cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ptp_kvm_common.c (3192B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Virtual PTP 1588 clock for use with KVM guests
      4 *
      5 * Copyright (C) 2017 Red Hat Inc.
      6 */
      7#include <linux/device.h>
      8#include <linux/err.h>
      9#include <linux/init.h>
     10#include <linux/kernel.h>
     11#include <linux/slab.h>
     12#include <linux/module.h>
     13#include <linux/ptp_kvm.h>
     14#include <uapi/linux/kvm_para.h>
     15#include <asm/kvm_para.h>
     16#include <uapi/asm/kvm_para.h>
     17
     18#include <linux/ptp_clock_kernel.h>
     19
     20struct kvm_ptp_clock {
     21	struct ptp_clock *ptp_clock;
     22	struct ptp_clock_info caps;
     23};
     24
     25static DEFINE_SPINLOCK(kvm_ptp_lock);
     26
     27static int ptp_kvm_get_time_fn(ktime_t *device_time,
     28			       struct system_counterval_t *system_counter,
     29			       void *ctx)
     30{
     31	long ret;
     32	u64 cycle;
     33	struct timespec64 tspec;
     34	struct clocksource *cs;
     35
     36	spin_lock(&kvm_ptp_lock);
     37
     38	preempt_disable_notrace();
     39	ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs);
     40	if (ret) {
     41		spin_unlock(&kvm_ptp_lock);
     42		preempt_enable_notrace();
     43		return ret;
     44	}
     45
     46	preempt_enable_notrace();
     47
     48	system_counter->cycles = cycle;
     49	system_counter->cs = cs;
     50
     51	*device_time = timespec64_to_ktime(tspec);
     52
     53	spin_unlock(&kvm_ptp_lock);
     54
     55	return 0;
     56}
     57
     58static int ptp_kvm_getcrosststamp(struct ptp_clock_info *ptp,
     59				  struct system_device_crosststamp *xtstamp)
     60{
     61	return get_device_system_crosststamp(ptp_kvm_get_time_fn, NULL,
     62					     NULL, xtstamp);
     63}
     64
     65/*
     66 * PTP clock operations
     67 */
     68
     69static int ptp_kvm_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
     70{
     71	return -EOPNOTSUPP;
     72}
     73
     74static int ptp_kvm_adjtime(struct ptp_clock_info *ptp, s64 delta)
     75{
     76	return -EOPNOTSUPP;
     77}
     78
     79static int ptp_kvm_settime(struct ptp_clock_info *ptp,
     80			   const struct timespec64 *ts)
     81{
     82	return -EOPNOTSUPP;
     83}
     84
     85static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
     86{
     87	long ret;
     88	struct timespec64 tspec;
     89
     90	spin_lock(&kvm_ptp_lock);
     91
     92	ret = kvm_arch_ptp_get_clock(&tspec);
     93	if (ret) {
     94		spin_unlock(&kvm_ptp_lock);
     95		return ret;
     96	}
     97
     98	spin_unlock(&kvm_ptp_lock);
     99
    100	memcpy(ts, &tspec, sizeof(struct timespec64));
    101
    102	return 0;
    103}
    104
    105static int ptp_kvm_enable(struct ptp_clock_info *ptp,
    106			  struct ptp_clock_request *rq, int on)
    107{
    108	return -EOPNOTSUPP;
    109}
    110
    111static const struct ptp_clock_info ptp_kvm_caps = {
    112	.owner		= THIS_MODULE,
    113	.name		= "KVM virtual PTP",
    114	.max_adj	= 0,
    115	.n_ext_ts	= 0,
    116	.n_pins		= 0,
    117	.pps		= 0,
    118	.adjfreq	= ptp_kvm_adjfreq,
    119	.adjtime	= ptp_kvm_adjtime,
    120	.gettime64	= ptp_kvm_gettime,
    121	.settime64	= ptp_kvm_settime,
    122	.enable		= ptp_kvm_enable,
    123	.getcrosststamp = ptp_kvm_getcrosststamp,
    124};
    125
    126/* module operations */
    127
    128static struct kvm_ptp_clock kvm_ptp_clock;
    129
    130static void __exit ptp_kvm_exit(void)
    131{
    132	ptp_clock_unregister(kvm_ptp_clock.ptp_clock);
    133}
    134
    135static int __init ptp_kvm_init(void)
    136{
    137	long ret;
    138
    139	ret = kvm_arch_ptp_init();
    140	if (ret) {
    141		if (ret != -EOPNOTSUPP)
    142			pr_err("fail to initialize ptp_kvm");
    143		return ret;
    144	}
    145
    146	kvm_ptp_clock.caps = ptp_kvm_caps;
    147
    148	kvm_ptp_clock.ptp_clock = ptp_clock_register(&kvm_ptp_clock.caps, NULL);
    149
    150	return PTR_ERR_OR_ZERO(kvm_ptp_clock.ptp_clock);
    151}
    152
    153module_init(ptp_kvm_init);
    154module_exit(ptp_kvm_exit);
    155
    156MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>");
    157MODULE_DESCRIPTION("PTP clock using KVMCLOCK");
    158MODULE_LICENSE("GPL");