-scsi-ccw,iothread=iothread0 work even
>>>> when KVM is disabled.
>>>>
>>>> I have tested that virtio-scsi-ccw works under tcg both with and without
>>>> iothread.
>>>>
>>>> This patch fixes qemu-iotests 068, which was accidentally merged early
>>>> despite the dependency on ioeventfd.
>>>>
>>>> Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
>>>> ---
>>>>    hw/s390x/virtio-ccw.c | 2 +-
>>>>    target/s390x/kvm.c    | 3 +++
>>>>    2 files changed, 4 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
>>>> index 90d37cb9ff..35896eb007 100644
>>>> --- a/hw/s390x/virtio-ccw.c
>>>> +++ b/hw/s390x/virtio-ccw.c
>>>> @@ -711,7 +711,7 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
>>>>            sch->cssid, sch->ssid, sch->schid, sch->devno,
>>>>            ccw_dev->devno.valid ? "user-configured" : "auto-configured");
>>>>
>>>> -    if (!kvm_eventfds_enabled()) {
>>>> +    if (kvm_enabled() && !kvm_eventfds_enabled()) {
>>>>            dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
>>>>        }
>>>>
>>>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>>>> index a3d00196f4..c37f9c3b9e 100644
>>>> --- a/target/s390x/kvm.c
>>>> +++ b/target/s390x/kvm.c
>>>> @@ -2220,6 +2220,9 @@ int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
>>>>            .addr = sch,
>>>>            .len = 8,
>>>>        };
>>>> +    if (!kvm_enabled()) {
>>>> +        return 0;
>>>> +    }
>>> thinking more about it. wouldnt it be better to do something like this instead
>>>
>>> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
>>> index 058ddad..cc47831 100644
>>> --- a/target/s390x/cpu.h
>>> +++ b/target/s390x/cpu.h
>>> @@ -1240,7 +1240,11 @@ static inline int s390_assign_subch_ioeventfd(EventNotifier *notifier,
>>>                                                  uint32_t sch_id, int vq,
>>>                                                  bool assign)
>>>    {
>>> -    return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
>>> +    if (kvm_enabled()) {
>>> +        return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
>>> +    } else {
>>> +        return 0;
>>> +    }
>>>    }
>> Thanks. It makes sense. I'll change it.
>>>    static inline void s390_crypto_reset(void)
>>>
>>>
>>> FWIW, it seems that we (s390) do not have a functional equivalent function as commit
>>> 8c56c1a592b5092d91da8d8943c17777d6462a6f ("memory: emulate ioeventfd") , so we will
>>> not use the iothreads.
>> Ok, but might s390 have skipped the iothread arguments and passed the test, so we could
>> still keep this test case?
> Yes, lets just fix the test case. We can implement emulated ioeventfds later.
Fine, thanks!
>

-- 
Regards
QingFeng Hao