diff mbox series

[v18,3/7] ptp: Reorganize ptp_kvm.c to make it arch-independent

Message ID 20210208134029.3269384-4-maz@kernel.org
State Superseded
Headers show
Series KVM: arm64: Add host/guest KVM-PTP support | expand

Commit Message

Marc Zyngier Feb. 8, 2021, 1:40 p.m. UTC
From: Jianyong Wu <jianyong.wu@arm.com>

Currently, the ptp_kvm module contains a lot of x86-specific code.
Let's move this code into a new arch-specific file in the same directory,
and rename the arch-independent file to ptp_kvm_common.c.

Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201209060932.212364-4-jianyong.wu@arm.com
---
 drivers/ptp/Makefile                        |  1 +
 drivers/ptp/{ptp_kvm.c => ptp_kvm_common.c} | 84 +++++-------------
 drivers/ptp/ptp_kvm_x86.c                   | 97 +++++++++++++++++++++
 include/linux/ptp_kvm.h                     | 19 ++++
 4 files changed, 139 insertions(+), 62 deletions(-)
 rename drivers/ptp/{ptp_kvm.c => ptp_kvm_common.c} (60%)
 create mode 100644 drivers/ptp/ptp_kvm_x86.c
 create mode 100644 include/linux/ptp_kvm.h

Comments

Andre Przywara Feb. 10, 2021, 4:19 p.m. UTC | #1
On Mon,  8 Feb 2021 13:40:25 +0000
Marc Zyngier <maz@kernel.org> wrote:

> From: Jianyong Wu <jianyong.wu@arm.com>

> 

> Currently, the ptp_kvm module contains a lot of x86-specific code.

> Let's move this code into a new arch-specific file in the same directory,

> and rename the arch-independent file to ptp_kvm_common.c.

> 

> Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>

> Signed-off-by: Marc Zyngier <maz@kernel.org>

> Link: https://lore.kernel.org/r/20201209060932.212364-4-jianyong.wu@arm.com


Verified that the code movements are correct. Test compiled for x86.

1.5 nits below, but regardless:

Reviewed-by: Andre Przywara <andre.przywara@arm.com>



> ---

>  drivers/ptp/Makefile                        |  1 +

>  drivers/ptp/{ptp_kvm.c => ptp_kvm_common.c} | 84 +++++-------------

>  drivers/ptp/ptp_kvm_x86.c                   | 97 +++++++++++++++++++++

>  include/linux/ptp_kvm.h                     | 19 ++++

>  4 files changed, 139 insertions(+), 62 deletions(-)

>  rename drivers/ptp/{ptp_kvm.c => ptp_kvm_common.c} (60%)

