KVM: s390: Base infrastructure for enabling capabilities.

Make s390 support KVM_ENABLE_CAP.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

2 files changed, 27 insertions, 1 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 8a0de309932f..73bd159c5559 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -913,7 +913,7 @@ documentation when it pops into existence).
 4.37 KVM_ENABLE_CAP
 
 Capability: KVM_CAP_ENABLE_CAP
-Architectures: ppc
+Architectures: ppc, s390
 Type: vcpu ioctl
 Parameters: struct kvm_enable_cap (in)
 Returns: 0 on success; -1 on error
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index f718bc65835c..5ff26033825c 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -140,6 +140,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 #endif
         case KVM_CAP_SYNC_REGS:
         case KVM_CAP_ONE_REG:
+        case KVM_CAP_ENABLE_CAP:
                 r = 1;
                 break;
         case KVM_CAP_NR_VCPUS:
@@ -808,6 +809,22 @@ int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr)
         return 0;
 }
 
+static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
+                                     struct kvm_enable_cap *cap)
+{
+        int r;
+
+        if (cap->flags)
+                return -EINVAL;
+
+        switch (cap->cap) {
+        default:
+                r = -EINVAL;
+                break;
+        }
+        return r;
+}
+
 long kvm_arch_vcpu_ioctl(struct file *filp,
                          unsigned int ioctl, unsigned long arg)
 {
@@ -894,6 +911,15 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
                         r = 0;
                 break;
         }
+        case KVM_ENABLE_CAP:
+        {
+                struct kvm_enable_cap cap;
+                r = -EFAULT;
+                if (copy_from_user(&cap, argp, sizeof(cap)))
+                        break;
+                r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
+                break;
+        }
         default:
                 r = -ENOTTY;
         }