diff options
Diffstat (limited to 'arch/x86/kvm/i8254.c')
| -rw-r--r-- | arch/x86/kvm/i8254.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 11300d2fa71..518d86471b7 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -37,6 +37,7 @@ #include "irq.h" #include "i8254.h" +#include "x86.h" #ifndef CONFIG_X86_64 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y)) @@ -122,7 +123,6 @@ static s64 __kpit_elapsed(struct kvm *kvm) */ remaining = hrtimer_get_remaining(&ps->timer); elapsed = ps->period - ktime_to_ns(remaining); - elapsed = mod_64(elapsed, ps->period); return elapsed; } @@ -291,8 +291,8 @@ static void pit_do_work(struct kthread_work *work) } spin_unlock(&ps->inject_lock); if (inject) { - kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1); - kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0); + kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1, false); + kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0, false); /* * Provides NMI watchdog support via Virtual Wire mode. @@ -350,6 +350,23 @@ static void create_pit_timer(struct kvm *kvm, u32 val, int is_period) atomic_set(&ps->pending, 0); ps->irq_ack = 1; + /* + * Do not allow the guest to program periodic timers with small + * interval, since the hrtimers are not throttled by the host + * scheduler. + */ + if (ps->is_periodic) { + s64 min_period = min_timer_period_us * 1000LL; + + if (ps->period < min_period) { + pr_info_ratelimited( + "kvm: requested %lld ns " + "i8254 timer period limited to %lld ns\n", + ps->period, min_period); + ps->period = min_period; + } + } + hrtimer_start(&ps->timer, ktime_add_ns(ktime_get(), interval), HRTIMER_MODE_ABS); } |