1 files changed, 41 insertions, 1 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 13f30aac460b..e16cdc9ec0c1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -680,7 +680,8 @@ static void kvm_write_guest_time(struct kvm_vcpu *v)
         /* With all the info we got, fill in the values */
 
         vcpu->hv_clock.system_time = ts.tv_nsec +
-                                     (NSEC_PER_SEC * (u64)ts.tv_sec);
+                                     (NSEC_PER_SEC * (u64)ts.tv_sec) + v->kvm->arch.kvmclock_offset;
+
         /*
          * The interface expects us to write an even number signaling that the
          * update is finished. Since the guest won't see the intermediate
@@ -1262,6 +1263,7 @@ int kvm_dev_ioctl_check_extension(long ext)
         case KVM_CAP_PIT_STATE2:
         case KVM_CAP_SET_IDENTITY_MAP_ADDR:
         case KVM_CAP_XEN_HVM:
+        case KVM_CAP_ADJUST_CLOCK:
                 r = 1;
                 break;
         case KVM_CAP_COALESCED_MMIO:
@@ -2468,6 +2470,44 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 r = 0;
                 break;
         }
+        case KVM_SET_CLOCK: {
+                struct timespec now;
+                struct kvm_clock_data user_ns;
+                u64 now_ns;
+                s64 delta;
+
+                r = -EFAULT;
+                if (copy_from_user(&user_ns, argp, sizeof(user_ns)))
+                        goto out;
+
+                r = -EINVAL;
+                if (user_ns.flags)
+                        goto out;
+
+                r = 0;
+                ktime_get_ts(&now);
+                now_ns = timespec_to_ns(&now);
+                delta = user_ns.clock - now_ns;
+                kvm->arch.kvmclock_offset = delta;
+                break;
+        }
+        case KVM_GET_CLOCK: {
+                struct timespec now;
+                struct kvm_clock_data user_ns;
+                u64 now_ns;
+
+                ktime_get_ts(&now);
+                now_ns = timespec_to_ns(&now);
+                user_ns.clock = kvm->arch.kvmclock_offset + now_ns;
+                user_ns.flags = 0;
+
+                r = -EFAULT;
+                if (copy_to_user(argp, &user_ns, sizeof(user_ns)))
+                        goto out;
+                r = 0;
+                break;
+        }
+
         default:
                 ;
         }