diff options
Diffstat (limited to 'arch/s390/kvm/kvm-s390.c')
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 76 |
1 files changed, 74 insertions, 2 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 2118a2250ac7..76b99149dc65 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -158,6 +158,8 @@ static int kvm_clock_sync(struct notifier_block *notifier, unsigned long val, kvm->arch.epoch -= *delta; kvm_for_each_vcpu(i, vcpu, kvm) { vcpu->arch.sie_block->epoch -= *delta; + if (vcpu->arch.cputm_enabled) + vcpu->arch.cputm_start += *delta; } } return NOTIFY_OK; @@ -1429,16 +1431,78 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) return 0; } +/* needs disabled preemption to protect from TOD sync and vcpu_load/put */ +static void __start_cpu_timer_accounting(struct kvm_vcpu *vcpu) +{ + WARN_ON_ONCE(vcpu->arch.cputm_start != 0); + vcpu->arch.cputm_start = get_tod_clock_fast(); +} + +/* needs disabled preemption to protect from TOD sync and vcpu_load/put */ +static void __stop_cpu_timer_accounting(struct kvm_vcpu *vcpu) +{ + WARN_ON_ONCE(vcpu->arch.cputm_start == 0); + vcpu->arch.sie_block->cputm -= get_tod_clock_fast() - vcpu->arch.cputm_start; + vcpu->arch.cputm_start = 0; +} + +/* needs disabled preemption to protect from TOD sync and vcpu_load/put */ +static void __enable_cpu_timer_accounting(struct kvm_vcpu *vcpu) +{ + WARN_ON_ONCE(vcpu->arch.cputm_enabled); + vcpu->arch.cputm_enabled = true; + __start_cpu_timer_accounting(vcpu); +} + +/* needs disabled preemption to protect from TOD sync and vcpu_load/put */ +static void __disable_cpu_timer_accounting(struct kvm_vcpu *vcpu) +{ + WARN_ON_ONCE(!vcpu->arch.cputm_enabled); + __stop_cpu_timer_accounting(vcpu); + vcpu->arch.cputm_enabled = false; +} + +static void enable_cpu_timer_accounting(struct kvm_vcpu *vcpu) +{ + preempt_disable(); /* protect from TOD sync and vcpu_load/put */ + __enable_cpu_timer_accounting(vcpu); + preempt_enable(); +} + +static void disable_cpu_timer_accounting(struct kvm_vcpu *vcpu) +{ + preempt_disable(); /* protect from TOD sync and vcpu_load/put */ + __disable_cpu_timer_accounting(vcpu); + preempt_enable(); +} + /* set the cpu timer - may only be called from the VCPU thread itself */ void kvm_s390_set_cpu_timer(struct kvm_vcpu *vcpu, __u64 cputm) { + preempt_disable(); /* protect from TOD sync and vcpu_load/put */ + if (vcpu->arch.cputm_enabled) + vcpu->arch.cputm_start = get_tod_clock_fast(); vcpu->arch.sie_block->cputm = cputm; + preempt_enable(); } -/* get the cpu timer - can also be called from other VCPU threads */ +/* update and get the cpu timer - can also be called from other VCPU threads */ __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu) { - return vcpu->arch.sie_block->cputm; + __u64 value; + int me; + + if (unlikely(!vcpu->arch.cputm_enabled)) + return vcpu->arch.sie_block->cputm; + + me = get_cpu(); /* also protects from TOD sync and vcpu_load/put */ + value = vcpu->arch.sie_block->cputm; + if (likely(me == vcpu->cpu)) { + /* the VCPU itself will always read consistent values */ + value -= get_tod_clock_fast() - vcpu->arch.cputm_start; + } + put_cpu(); + return value; } void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) @@ -1461,12 +1525,16 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) restore_access_regs(vcpu->run->s.regs.acrs); gmap_enable(vcpu->arch.gmap); atomic_or(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags); + if (vcpu->arch.cputm_enabled) + __start_cpu_timer_accounting(vcpu); vcpu->cpu = cpu; } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { vcpu->cpu = -1; + if (vcpu->arch.cputm_enabled) + __stop_cpu_timer_accounting(vcpu); atomic_andnot(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags); gmap_disable(vcpu->arch.gmap); @@ -2277,10 +2345,12 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) */ local_irq_disable(); __kvm_guest_enter(); + __disable_cpu_timer_accounting(vcpu); local_irq_enable(); exit_reason = sie64a(vcpu->arch.sie_block, vcpu->run->s.regs.gprs); local_irq_disable(); + __enable_cpu_timer_accounting(vcpu); __kvm_guest_exit(); local_irq_enable(); vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); @@ -2358,6 +2428,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) } sync_regs(vcpu, kvm_run); + enable_cpu_timer_accounting(vcpu); might_fault(); rc = __vcpu_run(vcpu); @@ -2377,6 +2448,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) rc = 0; } + disable_cpu_timer_accounting(vcpu); store_regs(vcpu, kvm_run); if (vcpu->sigset_active) |