>  create mode 100644 drivers/ptp/ptp_kvm_x86.c

>  create mode 100644 include/linux/ptp_kvm.h

> 

> diff --git a/drivers/ptp/Makefile b/drivers/ptp/Makefile

> index db5aef3bddc6..d11eeb5811d1 100644

> --- a/drivers/ptp/Makefile

> +++ b/drivers/ptp/Makefile

> @@ -4,6 +4,7 @@

>  #

>  

>  ptp-y					:= ptp_clock.o ptp_chardev.o ptp_sysfs.o

> +ptp_kvm-$(CONFIG_X86)			:= ptp_kvm_x86.o ptp_kvm_common.o

>  obj-$(CONFIG_PTP_1588_CLOCK)		+= ptp.o

>  obj-$(CONFIG_PTP_1588_CLOCK_DTE)	+= ptp_dte.o

>  obj-$(CONFIG_PTP_1588_CLOCK_INES)	+= ptp_ines.o

> diff --git a/drivers/ptp/ptp_kvm.c b/drivers/ptp/ptp_kvm_common.c

> similarity index 60%

> rename from drivers/ptp/ptp_kvm.c

> rename to drivers/ptp/ptp_kvm_common.c

> index 658d33fc3195..721ddcede5e1 100644

> --- a/drivers/ptp/ptp_kvm.c

> +++ b/drivers/ptp/ptp_kvm_common.c

> @@ -8,11 +8,11 @@

>  #include <linux/err.h>

>  #include <linux/init.h>

>  #include <linux/kernel.h>

> +#include <linux/slab.h>

>  #include <linux/module.h>

> +#include <linux/ptp_kvm.h>

>  #include <uapi/linux/kvm_para.h>

>  #include <asm/kvm_para.h>

> -#include <asm/pvclock.h>

> -#include <asm/kvmclock.h>

>  #include <uapi/asm/kvm_para.h>

>  

>  #include <linux/ptp_clock_kernel.h>

> @@ -24,56 +24,29 @@ struct kvm_ptp_clock {

>  

>  static DEFINE_SPINLOCK(kvm_ptp_lock);

>  

> -static struct pvclock_vsyscall_time_info *hv_clock;

> -

> -static struct kvm_clock_pairing clock_pair;

> -static phys_addr_t clock_pair_gpa;

> -

>  static int ptp_kvm_get_time_fn(ktime_t *device_time,

>  			       struct system_counterval_t *system_counter,

>  			       void *ctx)

>  {

> -	unsigned long ret;

> +	long ret;

> +	u64 cycle;

>  	struct timespec64 tspec;

> -	unsigned version;

> -	int cpu;

> -	struct pvclock_vcpu_time_info *src;

> +	struct clocksource *cs;

>  

>  	spin_lock(&kvm_ptp_lock);

>  

>  	preempt_disable_notrace();

> -	cpu = smp_processor_id();

> -	src = &hv_clock[cpu].pvti;

> -

> -	do {

> -		/*

> -		 * We are using a TSC value read in the hosts

> -		 * kvm_hc_clock_pairing handling.

> -		 * So any changes to tsc_to_system_mul

> -		 * and tsc_shift or any other pvclock

> -		 * data invalidate that measurement.

> -		 */

> -		version = pvclock_read_begin(src);

> -

> -		ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,

> -				     clock_pair_gpa,

> -				     KVM_CLOCK_PAIRING_WALLCLOCK);

> -		if (ret != 0) {

> -			pr_err_ratelimited("clock pairing hypercall ret %lu\n", ret);

> -			spin_unlock(&kvm_ptp_lock);

> -			preempt_enable_notrace();

> -			return -EOPNOTSUPP;

> -		}

> -

> -		tspec.tv_sec = clock_pair.sec;

> -		tspec.tv_nsec = clock_pair.nsec;

> -		ret = __pvclock_read_cycles(src, clock_pair.tsc);

> -	} while (pvclock_read_retry(src, version));

> +	ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs);

> +	if (ret) {

> +		spin_unlock(&kvm_ptp_lock);

> +		preempt_enable_notrace();

> +		return ret;

> +	}

>  

>  	preempt_enable_notrace();

>  

> -	system_counter->cycles = ret;

> -	system_counter->cs = &kvm_clock;

> +	system_counter->cycles = cycle;

> +	system_counter->cs = cs;

>  

>  	*device_time = timespec64_to_ktime(tspec);

>  

> @@ -111,22 +84,17 @@ static int ptp_kvm_settime(struct ptp_clock_info *ptp,

>  

>  static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)

>  {

> -	unsigned long ret;

> +	long ret;

>  	struct timespec64 tspec;

>  

>  	spin_lock(&kvm_ptp_lock);

>  

> -	ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,

> -			     clock_pair_gpa,

> -			     KVM_CLOCK_PAIRING_WALLCLOCK);

> -	if (ret != 0) {

> -		pr_err_ratelimited("clock offset hypercall ret %lu\n", ret);

> +	ret = kvm_arch_ptp_get_clock(&tspec);

> +	if (ret) {

>  		spin_unlock(&kvm_ptp_lock);

> -		return -EOPNOTSUPP;

> +		return ret;

>  	}

>  

> -	tspec.tv_sec = clock_pair.sec;

> -	tspec.tv_nsec = clock_pair.nsec;

