[3/5] KVM: s390: add debug tracing for cpu features of CPU model

Commit Message

Christian Borntraeger Dec. 20, 2017, 3:52 p.m. UTC

The cpu model already traces the cpu facilities, the ibc and
guest CPU ids. We should do the same for the cpu features (on
success only).

Signed-off-by: Christian Borntraeger <[e-mail]>
Reviewed-by: Halil Pasic <[e-mail]>
---
 arch/s390/kvm/kvm-s390.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

Comments

Cornelia Huck Dec. 20, 2017, 4:37 p.m. UTC | #1

On Wed, 20 Dec 2017 16:52:58 +0100
Christian Borntraeger <[e-mail]> wrote:

> The cpu model already traces the cpu facilities, the ibc and
> guest CPU ids. We should do the same for the cpu features (on
> success only).
> 
> Signed-off-by: Christian Borntraeger <[e-mail]>
> Reviewed-by: Halil Pasic <[e-mail]>
> ---
>  arch/s390/kvm/kvm-s390.c | 24 ++++++++++++++++++------
>  1 file changed, 18 insertions(+), 6 deletions(-)

Reviewed-by: Cornelia Huck <[e-mail]>

David Hildenbrand Jan. 8, 2018, 11:14 a.m. UTC | #2

On 20.12.2017 16:52, Christian Borntraeger wrote:

"We already trace ... related to the CPU model. We should ..."

> The cpu model already traces the cpu facilities, the ibc and
> guest CPU ids. We should do the same for the cpu features (on
> success only).

Reviewed-by: David Hildenbrand <[e-mail]>

Patch

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 00ef6f47e466..c85d7c4e8a38 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1084,7 +1084,6 @@  static int kvm_s390_set_processor_feat(struct kvm *kvm,
 				       struct kvm_device_attr *attr)
 {
 	struct kvm_s390_vm_cpu_feat data;
-	int ret = -EBUSY;
 
 	if (copy_from_user(&data, (void __user *)attr->addr, sizeof(data)))
 		return -EFAULT;
@@ -1094,13 +1093,18 @@  static int kvm_s390_set_processor_feat(struct kvm *kvm,
 		return -EINVAL;
 
 	mutex_lock(&kvm->lock);
-	if (!kvm->created_vcpus) {
-		bitmap_copy(kvm->arch.cpu_feat, (unsigned long *) data.feat,
-			    KVM_S390_VM_CPU_FEAT_NR_BITS);
-		ret = 0;
+	if (kvm->created_vcpus) {
+		mutex_unlock(&kvm->lock);
+		return -EBUSY;
 	}
+	bitmap_copy(kvm->arch.cpu_feat, (unsigned long *) data.feat,
+		    KVM_S390_VM_CPU_FEAT_NR_BITS);
 	mutex_unlock(&kvm->lock);
-	return ret;
+	VM_EVENT(kvm, 3, "SET: guest feat: 0x%16.16llx.0x%16.16llx.0x%16.16llx",
+			 data.feat[0],
+			 data.feat[1],
+			 data.feat[2]);
+	return 0;
 }
 
 static int kvm_s390_set_processor_subfunc(struct kvm *kvm,
@@ -1202,6 +1206,10 @@  static int kvm_s390_get_processor_feat(struct kvm *kvm,
 		    KVM_S390_VM_CPU_FEAT_NR_BITS);
 	if (copy_to_user((void __user *)attr->addr, &data, sizeof(data)))
 		return -EFAULT;
+	VM_EVENT(kvm, 3, "GET: guest feat: 0x%16.16llx.0x%16.16llx.0x%16.16llx",
+			 data.feat[0],
+			 data.feat[1],
+			 data.feat[2]);
 	return 0;
 }
 
@@ -1215,6 +1223,10 @@  static int kvm_s390_get_machine_feat(struct kvm *kvm,
 		    KVM_S390_VM_CPU_FEAT_NR_BITS);
 	if (copy_to_user((void __user *)attr->addr, &data, sizeof(data)))
 		return -EFAULT;
+	VM_EVENT(kvm, 3, "GET: host feat:  0x%16.16llx.0x%16.16llx.0x%16.16llx",
+			 data.feat[0],
+			 data.feat[1],
+			 data.feat[2]);
 	return 0;
 }