Re: [Qemu-devel] [PATCH v3 4/7] s390x/kvm: interface to interpret AP instructions

2018-04-02 Thread Tony Krowiak 

On 03/26/2018 04:38 AM, David Hildenbrand wrote:

On 16.03.2018 00:24, Tony Krowiak wrote:

The VFIO AP device exploits interpretive execution of AP
instructions (APIE). APIE is enabled by setting a device attribute
via the KVM_SET_DEVICE_ATTR ioctl.

Signed-off-by: Tony Krowiak 
---
  target/s390x/kvm.c   |   16 
  target/s390x/kvm_s390x.h |2 ++
  2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 33e5ec3..2812e28 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -277,6 +277,22 @@ static void kvm_s390_init_dea_kw(void)
  }
  }
  
+int kvm_s390_set_interpret_ap(uint8_t enable)

+{
+struct kvm_device_attr attribute = {
+.group = KVM_S390_VM_CRYPTO,
+.attr  = KVM_S390_VM_CRYPTO_INTERPRET_AP,
+.addr = 1,
+};
+
+if (!kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO,
+   KVM_S390_VM_CRYPTO_INTERPRET_AP)) {
+return -EOPNOTSUPP;
+}
+
+return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attribute);
+}
+
  void kvm_s390_crypto_reset(void)
  {
  if (s390_has_feat(S390_FEAT_MSA_EXT_3)) {
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index 34ee7e7..0d6c6e7 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -40,4 +40,6 @@ void kvm_s390_crypto_reset(void);
  void kvm_s390_restart_interrupt(S390CPU *cpu);
  void kvm_s390_stop_interrupt(S390CPU *cpu);
  
+int kvm_s390_set_interpret_ap(uint8_t enable);

+
  #endif /* KVM_S390X_H */


Wonder if a capability - like we use e.g. for SIGP user space
interpretation - would be a better fit.

We can provide the AP feature to the guest in case:
- KVM_S390_VM_CPU_FEAT_AP ("interpretation support") is available
- KVM_S390_VM_CRYPTO_INTERPRET_AP ("interception support") is available

I don't think we need this. I have found a way to set ECA_APIE from the
vfio_ap device driver, so there is no need to do it from the guest. Stay
tuned to this station for v4 of the patch series.


I am missing the second check in your code. (for now you only rely on
KVM_S390_VM_CPU_FEAT_AP)

For what else are you suggesting we need to check?


I think you have to change the order of the patches so they work also
properly when bisectin.

I'll take a look at it.

Re: [Qemu-devel] [PATCH v3 4/7] s390x/kvm: interface to interpret AP instructions

2018-03-26 Thread David Hildenbrand 
On 16.03.2018 00:24, Tony Krowiak wrote:
> The VFIO AP device exploits interpretive execution of AP
> instructions (APIE). APIE is enabled by setting a device attribute
> via the KVM_SET_DEVICE_ATTR ioctl.
> 
> Signed-off-by: Tony Krowiak 
> ---
>  target/s390x/kvm.c   |   16 
>  target/s390x/kvm_s390x.h |2 ++
>  2 files changed, 18 insertions(+), 0 deletions(-)
> 
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index 33e5ec3..2812e28 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -277,6 +277,22 @@ static void kvm_s390_init_dea_kw(void)
>  }
>  }
>  
> +int kvm_s390_set_interpret_ap(uint8_t enable)
> +{
> +struct kvm_device_attr attribute = {
> +.group = KVM_S390_VM_CRYPTO,
> +.attr  = KVM_S390_VM_CRYPTO_INTERPRET_AP,
> +.addr = 1,
> +};
> +
> +if (!kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO,
> +   KVM_S390_VM_CRYPTO_INTERPRET_AP)) {
> +return -EOPNOTSUPP;
> +}
> +
> +return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attribute);
> +}
> +
>  void kvm_s390_crypto_reset(void)
>  {
>  if (s390_has_feat(S390_FEAT_MSA_EXT_3)) {
> diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
> index 34ee7e7..0d6c6e7 100644
> --- a/target/s390x/kvm_s390x.h
> +++ b/target/s390x/kvm_s390x.h
> @@ -40,4 +40,6 @@ void kvm_s390_crypto_reset(void);
>  void kvm_s390_restart_interrupt(S390CPU *cpu);
>  void kvm_s390_stop_interrupt(S390CPU *cpu);
>  
> +int kvm_s390_set_interpret_ap(uint8_t enable);
> +
>  #endif /* KVM_S390X_H */
> 

Wonder if a capability - like we use e.g. for SIGP user space
interpretation - would be a better fit.

We can provide the AP feature to the guest in case:
- KVM_S390_VM_CPU_FEAT_AP ("interpretation support") is available
- KVM_S390_VM_CRYPTO_INTERPRET_AP ("interception support") is available

I am missing the second check in your code. (for now you only rely on
KVM_S390_VM_CPU_FEAT_AP)

I think you have to change the order of the patches so they work also
properly when bisectin.