>  	spin_unlock(&kvm_ptp_lock);

>  

>  	memcpy(ts, &tspec, sizeof(struct timespec64));

> @@ -168,19 +136,11 @@ static int __init ptp_kvm_init(void)

>  {

>  	long ret;

>  

> -	if (!kvm_para_available())

> -		return -ENODEV;

> -

> -	clock_pair_gpa = slow_virt_to_phys(&clock_pair);

> -	hv_clock = pvclock_get_pvti_cpu0_va();

> -

> -	if (!hv_clock)

> -		return -ENODEV;

> -

> -	ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa,

> -			KVM_CLOCK_PAIRING_WALLCLOCK);

> -	if (ret == -KVM_ENOSYS || ret == -KVM_EOPNOTSUPP)

> -		return -ENODEV;

> +	ret = kvm_arch_ptp_init();

> +	if (ret) {

> +		pr_err("fail to initialize ptp_kvm");

> +		return ret;

> +	}

>  

>  	kvm_ptp_clock.caps = ptp_kvm_caps;

>  

> diff --git a/drivers/ptp/ptp_kvm_x86.c b/drivers/ptp/ptp_kvm_x86.c

> new file mode 100644

> index 000000000000..82a6be9a7479

> --- /dev/null

> +++ b/drivers/ptp/ptp_kvm_x86.c

> @@ -0,0 +1,97 @@

> +// SPDX-License-Identifier: GPL-2.0-or-later

> +/*

> + * Virtual PTP 1588 clock for use with KVM guests

> + *

> + * Copyright (C) 2017 Red Hat Inc.

> + */

> +

> +#include <linux/device.h>

> +#include <linux/kernel.h>

> +#include <asm/pvclock.h>

> +#include <asm/kvmclock.h>

> +#include <linux/module.h>

> +#include <uapi/asm/kvm_para.h>

> +#include <uapi/linux/kvm_para.h>

> +#include <linux/ptp_clock_kernel.h>

> +#include <linux/ptp_kvm.h>

> +

> +struct pvclock_vsyscall_time_info *hv_clock;

> +

> +static phys_addr_t clock_pair_gpa;

> +static struct kvm_clock_pairing clock_pair;

> +

> +int kvm_arch_ptp_init(void)

> +{

> +	long ret;

> +

> +	if (!kvm_para_available())

> +		return -ENODEV;

> +

> +	clock_pair_gpa = slow_virt_to_phys(&clock_pair);

> +	hv_clock = pvclock_get_pvti_cpu0_va();

> +	if (!hv_clock)

> +		return -ENODEV;

> +

> +	ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa,

> +			     KVM_CLOCK_PAIRING_WALLCLOCK);

> +	if (ret == -KVM_ENOSYS || ret == -KVM_EOPNOTSUPP)

> +		return -ENODEV;

> +

> +	return 0;

> +}

> +

> +int kvm_arch_ptp_get_clock(struct timespec64 *ts)

> +{

> +	unsigned long ret;


Nit: The return value type of kvm_hypercall2 is signed, so you can use
just "long" here. The former code used unsigned because ret was re-used
again for another call. This is now gone.

> +

> +	ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,

> +			     clock_pair_gpa,

> +			     KVM_CLOCK_PAIRING_WALLCLOCK);

> +	if (ret != 0) {

> +		pr_err_ratelimited("clock offset hypercall ret %lu\n", ret);

> +		return -EOPNOTSUPP;

> +	}

> +

> +	ts->tv_sec = clock_pair.sec;

> +	ts->tv_nsec = clock_pair.nsec;

> +

> +	return 0;

> +}

> +

> +int kvm_arch_ptp_get_crosststamp(u64 *cycle, struct timespec64 *tspec,

> +			      struct clocksource **cs)

> +{

> +	unsigned long ret;


Same here.

