---

yaml
---
r: 172314
b: refs/heads/master
c: afbcf7a
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: cd5a2685de4a642fd0bd763e8c19711ef08dbe27
+refs/heads/master: afbcf7ab8d1bc8c2d04792f6d9e786e0adeb328d

trunk/Documentation/kvm/api.txt

@@ -617,6 +617,42 @@ struct kvm_xen_hvm_config {
 	__u8 pad2[30];
 };
 
+4.27 KVM_GET_CLOCK
+
+Capability: KVM_CAP_ADJUST_CLOCK
+Architectures: x86
+Type: vm ioctl
+Parameters: struct kvm_clock_data (out)
+Returns: 0 on success, -1 on error
+
+Gets the current timestamp of kvmclock as seen by the current guest. In
+conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios
+such as migration.
+
+struct kvm_clock_data {
+	__u64 clock;  /* kvmclock current value */
+	__u32 flags;
+	__u32 pad[9];
+};
+
+4.28 KVM_SET_CLOCK
+
+Capability: KVM_CAP_ADJUST_CLOCK
+Architectures: x86
+Type: vm ioctl
+Parameters: struct kvm_clock_data (in)
+Returns: 0 on success, -1 on error
+
+Sets the current timestamp of kvmclock to the valued specific in its parameter.
+In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios
+such as migration.
+
+struct kvm_clock_data {
+	__u64 clock;  /* kvmclock current value */
+	__u32 flags;
+	__u32 pad[9];
+};
+
 5. The kvm_run structure
 
 Application code obtains a pointer to the kvm_run structure by

trunk/arch/x86/include/asm/kvm_host.h

@@ -413,6 +413,7 @@ struct kvm_arch{
 
 	unsigned long irq_sources_bitmap;
 	u64 vm_init_tsc;
+	s64 kvmclock_offset;
 
 	struct kvm_xen_hvm_config xen_hvm_config;
 };

trunk/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:
 		;
 	}

trunk/include/linux/kvm.h

@@ -439,6 +439,7 @@ struct kvm_ioeventfd {
 #ifdef __KVM_HAVE_XEN_HVM
 #define KVM_CAP_XEN_HVM 38
 #endif
+#define KVM_CAP_ADJUST_CLOCK 39
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -512,6 +513,12 @@ struct kvm_irqfd {
 	__u8  pad[20];
 };
 
+struct kvm_clock_data {
+	__u64 clock;
+	__u32 flags;
+	__u32 pad[9];
+};
+
 /*
  * ioctls for VM fds
  */
@@ -562,6 +569,9 @@ struct kvm_irqfd {
 #define KVM_SET_BOOT_CPU_ID        _IO(KVMIO, 0x78)
 #define KVM_IOEVENTFD             _IOW(KVMIO, 0x79, struct kvm_ioeventfd)
 #define KVM_XEN_HVM_CONFIG        _IOW(KVMIO, 0x7a, struct kvm_xen_hvm_config)
+#define KVM_SET_CLOCK             _IOW(KVMIO, 0x7b, struct kvm_clock_data)
+#define KVM_GET_CLOCK             _IOR(KVMIO, 0x7c, struct kvm_clock_data)
+
 
 /*
  * ioctls for vcpu fds