3 files changed, 97 insertions, 1 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 579d40b26a5a..ee394b263261 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1496,6 +1496,44 @@ following algorithm:
 Some guests configure the LINT1 NMI input to cause a panic, aiding in
 debugging.
 
+4.64 KVM_S390_UCAS_MAP
+
+Capability: KVM_CAP_S390_UCONTROL
+Architectures: s390
+Type: vcpu ioctl
+Parameters: struct kvm_s390_ucas_mapping (in)
+Returns: 0 in case of success
+
+The parameter is defined like this:
+        struct kvm_s390_ucas_mapping {
+                __u64 user_addr;
+                __u64 vcpu_addr;
+                __u64 length;
+        };
+
+This ioctl maps the memory at "user_addr" with the length "length" to
+the vcpu's address space starting at "vcpu_addr". All parameters need to
+be alligned by 1 megabyte.
+
+4.65 KVM_S390_UCAS_UNMAP
+
+Capability: KVM_CAP_S390_UCONTROL
+Architectures: s390
+Type: vcpu ioctl
+Parameters: struct kvm_s390_ucas_mapping (in)
+Returns: 0 in case of success
+
+The parameter is defined like this:
+        struct kvm_s390_ucas_mapping {
+                __u64 user_addr;
+                __u64 vcpu_addr;
+                __u64 length;
+        };
+
+This ioctl unmaps the memory in the vcpu's address space starting at
+"vcpu_addr" with the length "length". The field "user_addr" is ignored.
+All parameters need to be alligned by 1 megabyte.
+
 5. The kvm_run structure
 
 Application code obtains a pointer to the kvm_run structure by
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index f0937552175b..2d3248895def 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -233,6 +233,10 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
                 (__u64) vcpu->arch.sie_block)
                 vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sda = 0;
         smp_mb();
+
+        if (kvm_is_ucontrol(vcpu->kvm))
+                gmap_free(vcpu->arch.gmap);
+
         free_page((unsigned long)(vcpu->arch.sie_block));
         kvm_vcpu_uninit(vcpu);
         kfree(vcpu);
@@ -263,12 +267,20 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
         kvm_free_vcpus(kvm);
         free_page((unsigned long)(kvm->arch.sca));
         debug_unregister(kvm->arch.dbf);
-        gmap_free(kvm->arch.gmap);
+        if (!kvm_is_ucontrol(kvm))
+                gmap_free(kvm->arch.gmap);
 }
 
 /* Section: vcpu related */
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 {
+        if (kvm_is_ucontrol(vcpu->kvm)) {
+                vcpu->arch.gmap = gmap_alloc(current->mm);
+                if (!vcpu->arch.gmap)
+                        return -ENOMEM;
+                return 0;
+        }
+
         vcpu->arch.gmap = vcpu->kvm->arch.gmap;
         return 0;
 }
@@ -687,6 +699,42 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
         case KVM_S390_INITIAL_RESET:
                 r = kvm_arch_vcpu_ioctl_initial_reset(vcpu);
                 break;
+#ifdef CONFIG_KVM_S390_UCONTROL
+        case KVM_S390_UCAS_MAP: {
+                struct kvm_s390_ucas_mapping ucasmap;
+
+                if (copy_from_user(&ucasmap, argp, sizeof(ucasmap))) {
+                        r = -EFAULT;
+                        break;
+                }
+
+                if (!kvm_is_ucontrol(vcpu->kvm)) {
+                        r = -EINVAL;
+                        break;
+                }
+
+                r = gmap_map_segment(vcpu->arch.gmap, ucasmap.user_addr,
+                                     ucasmap.vcpu_addr, ucasmap.length);
+                break;
+        }
+        case KVM_S390_UCAS_UNMAP: {
+                struct kvm_s390_ucas_mapping ucasmap;
+
+                if (copy_from_user(&ucasmap, argp, sizeof(ucasmap))) {
+                        r = -EFAULT;
+                        break;
+                }
+
+                if (!kvm_is_ucontrol(vcpu->kvm)) {
+                        r = -EINVAL;
+                        break;
+                }
+
+                r = gmap_unmap_segment(vcpu->arch.gmap, ucasmap.vcpu_addr,
+                        ucasmap.length);
+                break;
+        }
+#endif
         default:
                 r = -EINVAL;
         }
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index bba393a6760f..0a66c1072691 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -658,6 +658,16 @@ struct kvm_clock_data {
                                         struct kvm_userspace_memory_region)
 #define KVM_SET_TSS_ADDR          _IO(KVMIO,   0x47)
 #define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO,  0x48, __u64)
+
+/* enable ucontrol for s390 */
+struct kvm_s390_ucas_mapping {
+        __u64 user_addr;
+        __u64 vcpu_addr;
+        __u64 length;
+};
+#define KVM_S390_UCAS_MAP        _IOW(KVMIO, 0x50, struct kvm_s390_ucas_mapping)
+#define KVM_S390_UCAS_UNMAP      _IOW(KVMIO, 0x51, struct kvm_s390_ucas_mapping)
+
 /* Device model IOC */
 #define KVM_CREATE_IRQCHIP        _IO(KVMIO,   0x60)
 #define KVM_IRQ_LINE              _IOW(KVMIO,  0x61, struct kvm_irq_level)