Cheers,
Andre

> +	unsigned int version;

> +	int cpu;

> +	struct pvclock_vcpu_time_info *src;

> +

> +	cpu = smp_processor_id();

> +	src = &hv_clock[cpu].pvti;

> +

> +	do {

> +		/*

> +		 * We are using a TSC value read in the hosts

> +		 * kvm_hc_clock_pairing handling.

> +		 * So any changes to tsc_to_system_mul

> +		 * and tsc_shift or any other pvclock

> +		 * data invalidate that measurement.

> +		 */

> +		version = pvclock_read_begin(src);

> +

> +		ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,

> +				     clock_pair_gpa,

> +				     KVM_CLOCK_PAIRING_WALLCLOCK);

> +		if (ret != 0) {

> +			pr_err_ratelimited("clock pairing hypercall ret %lu\n", ret);

> +			return -EOPNOTSUPP;

> +		}

> +		tspec->tv_sec = clock_pair.sec;

> +		tspec->tv_nsec = clock_pair.nsec;

> +		*cycle = __pvclock_read_cycles(src, clock_pair.tsc);

> +	} while (pvclock_read_retry(src, version));

> +

> +	*cs = &kvm_clock;

> +

> +	return 0;

> +}

> diff --git a/include/linux/ptp_kvm.h b/include/linux/ptp_kvm.h

> new file mode 100644

> index 000000000000..f960a719f0d5

> --- /dev/null

> +++ b/include/linux/ptp_kvm.h

> @@ -0,0 +1,19 @@

> +/* SPDX-License-Identifier: GPL-2.0-or-later */

> +/*

> + * Virtual PTP 1588 clock for use with KVM guests

> + *

> + * Copyright (C) 2017 Red Hat Inc.

> + */

> +

> +#ifndef _PTP_KVM_H_

> +#define _PTP_KVM_H_

> +

> +struct timespec64;

> +struct clocksource;

> +

> +int kvm_arch_ptp_init(void);

> +int kvm_arch_ptp_get_clock(struct timespec64 *ts);

> +int kvm_arch_ptp_get_crosststamp(u64 *cycle,

> +		struct timespec64 *tspec, struct clocksource **cs);

> +

> +#endif /* _PTP_KVM_H_ */
diff mbox series

Patch

diff --git a/drivers/ptp/Makefile b/drivers/ptp/Makefile
index db5aef3bddc6..d11eeb5811d1 100644
--- a/drivers/ptp/Makefile
+++ b/drivers/ptp/Makefile
@@ -4,6 +4,7 @@ 
 #
 
 ptp-y					:= ptp_clock.o ptp_chardev.o ptp_sysfs.o
+ptp_kvm-$(CONFIG_X86)			:= ptp_kvm_x86.o ptp_kvm_common.o
 obj-$(CONFIG_PTP_1588_CLOCK)		+= ptp.o
 obj-$(CONFIG_PTP_1588_CLOCK_DTE)	+= ptp_dte.o
 obj-$(CONFIG_PTP_1588_CLOCK_INES)	+= ptp_ines.o
diff --git a/drivers/ptp/ptp_kvm.c b/drivers/ptp/ptp_kvm_common.c
similarity index 60%
rename from drivers/ptp/ptp_kvm.c
rename to drivers/ptp/ptp_kvm_common.c
index 658d33fc3195..721ddcede5e1 100644
--- a/drivers/ptp/ptp_kvm.c
+++ b/drivers/ptp/ptp_kvm_common.c
@@ -8,11 +8,11 @@ 
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/ptp_kvm.h>
 #include <uapi/linux/kvm_para.h>
 #include <asm/kvm_para.h>
-#include <asm/pvclock.h>
-#include <asm/kvmclock.h>
 #include <uapi/asm/kvm_para.h>
 
 #include <linux/ptp_clock_kernel.h>
@@ -24,56 +24,29 @@  struct kvm_ptp_clock {
 
 static DEFINE_SPINLOCK(kvm_ptp_lock);
 
