93 lines
2.0 KiB
C
93 lines
2.0 KiB
C
|
// 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>
|
||
|
|
|
||
|
|
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);
|
||
|
|
if (!pvclock_get_pvti_cpu0_va())
|
||
|
|
return -ENODEV;
|
||
|
|
|
||
|
|
ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa,
|
||
|
|
KVM_CLOCK_PAIRING_WALLCLOCK);
|
||
|
|
if (ret == -KVM_ENOSYS)
|
||
|
|
return -ENODEV;
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
int kvm_arch_ptp_get_clock(struct timespec64 *ts)
|
||
|
|
{
|
||
|
|
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)
|
||
|
|
{
|
||
|
|
struct pvclock_vcpu_time_info *src;
|
||
|
|
unsigned int version;
|
||
|
|
long ret;
|
||
|
|
|
||
|
|
src = this_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;
|
||
|
|
}
|