diff options
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 94 |
1 files changed, 93 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1155059c512..c077b817d1c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -46,6 +46,8 @@ #include <linux/uaccess.h> #include <linux/hash.h> #include <linux/pci.h> +#include <linux/timekeeper_internal.h> +#include <linux/pvclock_gtod.h> #include <trace/events/kvm.h> #define CREATE_TRACE_POINTS @@ -901,6 +903,55 @@ static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data) return kvm_set_msr(vcpu, index, *data); } +#ifdef CONFIG_X86_64 +struct pvclock_gtod_data { + seqcount_t seq; + + struct { /* extract of a clocksource struct */ + int vclock_mode; + cycle_t cycle_last; + cycle_t mask; + u32 mult; + u32 shift; + } clock; + + /* open coded 'struct timespec' */ + u64 monotonic_time_snsec; + time_t monotonic_time_sec; +}; + +static struct pvclock_gtod_data pvclock_gtod_data; + +static void update_pvclock_gtod(struct timekeeper *tk) +{ + struct pvclock_gtod_data *vdata = &pvclock_gtod_data; + + write_seqcount_begin(&vdata->seq); + + /* copy pvclock gtod data */ + vdata->clock.vclock_mode = tk->clock->archdata.vclock_mode; + vdata->clock.cycle_last = tk->clock->cycle_last; + vdata->clock.mask = tk->clock->mask; + vdata->clock.mult = tk->mult; + vdata->clock.shift = tk->shift; + + vdata->monotonic_time_sec = tk->xtime_sec + + tk->wall_to_monotonic.tv_sec; + vdata->monotonic_time_snsec = tk->xtime_nsec + + (tk->wall_to_monotonic.tv_nsec + << tk->shift); + while (vdata->monotonic_time_snsec >= + (((u64)NSEC_PER_SEC) << tk->shift)) { + vdata->monotonic_time_snsec -= + ((u64)NSEC_PER_SEC) << tk->shift; + vdata->monotonic_time_sec++; + } + + write_seqcount_end(&vdata->seq); +} +#endif + + static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) { int version; @@ -997,6 +1048,8 @@ static inline u64 get_kernel_ns(void) return timespec_to_ns(&ts); } +static atomic_t kvm_guest_has_master_clock = ATOMIC_INIT(0); + static DEFINE_PER_CPU(unsigned long, cpu_tsc_khz); unsigned long max_tsc_khz; @@ -1229,7 +1282,6 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) vcpu->last_kernel_ns = kernel_ns; vcpu->last_guest_tsc = tsc_timestamp; - /* * The interface expects us to write an even number signaling that the * update is finished. Since the guest won't see the intermediate @@ -4857,6 +4909,39 @@ static void kvm_set_mmio_spte_mask(void) kvm_mmu_set_mmio_spte_mask(mask); } +#ifdef CONFIG_X86_64 +static void pvclock_gtod_update_fn(struct work_struct *work) +{ +} + +static DECLARE_WORK(pvclock_gtod_work, pvclock_gtod_update_fn); + +/* + * Notification about pvclock gtod data update. + */ +static int pvclock_gtod_notify(struct notifier_block *nb, unsigned long unused, + void *priv) +{ + struct pvclock_gtod_data *gtod = &pvclock_gtod_data; + struct timekeeper *tk = priv; + + update_pvclock_gtod(tk); + + /* disable master clock if host does not trust, or does not + * use, TSC clocksource + */ + if (gtod->clock.vclock_mode != VCLOCK_TSC && + atomic_read(&kvm_guest_has_master_clock) != 0) + queue_work(system_long_wq, &pvclock_gtod_work); + + return 0; +} + +static struct notifier_block pvclock_gtod_notifier = { + .notifier_call = pvclock_gtod_notify, +}; +#endif + int kvm_arch_init(void *opaque) { int r; @@ -4898,6 +4983,10 @@ int kvm_arch_init(void *opaque) host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK); kvm_lapic_init(); +#ifdef CONFIG_X86_64 + pvclock_gtod_register_notifier(&pvclock_gtod_notifier); +#endif + return 0; out: @@ -4912,6 +5001,9 @@ void kvm_arch_exit(void) cpufreq_unregister_notifier(&kvmclock_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER); unregister_hotcpu_notifier(&kvmclock_cpu_notifier_block); +#ifdef CONFIG_X86_64 + pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier); +#endif kvm_x86_ops = NULL; kvm_mmu_module_exit(); } |