-- 

Thanks,

David / dhildenb

Re: [Qemu-devel] [PATCH v3 4/7] s390x/kvm: interface to interpret AP instructions

2018-03-20 Thread Tony Krowiak 

On 03/15/2018 07:24 PM, Tony Krowiak wrote:

The VFIO AP device exploits interpretive execution of AP
instructions (APIE). APIE is enabled by setting a device attribute
via the KVM_SET_DEVICE_ATTR ioctl.

Signed-off-by: Tony Krowiak 
---
  target/s390x/kvm.c   |   16 
  target/s390x/kvm_s390x.h |2 ++
  2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 33e5ec3..2812e28 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -277,6 +277,22 @@ static void kvm_s390_init_dea_kw(void)
  }
  }

+int kvm_s390_set_interpret_ap(uint8_t enable)
+{
+struct kvm_device_attr attribute = {
+.group = KVM_S390_VM_CRYPTO,
+.attr  = KVM_S390_VM_CRYPTO_INTERPRET_AP,
+.addr = 1,
+};
+
+if (!kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO,
+   KVM_S390_VM_CRYPTO_INTERPRET_AP)) {
+return -EOPNOTSUPP;
+}
+
+return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attribute);
+}
I proposed removing the KVM_S390_VM_CRYPTO_INTERPRET_AP device attribute 
from the kernel in
Message ID <1347ed2e-7bdb-e455-971a-cf60899e3...@linux.vnet.ibm.com> on 
the kernel mailing list
and proposed setting interpretive execution for AP instructions via the 
mdev open callback. That

would eliminate the need for this patch.

+
  void kvm_s390_crypto_reset(void)
  {
  if (s390_has_feat(S390_FEAT_MSA_EXT_3)) {
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index 34ee7e7..0d6c6e7 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -40,4 +40,6 @@ void kvm_s390_crypto_reset(void);
  void kvm_s390_restart_interrupt(S390CPU *cpu);
  void kvm_s390_stop_interrupt(S390CPU *cpu);

+int kvm_s390_set_interpret_ap(uint8_t enable);
+
  #endif /* KVM_S390X_H */

Re: [Qemu-devel] [PATCH v3 4/7] s390x/kvm: interface to interpret AP instructions

2018-03-16 Thread Tony Krowiak 

On 03/16/2018 06:36 AM, Pierre Morel wrote:

On 16/03/2018 00:24, Tony Krowiak wrote:

The VFIO AP device exploits interpretive execution of AP
instructions (APIE). APIE is enabled by setting a device attribute
via the KVM_SET_DEVICE_ATTR ioctl.

Signed-off-by: Tony Krowiak 
---
  target/s390x/kvm.c   |   16 
  target/s390x/kvm_s390x.h |2 ++
  2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 33e5ec3..2812e28 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -277,6 +277,22 @@ static void kvm_s390_init_dea_kw(void)
  }
  }

+int kvm_s390_set_interpret_ap(uint8_t enable)
+{
+struct kvm_device_attr attribute = {
+.group = KVM_S390_VM_CRYPTO,
+.attr  = KVM_S390_VM_CRYPTO_INTERPRET_AP,
+.addr = 1,
+};
+
+if (!kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO,
+   KVM_S390_VM_CRYPTO_INTERPRET_AP)) {


Isn't it enough to have the CPU feature ?

I don't understand this question within this context. The code above checks
to see whether the KVM_S390_VM_CRYPTO_INTERPRET_AP attribute is supported.


What are expecting here?

I'm expecting that if the KVM_S390_VM_CRYPTO_INTERPRET_AP attribute can
not be set then that is an error condition that should be returned to
the caller.



+return -EOPNOTSUPP;
+}
+
+return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attribute);


Shouldn't you use the "enable" parameter somewhere?
If attribute.addr is not zero, then that indicates enable. If that is 
objectionable,

I can change it.



+}
+
  void kvm_s390_crypto_reset(void)
  {
  if (s390_has_feat(S390_FEAT_MSA_EXT_3)) {
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index 34ee7e7..0d6c6e7 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -40,4 +40,6 @@ void kvm_s390_crypto_reset(void);
  void kvm_s390_restart_interrupt(S390CPU *cpu);
  void kvm_s390_stop_interrupt(S390CPU *cpu);

+int kvm_s390_set_interpret_ap(uint8_t enable);
+
  #endif /* KVM_S390X_H */

Re: [Qemu-devel] [PATCH v3 4/7] s390x/kvm: interface to interpret AP instructions

2018-03-16 Thread Pierre Morel 

On 16/03/2018 00:24, Tony Krowiak wrote:

The VFIO AP device exploits interpretive execution of AP
instructions (APIE). APIE is enabled by setting a device attribute
via the KVM_SET_DEVICE_ATTR ioctl.