-static struct pvclock_vsyscall_time_info *hv_clock;
-
-static struct kvm_clock_pairing clock_pair;
-static phys_addr_t clock_pair_gpa;
-
 static int ptp_kvm_get_time_fn(ktime_t *device_time,
 			       struct system_counterval_t *system_counter,
 			       void *ctx)
 {
-	unsigned long ret;
+	long ret;
+	u64 cycle;
 	struct timespec64 tspec;
-	unsigned version;
-	int cpu;
-	struct pvclock_vcpu_time_info *src;
+	struct clocksource *cs;
 
 	spin_lock(&kvm_ptp_lock);
 
 	preempt_disable_notrace();
-	cpu = smp_processor_id();
-	src = &hv_clock[cpu].pvti;
-
-	do {
-		/*
-		 * We are using a TSC value read in the hosts
-		 * kvm_hc_clock_pairing handling.
-		 * So any changes to tsc_to_system_mul
-		 * and tsc_shift or any other pvclock
-		 * data invalidate that measurement.
-		 */
-		version = pvclock_read_begin(src);
-
-		ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
-				     clock_pair_gpa,
-				     KVM_CLOCK_PAIRING_WALLCLOCK);
-		if (ret != 0) {
-			pr_err_ratelimited("clock pairing hypercall ret %lu\n", ret);
-			spin_unlock(&kvm_ptp_lock);
-			preempt_enable_notrace();
-			return -EOPNOTSUPP;
-		}
-
-		tspec.tv_sec = clock_pair.sec;
-		tspec.tv_nsec = clock_pair.nsec;
-		ret = __pvclock_read_cycles(src, clock_pair.tsc);
-	} while (pvclock_read_retry(src, version));
+	ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs);
+	if (ret) {
+		spin_unlock(&kvm_ptp_lock);
+		preempt_enable_notrace();
+		return ret;
+	}
 
 	preempt_enable_notrace();
 
-	system_counter->cycles = ret;
-	system_counter->cs = &kvm_clock;
+	system_counter->cycles = cycle;
+	system_counter->cs = cs;
 
 	*device_time = timespec64_to_ktime(tspec);
 
@@ -111,22 +84,17 @@  static int ptp_kvm_settime(struct ptp_clock_info *ptp,
 
 static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
 {
-	unsigned long ret;
+	long ret;
 	struct timespec64 tspec;
 
 	spin_lock(&kvm_ptp_lock);
 
-	ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
-			     clock_pair_gpa,
-			     KVM_CLOCK_PAIRING_WALLCLOCK);
-	if (ret != 0) {
-		pr_err_ratelimited("clock offset hypercall ret %lu\n", ret);
+	ret = kvm_arch_ptp_get_clock(&tspec);
+	if (ret) {
 		spin_unlock(&kvm_ptp_lock);
-		return -EOPNOTSUPP;
+		return ret;
 	}
 
-	tspec.tv_sec = clock_pair.sec;
-	tspec.tv_nsec = clock_pair.nsec;
 	spin_unlock(&kvm_ptp_lock);
 
 	memcpy(ts, &tspec, sizeof(struct timespec64));
@@ -168,19 +136,11 @@  static int __init ptp_kvm_init(void)
 {
 	long ret;
 
-	if (!kvm_para_available())
-		return -ENODEV;
-
-	clock_pair_gpa = slow_virt_to_phys(&clock_pair);
-	hv_clock = pvclock_get_pvti_cpu0_va();
-
-	if (!hv_clock)
-		return -ENODEV;
-
-	ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa,
-			KVM_CLOCK_PAIRING_WALLCLOCK);
-	if (ret == -KVM_ENOSYS || ret == -KVM_EOPNOTSUPP)
-		return -ENODEV;
+	ret = kvm_arch_ptp_init();
+	if (ret) {
+		pr_err("fail to initialize ptp_kvm");
+		return ret;
+	}
 
 	kvm_ptp_clock.caps = ptp_kvm_caps;
 
