c2402d43d1
Commit a86ed2cfa1 ("ptp: Don't print an error if ptp_kvm is not supported")
fixes the error message print on ARM platform by only concerning about
the case that the error returned from kvm_arch_ptp_init() is not -EOPNOTSUPP.
Although the ARM platform returns -EOPNOTSUPP if ptp_kvm is not supported
while X86_64 platform returns -KVM_EOPNOTSUPP, both error codes share the
same value 95.
Actually kvm_arch_ptp_init() on X86_64 platform can return three kinds of
errors (-KVM_ENOSYS, -KVM_EOPNOTSUPP and -KVM_EFAULT). The problem is that
-KVM_EOPNOTSUPP is masked out and -KVM_EFAULT is ignored among them.
This patch fixes this by returning them to ptp_kvm_init() respectively.
Signed-off-by: Kele Huang <huangkele@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
93 lines
2.0 KiB
C
93 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Virtual PTP 1588 clock for use with KVM guests
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*
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* Copyright (C) 2017 Red Hat Inc.
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*/
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <asm/pvclock.h>
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#include <asm/kvmclock.h>
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#include <linux/module.h>
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#include <uapi/asm/kvm_para.h>
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#include <uapi/linux/kvm_para.h>
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#include <linux/ptp_clock_kernel.h>
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#include <linux/ptp_kvm.h>
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static phys_addr_t clock_pair_gpa;
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static struct kvm_clock_pairing clock_pair;
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int kvm_arch_ptp_init(void)
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{
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long ret;
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if (!kvm_para_available())
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return -ENODEV;
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clock_pair_gpa = slow_virt_to_phys(&clock_pair);
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if (!pvclock_get_pvti_cpu0_va())
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return -ENODEV;
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ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa,
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KVM_CLOCK_PAIRING_WALLCLOCK);
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if (ret == -KVM_ENOSYS)
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return -ENODEV;
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return ret;
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}
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int kvm_arch_ptp_get_clock(struct timespec64 *ts)
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{
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long ret;
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ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
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clock_pair_gpa,
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KVM_CLOCK_PAIRING_WALLCLOCK);
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if (ret != 0) {
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pr_err_ratelimited("clock offset hypercall ret %lu\n", ret);
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return -EOPNOTSUPP;
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}
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ts->tv_sec = clock_pair.sec;
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ts->tv_nsec = clock_pair.nsec;
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return 0;
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}
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int kvm_arch_ptp_get_crosststamp(u64 *cycle, struct timespec64 *tspec,
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struct clocksource **cs)
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{
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struct pvclock_vcpu_time_info *src;
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unsigned int version;
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long ret;
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src = this_cpu_pvti();
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do {
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/*
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* We are using a TSC value read in the hosts
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* kvm_hc_clock_pairing handling.
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* So any changes to tsc_to_system_mul
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* and tsc_shift or any other pvclock
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* data invalidate that measurement.
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*/
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version = pvclock_read_begin(src);
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ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
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clock_pair_gpa,
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KVM_CLOCK_PAIRING_WALLCLOCK);
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if (ret != 0) {
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pr_err_ratelimited("clock pairing hypercall ret %lu\n", ret);
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return -EOPNOTSUPP;
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}
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tspec->tv_sec = clock_pair.sec;
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tspec->tv_nsec = clock_pair.nsec;
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*cycle = __pvclock_read_cycles(src, clock_pair.tsc);
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} while (pvclock_read_retry(src, version));
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*cs = &kvm_clock;
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return 0;
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}
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