Signed-off-by: Tony Krowiak 
---
  target/s390x/kvm.c   |   16 
  target/s390x/kvm_s390x.h |2 ++
  2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 33e5ec3..2812e28 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -277,6 +277,22 @@ static void kvm_s390_init_dea_kw(void)
  }
  }

+int kvm_s390_set_interpret_ap(uint8_t enable)
+{
+struct kvm_device_attr attribute = {
+.group = KVM_S390_VM_CRYPTO,
+.attr  = KVM_S390_VM_CRYPTO_INTERPRET_AP,
+.addr = 1,
+};
+
+if (!kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO,
+   KVM_S390_VM_CRYPTO_INTERPRET_AP)) {


Isn't it enough to have the CPU feature ?
What are expecting here?


+return -EOPNOTSUPP;
+}
+
+return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attribute);


Shouldn't you use the "enable" parameter somewhere?


+}
+
  void kvm_s390_crypto_reset(void)
  {
  if (s390_has_feat(S390_FEAT_MSA_EXT_3)) {
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index 34ee7e7..0d6c6e7 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -40,4 +40,6 @@ void kvm_s390_crypto_reset(void);
  void kvm_s390_restart_interrupt(S390CPU *cpu);
  void kvm_s390_stop_interrupt(S390CPU *cpu);

+int kvm_s390_set_interpret_ap(uint8_t enable);
+
  #endif /* KVM_S390X_H */



--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany

Re: [Qemu-devel] [PATCH v3 4/7] s390x/kvm: interface to interpret AP instructions

2018-03-16 Thread Pierre Morel 

On 16/03/2018 00:24, Tony Krowiak wrote:

The VFIO AP device exploits interpretive execution of AP
instructions (APIE). APIE is enabled by setting a device attribute
via the KVM_SET_DEVICE_ATTR ioctl.

Signed-off-by: Tony Krowiak 
---
  target/s390x/kvm.c   |   16 
  target/s390x/kvm_s390x.h |2 ++
  2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 33e5ec3..2812e28 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -277,6 +277,22 @@ static void kvm_s390_init_dea_kw(void)
  }
  }

+int kvm_s390_set_interpret_ap(uint8_t enable)
+{
+struct kvm_device_attr attribute = {
+.group = KVM_S390_VM_CRYPTO,
+.attr  = KVM_S390_VM_CRYPTO_INTERPRET_AP,
+.addr = 1,
+};
+
+if (!kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO,
+   KVM_S390_VM_CRYPTO_INTERPRET_AP)) {


Isn't it enough to have the CPU feature ?
What are expecting here?


+return -EOPNOTSUPP;
+}
+
+return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attribute);


shouldn't you use the "enable" parameter somewhere?


+}
+
  void kvm_s390_crypto_reset(void)
  {
  if (s390_has_feat(S390_FEAT_MSA_EXT_3)) {
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index 34ee7e7..0d6c6e7 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -40,4 +40,6 @@ void kvm_s390_crypto_reset(void);
  void kvm_s390_restart_interrupt(S390CPU *cpu);
  void kvm_s390_stop_interrupt(S390CPU *cpu);

+int kvm_s390_set_interpret_ap(uint8_t enable);
+
  #endif /* KVM_S390X_H */




--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany

[Qemu-devel] [PATCH v3 4/7] s390x/kvm: interface to interpret AP instructions

2018-03-15 Thread Tony Krowiak 
The VFIO AP device exploits interpretive execution of AP
instructions (APIE). APIE is enabled by setting a device attribute
via the KVM_SET_DEVICE_ATTR ioctl.

Signed-off-by: Tony Krowiak 
---
 target/s390x/kvm.c   |   16 
 target/s390x/kvm_s390x.h |2 ++
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 33e5ec3..2812e28 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -277,6 +277,22 @@ static void kvm_s390_init_dea_kw(void)
 }
 }
 
+int kvm_s390_set_interpret_ap(uint8_t enable)
+{
+struct kvm_device_attr attribute = {
+.group = KVM_S390_VM_CRYPTO,
+.attr  = KVM_S390_VM_CRYPTO_INTERPRET_AP,
+.addr = 1,
+};
+
+if (!kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO,
+   KVM_S390_VM_CRYPTO_INTERPRET_AP)) {
+return -EOPNOTSUPP;
+}
+
+return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attribute);
+}
+
 void kvm_s390_crypto_reset(void)
 {
 if (s390_has_feat(S390_FEAT_MSA_EXT_3)) {
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index 34ee7e7..0d6c6e7 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -40,4 +40,6 @@ void kvm_s390_crypto_reset(void);
 void kvm_s390_restart_interrupt(S390CPU *cpu);
 void kvm_s390_stop_interrupt(S390CPU *cpu);
 
+int kvm_s390_set_interpret_ap(uint8_t enable);
+
 #endif /* KVM_S390X_H */
-- 
1.7.1