diff --git a/drivers/ptp/ptp_kvm_x86.c b/drivers/ptp/ptp_kvm_x86.c
new file mode 100644
index 000000000000..82a6be9a7479
--- /dev/null
+++ b/drivers/ptp/ptp_kvm_x86.c
@@ -0,0 +1,97 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtual PTP 1588 clock for use with KVM guests
+ *
+ * Copyright (C) 2017 Red Hat Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <asm/pvclock.h>
+#include <asm/kvmclock.h>
+#include <linux/module.h>
+#include <uapi/asm/kvm_para.h>
+#include <uapi/linux/kvm_para.h>
+#include <linux/ptp_clock_kernel.h>
+#include <linux/ptp_kvm.h>
+
+struct pvclock_vsyscall_time_info *hv_clock;
+
+static phys_addr_t clock_pair_gpa;
+static struct kvm_clock_pairing clock_pair;
+
+int kvm_arch_ptp_init(void)
+{
+	long ret;
+
+	if (!kvm_para_available())
+		return -ENODEV;
+
+	clock_pair_gpa = slow_virt_to_phys(&clock_pair);
+	hv_clock = pvclock_get_pvti_cpu0_va();
+	if (!hv_clock)
+		return -ENODEV;
+
+	ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa,
+			     KVM_CLOCK_PAIRING_WALLCLOCK);
+	if (ret == -KVM_ENOSYS || ret == -KVM_EOPNOTSUPP)
+		return -ENODEV;
+
+	return 0;
+}
+
+int kvm_arch_ptp_get_clock(struct timespec64 *ts)
+{
+	unsigned long ret;
+
+	ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
+			     clock_pair_gpa,
+			     KVM_CLOCK_PAIRING_WALLCLOCK);
+	if (ret != 0) {
+		pr_err_ratelimited("clock offset hypercall ret %lu\n", ret);
+		return -EOPNOTSUPP;
+	}
+
+	ts->tv_sec = clock_pair.sec;
+	ts->tv_nsec = clock_pair.nsec;
+
+	return 0;
+}
+
+int kvm_arch_ptp_get_crosststamp(u64 *cycle, struct timespec64 *tspec,
+			      struct clocksource **cs)
+{
+	unsigned long ret;
+	unsigned int version;
+	int cpu;
+	struct pvclock_vcpu_time_info *src;
+
+	cpu = smp_processor_id();
+	src = &hv_clock[cpu].pvti;
+
+	do {
+		/*
+		 * We are using a TSC value read in the hosts
+		 * kvm_hc_clock_pairing handling.
+		 * So any changes to tsc_to_system_mul
+		 * and tsc_shift or any other pvclock
+		 * data invalidate that measurement.
+		 */
+		version = pvclock_read_begin(src);
+
+		ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
+				     clock_pair_gpa,
+				     KVM_CLOCK_PAIRING_WALLCLOCK);
+		if (ret != 0) {
+			pr_err_ratelimited("clock pairing hypercall ret %lu\n", ret);
+			return -EOPNOTSUPP;
+		}
+		tspec->tv_sec = clock_pair.sec;
+		tspec->tv_nsec = clock_pair.nsec;
+		*cycle = __pvclock_read_cycles(src, clock_pair.tsc);
+	} while (pvclock_read_retry(src, version));
+
+	*cs = &kvm_clock;
+
+	return 0;
+}
diff --git a/include/linux/ptp_kvm.h b/include/linux/ptp_kvm.h
new file mode 100644
index 000000000000..f960a719f0d5
--- /dev/null
+++ b/include/linux/ptp_kvm.h
@@ -0,0 +1,19 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Virtual PTP 1588 clock for use with KVM guests
+ *
+ * Copyright (C) 2017 Red Hat Inc.
+ */
+
+#ifndef _PTP_KVM_H_
+#define _PTP_KVM_H_
+
+struct timespec64;
+struct clocksource;
+
+int kvm_arch_ptp_init(void);
+int kvm_arch_ptp_get_clock(struct timespec64 *ts);
+int kvm_arch_ptp_get_crosststamp(u64 *cycle,
+		struct timespec64 *tspec, struct clocksource **cs);
+
+#endif /* _PTP_KVM_H_ */